CMP Journal 2026-11-10
Statistics
Physical Review Letters: 9
Physical Review X: 2
arXiv: 156
Research Square: 4
Physical Review Letters
Dark-Matter-Induced Nuclear Deexcitation at the Short-Baseline Near Detector with Ab Initio Nuclear Theory
Article | Particles and Fields | 2026-11-09 05:00 EST
Bhaskar Dutta, Debopam Goswami, Baishan Hu, Wei-Chih Huang, and Vishvas Pandey
We explore the sensitivity of the short-baseline near detector (SBND) experiment to light dark matter using MeV-scale electromagnetic activity. Inelastic scattering of dark matter with argon nuclei can excite nuclear states that subsequently deexcite via the emission of MeV-scale photons, producing …
Phys. Rev. Lett. 137, 201801 (2026)
Particles and Fields
Atomistic Simulation of Subcritical Crack Growth in Glass in Vacuum
Article | Condensed Matter and Materials | 2026-11-09 05:00 EST
Swati Gupta, Mark A. Wilson, Scott J. Grutzik, and Derek H. Warner
We report atomistic simulations of subcritical crack growth rates in silica glass that quantitatively align with experimental data. This result was achieved by a careful selection of simulation cell geometry and boundary conditions, a novel crack tip tracking algorithm, a robust interatomic potentia…
Phys. Rev. Lett. 137, 206101 (2026)
Condensed Matter and Materials
Hydrodynamics of the Viscous Electron Fluid in Cadmium
Article | Condensed Matter and Materials | 2026-11-09 05:00 EST
Xiaodong Guo, Xiaokang Li, Benoît Fauqué, Alaska Subedi, Lingxiao Zhao, Zengwei Zhu, and Kamran Behnia
Measurements on micrometer-scale cadmium samples provide definitive evidence of an unusual charge-transport regime in a 3D metal.
Phys. Rev. Lett. 137, 206301 (2026)
Condensed Matter and Materials
First-Principles Effective Mass in the Three-Dimensional Uniform Electron Gas
Article | Condensed Matter and Materials | 2026-11-09 05:00 EST
Pengcheng Hou, Daniel Cerkoney, Zhiyi Li, Tao Wang, Xiansheng Cai, Lei Wang, Gabriel Kotliar, Youjin Deng, and Kun Chen
The quasiparticle effective mass of the three-dimensional uniform electron gas is a fundamental Fermi-liquid parameter whose value and density dependence have remained controversial for decades. Using renormalized perturbation theory with explicit counterterms, we determine in the metallic reg…
Phys. Rev. Lett. 137, 206501 (2026)
Condensed Matter and Materials
Superparamagnetism in an Interacting Nanomagnet Array: A Tale of Three Temperatures
Article | Condensed Matter and Materials | 2026-11-09 05:00 EST
Anthony Hurben, Ioan-Augustin Chioar, Cristiano Nisoli, and Peter Schiffer
Superparamagnetic collections of thermally fluctuating nanomagnet moments undergo a dynamic freezing known as a blocking transition upon cooling. The collective behavior becomes more complex when neighboring nanomagnets interact, and is further complicated when the constituent material of the nanoma…
Phys. Rev. Lett. 137, 206701 (2026)
Condensed Matter and Materials
Terahertz Switching of Two-dimensional Antiferromagnetic Order
Article | Condensed Matter and Materials | 2026-11-09 05:00 EST
Chenyu Wang, En Wang, Yaxian Wang, and Sheng Meng
Identifying the transition pathway for ultrafast switching between distinct antiferromagnetic orders, while holding promise to realize unprecedentedly small and fast spin devices, remains largely unexplored. Herein, we show that rectifying structure with light can serve as a powerful tool to achieve…
Phys. Rev. Lett. 137, 206702 (2026)
Condensed Matter and Materials
Deconfined Quantum Critical Point in a Dissipative Spin-1/2 Chain
Article | Condensed Matter and Materials | 2026-11-09 05:00 EST
Longye Lu, Shifeng Cui, and Wenan Guo
Open quantum spin systems offer a previously unexplored route to realizing deconfined quantum criticality. We consider a spin- chain composed of an antiferromagnetic (AFM) Heisenberg exchange and a competing multispin interaction favoring a valence-bond solid (VBS) state, with each spin comp…
Phys. Rev. Lett. 137, 206703 (2026)
Condensed Matter and Materials
Intracycle Interference in Strong-Field Photoemission from a Tungsten Needle Tip
Article | Condensed Matter and Materials | 2026-11-09 05:00 EST
Timo Wirth, Jonas Heimerl, Stefan Meier, and Peter Hommelhoff
Electrons photoemitted by strong laser fields can rescatter, generating attosecond high harmonics. Spectral peaks arise from inter- and intracycle interference of coherent electron wave packets. While intercycle interference is well known, intracycle interference of plateau electrons has not been ob…
Phys. Rev. Lett. 137, 206901 (2026)
Condensed Matter and Materials
Universal Criticality of Entropy Production in Chemical Reaction Networks
Article | Statistical Physics; Classical, Nonlinear, and Complex Systems | 2026-11-09 05:00 EST
Kyota Tamano and Keiji Saito
In homogeneous reversible chemical reactions, a prototypical nonequilibrium phenomenon, entropy-production fluctuations represent a sharper probe of nonequilibrium criticality than entropy-production response to variations in the chemical species concentrations.
Phys. Rev. Lett. 137, 207101 (2026)
Statistical Physics; Classical, Nonlinear, and Complex Systems
Physical Review X
Spectral Small-Incremental Entangling: Breaking Quasipolynomial Complexity Barriers in Long-Range Interacting Systems
Article | | 2026-11-09 05:00 EST
Donghoon Kim, Yusuke Kimura, Hugo Mackay, Yosuke Mitsuhashi, Hideaki Nishikawa, Carla Rubiliani, Cheng Shang, Ayumi Ukai, and Tomotaka Kuwahara
Researchers establish universal limits on quantum entanglement-spectrum evolution, enabling efficient classical simulations of long-range interacting systems.
Phys. Rev. X 16, 041035 (2026)
Noninvertible Bosonic Chiral Symmetry on the Lattice
Article | | 2026-11-09 05:00 EST
Lukasz Fidkowski, Cenke Xu, and Carolyn Zhang
Construction of a continuous chiral symmetry in a 3D quantum rotor model demonstrates that gauging charge symmetry yields noninvertible, duality-like lattice operations.
Phys. Rev. X 16, 041036 (2026)
arXiv
Interpretable machine learning of formation energies and band gaps in hybrid perovskites through SHAP analysis and SISSO modelling
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-11-10 20:00 EST
Christopher Xia, Hao Zhang, Qingyuan Jin
Accurate and interpretable property prediction is essential for exploring hybrid organic-inorganic perovskites. Here, we combine machine-learning screening with SHAP analysis and SISSO descriptor discovery. Using 4,456 compounds, optimized XGBoost models achieved test-set $ R^2$ values of 0.99 for formation energy and 0.93 for band gap and were applied to over 180,000 candidates. Comparison across approximately 17,000 common compounds revealed broadly overlapping distributions from XGBoost and CGCNN but substantially lower predictions from UPET, suggesting potential limitations in its transferability to hybrid organic-inorganic perovskites. SHAP analysis and correlation-based pruning retained eight primary features for each property, from which SISSO derived expressions comprising four nonlinear descriptors. These expressions couple molecular and inorganic properties for formation energy and emphasize relative atomic sizes and B-site characteristics for band gap. This framework supports efficient candidate prioritization and interpretable analysis of learned structures-property relationships in hybrid perovskites.
Materials Science (cond-mat.mtrl-sci)
17 pages, 4 figures
Two-dimensional liquid-like order in a confined population of swimming Eudorina colonies
New Submission | Soft Condensed Matter (cond-mat.soft) | 2026-11-10 20:00 EST
Swimming microorganisms accumulate at boundaries, but the spatial statistics of the resulting layers are rarely measured. We report a population of colonial green algae, of order 71 $ \mu$ m across, that accumulates against the rigid upper wall of a closed 1-2 mm chamber and holds a two-dimensional non-contacting arrangement for about 105 min. The pair correlation function has a first shell at $ r/\bar{D} = 1.73$ , $ g = 4.8$ ; a hard-disc null at the same area fraction reaches only $ g = 2.1$ , so the ordering is not excluded volume alone. Nearest-neighbour separation is $ 1.80 \pm 0.13$ diameters. The bond-orientational order parameter is $ \langle|\psi_6|\rangle = 0.456$ against 0.385 for the null, only 36% of interior colonies are six-coordinated, and the orientational correlation $ g_6(r)$ decays over 1.5 diameters with $ \eta_6 = 1.31$ against the hexatic bound of 1/4: the arrangement is a two-dimensional liquid, not a crystal or a hexatic. Colonies execute a persistent random walk with reorientation time 1.4-1.7 s at Reynolds number $ \sim 9\times 10^{-4}$ . Breakup begins at 127 min. Thermal convection is excluded on Rayleigh-number grounds. Caveats: the length calibration is nominal rather than metrological, and this is a single population observed once. All data and code are deposited.
Soft Condensed Matter (cond-mat.soft), Adaptation and Self-Organizing Systems (nlin.AO), Biological Physics (physics.bio-ph)
11 pages, 5 figures, 1 table. Data, code and video: doi:https://doi.org/10.7267/0g354q328
Interception Focusing of Colloid Transport in Granular Porous Media
New Submission | Soft Condensed Matter (cond-mat.soft) | 2026-11-10 20:00 EST
William P. Johnson (1), Noah G. Willis (1), Luis A. Ullauri (1), Bashar M. Al-Zghoul (2), Diogo Bolster (3) ((1) University of Utah, Geology and Geophysics, Salt Lake City, Utah, USA (2) University of California Davis, Civil and Environ. Eng., Davis, California, USA (3) University of Notre Dame, Civil and Environmental Engineering and Earth Sciences, Notre Dame, Indiana, United States)
Colloid transport and retention in environmental granular porous media underlie groundwater resource protection from, and remediation using, biological and non-biological nano- and micro-particles (colloids). During transport, colloids periodically intercept grain surfaces and translate along them at separation distances across several tens of nm corresponding to the secondary minimum between the opposing forces of longer-range of van der Waals (VDW) attraction and shorter-range electric double layer (EDL) repulsion. Relatively weak diffusive translation of colloids supports their continued translation in secondary minimum association until they are expelled to bulk fluid at rear flow stagnation zones on grain leeward sides. We herein show that this dynamic focuses colloids into a network of fluid streamlines (incomplete mixing lamellae) that enhances their subsequent likelihood of interception with downgradient grains, i.e., increases the so-called collector efficiency (typically denoted by Greek letter eta). Interception focusing of colloids in granular porous media explains well-observed outcomes of colloid transport under environmental conditions, including nonmonotonic nonexponential profiles of retained colloids and the non-Markovian nature of extended tailing of low colloid concentrations following initial elution. Interception focusing is a fundamental process that distinguishes colloids from solutes and renders inapplicable to colloids the assumption that is often invoked for solutes of complete pore scale mixing in granular porous media.
Soft Condensed Matter (cond-mat.soft), Fluid Dynamics (physics.flu-dyn)
Pages: 57. Figures: 6 in main manuscript plus 5 tables and 10 figures in Supporting Information. Submitted to Environmental Science & Technology
Rapid Antigen Detection Tests Empowered by Cholesteric Spherical Reflectors for Expanded Capabilities
New Submission | Soft Condensed Matter (cond-mat.soft) | 2026-11-10 20:00 EST
Chih-Chieh Chien, Yan-Song Zhang, Jean-François Conrotte, Carole L. Linster, Sivashankar Krishnamoorthy, Jan P.F. Lagerwall
While Rapid Antigen Detection Tests (RADTs) have proved their value in point-of-care detection of respiratory diseases, their poor-contrast readout limits their use at early stages of infection where viral concentrations are low, and most RADTs test only for one disease, leaving a sick patient ignorant in case of a negative result. We explore the potential of Cholesteric Spherical Reflectors (CSRs) as enhanced optical labeling probes for RADTs, leveraging their circularly polarized reflections to maximize contrast by background subtraction and thereby lower the analyte concentration required for detection. Moreover, we demonstrate how the ease in tuning the CSR reflection color and the freedom to choose between right- and left-handed circularly polarized reflection allow us to design CSRs to distinguish optically between multiple diseases, eventually enabling RADTs capable of screening for a set of multiple diseases in a single test. We develop a method for functionalizing CSRs with appropriate antibodies and we propose a new type of RADT specifically designed for use with CSRs as detection label, demonstrating that the comparatively large size of CSRs (tens of microns in diameter) does not prevent viral analytes to tether them to an antibody-coated test surface. The strength of the optical CSR signal quantitatively reflects the antigen concentration.
Soft Condensed Matter (cond-mat.soft), Medical Physics (physics.med-ph)
Manufacturing Complex Structures Through Interfacial Self-Organization
New Submission | Soft Condensed Matter (cond-mat.soft) | 2026-11-10 20:00 EST
Jacob Garrett, Abhinit Sati, Edward Chien, Emily Whiting, Valeri Frumkin
Conventional manufacturing constructs three-dimensional geometries through localized material deposition, removal, or shaping, with fabrication effort greatly increasing with geometric complexity. Here, we introduce a manufacturing approach in which target geometry is encoded into sparse wireframe scaffolds that guide liquid self-organization through interfacial forces. We apply a computational framework that approximates arbitrary target geometries using constant-mean-curvature surface domains and extracts their boundaries to construct the scaffolds. Under neutral buoyancy conditions, curable liquids injected into these scaffolds self-organize into the prescribed geometries, which are subsequently solidified into mechanically isotropic structures with optically smooth surfaces. We demonstrate the fabrication of complex anatomical models and topology-optimized structures featuring intricate branching geometries, internal cavities, and integrated materials. This approach opens new possibilities for scalable fabrication of complex geometric designs.
Soft Condensed Matter (cond-mat.soft), Materials Science (cond-mat.mtrl-sci), Applied Physics (physics.app-ph)
Hierarchical Design of Ambidirectional LCE Sheets for Three-State Gaussian Shape Morphs
New Submission | Soft Condensed Matter (cond-mat.soft) | 2026-11-10 20:00 EST
Atalaya Milan Wilborn, Gurminder K. Paink, Raphael Kay, Patryk Wasik, Friedrich Stricker, Jacopo Movilli, Shucong Li, Joanna Aizenberg
Modulation of surface curvature is a commonly exploited strategy to achieve adaptability within natural and synthetic systems where structure governs function. While Gaussian curvature of inextensible surfaces is fixed, surfaces made of extensible materials can adapts their Gaussian curvature under strain, unlocking capabilities such as locomotion, dynamic coloration, and tunable stiffness. This feature is commonly exploited to develop soft actuators capable of complex functionalities; however, traversing the entire spectrum of Gaussian curvature was previously difficult to achieve without the use of multi-material constructs or spatially varied stimulus fields. In this work, we present a strategy for generating a diverse range of dynamic Gaussian shape morphs using multiphase liquid crystal elastomers (LCEs) as ambidirectionally deforming building blocks. Taking advantage of the materials sequential contraction and elongation during phase transitions, we design and investigate the deformation response of radially aligned flat LCE sheets which consecutively morph into negatively and positively curved flat surfaces in response to monotonically increasing temperature. We then investigate the influence of mesoscale asymmetry and macroscale geometry on curvature magnitude and bending symmetry, thereby demonstrating that a single form factor can be programmed to undergo a rich library of deformation behaviors. Finally, inspired by the strategy of cephalopods to couple mechanical deformability to dynamic optical properties, we fabricate a structurally colored LCE sheet which couples its dynamic Gaussian curvature to a dynamic color-changing response. This approach offers a route toward adaptive structures capable of multistate shape reconfiguration for applications in soft robotics, deployable systems, and responsive surfaces.
Soft Condensed Matter (cond-mat.soft), Materials Science (cond-mat.mtrl-sci)
25 pages, 4 main figures, 6 supplementary figures
A liquid implant that grows into a stable scaffold in situ
New Submission | Soft Condensed Matter (cond-mat.soft) | 2026-11-10 20:00 EST
Wenqiang Li, Qichen Peng, Fuhong Wang, Zhentan Quan, Shengxiang Cai, Zhuoming Zhou, Jin Zhang, Ting Liu, Xuanping Xie, Lin Zhu, Bo Wang, Shuang Wang, Yuan An, Yingtong Zhou, Zirong Liu, Haohui Li, Songshen Li, Ben Wang, Xinjian Yang, Quanshui Zheng, Hongzhang Wang
Endovascular embolization requires materials that can pass through narrow microcatheters yet form stable, conformal occlusions within irregular vascular lesions, but reconciling these competing requirements remains challenging. Here we report a wirelessly activated liquid precursor whose final architecture is constructed only after target localization. A gallium-based liquid metal containing iron microparticles and gas microcavities remains deformable, magnetically navigable, and retrievable before activation. Wireless induction heating activates the internal reactive microenvironment, coupling gas-driven microcavity growth with oxidative mineralization of newly generated gallium interfaces to form a porous, self-supporting scaffold. In aneurysm and arteriovenous malformation models, activation enabled durable occlusion, aneurysm-neck healing, and six-month stability in a porcine aneurysm model. These findings establish post-delivery construction as a strategy for creating stable therapeutic implants from minimally invasive liquid precursors.
Soft Condensed Matter (cond-mat.soft), Materials Science (cond-mat.mtrl-sci), Medical Physics (physics.med-ph)
Topology and Information in Regularized Transport on Graphs
New Submission | Soft Condensed Matter (cond-mat.soft) | 2026-11-10 20:00 EST
We study how two geometries of mass on a finite graph interact: the information geometry of the generalized entropy $ F_q$ used for regularized transport, and the arithmetic of divisors governed by the Riemann–Roch theorem of Baker and Norine and by the Jacobian. Because the correction term of $ F_q$ is affine, $ F_q$ -regularization at strength $ \gamma$ is Tsallis regularization at temperature $ \gamma/q$ . Over the reals, chip-firing connects all configurations of equal degree, so the Jacobian enters transport only through integrality. We introduce the transport defect, the worst-case cost of steering $ d$ chips towards a target by chip-firing, and prove $ 1/d\le\delta_{\TV}(D)\le(d-r(D))/d=(g-1-r(K-D))/d\le\min(1,g/d)$ whenever $ g\ge1$ ; vertex multiplicities give a lower bound and an equality criterion. A regularized topological gap $ \Gamma_{q,\gamma}(D,E)$ tends to the chip-move defect as $ \gamma\to0$ , lies in an explicit window, has a high-temperature slope given by Tsallis coupling entropies, and admits a positive regime if and only if $ g\ge1$ . Dual potentials certify exactly the convex relaxation of a linear system; the remainder is an integrality gap. Zeros in optimal plans occur only for $ q>1$ , by a mechanism different from the sign change of $ \Gamma$ . Exact computations on $ 1784$ divisor classes find the rank bound $ (d-r(D))/d$ attained in $ 1769$ of them, an observed frequency. Experiments on honeycomb and Erdős–Rényi networks with $ 10^2$ to $ 10^5$ nodes test the statements on regularized plans, not $ \Gamma$ ; over $ 10^3\le n\le10^5$ their transport costs are consistent with growth like $ n^{1/2}$ and $ \log n$ , respectively.
Soft Condensed Matter (cond-mat.soft), Discrete Mathematics (cs.DM), Information Theory (cs.IT)
50 pages
Enhancement of the magnetorheological effect using discontinuous shear thickening with a mixture of magnetic and non magnetic particles
New Submission | Soft Condensed Matter (cond-mat.soft) | 2026-11-10 20:00 EST
Georges Bossis (INPHYNI), Yan Grasselli, Olga Volkova (INPHYNI)
The phenomenon of discontinuous shear thickening (DST) is observed in suspensions of solid particles with a very high-volume fraction. Using a suspension of magnetic particles at high-volume fraction we have, for the first time, demonstrated experimentally the presence of a frictional network of particles by a simultaneous measurement of the electrical resistance of the suspension and of the rheological curve. An obstacle for the applications of MRS remains the sedimentation and aggregation linked to the high density of the iron microparticles. We have recently found that a small fraction of ferromagnetic particles within a concentrated suspension of calcium carbonate particles is not only sufficient to trigger the transition by application of a magnetic field but also optimum for the amplitude of the jump in viscosity observed in DST. We shall explain this result from stress transmission between the magnetic particles and nonmagnetic ones, both inserted in the percolated network of particles. We will also highlight the role of the polyelectrolyte adsorbed on the surface of the particles in the DST transition through the balance between the repulsive entropic force between two layers of polymer adsorbed on different particles and the magnetic attraction force.
Soft Condensed Matter (cond-mat.soft)
Journal of Intelligent Material Systems and Structures, 2026, 37 (14), pp.829-836
Conductance scaling in nanopore arrays: disentangling roles of pore arrangement and reservoir geometry
New Submission | Soft Condensed Matter (cond-mat.soft) | 2026-11-10 20:00 EST
Jacob Bair, Zachery Gottshall, Matthias Kuehne
The scaling of electrical conductance with the number of nanopores, $ N$ , in an array is of fundamental importance for applications in membrane separation and ion transport across biological membranes, and has been the subject of longstanding disagreement in the field. Combining finite element calculations with theory, we resolve this disagreement for pores with negligible surface charge by showing that two previously conflicting predictions are each correct in their own limiting reservoir geometry: cuboidal reservoirs commensurate with the interpore spacing, for which the conductance scales linearly with $ N$ , and infinite reservoirs, for which the scaling is sublinear in $ N$ for closely spaced pores. We show the transition between these limits with increasing reservoir size and, for infinite reservoirs, we show that a simple analytical model from electrical contact theory is mathematically equivalent to an existing point-charge capacitance model for nanopore arrays and validate its applicability against finite element and method-of-moments calculations. Using this model, we derive a characteristic coupling length, $ \ell_\mathrm{c,95}$ , the interpore spacing at which the array conductance reaches $ 95%$ of that of the same number of independent pores. $ \ell_\mathrm{c,95}$ scales linearly with pore diameter $ d$ , and grows with $ N$ as $ \sim\log N$ for linear arrays and $ \sim\sqrt{N}$ for square arrays, so that pore coupling persists to surprisingly large separations in large arrays. Our work provides a general framework for predicting nanopore array conductance as a function of pore arrangement and reservoir geometry, of importance to nanofluidics research and the targeted design of functional devices.
Soft Condensed Matter (cond-mat.soft), Classical Physics (physics.class-ph), Fluid Dynamics (physics.flu-dyn)
Memory flows: geometry and dynamics of sequential retrieval in input-driven Hopfield networks
New Submission | Disordered Systems and Neural Networks (cond-mat.dis-nn) | 2026-11-10 20:00 EST
Simone Betteti, Matteo Martin, Morten Gram Pedersen, Sandro Zampieri, Giacomo Baggio
Associative memory models classically describe retrieval as convergence to stored patterns, but the theory of sequential retrieval remains comparatively limited. We develop a two-timescale input-driven Hopfield network in which fast associative retrieval is modulated by a slow feedback variable evolving over a prescribed memory-transition graph. This yields autonomous, graph-constrained transitions while preserving analytical tractability. Using slow-fast and geometric singular perturbation theory, we characterize memory fixation via memory manifolds and identify the geometric regions that govern stability loss and escape from retrieved memories. We further derive reduced slow dynamics and explicit criteria for transition onset, self-sustained retrieval, and collapse, expressed through escape times, gain thresholds, and fixed points. Together, these results provide a tractable framework for analyzing feedback-driven sequential retrieval in Hopfield networks.
Disordered Systems and Neural Networks (cond-mat.dis-nn), Artificial Intelligence (cs.AI), Dynamical Systems (math.DS), Neurons and Cognition (q-bio.NC)
A transversely isotropic constitutive model for semisoft elasticity in main-chain liquid crystal elastomers
New Submission | Soft Condensed Matter (cond-mat.soft) | 2026-11-10 20:00 EST
Monodomain main-chain liquid crystal elastomers exhibit pronounced stiffness anisotropy and broad semisoft plateaus following finite onset strains. At fixed chain anisotropy, the neo-classical model predicts equal principal Young’s moduli, while its transversely isotropic extension with a constant semisoft modulus constrains the relation between reorientation onset and subsequent stress growth. We develop a finite-strain, isothermal elastic model combining transversely isotropic network elasticity with a deformation-dependent quadratic semisoft penalty. Within a weak-fluctuation approximation, a reduced statistical closure based on assumed linear contraction of effective local anisotropy fluctuations at fixed mean anisotropy yields an exponential transition from an initial to a residual semisoft modulus. The network energy preserves ideal soft modes, and the formulation recovers the de Gennes strain-director coupling in the infinitesimal limit. Analytical relations for perpendicular tension show that the rotating-stage stress depends on both the current semisoft modulus and its derivative with respect to the first deformation invariant. This permits a finite onset followed by a substantially flatter rotating response than in the constant-modulus limit. Oblique tension couples director rotation, shear and lateral contraction. Comparisons with orientation-dependent measurements using a common parameter set capture the principal stiffness contrast and broad perpendicular plateau, with discrepancies remaining in oblique stresses and intermediate-angle initial moduli.
Soft Condensed Matter (cond-mat.soft)
Roadmap on Nanoscale Superconductivity for Quantum Technologies
New Submission | Superconductivity (cond-mat.supr-con) | 2026-11-10 20:00 EST
Oleksandr Dobrovolskiy, Hermann Suderow, Francesco Tafuri, Annica M. Black-Schaffer, Jose L. Lado, Asle Sudbø, Daniela Stornaioulo, Chuan Li, Anna E. Böhmer, Lan Maria Tran, Andrzej J. Zaleski, Adrian Crisan, Massimiliano Polichetti, Armando Galluzzi, Ali Gencer, Bernd Aichner, Neven Barišić, Wolfgang Lang, Tomas Samuely, Martin Gmitra, Tristan Cren, Mateo Calandra, Peter Samuely, Jeroen Custers, Rosa Córdoba, Vladimir M. Fomin, Nicola Poccia, Pavol Szabó, Fabrizio Porrati, Gleb Kakazei, Jan Aarts, Jason Robinson, Javier E. Villegas, Matthias Althammer, Hans Huebl, Akashdeep Kamra, Mathias Weiler, J. Hugo Dil, Daniil Evtushinsky, Beena Kalisky, Yonathan Anahory, Simon Bending, Peter Liljeroth, Abdou Hassanien, Isabel Guillamón, Edwin Herrera, Alejandro V. Silhanek, Joris Van de Vondel, Anna Palau, Ilya Charaev, Maria Sidorova, Floriana Lombardi, Thilo Bauch, Cheryl Feuillet-Palma, Vasily Stolyarov, Dimitri Roditchev, Vladimir M. Krasnov, Benedikt Hampel, María José Martínez-Pérez, Javier Sesé, Dieter Koelle, Stefano Poletto, Alessandro Bruno, Davide Massarotti
In 2025, the Year of Quantum Science and Technology, we celebrate a century of quantum mechanics, witnessing a surge in activities that illuminate its inherent strangeness and drive technological innovation. Superconductivity, discovered 114 years ago, stands as a prime example, offering direct and compelling evidence of macroscopic quantum phenomena. Beyond its ability to conduct immense currents without loss, superconductivity reveals the quantum realm operating on a scale we can directly observe and manipulate. The macroscopic quantum coherence, where an ensemble of particles is described by a single wave function, leads to remarkable consequences: dissipation-less current and flux quantization - the basic properties exploited in superconducting quantum circuit fabrication. This Roadmap has been inspired by intensive discussions and collaborations emerging from the European COST Action CA21144 (SuperQuMap - Superconducting Nanodevices and Quantum Materials for Coherent Manipulation). The roadmap outlines the network’s concrete activities, driving advancements in superconductor-based quantum technologies and charting future directions. Spanning fundamental research to practical applications, the roadmap incorporates insights from industry partners developing quantum computation. It begins by exploring quantum materials, highlighting how topology and electronic correlations could catalyze a quantum leap in technology. We then delve into manipulating the superconducting phase, leveraging advancements in magnetism, 3D fabrication, and tunable correlations. Further, we showcase the advanced microscopy techniques - such as angle-resolved photoemission spectroscopy and scanning probes - used to visualize quantum behavior. Finally, and crucially, we detail the quantum devices developed within the network, and their transformative impact on modern quantum computing approaches.
Superconductivity (cond-mat.supr-con), Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Materials Science (cond-mat.mtrl-sci), Strongly Correlated Electrons (cond-mat.str-el), Quantum Physics (quant-ph)
120 pages, 39 figures
Supercond. Sci. Technol. 39 (2026) 023502
Exceptional Topological Bound States in the Continuum
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2026-11-10 20:00 EST
Luohong Liu, Qicheng Zhang, Shuaishuai Tong, Chunyin Qiu
Topological phases, exceptional points, and bound states in the continuum (BICs) are three key concepts in condensed matter and classical wave physics. Their pairwise combinations have yielded a rich variety of intriguing singular modes, but the triple merger–exceptional topological BICs (ET-BICs)–has yet to be explored. In this Letter, we theoretically propose and experimentally demonstrate a universal approach for constructing such elusive exceptional structures. The system consists of four coupled topological chains: y-mirror stacking generates pairs of topological BICs, while z-stacking with biased loss yields a generalized mirror symmetry under which each pair–separated in different subspaces until their collapse–merges into an ET-BIC at a critical loss. Experimentally, using an acoustic platform with electrically tunable loss, we not only directly observe the coalescence of eigenenergies but also the coalescence of eigenstates, offering a complete verification of the ET-BIC formation. The triply synergistic ET-BICs may pave the way for wave devices that simultaneously demand robustness, sensitivity, and BIC confinement.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Materials Science (cond-mat.mtrl-sci), Applied Physics (physics.app-ph)
Pelletization Pressure Engineering of the Superconducting Properties of Fluorine-Doped PrFeAsO
New Submission | Superconductivity (cond-mat.supr-con) | 2026-11-10 20:00 EST
Jayant Kumar, Konrad Kwatek, Tatiana Zajarniuk, Taras Palasyuk, Yaroslaw Konopelnyk, Tomasz Cetner, Cezariusz Jastrzębski, Shiv J. Singh
We investigate the influence of the pelletization pressure on the structural, microstructural, and superconducting properties of fluorine-doped PrFeAsO0.7F0.3 (Pr1111). Precursor powders are pressed into pellets at pressures ranging from 174 to 1131 MPa, after which the applied pressure is released and all samples undergo an identical two-step conventional synthesis process at ambient pressure (CSP-AP). All samples predominantly exhibit the tetragonal P4/nmm structure, and the lattice parameter a and unit-cell volume V decrease with increasing pelletization pressure up to an intermediate-pressure range (~900 MPa) before increasing at higher pressures. The actual fluorine-content derived from energy-dispersive X-ray spectroscopy (EDX) also increase with pelletization pressure, while Raman spectra show only modest variations in the characteristic vibrational modes associated with Fe and As. The superconducting response exhibits a non-monotonic dependence on the pelletization pressure. Among the investigated samples, the sample pelletized at 870 MPa exhibits the most favorable overall superconducting properties, with a superconducting onset temperature of 44.2 K, ~5 K higher than that of the lowest-pressure sample. It also displays a narrower superconducting transition, the highest relative sample density, a favorable effective magnetic critical current density at high fields, and a relatively large effective thermally activated flux-flow activation energy. At higher pelletization pressures, the superconducting response deteriorates, coinciding with increases in the lattice parameters, increased secondary-phase contributions, and reduced relative density. These findings establish the pelletization pressure as a relevant processing parameter for modifying the structural, microstructural and superconducting properties of Pr1111 during CSP-AP.
Superconductivity (cond-mat.supr-con), Materials Science (cond-mat.mtrl-sci), Applied Physics (physics.app-ph)
47 pages, 9 pages
Superconductivity in the Metallic Wigner Crystals of Rhombohedral Graphene: Possible Realization of an Electronic Supersolid
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2026-11-10 20:00 EST
Félix Desrochers, Mark R. Hirsbrunner, Yong Baek Kim, Ashvin Vishwanath
Recent experiments on rhombohedral multilayer graphene have reported metallic Wigner crystals (MWCs), in which spontaneously broken translational symmetry coexists with mobile charge carriers. Their proximity to time-reversal-symmetry-breaking superconductivity raises the intriguing possibility that collective excitations of the electron crystal mediate pairing among the residual itinerant carriers, giving rise to a superconducting Wigner crystal—an electronic analog of a supersolid. Here we investigate this possibility using a realistic model of electron-doped rhombohedral multilayer graphene with spin and valley polarization, whose low symmetry removes the usual Cooper instability. We use self-consistent and time-dependent Hartree-Fock theory to map the evolution of the self-doping fraction and characterize the collective-mode spectrum of the MWCs, followed by a multiband linearized Eliashberg analysis of pairing. Upon increasing density, we find an instability of the MWC, triggered by a weakly dispersing unoccupied band approaching the chemical potential. Pairing remains weak deep in the stable MWC. However, on approaching the instability, we identify a collective mode composed of interband electron-hole excitations that softens. We show that this mode drives pairing at experimentally relevant temperatures. The leading pairing instability is at finite momentum and combines Fermi surface states with states in the incipient band, making a Fermi surface or single-band pairing analysis inadequate. Our results establish collective-mode-mediated superconductivity in MWCs as a viable scenario for rhombohedral graphene and motivate experimental searches for coexisting electronic charge order in its superconducting phases.
Strongly Correlated Electrons (cond-mat.str-el)
10+9pages, 4+2 figures
Energy-resolved current response and the crossover between two approximately linear-in-$T$ resistivity regimes in the infinite-$U$ Hubbard model
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2026-11-10 20:00 EST
Shuo Liu, Aman Kumar, Yuhao Ma, Philip W. Phillips, Hitesh J. Changlani, B. Andrei Bernevig
We study charge transport in the two-dimensional infinite-$ U$ Hubbard model with hopping amplitude $ t$ using full exact diagonalization (ED) on $ N=16$ - and $ 18$ -site square clusters with a single doped hole. We first provide a proof, treating degeneracies explicitly, that a constant dc $ f_x$ function, defined as the sum of the squared current matrix elements connecting eigenstates at a given energy to eigenstates of nearly the same energy, averaged over degenerate initial states, is necessary and sufficient for strictly linear-in-$ T$ resistivity: $ \rho_x(T)=\alpha T$ for all $ T>0$ with a constant $ \alpha$ . The numerically extrapolated dc $ f_x$ is not exactly constant, but it is approximately flat over a broad region in the interior of the many-body spectrum and varies strongly within a scale $ \varepsilon_{f_x}$ of the spectral edges. This scale $ \varepsilon_{f_x}$ is related to a characteristic temperature $ T_{\mathrm{cr}}$ , which quantifies the leading departure of the resistivity from high-temperature linearity upon cooling. Within the studied temperature range $ T/t \geq 0.05$ , our ED resistivity results reveal a gradual crossover between high- and low-temperature approximately linear-in-$ T$ regimes, with characteristic crossover temperatures $ T_{\mathrm{cr}}/t\approx0.414$ and $ 0.467$ for $ N=16$ and $ 18$ , respectively. We also find a broad specific-heat peak associated with this gradual crossover, at $ T/t \approx 0.70$ and $ 0.68$ for $ N=16$ and $ 18$ , respectively.
Strongly Correlated Electrons (cond-mat.str-el)
4.5 pages and 3 figures
Mimicry of $\textit{d}$-wave Andreev Signatures by Interlayer Pairing
New Submission | Superconductivity (cond-mat.supr-con) | 2026-11-10 20:00 EST
Zhongyi Zhang, Shengshan Qin, Chui-Zhen Chen, Hoi Chun Po, Jiangping Hu, Xianxin Wu
The recent discovery of high-$ T_{\rm c}$ superconductivity in bilayer nickelates has attracted enormous attention. Despite dominant theoretical studies pointing to interlayer pairing, the pairing symmetry is strongly debated due to conflicting evidence on nodeless bulk gaps and $ d$ -wave-like transport signatures. Here, we demonstrate that a nodeless interlayer pairing can naturally mimic $ d$ -wave Andreev signatures when the point contact is not evenly coupled to the two layers. The phenomenon can be understood by recognizing how a contact potential, which is odd under the layer-exchanging mirror symmetry, acts like an effective Zeeman field on the layer pseudospin. This pseudo field then binds in-gap Andreev states that sweep through the gap with the width and strength of the barrier. We further demonstrate in a realistic model for La$ _3$ Ni$ _2$ O$ _7$ that the simulated subgap conductance for a top-layer barrier can reproduce the orientation dependent ZBCP usually interpreted as a fingerprint of $ \textit{d}$ -wave pairing. By revealing this mirror-selective Andreev response from an interlayer pairing state, our work offers a natural scenario to reconcile the conflicting experimental evidence in bilayer nickelates and advances our understanding of unconventional superconductivity.
Superconductivity (cond-mat.supr-con), Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
8 pages, 4 figures
Controlled Oxidation of Tellurium Nanoparticles for Telecom Detection
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-11-10 20:00 EST
Surface oxidation plays an important role in governing charge transport in semiconductor nanoparticle assemblies. Here, we investigate the optoelectronic properties of solution-processed tellurium (Te) nanoparticle ensembles prepared through gradual ambient-air exposure. Structural and spectroscopic analyses reveal interconnected elemental Te nanoparticles with coexisting alpha-TeO2 and hydroxyl-containing surface species, exhibiting a lower relative contribution of oxidized Te than previously investigated forced-air-oxidized ensembles. The resulting photodetectors demonstrate photoresponse at 405, 532, and 1550 nm, with maximum responsivities of 10.1, 14.4, and 8.5 mA/W, respectively. At 1550 nm, the device exhibits rise and fall times of 17.7 and 40.2 s, respectively, and an estimated shot-noise-limited specific detectivity of 1.3 \ast 10^6 Jones. These findings highlight the importance of controlling surface oxidation to balance interparticle charge transport and dark-current suppression, offering insights for the development of solution-processed Te-based photodetectors for short-wave infrared applications.
Materials Science (cond-mat.mtrl-sci)
The main manuscript and Supporting Information have been combined into a single PDF file
Hidden memory above the Neel temperature programs antiferromagnetic order in Cr2O3
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-11-10 20:00 EST
Josiah Keagy, Sumukh Mahesh, Wei-Cheng Liao, Jing Shi
Control of antiferromagnetic order is central to magnetoelectric and antiferromagnetic spintronic devices. In the prototypical magnetoelectric antiferromagnet Cr2O3, domains are conventionally selected by simultaneous application of electric and magnetic fields during cooling through the Neel temperature (T_N) or at a fixed temperature below T_N. Here, we show that antiferromagnetic order can instead be programmed by electric-field conditioning entirely in the paramagnetic state above T_N. By measuring the magnetoelectric coefficient (alpha_zz) of bulk Cr2O3 crystals under different thermal and field histories, we find that a sufficiently large electric field above T_N establishes a reversible state that persists after the field is removed. Subsequent magnetic-field cooling with no applied electric field produces a single-domain state with the opposite Neel-vector orientation from conventional magnetoelectric field cooling. The electrically induced state can be reversibly written, erased, and allowed to relax at high temperatures, demonstrating a long-lived internal electric bias that governs domain selection. The observed behavior is consistent with a metastable surface-associated polar state that may generate this internal bias. These results reveal an unexpected coupling between electrically programmed memory and antiferromagnetic domain formation in Cr2O3.
Materials Science (cond-mat.mtrl-sci)
Optimizing one-dimensional lithographically defined nanowires in semiconducting heterostructures
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2026-11-10 20:00 EST
Leah Tom, Yik Kheng Lee, Karina L. Hudson, Krittika Kumar, Jackson S. Smith, Alex R. Hamilton, S. N. Coppersmith, Jared H. Cole, Mark Friesen
One-dimensional nanowires can host remarkable electronic properties and are central to studying quantum transport. Although heterostructure-defined confinement combined with gate-defined potentials can greatly reduce the effects of impurities as measured via electron mobilities, the realization and interpretation of novel effects at this scale are complicated by disorder. Experiments on lithographically defined one-dimensional nanowires therefore do not exhibit ideal behavior. Using theoretical and computational models, we predict that optimizing the geometry of split gates in semiconducting heterostructures will lead to higher-quality channels for transport measurements. Further, we show that this optimization is essential for resolving features of interest such as the Rashba-induced spin gap. This new approach to lithographically defined conduction channels provides better energy resolution and is less susceptible to disorder.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
9 pages, 7 figures
Current-voltage characteristics of layered cuprate superconductors with intrinsic Josephson junctions
New Submission | Superconductivity (cond-mat.supr-con) | 2026-11-10 20:00 EST
T.B. Charikova, V.N. Neverov, M.R. Popov, S.D. Popov, N.G. Shelushinina
A brief review of the results for the current-voltage characteristics study in highly anisotropic cuprate superconductors is presented, considering the existence of the intrinsic Josephson effect in multilayer HTSC compounds. We analyzed the observations of multi-branch current-voltage characteristics for current in the c-direction both for the hole-doped and electron-doped cuprate SCs wich conveniently viewed as a strack of intrinsic Josephson junctions, where the CuO2 layers serve as superconducting plates and the buffer layers as dielectric interlayers. It was shown that the tunneling characteristics of intrinsic Josephson junctions in optimally doped p- and n-type cuprates indicate a predominantly d-wave symmetry of the order parameter, demonstrating high conductivity in the subgap regime: U < 2delta/e. The analysis carried out confirms the theoretically predicted power-law dependences U ~ I^gamma with gamma = (0.33 - 0.50) in the hole-doped Bi- and Tl-compounds, which is typical for SCs with monotonic dx^2-y^2 - wave symmetry of the order parameter and with gamma = (0.70 - 0.76) for electron-doped SCs with a non-monotonic d-wave symmetry within the framework of the two-band/two-gap model.
Superconductivity (cond-mat.supr-con)
26 pages, 13 figures, 3 tables
Temperature-Driven Evolution of Magnetization Dynamics in Cobalt-Doped Fe$_5$GeTe$_2$
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-11-10 20:00 EST
Sourabh Singh, Soumik Aon, Andrew F. May, Joost Ridderbos, Ramanathan Mahendiran, Wilfred G. van der Wiel
Understanding magnetization dynamics in metallic van der Waals ferromagnets is essential to uncover their magnetic interactions and evaluate their potential for high-frequency spintronics applications. In this study, we investigate the temperature-dependent magnetization dynamics of a single crystal of cobalt-doped $ Fe_{5}GeTe_{2}$ (CFGT) using broadband ferromagnetic resonance (FMR) spectroscopy. At high temperatures, the FMR response is dominated by a single broad resonance that shifts toward lower magnetic fields upon cooling. Fits to the frequency dependence of the resonance field and linewidth yield an effective $ g$ factor of approximately 2.45 and an effective Gilbert damping parameter of approximately 0.15 near room temperature. The effective magnetic anisotropy evolves strongly with temperature, with an increasingly pronounced easy-plane contribution upon cooling toward 200 K. Below approximately 200 K, an additional resonance emerges and evolves into a distinct two-mode response that persists to the lowest measured temperature of 25 K. The two branches exhibit different temperature dependences of their resonance fields and linewidths, and the emergence of the additional mode is not accompanied by a comparably pronounced anomaly in the static magnetization. These results reveal a dynamical crossover in CFGT that is not readily apparent from bulk magnetometry and highlight the sensitivity of FMR to the magnetic behavior of chemically substituted van der Waals ferromagnets.
Materials Science (cond-mat.mtrl-sci), Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
26 pages, 5 figures in the main text, 5 figures in Supplementary Information
A Transport-Constrained Gradient-Flow Description of Continuum Dislocation Dynamics
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-11-10 20:00 EST
Paria Behnoud, Anthony Rollett, Carlos Mora-Corral, Kaushik Dayal
Gradient flow frameworks are fundamental to numerous models of defect and microstructure evolution. This work develops a gradient flow formulation for continuum dislocation dynamics, with the key distinction that the admissible rates are transport-constrained. Using the dislocation density and compatible slip fields as the primary state variables, their admissible rates are restricted by geometric conservation laws. The corresponding transport velocities are then selected variationally through a constrained Onsager principle. The resulting model has both a variational gradient flow structure and consistency with the geometric dislocation conservation statement; existing models of dislocation evolution typically have either one or the other feature.
This thermodynamic structure provides a dislocation driving force that includes elastic stress contributions – corresponding to the classical Peach–Koehler force – as well as contributions from the core and nonconvex lattice energies. A simplified version of the model is used to study the energetics and dynamics of an opposite-sign dislocation pair. The lattice energy keeps the cores compact, and an external applied shear either assists annihilation or, above a threshold, separates the pair.
Materials Science (cond-mat.mtrl-sci)
Accepted to appear in Journal of the Mechanics and Physics of Solids
On the nature of low-energy electronic states in twisted bilayer graphene: a first-principles study
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2026-11-10 20:00 EST
Albert Zhu, Daniel Bennett, Daniel T. Larson, Mohammed M. Al Ezzi, Efstratios Manousakis, Efthimios Kaxiras
The nature of low-energy electronic states in twisted bilayer graphene (TBG) near the magic angle has been extensively discussed in the literature on qualitative grounds, since these states play a key role in the construction of effective few-band models toward a many-body theory. Here, we report extensive and systematic first-principles calculations of TBG electronic states in the magic-angle range, using density functional theory with no further approximations. We construct moiré-scale localized Wannier states for the low-energy bands and develop an effective ten-band model for each $ K$ valley. The Wannier orbitals contain both atomic and moiré-scale details and are centered near the high-symmetry stackings in the moiré cell. We calculate Coulomb and exchange integrals of these localized states, quantities that are the basic ingredients in many-body models. We also compare the values of these integrals to those obtained or assumed in previous works. By symmetrizing the ten-band Hamiltonians and basis orbitals, we provide insight into how the dominant hoppings between the flat-band orbitals evolve as a function of twist angle.
Strongly Correlated Electrons (cond-mat.str-el), Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
Atomically abrupt sp-sp$^2$ all-carbon heterojunction preserving the electronic identity of constituent allotropes
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-11-10 20:00 EST
Alice Cartoceti, Masoumeh Alihosseini, Gianni Conti, Eliecer Pelaez-Sifonte, Alessio Orbelli Biroli, Francesco Sedona, Paolo D’Agosta, Francesco Tumino, Andrea Li Bassi, Jorge Lobo-Checa, Carlo S. Casari, Simona Achilli
Covalently integrating distinct carbon allotropes with atomic precision remains, to date, elusive, despite the clear advantage of combining complementary functionalities while preserving their electronic identities. Here, we realize an all-carbon lateral heterojunction combining ($ sp^2$ ) armchair graphene nanoribbons (GNRs) and $ sp$ -$ sp^2$ hydrogenated graphdiyne (hGDY) on Au(111) through Fe-mediated hierarchical on-surface synthesis. Low-temperature scanning tunnelling microscopy and spectroscopy combined with density-functional theory reveal an atomically abrupt (<0.5 nm), asymmetric type-I interface. Redistribution of an edge-localized GNR state onto the first hGDY unit demonstrates local electronic continuity, whereas their characteristic electronic structures re-emerge immediately beyond the interface. Calculations further indicate that heterojunction formation weakens the interaction of both constituents with the underlying Au(111) substrate, widening their gaps and reducing adsorption-induced interfacial polarization. These results establish lateral covalent integration as a route to engineer atomically defined electronic interfaces and substrate coupling in all-carbon nanostructures.
Materials Science (cond-mat.mtrl-sci)
Coherent Electrometer Using Hybridised Double Quantum Dot - Resonator States
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2026-11-10 20:00 EST
Samuel Andersson, Pierre Glidic, Andrea Cicovic, Harald Havir, Sebastian Lehmann, Kimberly A. Dick, Ville F. Maisi
Probing the change in conductance or reactance of a charge sensitive system using an rf cavity is a standard way of doing fast single-charge electrometry. In this article, we present a detector concept which is instead based on coherent interaction. We show that the coherent interaction between a microwave resonator and double quantum dot gives rise to a fast, highly sensitive electrometer. The coherent electrometer achieves a state-of-the-art readout speed, resolving two charge states with SNR of 11.7 in 16 $ \mu$ s, with a readout signal two orders of magnitude lower in power than previously required to reach this speed. In this way, heating of the sample becomes negligible. Thanks to its sensitivity and low dissipation, the coherent electrometer opens up the avenue for quantum limited charge detection with nanosecond speed and minimal back-action.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Quantum Physics (quant-ph)
9 pages, 5 figures
Fabrication and Characterization of Flexible In2O3 Thin-Film Transistors on Mica Substrates
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-11-10 20:00 EST
Hyeonjun Kong, Ping-Hsein Wu, Xian-Ye Jiang, Yasutaka Matsuo, Ying-Hao Chu, Hiromichi Ohta
Flexible oxide-semiconductor thin-film transistors (TFTs) with high field-effect mobility (uFE > 70 cm^2/Vs) are required for next-generation flexible displays. Polycrystalline In2O3-based TFTs are promising candidates; however, conventional flexible substrates such as plastics are not suitable because their fabrication typically requires relatively high temperatures (~350 deg.C). In this study, we used mica as a flexible substrate to fabricate polycrystalline In2O3-based TFTs, motivated by previous demonstrations of crystalline oxide growth on mica. The resulting TFTs exhibited a uFE of approximately 75 cm^2/Vs. The devices maintained gate-modulated operation after 10^3 flex-out bending cycles at a 5 mm radius, whereas flex-in cycling caused early electrical failure, likely due to In2O3 film degradation. The TFTs also operated normally after exposure to 85 deg.C and 40% relative humidity for one day. These results demonstrate that mica substrates enable high-mobility, flex-out-compatible In2O3-based TFTs.
Materials Science (cond-mat.mtrl-sci)
13 pages, 5 figures, 1 table
Discovery of Kondo-Kramers Nodal Line Topological State in strongly correlated material CeAuAl$_3$
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2026-11-10 20:00 EST
Hari Bhandari, Kevin Allen, Kuan-Sen Li, Yuan Fang, Arushi, Karthik Rao, Mounica Mahankali, Sanu Mishra, Jian-Xin Zhu, Christopher Lane, Qimiao Si, Emilia Morosan
Kramers nodal lines (KNLs) are predicted in all achiral, non-centrosymmetric crystal structures, and yet there are very few experimental realizations of KNLs, only in weakly correlated systems. Especially, their realization in strongly correlated systems remains unexplored. Here we investigate KNL topology in the non-centrosymmetric, achiral Kondo lattice CeAuAl$ _3$ , using magnetotransport, thermodynamic measurements, density functional theory (DFT), and tight-binding toy model calculations. We find that CeAuAl$ _3$ hosts KNLs in the $ \mathit{\Gamma}\text{-}Z$ and $ X\text{-}P$ directions, protected by time-reversal and mirror symmetries. Breaking of these crystalline symmetries, along with time-reversal symmetry via spin polarization, lifts the KNL degeneracy, which, in turn, generates Berry curvature resulting in an intrinsic anomalous Hall effect (AHE). More importantly, CeAuAl$ _3$ shows large AHE not only below the magnetic ordering temperature $ T_N$ but rather below the Kondo temperature. This underscores the role of the Kondo correlations in bringing the KNLs at the Fermi surface rather than at accidental energies, as would be expected without correlations. Our work identifies a new topological state, Kondo-Kramers Nodal Line, with CeAuAl$ _3$ being the first compound explicitly identified to host this new correlated topological state, and demonstrating the expected AHE associated with it. More generally, our work outlines the pathway for finding Kondo-KNL systems in all compounds that combine achiral, non-centrosymmetric structure with Kondo correlations.
Strongly Correlated Electrons (cond-mat.str-el)
16 pages, 11 Figures
Momentum-Resolved Kondo Hybridization of Nonsymmorphic Dirac-Derived Bands in CeAgBi$_2$
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2026-11-10 20:00 EST
Yang Luo, Hao Liu, Zhong-Tuo Fu, Qi-Yi Wu, Bo Chen, Zheng-Tai Liu, Mao Ye, Da-Wei Shen, Chen Zhang, Ying Zhou, Cun-Hui Lyu, Jin-Dong Bai, Zi-Jie Xu, Hai-Long Deng, Zhen-Xing Wu, Jun-Jie Wu, Sai-Chao Deng, Yu-Xia Duan, Jian-Qiao Meng
How symmetry-constrained conduction states acquire heavy-quasiparticle character is a central question in correlated quantum materials. Combining angle-resolved photoemission spectroscopy, Ce $ 4d \rightarrow 4f$ resonant photoemission, and first-principles calculations, we investigate the nonsymmorphic Kondo lattice CeAgBi$ _2$ . We identify quasi-two-dimensional Bi-square-net-derived bands consistent with calculated Dirac crossings and nodal lines. Resonant photoemission resolves a nearly dispersionless Ce 4$ f$ band near the Fermi level, establishing Kondo heavy-quasiparticle states. Its pronounced momentum-dependent spectral weight at intersections with the identified Dirac-derived branches provides direct spectroscopic evidence for their participation in $ c$ -$ f$ hybridization. Complementary measurements on independently cleaved samples and an effective hybridization model connect these branches to the Kondo heavy-quasiparticle spectrum. The combined results support preservation of nonsymmorphic Dirac-band connectivity under Kondo renormalization, showing how symmetry-constrained conduction states become constituents of correlated heavy quasiparticles.
Strongly Correlated Electrons (cond-mat.str-el)
7 pages, 4 figures
Multifractality in sputtered crystalline and amorphous transition metal nitride thin films
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-11-10 20:00 EST
K. Anantha Padmanabhan, Kuraganti Vasu, P. Manimaran, M. Ghanashyam Krishna
In this work, we present evidence for multifractal growth in Titanium and Niobium nitride thin films on different substrates. Self-similar multifractal structures such as dendrites and multi-branched snowflake-like structures are reported. The fractal dimensions are controlled by a combination of processing parameters and conditions at the film-substrate interface. Significantly, fractal growth is observed not only in crystalline films on crystalline and amorphous substrates but also on amorphous films on crystalline substrates. The 2D Multifractal Detrended Fluctuation Analysis (2D MFDFA) carried out on the scanning electron micrographs, clearly reveals the multifractal nature of the nitride thin films. The statistical moments were varied between -5 to +5. The Hausdorff dimensions for the TiN films are in the range of 1.65 to 1.79 while it is 1.64 to 1.74 for the NbN thin films. It is proposed that the observed multifractality is due to a competition between morphological instabilities and Diffusion-Limited Aggregation
Materials Science (cond-mat.mtrl-sci)
17 pages, 7 figures, 2 tables
Transverse quasiparticle heat transport in p-wave magnetic Josephson junctions
New Submission | Superconductivity (cond-mat.supr-con) | 2026-11-10 20:00 EST
Jin-Xing Hou, Pritam Chatterjee, Song-Bo Zhang
We study transverse heat currents carried by Bogoliubov quasiparticles in $ p$ -wave magnetic Josephson junctions under a longitudinal temperature bias. We find that such a junction supports a transverse spin heat current while the net transverse heat current vanishes. This effect stems from the $ p$ -wave magnetism, which shifts the two spin sectors oppositely in transverse momentum space and thereby causes them to carry opposite heat currents. A weak Zeeman field lifts the compensation between the two spin-sector contributions, thereby generating a finite net transverse heat current. The directions of both currents can be switched by reversing the sign of the $ p$ -wave magnetic splitting or tuning the superconducting phase difference, while both currents vanish in the absence of $ p$ -wave magnetism. These findings highlight $ p$ -wave magnetic Josephson junctions as a versatile platform for switchable transverse heat transport and controllable spin caloritronics.
Superconductivity (cond-mat.supr-con)
7 pages, 4 figures
Extended No-Go Theorem and Its Verification in Spin-Selective Transport through Chiral Cyclodextrin Assemblies
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2026-11-10 20:00 EST
Kai-Yuan Zhang, Shu-Zheng Zhou, Xi Sun, Hua-Hua Fu
The classical two-terminal single-channel no-go theorem relies on time-reversal symmetry (TRS) and scattering-matrix unitarity. In open systems, omitted channels or environment leakage break unitarity, so TRS and the symplectic reciprocity symmetry TRS(^{\dagger}) are no longer equivalent, invalidating the classical premises. We prove that if the two-terminal single-channel scattering matrix satisfies TRS(^{\dagger}) plus central inversion symmetry, transmission remains no spin selectivity; this result provides an important complement to the classical no-go theorem in nonunitary regime. When these conditions are violated or the single-channel constraint is lifted, spin-selective transport occurs. In charge transport through devices based on chiral (\gamma)-cyclodextrin molecular assemblies, we verify separately the classical no-go theorem in unitary case and its supplementary version together with its multichannel corollary in nonunitary case: when the conditions for the corresponding no-go theorem hold, the chirality-induced spin selectivity (CISS) of the assembly disappears, whereas when they are violated, CISS emerges. These results extend the no-go theorem to nonunitary scattering systems and establish an effective theoretical framework for studying CISS in real molecular assemblies.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
10 pages, 5 figures
Pseudogap in hole doped cuprates: a status report
New Submission | Superconductivity (cond-mat.supr-con) | 2026-11-10 20:00 EST
Saleh Hasan Naqib, Raihana Shams Islam
The pseudogap state, an anomalous momentum dependent partial suppression of low energy electronic excitations persisting well above the superconducting critical temperature in underdoped cuprates, remains one of the most profound enigmas in condensed physics today. This review summarizes over three decades of experimental and theoretical progress. It appears that pseudogap is not a mere precursor to superconductivity, but a distinct, intertwined state of matter characterized by a complex interplay of competing and cooperating electronic orders. We critically examine the bulk probes like resistivity and magnetic susceptibility and the surface hallmark spectroscopic signatures observed via angle resolved photoemission spectroscopy (ARPES) in this review. ARPES reveals a Fermi surface truncated into disconnected segments and scanning tunneling microscopy (STM) visualizes a spatially heterogeneous energy gap around the Fermi level. These observations are contextualized alongside transport anomalies, including resistivity and bulk magnetic susceptibility, to construct a phenomenological portrait of a phase that violates conventional Fermi liquid theory. By mapping the electronic phase diagram, we highlight the abrupt transition at above optimal doping. We conclude with open questions still to be answered. This review underscores the role of the pseudogap as a key to unlocking the unconventional pairing mechanism of hole doped cuprates and the broader physics of strongly correlated electron systems.
Superconductivity (cond-mat.supr-con), Strongly Correlated Electrons (cond-mat.str-el)
Dopant Cluster Engineering for Tunable Room-Temperature Ferromagnetism in 2D Transition Metal Dichalcogenides
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-11-10 20:00 EST
Shivangee, Sachin Grewal, Akash Singh
Two-dimensional transition metal dichalcogenides (2D-TMDs) offer a promising platform for realizing dilute magnetic semiconductors. However, simultaneously achieving large magnetic anisotropy energy (MAE) and high Curie temperature (T$ _\text{c}$ ) remains a major challenge. In this work, we employ DFT+U to systematically investigate the thermodynamic stability and magnetic properties of 2D-MoSe$ _2$ and 2D-WSe$ _2$ doped with transition metal atoms. We found that the paired dopant configurations are more stable than previously attributed isolated dopants. Despite their nearly identical crystal structures, 2D-MoSe$ _2$ and 2D-WSe$ _2$ show contrasting properties upon doping. All paired dopants in 2D-MoSe$ _2$ exhibit long-range ferromagnetic coupling (FMC) primarily due to carrier-mediated exchange interactions, whereas those in 2D-WSe$ _2$ show weak exchange coupling. Interestingly, 2Mn$ _\text{2W}$ shows a transition from less stable antiferromagnetic coupling (AFMC) in the short range to highly stable FMC in the long-range. The combined effect of spin-orbit coupling, exchange interactions, and orbital hybridization gives rise to a large MAE with maximum in-plane values of $ -$ 3.5 meV for 2V$ _\text{2Mo}$ and $ -$ 3.2 meV for 2Mn$ _\text{2W}$ . Monte Carlo simulations estimate T$ _\text{c}$ $ \simeq$ 440 K for 2Fe$ _\text{2Mo}$ and ensure its high-temperature stability in 2D-MoSe$ _2$ . Our results establish dopant clustering as an effective route to engineer high-temperature ferromagnetism in 2D-TMDs and highlight their potential for nano-spintronic applications.
Materials Science (cond-mat.mtrl-sci)
Thouless pumping and Haldane-model topology in a driven extended SSH chain
New Submission | Quantum Gases (cond-mat.quant-gas) | 2026-11-10 20:00 EST
Zhen Dong, Xin-Lei Zhao, Yi Zheng
Thouless pumping provides a powerful route for probing Chern topology through quantized motion in one-dimensional lattices. We investigate such a topological pump in an extended Su-Schrieffer-Heeger (SSH) model with tunable next-nearest-neighbor hoppings. A graphical representation in Bloch space is used to construct pumping schemes. In this framework, the Bloch vector traces a closed loop that evolves in time. The Chern number of the synthetic band is then determined by the motion of this loop. Quantum pumping phenomena are demonstrated for a filled band and for a bosonic wave packet driven by Bloch oscillations. We further show that the Haldane model can be mapped to the driven extended SSH chain by replacing a quasimomentum by the pumping time. The quantized charge pump indicates that the Chern number of a two-dimensional model can be read out from a one-dimensional pumping protocol, offering an accessible route for detecting higher-dimensional topology, such as in photonic and cold-atom platforms.
Quantum Gases (cond-mat.quant-gas), Quantum Physics (quant-ph)
9 pages, 11 figures
Quartet ferromagnetism in the small-exchange limit
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2026-11-10 20:00 EST
Samuel Ogundeji, Tianxiong Han, Tyler J. Slade, Olivia Medina, Joanna M. Blawat, Filip Ronning, John Singleton, Sean M. Thomas, Alimamy F. Bangura, Wei Tian, Eleanor M. Clements, Bing Li, Adam A. Aczel, Paul C. Canfield, Benjamin G. Ueland, Rebecca Flint, Robert J. McQueeney, Aashish Sapkota
Rare-earth magnets are often regarded as classical owing to their large angular momentum J, but this picture breaks down when exchange is smaller than the crystalline electric-field (CEF) energy scale, allowing the degeneracy of low-lying CEF manifolds to dictate the emergent quantum phases. Here, we uncover such a regime in the RV6Sn6 (R = rare-earth) kagome metals with strong magnetic anisotropy. Thermodynamic and neutron-diffraction measurements reveal successive axial and tilted ferromagnetic (FM) phases in DyV6Sn6, arising from independent ordering of the axial Mz and transverse Mx dipolar components enabled by a rare quasi-quartet ground state. On the other hand, HoV6Sn6 has a similar tilted magnetic anisotropy, but remains axial down to 0.03 K. This discrepancy can be traced back to the non-Kramers nature of Ho3+ where the CEF lifts the quartet degeneracy, leaving a quasi-triplet ground state. Unlike quartets or higher multiplets, we find that the effective spin-1 triplet does not allow independent dipolar ordering without strong quadrupolar (nematic) interactions that act to break rotational symmetry, revealing an essential multipolar prerequisite for tilted magnetic ground states. These results establish a quartet CEF manifold as the minimal degeneracy required for dipolar-driven independent ordering. Mapping the surrounding CEF parameter space further reveals competing magnetic, non-magnetic singlet, and potential quadrupolar phases, driven by multifold ground state degeneracies. These results establish CEF tuning as a versatile route to unconventional quantum phases across the broader RT6X6 (T = transition metal; X = Sn, Ge) family.
Strongly Correlated Electrons (cond-mat.str-el), Other Condensed Matter (cond-mat.other)
Dipolar Exchange and Emergent Electric-Dipole-Carrying Quasiparticles in Electronic Ferroelectrics
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2026-11-10 20:00 EST
Electronic correlations underpin diverse spontaneously ordered states in matter, whose collective excitations emerge as quasiparticles that encode the underlying order. While spin exchange interactions give rise to magnetic order and its quasiparticle excitations known as magnons, their counterparts in electronic ferroelectrics remain poorly understood. Here, we derive an analogous quantum dipolar-pseudospin exchange model for electronic ferroelectricity and identify the associated bosonic quasiparticles that carry intrinsic electric dipole moments. Unlike ferrons in conventional lattice-based ferroelectrics, these dipolar quasiparticles arise entirely from collective electronic dynamics without involving lattice vibrations. Their excitation spectrum exhibits a linear Stark shift under a static electric field, while coupling to an oscillating electric field enables their coherent excitation, leading to colossal, resonantly enhanced second-harmonic generation and optical rectification in the terahertz regime. These dipolar quasiparticles offer promising opportunities for electrically tunable nonlinear optics and open a route toward extending the paradigm of transport in electronic systems beyond conventional charge currents to electric dipole currents.
Strongly Correlated Electrons (cond-mat.str-el)
Pinching an elastic potato chip
New Submission | Soft Condensed Matter (cond-mat.soft) | 2026-11-10 20:00 EST
Kosei Kataoka, Tomohiko G. Sano
Thin shells deform by transmitting stress across their surface, yet how a shell of general shape carries a localized load remains unclear. Combining experiments, simulations, and theory on pinched saddle-shaped elastic shells, we show that the asymptotic lines, curves of zero normal curvature, dictate both deformation and stiffness. Isometry turns the shell mid-surface into a medium obeying a wave equation in space. Material points lit by the pinch are lifted, while those in its shadow sink. Finite thickness blurs the lit–shadow boundary, and the same rule maps where a clamped shell is rigid. Our findings indicate that light and shadow offer a unified framework for understanding mechanical stress propagation along shell structures.
Soft Condensed Matter (cond-mat.soft)
6 pages, 4 figures + Supplementary Material
Markov-Shielded Typicality for Thermal Quantum States
New Submission | Statistical Mechanics (cond-mat.stat-mech) | 2026-11-10 20:00 EST
Pure states of quantum many-body systems at thermal equilibrium are known to be typical, in a sense that a randomly chosen pure state from an appropriate energy shell reproduces the Gibbs-state expectation values of most observables acting on a small subsystem. However, such typical states are intrinsically stochastic, conventionally generated from the random high-temperature state, suffer from statistical fluctuations, and do not provide a continuous connection to the ground state. Here, we introduce a deterministic variational framework for constructing a Markov-Shielded Typical (MST) state, a unique thermal pure-state representative whose local reduced density matrices closely approximate those of the Gibbs state, from the ground state up to infinite-temperature limit. Our approach reformulates free-energy minimization by replacing the nonlocal von Neumann entropy with a local, computationally tractable Markov entropy, where we establish rigorous upper and lower bounds of MST free energy to lie in the very vicinity of the thermal free energy. This framework extends the concept of typicality to deterministic pure-state representations of thermal equilibrium, offering a scalable wave-function approach with potential applications to both classical and quantum computing.
Statistical Mechanics (cond-mat.stat-mech), Quantum Physics (quant-ph)
15 pages, 9 figures, including Supplemental Material
Hyperuniformity in active matter
New Submission | Soft Condensed Matter (cond-mat.soft) | 2026-11-10 20:00 EST
Disordered hyperuniform systems are characterized by an anomalously strong suppression of long-wavelength density fluctuations. As a result, these unusual materials behave as though virtually incompressible, even though the particle arrangement itself can remain fully disordered at short range. This peculiar state of matter has been the topic of intense research in physics and mathematics in recent years. Another flourishing research arena is active matter, composed of self-propelled agents that convert energy into motion. While the two fields remained largely disjunct for a long time, the paper by Lei and coworkers (2019) created a link between hyperuniformity and active matter by demonstrating that interacting circle swimmers self-organize into disordered hyperuniform structures. Inspired by this work, many other examples of hyperuniformity in active matter have been identified. We shall describe the impact and outgrowth of this development, and give a brief perspective on further links between hyperuniformity and active matter.
Soft Condensed Matter (cond-mat.soft), Statistical Mechanics (cond-mat.stat-mech)
KIM REVIEW 4, 5 (2026)
Dynamic Scaling and Aging in Hydrodynamic Coarsening of Vapor Bubbles in a Lennard-Jones Fluid
New Submission | Statistical Mechanics (cond-mat.stat-mech) | 2026-11-10 20:00 EST
We investigate the coarsening and aging dynamics of vapor bubbles during liquid-vapor phase separation in a three-dimensional single-component Lennard-Jones fluid using large-scale molecular dynamics simulations. Following a temperature quench from a homogeneous high-temperature state into the two-phase coexistence region, vapor bubbles nucleate and grow in the liquid background. The characteristic bubble size follows a power-law growth, $ \ell(t)\sim t^\alpha$ , with a growth exponent $ \alpha \simeq 2/3$ , characteristic of inertial hydrodynamic coarsening. We also investigate the two-time autocorrelation function $ C_{ag}(t,t_w)$ which follows waiting-time dependent relaxation, revealing aging. Furthermore, data at different waiting times collapse onto a scaling function when plotted as a function of the length ratio $ \ell(t)/\ell(t_w)$ , demonstrating dynamical scaling during aging. The corresponding scaling function exhibits an algebraic decay with an exponent $ \lambda \simeq 3$ . Interestingly, bubble and droplet growth exhibit distinctly different domain-growth and aging exponents despite both being disconnected morphologies.
Statistical Mechanics (cond-mat.stat-mech), Soft Condensed Matter (cond-mat.soft)
8 pages, 7 figures
Ferromagnetic resonance signatures of edge states for distinguishing chiral and helical $p$-wave superconductors
New Submission | Superconductivity (cond-mat.supr-con) | 2026-11-10 20:00 EST
Shun Muto, Yuya Ominato, Takeo Kato, Mamoru Matsuo, Ai Yamakage
We theoretically investigate ferromagnetic resonance (FMR) modulation at interfaces between ferromagnetic insulators and two-dimensional chiral and helical $ p$ -wave superconductors. We evaluate the surface dynamical spin susceptibility, including both edge and bulk quasiparticle excitations. For momentum-conserving interfacial exchange at zero temperature, the edge contribution to the Gilbert damping exhibits distinct frequency scalings for the excitation energies well above the spectral broadening, $ \hbar\omega\gg2\delta$ : $ \delta/(\hbar\omega)^{2}$ for the chiral state and $ 1/\hbar\omega$ for the helical state. For a clean superconducting boundary, edge-induced Ising spin anisotropy persists even when interfacial exchange disorder randomizes momentum transfer. The low-energy edge response is suppressed when the magnetization aligns with the edge-state spin axis. These results establish FMR modulation as a probe complementary to existing methods for distinguishing the chiral and helical states and constraining their $ d$ -vector directions.
Superconductivity (cond-mat.supr-con), Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
14 pages,6 figures
This Is Water: Relative Humidity as a Hidden Parameter in the Self-Assembly of CdSe Nanoplatelets into Threads
New Submission | Soft Condensed Matter (cond-mat.soft) | 2026-11-10 20:00 EST
Benoit Wagnon, Seungho Lee, Lilian Guillemeney, Frédéric Chaput, Rodolphe Valleix, Laurent Coolen, Benjamin Abécassis
When nanocrystals order into large-scale assemblies, interparticle coupling can give rise to new properties. In the case of semi-conducting nanoplatelets (NPL), stacking them orderly into threads yields highly efficient, ultrafast Förster Resonance Energy Transfer (FRET) over distances of hundreds of nanometers. Producing such assemblies reliably and reproducibly therefore matters. Yet, the mechanism by which dispersed NPL form stacked threads under evaporative self-assembly remains unclear. Here, we show that the relative humidity (RH) under which the NPL dispersion evaporation occurs is a critical, and so far overlooked, experimental parameter. Using a humidity-controlled chamber, we find that micrometer-long NPL stacks form only when evaporation occurs at RH > 50% rather than under dry conditions and when free oleic acid is present in the dispersion. Because such values lie within typical laboratory conditions, humidity is an easily overlooked parameter. We discuss how adventitious water may modify colloidal forces between NPL, through changes in solvent polarity, depletion, capillary or solvation interactions. Our experiments demonstrate that relative humidity is a key parameter for nanoparticle self-assembly and, more broadly, point to colloidal interactions at the nanoscale.
Soft Condensed Matter (cond-mat.soft)
Strong Collective Dynamics Hidden behind a Nearly Free Single-Particle Spectrum
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2026-11-10 20:00 EST
Zhixuan Zhao, Sicheng He, Hanxiang Di, Nayun Chen, Jiabai Xiong, Guyixue Gao, Yanling Wu, Jun Li
Single-particle spectroscopy has long served as a criterion for the strength of electronic correlations: strong collective motion is expected to shift and broaden spectral peaks and to renormalize the dispersion. Here we show that this correspondence can fail on the same microscopic orbital. The mechanism relies on local interference between two resonant side orbitals: one suppresses low-energy real transitions into the interacting environment, while the other suppresses spectral-weight backflow to the source orbital; virtual mixing nevertheless transfers the environmental spin polarization to the source. We prove a rigorous relative spectral bound that is uniform in environment size and interaction strength and holds for arbitrary stationary states; the protection becomes stronger as the relative frequency resolution improves. In a fully quantum two-cell device, a collective mode softens by 60%, whereas the particle intensity at the free peak changes by only 3.6 parts per million. Quantum Monte Carlo shows that the transferred spin response grows with spatial correlations and is quantitatively predicted by the free-band polarization. These results recast the meaning of a simple particle spectrum and provide a design principle for quantum probes that combine predictable particle spectra with strong collective sensitivity.
Strongly Correlated Electrons (cond-mat.str-el), Statistical Mechanics (cond-mat.stat-mech)
Identifying Contributions to the Superconducting Diode Effect through Nonreciprocal Superconducting Properties
New Submission | Superconductivity (cond-mat.supr-con) | 2026-11-10 20:00 EST
Ryo Iijima, Hisakazu Matsuki, Fugo Tokoro, Susumu Hirata, Akito Daido, Ryusuke Hisatomi, Yoichi Shiota, Shutaro Karube, Youichi Yanase, Teruo Ono
Nonreciprocal superconducting responses provide a sensitive probe of superconducting states in systems where inversion and time-reversal symmetries are broken. However, in the superconducting diode effect (SDE), where the critical current differs for opposite current directions, nonreciprocity can also arise from vortex-induced contributions caused by minute magnetic field misalignment, complicating its interpretation. Here, we investigate a noncentrosymmetric $ [Nb/V/Ta]{40}$ superlattice and demonstrate nonreciprocity in all three fundamental superconducting properties: the critical current, critical field, and superconducting transition temperature. By measuring the angular dependence of the nonreciprocal critical field $ \Delta B{\mathrm{c} 2}$ , we separate the contribution of misalignment-induced out-of-plane vortices from the in-plane response. We identify a sharply enhanced SDE emerging near $ B_{\mathrm{c} 2}$ , accompanied by nonreciprocal responses in $ T_{\mathrm{c}}$ . These observations exhibit phenomenology similar to that reported in layered superconductors, where an orbital-FFLO state with finite-momentum Cooper pairing has been reported. Our results establish a protocol for assessing out-of-plane vortex contributions to the superconducting diode effect and demonstrate that nonreciprocal responses provide complementary probes of unconventional superconducting states.
Superconductivity (cond-mat.supr-con)
19 pages, 13 figures
Sub-Thouless energy scale in interface-dominated unconventional superconductor junctions
New Submission | Superconductivity (cond-mat.supr-con) | 2026-11-10 20:00 EST
Léon Goedegebuur, Tim Kokkeler, Yukio Tanaka
We derive the conductance in unconventional superconductor - normal metal - normal metal junctions, taking into account the resistance between the normal metals. We show that applying Tanaka–Nazarov boundary conditions at both superconductor and normal metal interfaces reveals a new characteristic low-energy scale which is sub-Thouless in the experimentally relevant strong-interface regime. This scale governs, among other quantities, the curvature of the local density of states (LDOS) and the width of conductance dips near the zero-bias conductance peak in triplet superconductor junctions, thereby replacing the Thouless energy as the dominant low-energy parameter. We derive universal $ s$ -wave proximitized diffusive metal expressions for the zero-bias LDOS and differential conductance which solely depend on the interface and bulk resistances, independent of the superconducting gap and Thouless energy scale. This framework provides a possible origin of the anomalous low-bias conductance features observed in unconventional superconductors, offering a refined mechanism for interpreting interface and correlated electron physics in experimental hybrid junctions.
Superconductivity (cond-mat.supr-con)
26 pages, 23 figures
Scalable MoS2/Si Photodiode Arrays from Roll-to-Roll Mechanical Exfoliation
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-11-10 20:00 EST
Yigit Sozen, Thomas Pucher, Andres Castellanos-Gomez
We present a scalable, all-dry route to MoS2/Si photodiodes based on high-throughput roll-to-roll mechanical exfoliation. The method yields dense films of large-lateral-size MoS2 nanosheets and enables the formation of heterojunctions that operate in the photovoltaic regime when transferred onto locally etched Si regions. Individual devices show robust, fast photoresponses and broadband wavelength sensitivity. We further implemented a linear pixel array demonstrating position sensing capability and a 4x4 array as a proof-of-concept imaging sensor. These results indicate that roll-to-roll mechanical exfoliation can overcome common limitations of solution-processed films to enable low-cost, self-powered optoelectronic detectors for sensing and imaging applications.
Materials Science (cond-mat.mtrl-sci)
This is the authors’ version (post peer-review) of the manuscript
Y. Sozen, T. Pucher, and A. Castellanos-Gomez, Adv. Sci. 2026, e76787
Probing Chern Topology through Hall-Sensitive Photonic Spin Hall Shifts in a d-wave Altermagnet
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2026-11-10 20:00 EST
Mahnoor Sajid, Maha Siddiqui, Muzamil Shah
In this paper, we investigate the photonic spin Hall effect in a two-dimensional Rashba-coupled $ d$ -wave altermagnetic Chern system subjected to a uniform out-of-plane exchange field. We first analyze the energy-band structure and the Dirac mass distribution at the high-symmetry points, where $ m_{\Gamma}=m_M=\Delta_x, m_X=\Delta_x-4 t_J$ , and $ m_Y=\Delta_x+4 t_J$ . Band inversions at high-symmetry points generate both a topologically trivial regime $ (C=0)$ and Chern-insulating phases $ (C= \pm 1)$ . Employing the Kubo formalism for the optical conductivity together with the reflection matrix for a substrate-supported conducting sheet, we compute helicity-dependent finite-waist displacements of a reflected Gaussian beam. The resulting optical response exhibits a minimum interband absorption threshold, a Van Hove-type spectral feature, and distinct transitions at the $ X$ and $ Y$ points arising from the momentum dependence of the exchange field. Under the specified Hall-tensor and polarization sign conventions, the longitudinal helicity half-separation is odd upon reversal of the optical Hall conductivity and correspondingly changes sign between opposite-Chern phases, whereas the transverse half-separation is even in the Hall response. The maximal spin-dependent splitting occur in the vicinity of the pseudo-Brewster reflectance minimum. The longitudinal spin splitting reverses sign between opposite Chern phases, reflecting the exchange-controlled optical Hall response, while its pronounced spectral variations reveal the influence of inequivalent interband transitions induced by the $ d$ -wave altermagnetic exchange. These findings establish polarization-resolved photonic beam shifts as a sensitive probe of Hall-active topological phases and their characteristic optical spectra.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
13 pages
A new approach to measuring both the steady flow curve and the planar extensional viscosity of complex fluids using exponential shear
New Submission | Soft Condensed Matter (cond-mat.soft) | 2026-11-10 20:00 EST
Nicholas King, Eugene Pashkovski, Reid Patterson, Gareth H. McKinley
We revisit the protocol known as Exponential Shear (ES), first proposed by Doshi and Dealy in 1986. This is a transient strong flow that can be readily imposed in the laboratory using commercial strain-controlled (separate motor and transducer) rheometers which accurately measure both the (exponentially) time-varying torque and normal force exerted by the sample. Numerous studies over the years have proposed competing definitions of an appropriate material function for reporting data obtained from the exponentially time-varying imposed deformation. We revisit this unresolved challenge and carefully reconsider the exponential material kinematics involved and the proper definition of the corresponding material functions. We show that by understanding the time-varying eigenvalues and eigenvectors of both the shearing kinematics and the evolving state of stress in the sample it is, in fact, possible to use an exponential shear test to quantitatively map out \textit{both} the full flow curve (of shear viscosity vs. shear rate) and the steady planar extensional viscosity curve as a function of deformation rate. These findings are supported by numerical simulations of a number of nonlinear viscoelastic constitutive models, asymptotic analysis, as well as experiments with several polymeric liquids.
Soft Condensed Matter (cond-mat.soft), Fluid Dynamics (physics.flu-dyn)
Ising model on Calandre lattice
New Submission | Statistical Mechanics (cond-mat.stat-mech) | 2026-11-10 20:00 EST
F. A. Kassan-Ogly, A. V. Zarubin
In this paper, we proposed to consideration a noval (not yet exploited) planar lattice — Calandre lattice with the Ising model applied to it. In the framework of an exact analytical Kramers–Wannier transfer-matrix approach and using an extension of the combinatorial Vdovichenko–Feynman method, we have obtained exact solution for Helmholtz free energy and consequent expression for the principal eigenvalue of the Kramers–Wannier transfer-matrix. In addition, we derived the exact expression for spontaneous magnetization. The usage of both expressions made it possible to perform the comprehensive studies of thermodynamic and magnetic properties of the Calandre lattice itself and a wide variety of its affiliated lattices. Among them, diversified interrelations between Calandre lattice and already known and even some novel lattices. These lattices have also revealed such effects as magnetic frustrations, multiple phase transitions and magnetic reentrancy.
Statistical Mechanics (cond-mat.stat-mech)
A Geometry-Guided Feature-Space Framework for Interpretable Unsupervised 4D-STEM Analysis of Complex Multiphase Materials
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-11-10 20:00 EST
Arda Genc, Daniel A. Bolden, Albert Nguyen, Daniel S. Gianola, Ravit Silverstein
Rapid, high-fidelity analysis of four-dimensional scanning transmission electron microscopy (4D-STEM) datasets from heterogeneous materials remains challenging because coexisting phases, orientation variants, local strain gradients, and intrinsic TEM thin-foil effects produce complex, overlapping diffraction signatures. Here, we present a machine-learning (ML) framework that combines physics-informed geometric descriptors with weighted high-dimensional embeddings to identify latent structural patterns with minimal prior knowledge. By constructing a regularized descriptor space before embedding and density-based clustering, the method improves cluster stability, suppresses noise-driven fragmentation, and reduces sensitivity to embedding hyperparameters. Spatial weighting produced the largest stability gain, increasing median cluster persistence from 0.04 to 0.55 while reducing the noise fraction from approximately 22% to 0%. Rotation weighting increased DBCV from 0.80 to 0.92, although the noise fraction rose from 0.2% to 1.0%, highlighting a trade-off between improved density separation and noise rejection. We validate the framework on two benchmark systems: Si/Si$ _x$ Ge$ _{1-x}$ epitaxial layers with continuous lattice variation and deformation, and multiphase Ti-Nb alloys containing distinct phases and orientation variants. Comparisons with a pretrained vanilla autoencoder and model-free pattern vectorization show that the physics-informed geometric descriptor provides higher cluster fidelity, greater interpretability, and substantially lower dimensionality.
Materials Science (cond-mat.mtrl-sci), Artificial Intelligence (cs.AI)
Multilayer Heater Nano cryotrons: Electrothermal Modeling of Geometry-Dependent Switching
New Submission | Superconductivity (cond-mat.supr-con) | 2026-11-10 20:00 EST
Baibhari Priya Barua, Md Rahatul Islam Udoy, Shamiul Alam, Md Shafayat Hossain, Ahmedullah Aziz
This paper presents a finite-element framework to study how device geometry affects the switching current of multilayer heater nano cryotrons (hTrons). The device comprises a 50 nm Au/5 nm Ti heater, a 100 nm SiO2 spacer, a 23.6 nm NbN channel, and a Si substrate. Two-dimensional electrothermal simulations examine nine heater and channel width combinations using widths of 100, 500, and 1000 nm. Three-dimensional simulations show how heat flows through the layers and spreads across the channel near the heater-channel overlap. Heater electrical losses and heat transport are coupled, whereas the channel switching threshold is obtained separately from a temperature-dependent constitutive relation. Published global temperature measurements support the switching-law calibration, and heater-current measurements assess the resulting device response. The model measurement comparisons show a systematic reduction of switching-current density with heating, but also geometry-dependent discrepancies in the low-drive plateau and transition shape. A common extraction protocol is formulated for heater-current and heater-power requirements at a specified suppression level, while separating fitted device amplitudes from controlled geometry effects. The resulting comparisons connect thermal fields to design metrics while distinguishing calibration from validation and excluding transient-performance claims from the stationary analysis
Superconductivity (cond-mat.supr-con)
A data-driven approach for systematic correction of electronic bandgaps
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-11-10 20:00 EST
Pamela C. Carvalho, Asa Marif, Erna K. Delczeg-Czirjak, Sergei Simak, Utkarsh Singh, Olle Eriksson
We demonstrate that a single machine-learning correction, applied to bandgaps from density functional theory calculations with two of the most frequently used energy functionals, results in bandgaps that are close to the experimental values. This solves a classical problem of computationally efficient electronic structure methods, to give reliable bandgaps that can be compared to experiments. The employed approach relies on materials specific feature engineering of machine learning models, and is shown to have close accuracy to that of much more expensive calculations based on the GW-approximation or hybrid functionals. The findings reported here open the possibility to use efficient calculations in materials design workflows that need reliable bandgaps, with implications for investigations targeting large computational databases or for investigations that are entirely predictive in nature.
Materials Science (cond-mat.mtrl-sci)
Three-dimensional multipole states of the Bose-Einstein condensate of polar molecules in a shallow two-dimensional trapping potential
New Submission | Quantum Gases (cond-mat.quant-gas) | 2026-11-10 20:00 EST
S. Sanjay, S. Saravana Veni, Boris A. Malomed
We investigate the formation, stability, and dynamics of three-dimensional (3D) elongated multipole quantum droplets (QDs) in a Bose-Einstein condensate (BEC) of polar molecules with long-range interactions between molecular electric dipoles. The condensate is confined by a 2D trapping potential, which is a combination of the harmonic-oscillator potential and a central Gaussian potential hill. The system is modeled by an extended Gross-Pitaevskii (GP) equation, incorporating the dipole-dipole interactions and beyond-mean-field Lee-Huang-Yang (LHY) correction, which play a crucial role in stabilizing self-bound QD structures. In regimes of weak and strong confinement, stable multipole states with the number of lobes $ n=2S$ are created by means of the imaginary-time-propagation (ITP) method from inputs with vorticity $ S\leq 2$ . The so created multipole QDs carry no angular momentum. Stable higher-order multipole states can be produced by the ITP method from inputs with $ S\geq 3$ up to $ S=6$ (i.e., $ 2S=12$ lobes) only under strong confinement and when the molecule number $ N$ exceeds a threshold value. We analyze the dependence of the chemical potential, energy per particle, and peak density on $ N$ and $ S$ in the weak- and strong-confinement regimes. A noteworthy fact is that, below another threshold value of $ N$ , the minimum-energy (ground) state is created by the input with $ S=1$ , rather than $ S=0$ . Simulations of perturbed evolution reveal that, despite satisfying energetic stability criteria, only a subset of the multipole QDs are truly stable, with higher-order ones tending to develop instabilities or relax toward lower-order states. These results highlight the essential roles of the trapping potential, anisotropy of the dipole-dipole interactions, and LHY-induced repulsion in the formation and structural stability of multipole QDs.
Quantum Gases (cond-mat.quant-gas)
18 pages, 20 figures, To be published in Physical Review Research
Non-reciprocal Rouse chain model
New Submission | Soft Condensed Matter (cond-mat.soft) | 2026-11-10 20:00 EST
Apaza Leonardo, Sandoval Mario
We study the center-of-mass mean-squared displacement (MSD) of a free non-reciprocal Rouse chain. Three stochastic models are considered: an overdamped linear chain, an underdamped linear chain, and an underdamped nonlinear chain with finite natural bond length that fully takes into account the elastic interactions. For the overdamped model, an exact transient expression for the center-of-mass MSD is obtained from the associated Ornstein–Uhlenbeck process. We show that non-reciprocity enhances the effective diffusion with respect to the classic Rouse model, and that it separates the translational right and left zero modes, so the arithmetic center of mass is not, in general, the dynamically decoupled translational coordinate. It is found that the normalized left zero mode gives a closed expression for the effective diffusivity in terms of the non-reciprocal parameter and the number of beads ($ N$ ) which still scales as $ N^{-1}$ . Interestingly, the same long-time diffusivity coefficient is found for both, the underdamped linear model and for the less studied finite-natural-length nonlinear model. It is concluded that inertia and finite bond length, modify the transient dynamics of the system, while non-reciprocity determines the long-time diffusion coefficient.
Soft Condensed Matter (cond-mat.soft)
2D coherent spectroscopy of topological insulators
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2026-11-10 20:00 EST
Thaís V. Trevisan, Michał Papaj
Multidimensional coherent spectroscopy probes the response of a system to a sequence of time-separated light pulses, and has attracted significant interest in recent years. In the frequency space, it generates multidimensional spectra, in which information about different degrees of freedom of the system is generically disentangled. In this work, we develop a quantum geometric formulation of multidimensional optical susceptibilities in insulating systems. Focusing on a two-pulse setup and working in the velocity gauge, we derive analytical expressions for second-order and third-order two-dimensional coherent spectra (2DCS). We focus on the third-order ABB response, which remains finite in centrosymmetric systems where the second-order susceptibility vanishes by inversion symmetry. Its paramagnetic contribution supports an echo signal that probes products of four interband Berry-connection matrix elements, which reduce in two-band systems to bilinear combinations of the quantum geometric tensor of the occupied band. Using continuum and square-lattice models of two-dimensional Chern insulators, we show how the echo resolves the momentum-space sign structure of these geometric quantities. For the $ xxyx$ response of the models considered, the number of nodes in the echo signal is related to the band topology. Our results extend the quantum-geometric interpretation of multidimensional spectroscopy to higher-order responses, showing that third-order 2DCS provides access to geometric structures beyond those probed at lower orders.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
24 pages, 15 figures
Lifting mechanical zero modes without dispersion
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-11-10 20:00 EST
Floppy frameworks carry flat bands of zero-frequency mechanisms with no finite-frequency resonance, and couplings that lift them usually spread them. We show that an on-site tensor lifts a mechanism band without first-order dispersion exactly when, projected onto the mechanisms, it acts as wavevector-independent scalars on orthogonal pieces. Three structures achieve this: local normal modes, invariant symmetry sectors, and a balance law. A mechanism moves both ends of every bond between two vertex classes equally along it, and where the inter-class bond tensors are class scalars this balance law fixes its norm shares and hence the flat value from geometry alone. For the fluorite net the band lies outside the tensor spectrum, at 14/9 of the contact stiffness to first order, and stays flat to all orders in a fixed cage. A placement inside a tiling dual that keeps the common symmetry supplies such tensors, because each contact star inherits its site symmetry. Ten catalogued dual pairs lift flat; half are eigenvalue cases a resolved count matches, and the balance law explains flat bands in random cages too. Duality makes the rigid cage common. In a printable beam-frame lattice, contacts that lock joint rotation remove first-order bending dispersion whenever bonded mechanisms are orthogonal local normals.
Materials Science (cond-mat.mtrl-sci), Soft Condensed Matter (cond-mat.soft), Applied Physics (physics.app-ph)
61 pages, 4 figures in the main text; Supplementary Information included. Code and data: this https URL
In-Band Boundary Resonances from Coalescing Zero-Group-Velocity Points
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-11-10 20:00 EST
Amir Rajabpoor Alisepahi, Charles A. Downing, Jihong Ma
Boundary states generally reside in band gaps, whereas in-band confinement typically requires exact decoupling from propagating modes. We demonstrate an alternative mechanism in reciprocal, topologically trivial Hermitian lattices arising from the coalescence of two zero-group-velocity (ZGV) points. At coalescence, the group velocity and inverse effective mass vanish simultaneously, and the corresponding Bloch root acquires higher multiplicity. The coalesced root remains propagating, whereas nearby root splitting yields weakly evanescent channels that, together with a bulk-matched termination, generate a boundary-weighted resonance within the propagating spectrum. The mechanism is realized analytically in a two-leg ladder model through the coalescence of time-reversal-related ZGVs and extends to distinct ZGVs produced by longer-range interactions. Finite-size scaling distinguishes the resulting resonance from extended and defect-bound states. Scanning laser Doppler vibrometry on a 3D-printed elastic ladder reveals boundary enhancement in a nearly flat band region, consistent with operation slightly below criticality. ZGV coalescence thus provides a bulk framework for in-band boundary resonances in reciprocal Hermitian lattices.
Materials Science (cond-mat.mtrl-sci)
Deintercalation Equilibria Control the Composition, Structure, and Electronic Quality in the Synthesis of 2$M$-WS$_2$
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-11-10 20:00 EST
Brenna C. Bierman, Taeran Yang, Jon Ramos, Sara Yarworth, James Lazarcik, Daniel A. Rhodes
Alkali-metal intercalation-deintercalation (AMID) enables access to metastable layered materials such as 2$ M$ -WS$ _2$ . Mechanistic studies of AMID have focused on intercalation; how deintercalation proceeds and influences crystal properties is comparatively poorly understood. Here, we assess 34 deintercalation treatments of 2$ M$ -K$ _x$ WS$ _2$ and find that K$ ^+$ removal proceeds through coupled redox and ion-exchange equilibria, whose positions set the composition, structure, and electronic quality of the products. Across a series of neat solvents, K$ ^+$ deintercalation amount increased with solvent polarity and was driven to near-completion upon addition of nonoxidizing crown ether chelators, regardless of solvent polarity. Spontaneous reintercalation occurred when 2$ M$ -WS$ _2$ was placed in dilute aqueous solutions of the strong base KOH but not the neutral salt KCl. These results suggest that the extent of deintercalation is governed by the stability of K$ ^+$ in solution, rather than oxidant strength alone, consistent with a reaction under thermodynamic control. Treatments that bias the deintercalation equilibrium most strongly toward the products while avoiding deleterious side reactions produce the highest quality 2$ M$ -WS$ _2$ . A six-hour treatment with acidified K$ _2$ Cr$ _2$ O$ _7$ gave the highest average residual resistivity ratio ($ \overline{RRR}$ ). Residual K$ ^+$ , quantified by ICP-MS, was found in all treated samples and appeared to impose an upper bound on $ \overline{RRR}$ . Treatments yielding crystals with $ \overline{RRR}$ below this bound did not always afford 2$ M$ -WS$ _2$ ; we observed two new structures in bleach-treated samples and signatures of alternative phases under other conditions. This work demonstrates that deintercalation is not merely a processing step in AMID but a mechanistically rich reaction that might be rationally tuned to improve and control metastable materials.
Materials Science (cond-mat.mtrl-sci), Superconductivity (cond-mat.supr-con)
Imaging spin entanglement with a scanning tunneling microscope
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2026-11-10 20:00 EST
J. C. G. Henriques, B. Viña-Bausá, I. Brihuega, J. Fernández-Rossier
Artificial spin arrays assembled on surfaces enable atomic-scale studies of quantum correlations. Here we establish a hierarchy of connections between spin inelastic electron tunneling spectroscopy (IETS) and entanglement in spin-$ 1/2$ systems. We first show that the number of spectroscopically active transitions in a spin-$ 1/2$ dimer serves as an entanglement witness. Using the leading-order tunneling conductance for the tip placed on spin $ i$ , $ dI(i)/dV$ , we then relate spectral moments $ \mathcal{M}^{(n)}(i)=\int V^n(d^2I(i)/dV^2),dV$ to quantum correlations. The zeroth moment probes the one-tangle in systems with a gapped, nondegenerate ground state. For rotationally invariant Heisenberg systems, the first moment yields thermal spin correlators $ \langle\boldsymbol S(i)\cdot\boldsymbol S(j)\rangle$ , enabling reconstruction of nearest-neighbor concurrence and spatial imaging of entanglement in spin chains. It also provides access to the internal energy and magnetic specific heat, both usable as entanglement witnesses. Applying this approach to experimental IETS data from nanographene spin chains, we find good agreement with theory. We further discuss how the second moment probes longer-range correlations and the inverse moment relates to local spin susceptibility. For spin-$ 1/2$ trimers, we connect inter-multiplet inelastic spectral weight to genuine tripartite entanglement quantified by the concurrence fill. Finally, we reconcile the local character of IETS with its sensitivity to nonlocal entanglement through an analogy with digital quantum circuits, where Hamiltonian evolution implements multiqubit operations. These results establish IETS as a tool for quantifying and imaging entanglement in engineered on-surface spin systems.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Materials Science (cond-mat.mtrl-sci), Quantum Physics (quant-ph)
20 pages, 10 figures, 1 table
Superconductivity and Polar Metallicity in Atomically Thin Nitride Superlattices
New Submission | Superconductivity (cond-mat.supr-con) | 2026-11-10 20:00 EST
Huma Nawaz, Dawei Wang, C. S. Ting, Laurent Bellaiche
The integration of polar and superconducting materials in the atomically thin limit typically results in a competition that suppresses the superconducting order. Here, we challenge this conventional view by employing first-principles calculations to investigate 1:1 superlattices composed of alternating atomically thin layers of TiN/AlN and {\delta}-NbN/AlN. Contrary to the expectation that dense insulating barriers would quench superconductivity, we find that the polar interface can coexist with a superconducting state. We observe that the transition temperature (Tc) of TiN is enhanced by nearly 2 K over its bulk value, while {\delta}-NbN maintains a relatively high Tc exceeding 20 K. We demonstrate that this resilience arises from the formation of a polar metal, where the strong internal electric fields of the AlN layers are partially screened by a charge redistribution within the nitride layers. This screening mechanism, along with the geometric confinement, creates a quasi-two-dimensional electronic environment, establishing these superlattices as a novel platform for exploring the coexistence of structural inversion-symmetry breaking and superconductivity in the two-dimensional limit.
Superconductivity (cond-mat.supr-con)
Efficient Plane-to-Point Energy Transfer from Supramolecular Excitonic Systems to Molecular Acceptors
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-11-10 20:00 EST
Dimuthu H. Thanippuli Arachchi, Oliver M. Nix, Jianshu Cao, Moungi G. Bawendi (Massachusetts Institute of Technology)
Collective excitonic interactions in supramolecular assemblies offer opportunities for efficient light harvesting and directed energy transport. Here, we demonstrate efficient energy transfer from two-dimensional silica-encapsulated TDBC J-aggregate sheets to covalently attached ATTO 590 molecular acceptors. Silica encapsulation preserves the J-aggregate excitonic properties while enabling acceptor functionalization at a defined separation from the donor plane. Steady-state donor quenching and acceptor sensitization yield energy-transfer efficiencies of 75-81% in solution, while time-resolved photoluminescence measurements reveal donor lifetime shortening. We develop a generalized Forster resonance energy-transfer model for an extended planar donor coupled to localized molecular acceptors, predicting an inverse fourth-power dependence of the transfer rate on donor-acceptor separation. Using experimental spectroscopic data and estimated structural parameters, the model predicts an energy-transfer rate of 4.77 x 10^10 s^-1, approximately ten times faster than the intrinsic donor decay rate, corresponding to a theoretical energy-transfer efficiency of approximately 91%. These findings provide a framework for developing hybrid excitonic architectures for light harvesting.
Materials Science (cond-mat.mtrl-sci)
Learning Electronic Band Structures Across the s, p, d Blocks with an Empirical Pseudopotential Network
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-11-10 20:00 EST
Electronic band structures govern how crystals conduct electrons and absorb light. Density-functional theory (DFT) computes them through costly self-consistent iterations, while existing machine-learning models either predict isolated scalar properties or output Hamiltonians that still require DFT solvers. Here we present EpNet, a learned empirical pseudopotential for crystals spanning 63 elements across the \textit{s}, \textit{p} and \textit{d} blocks. An equivariant neural network builds its Hamiltonian from physics-motivated local potentials and nonlocal projectors. Trained solely on band energies, EpNet predicts complete band structures directly from atomic coordinates. On unseen chemical systems, its median errors are \winAll\ eV for band energies and \gapAll\ eV for band gaps. On 600,000 structures from an independent database, its band-gap errors are overall less than half those of existing models, at about 1% of DFT cost. EpNet thus enables fast screening of electronic properties for materials discovery and electronic-structure simulations of large systems.
Materials Science (cond-mat.mtrl-sci)
30 pages, 11 figures
Spin Conductivity: Insight From Perturbation Theory
New Submission | Other Condensed Matter (cond-mat.other) | 2026-11-10 20:00 EST
Xu Chen, Mingbo Dou, Yu Sui, Xianjie Wang, L. L. Tao
The investigation on the spin conductivity has now been blooming in burgeoning altermagnetic materials. Here, an alternative and elementary derivation for the spin conductivity expression is presented. This is done within the context of perturbation theory. It indicates that our derived expression for the $ \mathcal{T}$ -even ($ \mathcal{T}$ for time reversal) spin conductivity agrees exactly with those derived from the Kubo linear response theory and quantum kinetic theory. In addition, the expression for the $ \mathcal{T}$ -odd spin conductivity in the clean limit is exactly consistent with those presented previously. We show that the $ \mathcal{T}$ -odd ($ \mathcal{T}$ -even) spin conductivity arises from the contribution of zeroth-order (first-order) wave function correction. Our work provides some physical insight into the spin conductivity from the perturbation theory and shines more light on the charge-to-spin conversion mechanism in magnetic materials.
Other Condensed Matter (cond-mat.other)
Odd Darcy Law: Odd Viscosity and Edge Currents in Porous Media
New Submission | Soft Condensed Matter (cond-mat.soft) | 2026-11-10 20:00 EST
Raphael Maire, Ignacio Pagonabarraga
We derive and numerically validate an odd Darcy law for chiral active fluids in porous media, in which an antisymmetric permeability tensor induces a flow transverse to the applied pressure gradient. We identify two distinct mechanisms leading to this odd response: odd viscosity in the fluid or the nonlinear coupling of edge currents to inertia. We then show how the transverse transport depends on porosity, boundary friction, and chirality.
Soft Condensed Matter (cond-mat.soft), Statistical Mechanics (cond-mat.stat-mech), Fluid Dynamics (physics.flu-dyn)
Coherent Conversion of an Interacting Dark-State-Polariton Condensate into a Photonic Bose-Einstein Condensate
New Submission | Quantum Gases (cond-mat.quant-gas) | 2026-11-10 20:00 EST
G. D. de Moraes Neto, M. A. de Ponte, N. G. de Almeida, Miled H. Y. Moussa
An interacting condensate can retain an observable imprint of its preparation after the interactions are switched off. For light, accessing this regime requires separating the formation of a photon condensate from the material medium that redistributes its energy. We investigate a multimode-cavity scheme in which an interacting dark-state-polariton condensate is coherently converted into a confined photonic Bose-Einstein condensate as the atom-cavity coupling is removed. The polariton mass, matter fraction, and particle number control the condensate occupation during preparation. Remarkably, changing the mass also modifies the condensate’s response to repulsion through the spatial overlap of its orbitals, even when the entire single-particle spectrum is held fixed. Ideal mode-preserving conversion conserves the full natural-orbital occupation spectrum, while finite-time few-body calculations show that additional occupation changes during transfer are much smaller than those established during interacting preparation. Once decoupled from matter, the photons evolve under the free cavity Hamiltonian while retaining correlations acquired in the interacting gas. Interference between cavity modes produces oscillations in the photon density, while resonant pair correlations persist after interaction removal and distinguish the resulting photon state from a quadratic thermal state with the same one-body density matrix.
Quantum Gases (cond-mat.quant-gas), Quantum Physics (quant-ph)
Electron cooling mediated by transverse optical phonons in doped SrTiO$_3$
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2026-11-10 20:00 EST
Soft transverse optical (TO) phonons in doped SrTiO$ _3$ couple to electrons through the polarization field, quadratically in the paraelectric phase and, additionally, linearly in the polar phase due to the onset of spontaneous polarization. We investigate heat flow between a three-dimensional electron gas and soft TO phonons. For two-TO-phonon scattering, the heat flow of hot electrons crosses over from $ T^5$ to $ T^3$ at the Bloch-Gruneisen temperature. In the polar phase, an additional one-TO-phonon channel emerges, yielding a softer temperature dependence of the heat flow, $ T^3$ at low and $ T$ at high temperatures, with the spectral weight set by the spontaneous polarization. This channel may dominate at low temperatures and leads to a nonmonotonic temperature dependence of the heat flow in the vicinity of the polar transition.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Materials Science (cond-mat.mtrl-sci)
5 pages, 1 figure
The Outer Eshelby Problem in Amorphous Solids with Odd Dipole Screening
New Submission | Soft Condensed Matter (cond-mat.soft) | 2026-11-10 20:00 EST
Avanish Kumar, Jin Shang, Itamar Procaccia
The so-called “2-dimensional Eshelby problem” was defined by JD Eshelby, where a circle is cut out of an elastic sheet, deformed into an ellipse, and forced back into the material. This creates a quadrupolar response which turned out to be very relevant for describing plastic deformations in amorphous solids. Moreover, the resulting strain field has been used to describe how elasto-plastic models respond to external strains. It is thus important to examine carefully the Eshelby problem in amorphous solids, especially when anomalous elasticity is at play. Here we solve the Eshelby problem in amorphous solids with both even and odd dipole screening and a complete analytical result is obtained for the displacement and strain fields. The analytical results are crucial for understanding the anomalous responses in displacement fields measured directly from experiments and numerical simulations. The computation of strain fields clearly demonstrates the deviations from their classical counterparts for perfectly elastic solids. The decomposition of the displacement field shows the excitation of higher-order Fourier modes. The presence of higher excitations other than the imposed Eshelby geometry therefore suggests the possible nonlinear mode coupling that can influence and modify the anomalous responses.
Soft Condensed Matter (cond-mat.soft)
33 pages, 21 figures
Effect of Correlation on the Pressure-Induced Insulator to Metal Transition in Complex Spin-Orbit Coupled Double Perovskite La$2$CoIr${1-x}$Ti$_x$O$_6$
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-11-10 20:00 EST
Vineeta Yadav, Sromona Nandi, Rudra Sekhar Manna
We study the effect of electron correlation ($ U$ ) and hydrostatic pressure on the electronic properties of double perovskites La$ 2$ CoIr$ {1-x}$ Ti$ x$ O$ 6$ for $ x$ = 0, 0.5, and 1, using first-principles electronic structure calculations within density functional theory (DFT). At ambient pressure, we systematically vary the electron correlation, i.e., on-site Coulomb interaction to study its effect on band gap and structural parameters. Increasing the value of $ U$ enhances the band gap of all three compositions while producing only a slight variation in structural parameters. The effect of hydrostatic pressure is also studied for the same compositions. The estimated band gap values at ambient pressure closes at approximately 39, 42, and 53 GPa for $ x$ = 0 (for $ U\mathrm{Co}$ = 5 eV and $ U\mathrm{Ir}$ = 2 eV), 0.5 (for $ U\mathrm{Co}$ = 5 eV and $ U\mathrm{Ir}$ = 2 eV), and 1 (for $ U_\mathrm{Co}$ = 4 eV), respectively, indicating pressure-induced insulator-to-metal transitions. These results show that electron correlation stabilises the insulating state, whereas hydrostatic pressure favours the metallic state by closing the band gap. These findings highlight the tunability of correlated oxides through electron correlations and pressure, offering insights for materials design.
Materials Science (cond-mat.mtrl-sci), Strongly Correlated Electrons (cond-mat.str-el)
6 pages, 3 figures
Engineering ferroelectric nanocapacitors through interfacial phonon bias
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-11-10 20:00 EST
Iñigo Robredo-Magro, Urmimala Dey, Suehyun park, Karam Cho, Raseong Kim, Jorge Íñiguez-González
As ferroelectric devices approach the nanometer scale, their behavior becomes increasingly sensitive to boundary conditions. In perovskite oxide nanocapacitors, epitaxial strain and electrostatic screening are well-established control parameters. Then, while expected to contribute to the epitaxial stabilization of ferroelectric ultrathin films, the lattice-dynamical state of the electrodes has not been isolated as an independent tuning knob. Here we call this poorly explored coupling interfacial phonon bias, whereby the electrodes’ phonon energy landscape reshapes that of the adjacent ferroelectric across their shared interface. Using first-principles-accurate machine-learned interatomic potentials and molecular-dynamics simulations, we examine this mechanism in symmetric BiFeO$ {}_3$ nanocapacitors in contact with a metallic perovskite oxide. By independently controlling the orientatio and amplitude of the electrodes’ octahedral-tilt landscape, while keeping conventional elastic and electric boundary conditions fixed, we show that the electrodes’ phonon energy landscape can modify the stability of competing BiFeO$ {}_3$ phases. In particular, this allows us to shift the ferroelectric transition temperature and even induce antiferroelectric-like switching at ambient conditions. We thus showcase interfacial phonon bias as a complementary and powerful strategy to modify and optimize the properties of ultrathin epitaxial films.
Materials Science (cond-mat.mtrl-sci), Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
7 pages, 5 figures
Theory of spin-polarized scanning tunneling microscopy with topological insulator tips
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2026-11-10 20:00 EST
Zhuo-Yuan Shi, Chuang Li, Lin Jiao, Huiqiu Yuan, Zhenyu Wang, Xianhui Chen, Lun-Hui Hu
Topological insulators have enabled a new class of spin-sensitive scanning tunneling microscopy (STM) probes based on helical boundary states. However, how these probes generate a net spin-polarized tunneling current remains unclear. We present a theory of spin-polarized STM with topological insulator tips and show that asymmetric tunneling-contact geometry and spin dephasing enable helical boundary states to generate a spin-polarized tunneling current. Within the standard Landauer-Büttiker formalism, we demonstrate this mechanism for a quantum spin Hall (QSH) insulator tip: asymmetric contacts make the two counter-propagating helical edge states, which carry opposite spins, traverse path lengths that differ by $ \Delta L$ , and spin dephasing induces backscattering that reduces the conductance more strongly for the longer path. For a representative asymmetric contact and weak spin dephasing, the QSH tip exhibits a tunneling spin polarization of $ P_s=-17.2%$ under positive bias, whose magnitude can reach $ 50%$ for larger $ \Delta L$ , and which remains robust against Rashba spin-orbit coupling. Crucially, this polarization, dominated by helical edge transport rather than by bulk states, naturally reverses sign with the bias polarity owing to spin-momentum locking. Our findings are consistent with recent STM experiments using topological tips.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Materials Science (cond-mat.mtrl-sci)
7 pages, 5 figures, comments are welcome
Parametrizations of the solutions of Love equations and their momenta
New Submission | Quantum Gases (cond-mat.quant-gas) | 2026-11-10 20:00 EST
Marco Faccioli, Andrea Colcelli, Danny Laghi, Yu Zhou, Giacomo Gori, Andrea Trombettoni
The Love equation is a paradigmatic example of a Fredholm integral equation of great interest in mathematics and physics, where its applications range from electrostatic problems to exactly solvable models for one-dimensional systems. In this work we propose a method to approximate the normalized solutions of Love equations of the first and second kind via a parametrization obtained by Hermite interpolation at Chebyshev nodes. Following the same approach, we also obtain approximations for the second, fourth and sixth momenta of the solution of the Love equations. We focus in particular on one-dimensional quantum gases described by the Lieb-Liniger and the Gaudin-Yang models. For these models, the solutions of Love equations correspond to the normalized densities of pseudorapidities. We show that remarkably accurate results can be obtained using the Hermite-Chebyshev interpolation with a number of points as low as 17+2. In the case of the Lieb-Liniger model, we also propose a very accurate closed-form estimate of the dimensionless ground state energy valid for all values of the dimensionless interaction parameter incorporating known results for small and large couplings supplemented by the Hermite-Chebyshev interpolation for intermediate couplings. As an application of this result, we compute the dimensionless local two-particle correlation function and the black soliton solutions of the Lieb-Liniger model.
Quantum Gases (cond-mat.quant-gas), Mathematical Physics (math-ph)
Strain Controlled Hydrogen Interstitial Site Preference and Hydride Phase Suppression in Epitaxial Vanadium
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-11-10 20:00 EST
Understanding hydrogen behavior in transition metals is crucial for energy storage and sensing technologies. Here we combine density functional theory (DFT) calculations with in-situ electrical measurements to reveal how epitaxial strain governs hydrogen interstitial site selection and phase stability in vanadium. Our calculations demonstrate a robust thermodynamic preference for tetrahedral (T) over octahedral (O) sites, with the energy difference modulated by lattice anisotropy through strain-tunable H 1s-V 3d orbital hybridization. Experimentally, epitaxial V films on MgO(001) exhibit a critical thickness-dependent crossover: 50 nm films show characteristic first-order alpha-beta hydride transitions, while 10 nm films display continuous solid-solution behavior with complete transition suppression. This crossover is governed by the progressive relaxation of epitaxial strain with increasing film thickness: the 10 nm films retain strong coherent strain that flattens the free-energy landscape and suppresses hydride nucleation, whereas the 50 nm films approach the strain-relaxed bulk limit where long-range elastic interactions restore first-order phase behavior. Finite-size truncation of elastic fields and interfacial electronic reconstruction further reinforce this dimensional crossover. Our work establishes a unified framework connecting atomic-scale orbital physics to mesoscopic phase thermodynamics, providing design principles for strain-engineered metal-hydride systems.
Materials Science (cond-mat.mtrl-sci)
A Rule That’s Made to be Broken? Reframing the Arrhenius Law for Ionic Transport
New Submission | Soft Condensed Matter (cond-mat.soft) | 2026-11-10 20:00 EST
Vanessa K. Ward, Karen E. Johnston
The Arrhenius law is ubiquitous in the physical sciences. It describes how an observable property scales with temperature, $ T$ , as $ \exp(\pm E_A/k_BT)$ for a constant $ E_A$ , the ‘activation energy’. Fitting to the Arrhenius law is a common procedure for both experimental and computational data. However, the physical significance of any ‘activation energy’ calculated is unclear. Here we focus on self-diffusion coefficients for potential solid electrolytes, and by identifying the individual ‘diffusive steps’ within the system, show how a physically significant activation energy can be extracted. There are also many examples of non-Arrhenius behaviour including `super-Arrhenius’ curvature, where the effective activation energy appears to increase with decreasing temperature. We demonstrate how it is still possible to extract the underlying Arrhenius law, by quantifying self-correlations such as back-and-forth motion. The methodology described here is material-agnostic and can be utilised to analyse the molecular dynamics trajectories of both ordered and disordered materials.
Soft Condensed Matter (cond-mat.soft), Materials Science (cond-mat.mtrl-sci)
9 pages, 5 figures (SI - 4 pages, 5 figures)
sdos: spectral densities of large sparse Hermitian and generalized eigenproblems
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-11-10 20:00 EST
sdos is an open Python package that computes the density of states (DOS) and related spectral quantities of very large sparse Hermitian matrices A, and of generalized problems A psi = lambda B psi, from Chebyshev moments estimated with random vectors. The density is reconstructed by the kernel polynomial method (KPM, the default) or by maximum entropy (Maxent); the same interface gives band energies, Fermi levels, local and projected densities, harmonic thermodynamics, exact HOMO-LUMO gaps and eigenpairs in a spectral window. Interfaces cover electronic (empirical tight-binding, DFTB, SIESTA) and vibrational (matrix-free LAMMPS Hessians) problems. I checked most ingredients against dense diagonalization or an independent code; the exceptions are listed in Sec. V. On a workstation (4 threads, 19 GB) the DOS of an 884,736-atom amorphous silicon model (a 6^3 tiling of a 4096-atom cell; 3.5 million orbitals; the orthogonal empirical tight-binding model of Kwon et al.) takes 71 s (M=100, R=2, no exact moments; 383 s with the default exact moments), and a matrix-free 2,097,152-atom crystal 10 min in 1.8 GB. A 17^3 replica of a 216-atom amorphous cell (1,061,208 atoms) agrees with exact Bloch spectra: electronic DOS in 229 s, matrix-free ACE vibrational DOS in 2.2 h on one GPU. Shift-invert, incomplete-Cholesky setup, exact moments of high order and Maxent at high moment counts do not scale. The underlying methods are due to Silver, Roder, Kress, Voter, Drabold, Sankey and collaborators; the Introduction states what is added.
Materials Science (cond-mat.mtrl-sci)
This is a software package for the highly efficient computation of densities of states for large Hermitian matrices. This is the companion paper to the github project (all described in manuscript)
Visualizing d-wave pairing symmetry at the atomic scale in a cuprate high-Tc superconductor by Josephson tunneling
New Submission | Superconductivity (cond-mat.supr-con) | 2026-11-10 20:00 EST
Zhen Liang, Tianheng Wei, Jinpeng Lu, Wei Ren, Takenori Fujii, Takao Watanabe, Ziqiang Wang, Jian Wang
Superconducting pairing symmetry provides crucial insight into the microscopic mechanisms of Cooper pairing. However, probing the local manifestations of sign-changing superconducting order parameters remains experimentally challenging. Here, we investigate the superconducting condensate in optimally doped (OPT) Bi2Sr2Ca2Cu3O10+{\delta} (Bi-2223) using scanning Josephson tunneling microscopy (SJTM), equipped with an s-wave superconducting tip. Measurements at ultra-low temperatures reveal a pronounced modulation of the Josephson tunneling signal at different locations inside the crystallographic unit cell. A distinct Josephson tunneling signal is detected above O sites in the underlying CuO2 plane, whereas the signal nearly vanishes above the Cu-plaquette diagonals, including Cu sites and plaquette centers. This unique intra-unit-cell spatial pattern agrees with the theoretical prediction for the symmetry-dependent cancellation of Josephson tunneling between an s-wave superconducting tip and a d-wave superconducting sample. Our findings provide atomic-scale, real-space evidence for d-wave pairing symmetry in OPT high-Tc Bi-2223 and establish SJTM as a powerful approach for investigating the pairing symmetry of unconventional superconductors.
Superconductivity (cond-mat.supr-con), Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Materials Science (cond-mat.mtrl-sci), Strongly Correlated Electrons (cond-mat.str-el)
Ergotropy as distance from equilibrium
New Submission | Statistical Mechanics (cond-mat.stat-mech) | 2026-11-10 20:00 EST
We show that the ergotropy (a.k.a available energy) of a thermally isolated system is the $ 1$ -Wasserstein distance between two energy probability density functions. Specifically, between the energy profile of the system state, and the energy profile of its associated passive state. We prove this for both classical and quantum systems, and illustrate it with examples. Our result formalises the intuition that ergotropy is a quantifier of distance from equilibrium
Statistical Mechanics (cond-mat.stat-mech), Plasma Physics (physics.plasm-ph), Quantum Physics (quant-ph)
13 pages, 2 figures, no AI used
Crystal and magnetic structures of MnSi in zero magnetic field: Neutron diffraction and symmetry analysis
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-11-10 20:00 EST
Vladimir Pomjakushin, Igor Plokhikh, Douglas H. Fabini, Ekaterina Pomjakushina
Combining high-resolution wide-angle neutron powder diffraction with magnetic-superspace symmetry analysis, we refine the crystal structure and present, to our knowledge, the first systematic refinement of cubic $ P2_13$ MnSi’s zero-field magnetic structure across multiple magnetic satellite families. We compare single-arm rhombohedral 3+1D and cubic four-arm 3+4D magnetic superspace-group (MSSG) descriptions with propagation vectors along $ \langle111\rangle$ . Simultaneous extinction of the two satellite groups around $ {100}$ dictates a transverse circular-helix model. This suppression and refinements of 18 separately varied satellite-group intensities support this ideal limit with only one adjustable magnetic amplitude. In the ideal single-arm model with MSSG $ R3.1’(0,0,g)ts$ , the moment has constant magnitude 0.535(3) $ \mu_B$ per Mn. An explicit four-arm 3+4D cubic superspace construction presented here combines four interpenetrating helices and, for the illustrated phase choice, has moments ranging from zero to 0.874(5) $ \mu_B$ per Mn, with the same root-mean-square moment as the 3+1D structure. Their identical powder profiles prevent the present measurements from distinguishing them. The average crystal structure remains cubic within experimental resolution, providing structural motivation for the cubic magnetic model. The mean lattice parameter, determined with formal relative precision $ \sigma_a/a \lesssim 10^{-5}$ , exhibits nonmonotonic temperature dependence below the Néel temperature.
Materials Science (cond-mat.mtrl-sci), Other Condensed Matter (cond-mat.other)
18 pages, 8 figures
Industrial RPCVD growth of high-purity 28Si epilayers with 29Si content below 30 ppm for high-fidelity electron spin qubits
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2026-11-10 20:00 EST
Zhenzhen Kong, Weizhu Liao, Ning Chu, Yiwen Zhang, Ying Zhang, Jixuan Li, Changyang Xu, Yongliang Hao, Yi Zhou, Yanpeng Song, Xiaomeng Liu, Hailing Wang, Xiangsheng Wang, Jinbiao Liu, Chao Zhao, Hao Meng, Gang Cao, Guo-Ping Guo, Hai-Ou Li, Guilei Wang
Silicon quantum-dot spin qubits are among the most promising routes to large-scale quantum computation, but the residual 29Si nuclear spins in natural silicon impose a hyperfine dephasing limit that must be overcome by isotopic purification. Here, we report the epitaxial growth of high-purity 28Si on float-zone silicon using an industrial reduced-pressure chemical vapor deposition (RPCVD) system. Secondary-ion mass spectrometry (SIMS) confirms an 28Si isotopic purity of 99.997%, with the 29Si concentration below 30 ppm. Through a systematic vacuum annealing matrix (850-1150 C), combined with atomic force microscopy and SIMS, we investigate the defect-mediated decomposition of the native oxide and the injection of non-equilibrium vacancies. We identify a thermal-budget window below 950 C within which the thin-layer structure of 28Si remains intact. At 1.5 K, magnetotransport measurements reveal a peak Hall mobility of 12,858 cm^2 V^-1 s^-1 and a quantum scattering lifetime of 0.659 ps, corresponding to a single-particle level broadening of 499 micro-eV. A double quantum dot fabricated on this platform exhibits a T2\ast of 0.62 us, a Hahn-echo coherence time of 28.8 us, and single-qubit gate fidelities of up to 99.9% measured by randomized benchmarking. Our results establish industrial RPCVD as a promising route toward high-coherence, high-fidelity silicon spin qubits.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Quantum Physics (quant-ph)
Orbital texture of valence band and interband transitions of the type-II multiferroic van der Waals NiI$_2$
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-11-10 20:00 EST
A. De Vita, O. E. Giehl, T. Mukherjee, M. Wolf, L. Rettig, R. Ernstorfer, T. Pincelli, L. T. Lloyd
NiI$ _2$ is a van der Waals semiconductor characterized by complex electronic and magnetic phases, holding promise towards functional applications. For this purpose, a detailed understanding of its band structure and its excitations is essential to elucidate the electronic and transport properties. We present a comprehensive description of the band structure and of the lowest valence-to-conduction band transition in bulk NiI$ _2$ , by means of time- and angle-resolved photoemission spectroscopy supported by first-principles calculations. We describe the orbital character of Ni and I manifolds, and identify the main momentum-resolved features of the valence band and the shallow minima of the conduction band. With this study, we provide a foundational understanding of the electronic structure of NiI$ _2$ and its single-particle interband electronic excitation, a benchmark for theoretical models, and a framework for future investigations on this material.
Materials Science (cond-mat.mtrl-sci), Strongly Correlated Electrons (cond-mat.str-el)
Momentum-dependent phonon effects on spin-fluctuation $d$-wave pairing in bulk La$_6$Ni$5$O${12}$
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2026-11-10 20:00 EST
Dexi Shao, Zhiming Pan, Ming Zhang, Yupeng Li, Chen Lu
We study the effect of electron-phonon coupling on spin-fluctuation-mediated pairing in bulk La$ _6$ Ni$ _5$ O$ {12}$ . A five-layer Hubbard model treated within the random-phase approximation yields a leading $ d{x^2-y^2}$ pairing state. Two phenomenological couplings motivated by oxygen breathing modes favor $ s$ -wave pairing when considered alone, while their attractive scattering between opposite-sign regions of the spin-fluctuation-induced gap suppresses $ d$ -wave pairing. Electronic charge screening strongly reduces this suppression. Comparing the $ s$ - and $ d$ -wave pairing strengths with and without screening shows that screening shifts their boundary in favor of $ d$ -wave pairing. Momentum-resolved projections locate the reduction of the unfavorable scattering processes. At the representative electronic interaction, $ d$ -wave pairing remains dominant.
Strongly Correlated Electrons (cond-mat.str-el), Superconductivity (cond-mat.supr-con)
5 pages, 4 figures
Giant gas permeance through a nanoporous crystalline 2D polymer
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-11-10 20:00 EST
Jonathan D’Emidio, Daniel J. Murray, William B. Thompson, Jarvis C. Humlick, K. C. Schwab, Adrian Del Maestro, Benjamin T. King
Chemical separation processes represent one of the largest contributors to industrial energy consumption, underscoring the need for the most efficient separation strategies. Many separation processes rely on selective transport through porous media. In this context, two-dimensional (2D) materials offer a promising route to atomically precise porosity beyond the reach of traditional top-down fabrication, with the potential to enhance separation performance by increasing flow. Here we report measurements of gas transport through a one-molecule-thick layer of suspended, nanoporous poly(carboxyfantrip), a 2D polymer that has identical, nanometer-sized pores that cover nearly a quarter of the surface. This combination of ultimate thinness with high areal pore density gives normalized gas flows (permeances) that approach the effusion limit, three to four orders of magnitude above gas-sieving graphene membranes. We find that gases spanning nearly two orders of magnitude in molecular weight (H$ _2$ , He, N$ _2$ , CO$ _2$ , and SF$ _6$ ) obey Graham’s law and approach the ideal limit of non-interacting ballistic transport, despite strong, species-dependent gas-pore interactions. Simulations reproduce the measured permeances within experimental uncertainty and provide an atomistic picture of the transport process. This work demonstrates the potential of synthetic crystalline 2D polymers for chemical separation, water filtration, and quantum sensing.
Materials Science (cond-mat.mtrl-sci), Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
14 pages, 7 figures; includes Extended Data and Supplementary Material. For associated data and code repository see: this https URL
Overcoming speed-accuracy trade-offs with medium-sized interatomic potentials
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-11-10 20:00 EST
Flynn Walsh, Nicolas Bertin, Robert E. Rudd, Aurélien Perron
Current machine-learned interatomic potentials offer a choice between small, fast models and large, expressive networks. This study demonstrates how an intermediate potential can approach the limit of transferable accuracy at the cost of the cheapest existing formalisms. Specifically, we model He-bearing W-Ta-Hf-Cr-V-Ti alloys with an atomic cluster expansion that learns the radial components of each polynomial as independent linear transforms and embeds numerous densities with learned exponents. While (near-)training loss appears largely a function of model size, the error on a distinct validation set is close to that of leading potentials with ten times more parameters. Taking advantage of the new structure, we develop optimized implementations that run more than an order of magnitude faster than the larger models and many times faster than smaller models with equivalent polynomials. The potential is trained on systematically enumerated small structures but generalizes to point and planar defects and can be extended to even more complex chemistries. As a demonstration, we simulate radiation-damage cascades in billion-atom systems for hundreds of thousands of timesteps.
Materials Science (cond-mat.mtrl-sci)
14 pages, 10 figures
Ballistic transport through 3D flat bands in rhombohedral graphene in an in-plane magnetic field
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2026-11-10 20:00 EST
Eran Sela, Rafi Bistritzer, Yuval Oreg
We explore how an in-plane magnetic field reshapes the transmitting channels of a finite slab of rhombohedral multilayer graphene and redistributes the current across its thickness. The two-terminal conductance counts these channels, while the voltage at each surface reflects the relative spectral weights of right- and left-moving states on the contacted layer. In sufficiently thick slabs or at sufficiently strong fields, the nearly flat bulk zeroth Landau level gives rise to a three-dimensional Hall effect with a plateau in the four-terminal Hall resistance.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Strongly Correlated Electrons (cond-mat.str-el)
23 pages, 11 figures
Coherent Control of High-Order Lightwave Currents in Gate-Tunable Bilayer Graphene
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2026-11-10 20:00 EST
Samuel Haeuser, Martin Mootz, Dasol Kim, Avinash Khatri, Joong-Mok Park, Randall K. Chan, Richard H. J. Kim, Yongxing Yao, Ilias E. Perakis, Hou-Tong Chen, Thomas Koschny, Long Ju, Jigang Wang
The sub-cycle acceleration of charge carriers in an electronic circuit by tailored terahertz (THz) electric-field waveforms, rather than conventional pulsed bias voltages, opens a transformative frontier for lightwave electronics operating far beyond the scaling limits of gigahertz electronic technologies. Yet gate-tunable coherent control of multi-order and non-perturbative currents has remained elusive. Here, we demonstrate lightwave control over the amplitude, phase flips, and zero-crossings of THz field-driven high-order currents by utilizing phase-locked pairs of single-cycle THz fields in a dual-gated bilayer graphene (BLG) device. By leveraging the in-situ tuning of both bandgap and charge doping, we reveal extreme THz photocurrent rectification and sub-THz-cycle current generation that are governed by a strong field-driven crossover from interband multi-photon coherence to intraband lightwave acceleration, whose competition provides an exceptional sensitivity to the THz-pulse pair drive. Our interferometric nonlinear THz photocurrent spectroscopy of sub-cycle electronic excitations accesses and controls non-perturbative, multi-quantum photocurrents, which manifest as an extreme-order THz frequency comb. Quantum-kinetic simulations map these lightwave-controlled electron trajectories, revealing that sub-THz-cycle ballistic transport underpins gate- and THz-field-driven functionality enabled by electrostatic doping and bandgap tuning within the atomically thin device architecture. The demonstrated on-demand coherent control of nonperturbative photocurrent transport regimes can be extended to a broad range of atomically thin device architectures, opening new avenues for gate- and field-programmable logic, memory, and quantum simulators in which electronic pathways are steered on sub-cycle, petahertz timescales and atomic length scales.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Materials Science (cond-mat.mtrl-sci), Strongly Correlated Electrons (cond-mat.str-el)
Giant magnetoresistance rectification by Néel vector dynamics
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2026-11-10 20:00 EST
Zhiyi Che, Yifang Hao, Aakanksha Sud, Murat Cubukcu, Charlie W. F. Freeman, Chenghao Yang, Daniel Prestwood, Troy Dion, Shunsuke Fukami, Shigemi Mizukam, Hidekazu Kurebayashi
We observe room-temperature giant magnetoresistance (GMR) rectification driven by Néel vector dynamics in synthetic antiferromagnets. During spin-torque ferromagnetic resonance, the out-of-phase (optical) mode makes the relative angle between the two sub-moments oscillate, producing a rectified voltage due to GMR. This component is isolated from anisotropic and spin Hall magnetoresistance contributions by its angular symmetry, with its voltages scaling linearly with microwave power. We extract a GMR coefficient of 0.18-0.20 % from the rectification, which agrees with independently measured dc magnetoresistance. Reversing the Néel vector with a dc current changes the sign of the GMR rectification voltage in a non-volatile and controlled manner.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
6 pages, 4 figures (main) and Supplementary Material
Hydrogen Thermodiffusion in Tungsten: Trapped Hydrogen Distorts Heat of Transport Estimation from Total Concentration Profiles
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-11-10 20:00 EST
Ville Jantunen, Daniel R. Mason, Sanjeet Kaur
We investigate hydrogen diffusion in tungsten under thermal gradients in the presence of trapping sites using multiscale simulations. Using molecular dynamics simulations, we find that the heat of transport, which quantifies the coupling between temperature gradients and hydrogen transport, for hydrogen in tungsten is positive (thermophobic) at lower temperatures but changes sign near $ 1000$ K. We investigate the origin of the heat of transport and find that harmonic transition state theory with elastic thermal-expansion corrections is insufficient to explain the observed behaviour, consistent with either a breakdown of local thermodynamic equilibrium or non-negligible anharmonic contributions.
We further extend previous studies of hydrogen thermodiffusion by including the effect of trapping sites in both simulations and analytical models. We show that when trapped hydrogen accounts for a significant fraction of the total hydrogen concentration, the heat of transport inferred from measurements of the total concentration is dominated by the temperature dependence of the trapped hydrogen population and no longer reflects the gradient in the mobile hydrogen concentration. Consequently, experimentally measured heats of transport cannot in general be used directly in continuum-scale models that explicitly account for trapping and detrapping. In such models, the heat of transport should be based on mobile hydrogen concentrations only to avoid incorporating trapping effects twice.
Materials Science (cond-mat.mtrl-sci)
Strain-dependent Dynamics of Interactions of Iodine-vacancy pairs in CsPbI3: A DFT and Machine-Learning Molecular Dynamics Study
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-11-10 20:00 EST
Donggeun Kang, Seongju Lee, Yonggoon Jeon
Iodine-vacancy migration and association are important factors in the structural stability of halide perovskites. Although neighboring vacancies have been suggested to form energetically favorable pairs, their stability and reconfiguration under finite-temperature lattice deformation remain unclear. Here, we combine machine-learning molecular dynamics (MLMD) and density functional theory (DFT) to investigate neighboring iodine vacancies in tilted CsPbI3 under isotropic and biaxial strain. The MLMD trajectories reveal a nonmonotonic dependence of short-time hopping fractions on strain, with strong isotropic compression favoring point-like separation and tension promoting pair-preserving relay hopping. Notably, biaxial compression produces distinct orientation-dependent responses: vacancy pairs initially aligned with the compressed plane preferentially undergo separation, whereas those perpendicular to the plane predominantly exhibit relay hopping. Complementary static calculations using DFT and the SevenNet-0 potential yield repulsive interactions for all configurations examined. These findings highlight the importance of finite-temperature dynamics and strain-dependent local geometry in understanding vacancy-pair stability and reconfiguration in halide perovskites.
Materials Science (cond-mat.mtrl-sci)
23 pages, including supplementary information
Frustrated Magnetism from Dimerized $S = 1/2$ Co$^{2+}$ in Rose-Phase Na$_2$CoP$_2$O$_7$
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2026-11-10 20:00 EST
Shukun Li, Leon Ma, Xianghan Xu
We report the growth of high-quality single crystals and the magnetic, thermodynamic, and dielectric properties of rose-phase Na$ _2$ CoP$ _2$ O$ _7$ , a low-symmetry magnet in which corner-sharing Co$ ^{2+}$ dimers form an approximately triangular network. Magnetic measurements reveal dominant antiferromagnetic interactions and pronounced anisotropy among effective $ S=1/2$ Co$ ^{2+}$ moments. Broad low-temperature maxima in the magnetic susceptibility and heat capacity suggest the development of short-range magnetic correlations below approximately 4 K. The large separation between the absolute Curie–Weiss temperatures and the characteristic correlation temperature indicates strong magnetic frustration arising from competing interactions within the coupled-dimer network. Applied magnetic fields suppress these anomalies and reduce the recovered magnetic entropy, suggesting further enhancement of frustration under field. A systematic magnetodielectric response closely follows the field dependence of the magnetization, indicating coupling between magnetic and dielectric degrees of freedom. The low lattice symmetry enables multiple inequivalent exchange pathways and anisotropic interactions while relaxing symmetry constraints on coupling among spin, lattice, and dielectric degrees of freedom. These results establish rose-phase Na$ _2$ CoP$ _2$ O$ _7$ as a platform for exploring frustrated quantum magnetism and coupled functionalities in effective $ S=1/2$ magnets.
Strongly Correlated Electrons (cond-mat.str-el)
8 pages, 4 figures. Includes Supplementary Material. Submitted to Physical Review Materials
Supercurrent-controlled magnon transport via suppression of the superconducting gap
New Submission | Superconductivity (cond-mat.supr-con) | 2026-11-10 20:00 EST
Tetsuma Mandokoro, Yoichi Shiota, Hisakazu Matsuki, Ryusuke Hisatomi, Shutaro Karube, Akito Daido, Youichi Yanase, Teruo Ono
Understanding interactions between different low-energy excitations is a central theme in condensed-matter physics. Magnons and superconducting condensates represent two distinct macroscopic quantum states, yet their mutual interaction remains largely unexplored. Here, we demonstrate supercurrent-controlled magnon transport in a ferromagnet/superconductor heterostructure. We observe that the magnon transport signal decreases as the supercurrent increases. This suppression originates from a supercurrent-induced reduction of the superconducting gap, which enhances magnon dissipation into the superconductor via Bogoliubov quasiparticles. Our results provide direct experimental evidence of a supercurrent-controlled interaction between magnons and quasiparticles in the superconductor. The approach used in this study relies on supercurrents, enabling magnon modulation without Joule heating. These findings establish a new route to control magnons via superconductivity and pave the way for energy-efficient magnonic devices.
Superconductivity (cond-mat.supr-con), Materials Science (cond-mat.mtrl-sci)
10 pages, 9 figures, Accepted for publication in Physical Review Applied
More particles or the pair? An exact test of how to improve mode-coupling theory
New Submission | Soft Condensed Matter (cond-mat.soft) | 2026-11-10 20:00 EST
How a dense liquid arrests into a glass remains a central problem in physics. Mode-coupling theory (MCT), the leading microscopic theory of the glass transition, fails to reproduce mean-field caging. Two routes are proposed to repair it: tracking more-particle correlations, or enforcing repulsion within each colliding pair. Testing both on an exact benchmark liquid, we show that MCT lets touching spheres pass through each other at all orders: adding particles dilutes memory and worsens the transition, whereas restoring pair impenetrability recovers mean-field arrest and the cage size.
Soft Condensed Matter (cond-mat.soft), Optics (physics.optics)
The Photonic Bath at Infinity: Foundations, Derivations, and Consistency Checks
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2026-11-10 20:00 EST
The photonic bath at infinity represents the unbounded electromagnetic environment as an effective reservoir in the nonequilibrium Green’s function (NEGF) formalism. It accounts for outgoing radiation and incoming electromagnetic fluctuations, allowing radiative transport to be described consistently. We clarify how environmental fluctuations are incorporated without double-counting the outgoing radiation response already contained in the free retarded Green’s function. We develop four complementary approaches to deriving the bath self-energy: infinitesimal environmental absorption, semi-infinite leads, inversion of the free Green’s function, and sesquilinear forms with outgoing radiation boundary conditions. In particular, we present an explicit three-site matrix inversion for a planar geometry and introduce a sesquilinear form that relates the bath self-energy to the Silver–Müller radiation condition. We establish the connections among these approaches and obtain explicit bath self-energies for one-dimensional, planar, and spherical geometries. The resulting bath self-energies reproduce the Planck spectrum, the Stefan–Boltzmann law, and radiation pressure, and provide the radiative contribution required for energy conservation in photon NEGF.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Mathematical Physics (math-ph)
21 pages, 1 figure
How Path Integral Diffusion Decides a Finite Spin Glass
New Submission | Disordered Systems and Neural Networks (cond-mat.dis-nn) | 2026-11-10 20:00 EST
When an AI diffusion-type generator samples a frustrated spin glass, which macroscopic alternatives does it decide first, and when? We study this for bridge-diffusion models of the Path Integral Diffusion (PID) type started from a point source. We show that every isotropic PID is a time-changed Gaussian stochastic localization, and conversely every signal-to-noise schedule is realized by a PID protocol. What a continuous-time generator decides therefore does not depend on the protocol, which only sets when and at what cost. We describe the generator’s state by its partial commitments: the probabilities it assigns, at each moment, to nested classes of configurations fixed by the target. The partial commitments are martingales that move only along class contrasts. Their ensemble average gives the information about each level at an exact rate set by squared magnetization contrasts. Each split is decided, approximately, like a binary Gaussian channel at signal-to-noise ratio 1.04/\lambda_P, with \lambda_P the leading eigenvalue of the parent’s correlation matrix. The theory is applied to Bethe-lattice and Sherrington–Kirkpatrick (SK) glasses with up to 64 spins. It is observed generically that a trajectory first shifts its weight to one of the two mirror halves of the zero-field measure and then to the glassy classes inside it. These classes appear near the glass transition and keep their identity on cooling. Nested glassy levels have similar \lambda_P and are decided together, so a trajectory commits in one or two distinct events—the mirror choice and a compound glassy decision—which separate further with coupling and size, as the spectra predict. For a generator that takes finitely many steps, the protocol matters through the late, local stage rather than the macroscopic decisions.
Disordered Systems and Neural Networks (cond-mat.dis-nn), Statistical Mechanics (cond-mat.stat-mech), Artificial Intelligence (cs.AI), Machine Learning (stat.ML)
42 pages, 15 figures
Computing Classical Partition Functions via Cycle-Space Sampling
New Submission | Statistical Mechanics (cond-mat.stat-mech) | 2026-11-10 20:00 EST
Yoav Feigenbaum, Lev Barash, Itay Hen
We present a method for computing thermodynamic properties of classical spin systems by reformulating the partition function as a sum over even subgraphs of the interaction graph. Starting from the high-temperature expansion, we show that the expansion coefficients are determined by the weight distribution of the null space of the binary incidence matrix over $ \mathbb{F}_2$ , and that this statement holds verbatim for multi-spin interactions once the graph is replaced by a hypergraph. We introduce a Monte Carlo scheme based on the $ 1/t$ Wang-Landau algorithm that performs a random walk directly in this null space. Because the weight distribution is temperature independent, a single estimate yields the zero-field partition function, and the thermodynamic quantities obtained from its temperature derivatives, at arbitrary temperature. We validate the approach against exact finite-size results on the two-dimensional triangular-lattice Ising model, apply it to the three- and four-dimensional hypercubic Ising models where no exact solution is available, and to the two- and three-dimensional Baxter-Wu models, whose three-spin interactions place them outside the reach of Pfaffian methods. For the two-body models we compare against conventional Wang-Landau sampling in energy space; for the Baxter-Wu models we validate against exact enumeration at the smallest size in each dimension.
Statistical Mechanics (cond-mat.stat-mech)
22 pages, 10 figures
Topology to Elasticity Mapping in Thermal Glass
New Submission | Soft Condensed Matter (cond-mat.soft) | 2026-11-10 20:00 EST
Building on our previous work on thermal nonaffine metrics and thermal strain fields, we examine how local steric geometry controls thermally driven rearrangements in an amorphous glass-forming solid. As a structural descriptor, we employ the topological steric “theta-mismatch” order parameter, which quantifies local deviations of bond angles from the steric reference geometry and is used to distinguish low- and high-mismatch particle populations. We then compare their thermal nonaffine response, thermal deviatoric strain, and thermal volumetric strain over a broad temperature range at several state points. High-Delta-theta sites preferentially exhibit larger thermal nonaffine motion and stronger thermal deviatoric strain, particularly in the deeply jammed regime, indicating that geometrically frustrated regions are preferentially associated with localized mechanical distortions. The thermal volumetric response exhibits a distinct mismatch-dependent crossover: low-Delta-theta sites predominantly contribute to the small-strain response, whereas high-Delta-theta sites contribute more strongly to the large-strain tail. The contrast between low- and high-mismatch populations is most pronounced in the deeply jammed regime, remains identifiable through the intermediate viscoelastic regime, and progressively weakens upon heating toward the liquid state. These results establish a direct connection between local steric frustration and thermally activated mechanical response, showing that thermal nonaffine metrics and thermal strain fields provide a physically transparent bridge between local structure and thermally driven rearrangements in amorphous glasses.
Soft Condensed Matter (cond-mat.soft)
Submitted to Physica A: Statistical Mechanics and its Applications
Frank Elastic Anisotropy Induced by Anisotropic Attractive Interactions in Nematic Liquid Crystals
New Submission | Soft Condensed Matter (cond-mat.soft) | 2026-11-10 20:00 EST
We present a mean-field theory to calculate the Frank elastic constants of a nematic liquid crystal with an anisotropic Maier–Saupe (MS) attractive interaction restricted to a cylindrical interaction volume of height $ L_z$ and diameter $ L_c$ . The shape of the interaction volume is characterized by the aspect ratio $ \alpha_z=L_z/L_c$ , which controls the spatial anisotropy of the attractive interaction. We derive expressions for the splay $ (K_{11})$ , twist $ (K_{22})$ , and bend $ (K_{33})$ elastic constants and calculate them numerically as functions of concentration and temperature. At the special aspect ratio $ \alpha_z=\sqrt{3}/2$ , the transverse and axial second moments are equal, yielding the one-constant relation $ K_{11}=K_{22}=K_{33}$ over the full ranges of concentration and temperature considered. Away from this point, oblate and prolate interaction volumes produce distinct elastic anisotropies. Changes in concentration or temperature can also reverse the hierarchy of the three elastic constants.
Soft Condensed Matter (cond-mat.soft)
12 pages, 6 figures
Magnetotropic signatures of Fulde-Ferrell Pairing in a Pauli-limited superconductor
New Submission | Superconductivity (cond-mat.supr-con) | 2026-11-10 20:00 EST
Gulnaz Rakhmanova, Mikhail Lemeshko, Kimberly A. Modic, Ragheed Alhyder
Resonant torsion magnetometry measures the angular curvature of the free energy and is sensitive to magnetic anisotropy. We calculate its response for a clean Pauli-limited superconductor with single-plane-wave Fulde-Ferrell pairing. Field rotation drives a first-order transition from the uniform condensate into the finite-momentum phase and a continuous transition into the normal state. The first-order line produces a sharp softening whose integrated weight is fixed by the magnetization jump, so the dip alone does not identify finite momentum. The distinguishing response is a broad softening inside the Fulde-Ferrell phase, caused by relaxation of the gap and pairing momentum, followed by a finite step at the upper critical field.
Superconductivity (cond-mat.supr-con)
Connate Topological Superconductivity and Vortex-Position-Controlled Majorana Modes in the Intergrowth Superconductor Th$_2$Mo$_2$Ir$_2$Si$_4$C
New Submission | Superconductivity (cond-mat.supr-con) | 2026-11-10 20:00 EST
Jiayang Li, Qing Wang, Xun-Jiang Luo, Mingliang Tian, Ning Hao
The recently synthesized intergrowth compound Th$ _2$ Mo$ _2$ Ir$ _2$ Si$ _4$ C is an experimentally established bulk superconductor whose topological electronic structure remains unexplored. Here, we identify it as a candidate for connate topological superconductivity and reveal two microscopic routes to vortex Majorana zero modes. First-principles and tight-binding-model calculations uncover Mo–Th band inversion and helical surface states enabled by interorbital spin–orbit coupling between Mo–d$ _{xz/yz}$ and Th–d$ _{x^2-y^2}$ orbitals. Vortex Bogoliubov–de Gennes calculations further establish a relatively robust surface-state-associated Kitaev phase and a weakly gapped, Th-orbital-derived Kitaev phase. For the latter, shifting the vortex core closes and reopens the vortex-line gap and reverses its one-dimensional topological invariant, consistent with an effective Kitaev-chain mass inversion. Finite-length-vortex calculations reveal distinct spatial and spin-resolved signatures of their Majorana end modes. The orbital Kitaev phase can also exist without helical surface states in a modified model. Although the small orbital-derived gap limits quantitative predictions of experimental observability in this compound, the uncovered mechanism suggests a route to Majorana vortices in multiorbital superconductors beyond the conventional surface-state scenario.
Superconductivity (cond-mat.supr-con)
7 pages, 4 figures; Supplemental Material included (19 pages, 14 figures)
Where reconfiguration makes a structure stronger
New Submission | Soft Condensed Matter (cond-mat.soft) | 2026-11-10 20:00 EST
Mechanical metamaterials can reconfigure on command and learn, so adaptation is a central promise of the field. Can reconfiguration make a metamaterial stronger? The answer depends on the comparison. Against the best fixed design of the same mass, the advantage of reconfiguring is often exactly zero. Reconfiguring helps only if the self-stress the actuators add lowers every member at its limit simultaneously. It vanishes where a member at its limit is one no self-stress can change, which the geometry fixes, or where those members are coupled so that lowering one raises another, which depends on the geometry and the loads together. Where neither block applies the gain can be large, as in a twelve-spoke hub with its worst member utilisation reduced by 29.1%. Whether reconfiguration is worthwhile is decided by how the self-stress of a structure meets the members setting its capacity under load, and can be tested in advance.
Soft Condensed Matter (cond-mat.soft)
32 pages, 9 figures, 8 supplementary figures, 1 supplementary table
Topology, geometry and fabrication of volumetric plain weaves
New Submission | Soft Condensed Matter (cond-mat.soft) | 2026-11-10 20:00 EST
Samuel Poincloux, Lauren Carelli Dreier, Tian Chen
Plain weave is one of the simplest woven structures, formed by two sets of yarns that cross at right angles in an alternating over-under pattern. While such woven fabrics are usually confined to a 2D surface, here we propose a practical approach to fabricate volumetric plain weaves, entanglements featuring three mutually orthogonal families of yarns threaded through a cubic lattice. We develop an analytic framework that converts the crossing pattern topology into continuous yarn centreline geometries, which we then leverage to fabricate volumetric weave specimens. Each crossing is encoded by a matrix that defines the offsets of the three yarns at a vertex. These are formulated to preserve the plain weave topology in every plane, where each pair of yarn families interlaces as in a planar plain weave. Eight configurations in four opposite pairs exist, yet all are related by rotations and translations, so that the fully alternating volumetric plain weave has a single topology. We adopt sinusoidal yarn trajectories and show that the crossing matrix defines their phases. We select two solutions: in-phase planar zigzags and out-of-phase circular helices. Both are members of a family of elliptical helices that also admits a free choice of handedness for each yarn. We then derive the conditions under which yarns intersect between vertices. In-phase yarns never intersect, whereas helical yarns of equal handedness intersect at a critical offset of $ \sqrt{2}\lambda/16$ , with $ \lambda$ the wavelength of the cubic lattice. No assignment of handedness avoids these intersections. Finally, we fabricate volumetric plain weaves by 3D printing and manual assembly from cotton cord. The framework provides a direct basis for generating weave geometries for simulation and fabrication.
Soft Condensed Matter (cond-mat.soft), Mathematical Physics (math-ph)
21 pages, 6 figures
Spatial effects of Kuramoto modeling on the power-grid frequencies
New Submission | Disordered Systems and Neural Networks (cond-mat.dis-nn) | 2026-11-10 20:00 EST
Kristóf Benedek, Michelle T. Cirunay, Sangita Dutta, Attila Balogh, Bálint Hartmann, Géza Ódor
Spatial coupling and heterogeneity can generate complex power-grid frequency dynamics. We investigate the contributions of spatial structure, intrinsic nonlinear dynamics, and external driving using the Kuramoto model (KM), with and without uncorrelated noise, and compare its predictions with real-grid measurements.
We analyse one month of 100 ms frequency measurements from 16 Hungarian transmission-grid sites and simulate the KM on a 387-node transmission network and two-dimensional lattices. The measured power spectra exhibit two scaling regimes, with exponents of approximately 1.63 and 2.23. One-second frequency increments decorrelate rapidly, while correlations of their local inverse variance decay slowly, initially as a power law, $ \tau^{-0.26(2)}$ , up to 15 minutes. A superstatistical Gaussian mixture based on measured local variances captures much of the non-Gaussian increment distribution, but not the rare extreme events.
We also estimate the non-stationary long-time frequency autocorrelation exponent. KM simulations on low-dimensional networks exhibit algebraically decaying autocorrelations and power spectra, consistent with the measurements and the Wiener-Khinchin relation in the steady state. On the heterogeneous transmission network, partial synchronization and frequency locking produce persistent spatial patterns and multi-peaked frequency distributions. However, neither deterministic KM dynamics nor independent Gaussian driving reproduces the measured spectra and increment statistics simultaneously. Moreover, empirical frequency fluctuations are largely shared across substations, whereas simulated fluctuations mainly reflect relative node motion. These findings suggest that spatially coupled nonlinear dynamics contribute to observed frequency fluctuations alongside external driving, including 15-minute power dispatches.
Disordered Systems and Neural Networks (cond-mat.dis-nn), Statistical Mechanics (cond-mat.stat-mech), Physics and Society (physics.soc-ph)
Scaling up spin complexity in ultracold assembled molecules: association and quantum chemistry of Cr-bearing diatomics
New Submission | Quantum Gases (cond-mat.quant-gas) | 2026-11-10 20:00 EST
Beatrice Restivo, Stefano Finelli, Andrea Simoni, Andreas Trenkwalder, Matteo Zaccanti, Alessio Ciamei
The availability of ever more atomic elements in the ultracold regime potentially enables the extension of molecule assembly well beyond bi-alkali systems to targeted chemical species for novel quantum science and technologies. The concurrent need for single-quantum-state control and molecular constants from \emph{ab initio} calculations, especially for previously unexplored species, creates a trade-off between complexity and feasibility. Here, we address this challenge and exploit inter-isotope Feshbach spectroscopy as a tool to study three chromium-bearing diatomics ($ ^6$ Li$ ^X$ Cr, $ ^{50,52}$ Cr$ _2$ , and $ ^{53}$ Cr$ _2$ ) at different levels of complexity. The extracted molecular properties, including the number of vibrational levels and the dispersion coefficients, allow us to assess quantum chemistry methods. Moreover, our understanding of atomic scattering allows us to assemble LiCr and Cr$ _2$ molecules and clarify the observed association pathways with quantum state selectivity. Our results suggest unique prospects for the Li-Cr and Cr-Cr systems, and, more importantly, the experimental viability of a wider class of assembled high-spin molecules for many-body physics and precision measurements.
Quantum Gases (cond-mat.quant-gas)
The manuscript has a main text of about 11 pages (7 figures, 5 tables), 4 appendices of 7 pages (5 figures, 4 tables) and 95 references
Misorientations in dislocation cell structures: Modelling and statistical analysis
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-11-10 20:00 EST
Lei Zeng, Yufan Zhang, Michael Zaiser
Dislocation pattern formation is accompanied by the emergence of lattice rotations and concomitant misorientations across dislocation walls (cell boundaries). Recent advances in mesoscopic modelling of dislocation patterns enable for the first time a systematic simulation study of this phenomenon. We present simulation results for lattice rotation and misorientation patterns in crystals with face-centered cubic and rocksalt lattice structure. Statistical analysis of the orientation changes across cell walls reveals a transition associated with a symmetry-breaking bifurcation in slip system activity: Below the bifurcation, statistical tests indicate the presence of a single population of misoriented walls whereas, above the bifurcation, two sub-populations of ‘incidental’ and ‘geometrically necessary’ dislocation walls are present. Our data analytic approach demonstrates that this distinction does not require prior image segmentation and emphasizes the statistical robustness of the distinction between two types of dislocation walls.
Materials Science (cond-mat.mtrl-sci)
Quantum-geometry-controlled pseudogap and non-Fermi-liquid behavior
New Submission | Superconductivity (cond-mat.supr-con) | 2026-11-10 20:00 EST
The quantum metric plays an essential role in flat-band superconductivity, governing the superfluid weight and coherence length. While previous studies have primarily focused on mean-field superconducting properties, the role of quantum geometry in fluctuation phenomena remains largely unexplored, despite the importance of fluctuations in flat-band systems. To address this issue, we employ a multiorbital T-matrix approximation that retains the orbital structure of the Bloch wave functions. By analyzing models in which the quantum metric can be tuned independently of the band dispersion, we show that an enhanced quantum metric suppresses the fluctuation-induced pseudogap in both flat-band and dispersive-band systems. In dispersive-band systems, this suppression is accompanied by a crossover from non-Fermi-liquid to Fermi-liquid behavior. This spectral evolution suggests a quantum-metric-driven crossover from a BEC-like strong-coupling regime to a BCS-like weak-coupling regime. More broadly, our results establish the quantum metric as a control parameter of interaction-driven fluctuation phenomena beyond mean-field theory.
Superconductivity (cond-mat.supr-con), Strongly Correlated Electrons (cond-mat.str-el)
10 pages, 7 figures
Phonon emission due to dc-driven electron heating in a two-dimensional electron gas containing artificial scatterers
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2026-11-10 20:00 EST
Frederik Bartels, Mihai Cerchez, Jan Lange, Dominique Mailly, Klaus Pierz, Hans W. Schumacher, Thomas Heinzel
We report the observation of phonon-induced resistance oscillations (PIROs) up to order $ \varepsilon_\mathrm{ph} = 8$ in a two-dimensional electron gas containing artificial scatterers, activated by electron heating due to an applied dc current which enables phonon emission. Under equilibrium conditions, only two weak PIRO maxima are detectable. The dc current simultaneously generates Hall field induced resistance oscillations (HIROs). A precise analysis of their amplitude, which is modulated by the double resonance with PIROs, dramatically enhances the visibility of the latter compared to the equilibrium case. We identify transverse acoustic phonons with a sound velocity of $ s = 3.4$ ,km/s as the relevant mode and analyze the oscillatory amplitude modulation in the subsonic regime ($ \varepsilon_{\mathrm{dc}} < \varepsilon_{\mathrm{ph}}$ ) within the theoretical framework of Dmitriev \textit{et al.} At the sound barrier ($ \varepsilon_{\mathrm{dc}} = \varepsilon_{\mathrm{ph}}$ ), where the electron drift velocity reaches the speed of sound, we observe a phase shift in the oscillatory electron-phonon interaction that independently confirms recent experimental findings.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
9 pages, 4 figures
Lattice Commensurability and Majorana sectors of Pfaffian–Anti-Pfaffian interfaces
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2026-11-10 20:00 EST
We study Pfaffian and anti-Pfaffian non-Abelian fractional quantum anomalous Hall states in half-filled moiré lattice systems. Owing to crystal-momentum conservation modulo a reciprocal lattice vector, these lattice systems admit coupled-wire constructions of the two phases without requiring spatially varying magnetic-field-induced momentum shifts. For the resulting Pfaffian–anti-Pfaffian interface, a Umklapp process can gap the counter-propagating charge sector, while the remaining four co-propagating Majorana modes naturally group into two sectors organized by translation symmetries. Our results show that lattice commensurability qualitatively changes the coupled-wire accessibility of non-Abelian states while providing a microscopic momentum structure that directly constrains their edge and interface dynamics.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
10 pages, 2 figures
Plasmon excitations in monolayer stanene
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2026-11-10 20:00 EST
Monolayer stanene exhibits strong intrinsic spin-orbit coupling (SOC) and notably distinct low-energy band features involving both $ \Gamma$ and K valleys together with strong electron-hole asymmetry among group-IV monolayers. Its plasmonic properties and external-field tunability remain largely unclarified. Here, we systematically investigate its high-energy plasmon structures and low-energy collective excitation modulated by temperature, electrostatic doping and perpendicular electric field. Calculations use a $ sp^3$ tight-binding model with SOC and sublattice staggered potentials, combined with the finite-temperature multiband Lindhard function under the random-phase approximation. Besides the $ \pi$ and $ \pi+\sigma$ plasmon known in graphene/silicene, stanene supports two new high-energy plasmon branches. For low-energy plasmons, thermal excitation extends the accessible energy-momentum range while preserving high quality factors and collective coherence. Electrostatic doping yields distinct plasmon behaviors: moderate doping gives K-valley dominated intraband $ \sqrt{q}$ Dirac plasmons; heavy electron doping retains $ \sqrt{q}$ dispersion via Drude contributions from $ \Gamma$ and K valleys; heavy hole doping triggers interband transitions near the $ \Gamma$ point, producing new $ \sigma$ -$ \sigma$ and $ \sigma$ -$ \sigma^\ast$ interband plasmon modes and complex multi-branch spectra. Furthermore, the perpendicular electric field enables continuous tuning of the $ \sqrt{q}$ plasmon via band reconstruction below 0.3 V/Å and induces extra plasmon modes near band-gap closure. These tunable low-energy plasmons span terahertz-to-mid-infrared frequencies, promising for nanophotonic applications.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
Impact of multi-dot configurations on electron temperature and double quantum dot latching in gate-controlled qubit devices
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2026-11-10 20:00 EST
Jakob Walsh, Miriam Schweinböck, Jhih-Sian Tu, Yuji Yamamoto, Felix Reichmann, Lars R. Schreiber, Dominique Bougeard
Many currently envisaged scalable architectures for Si/SiGe spin qubit devices utilize gate-controlled multi-dot configurations characterized by their peculiar Coulomb blockade physics. One example is the concurrent use of a single electron transistor (SET) as a charge sensor and as a reservoir for adjacent qubit quantum dots (QD). We find that the SET energy spectrum impacts pulsed gate spectroscopy of the QD when the SET simultaneously acts as the reservoir and the sensor. Then, using the qubit QD as a probe, we quantify how strongly the electron temperature of the SET depends on the applied bias. It surpasses a reference experiment by 100 $ mK$ even at 50 $ \mu V$ bias. Our results provide a strong incentive for choosing spin qubit initialization schemes which do not rely on coupling to the reservoir in such devices. Switching to a double quantum dot connected to a single reservoir, a frequent configuration for qubit readout, we finally demonstrate the tunability of the characteristic latching behavior by systematically mapping it in the few-electron stability diagram.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
7 pages, 5 figures
Designed atomic displacements for finite-temperature phonons from few force calculations
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-11-10 20:00 EST
Finite-temperature phonons are usually fitted to first-principles forces in randomly displaced supercells, and each force calculation can be expensive. We introduce special optimal thermal cells (SOTCs), in which the displacements are designed rather than drawn at random. Our design, SOTC-D, starts from a harmonic trial model. It gives every supercell phonon mode its quantum-thermal amplitude, chooses the sign of each mode so that the force constants are best determined, and pairs each configuration with its inverse so that cubic forces cancel. Updating the trial leads to the self-consistent harmonic solution. Cells that match displacement correlations instead give good thermodynamics but not better dispersions. For eleven crystals, eight force calculations reproduce the effective dispersions within 0.03-0.31 THz, and SOTC-D is the most accurate of five designs in 9 of them. After one trial update, it beats random sampling in all crystals at 4-16 calculations and two-iteration stochastic sampling (sTDEP) in all at eight (supercell basis). On model potentials, the self-consistent form needs 2-16 times fewer calculations than the stochastic self-consistent harmonic approximation in 13 of 14 cases. With the HSE06 hybrid functional, it is ahead of pooled sTDEP at 4-16 calculations in Si and NaCl, and it gives the thermal expansion of Al within 3% of experiment at 300K. The method has limits: in Al and Si cells of more than 100 atoms, sTDEP is more accurate beyond 4-16 calculations (not so in NaCl up to 16); for dynamically stabilized bcc Zr, the outcome depends on the seed; and above 400 K, the free-energy curvature is not resolved.
Materials Science (cond-mat.mtrl-sci)
Topological phases and scattering protected by projective chiral symmetry
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2026-11-10 20:00 EST
Théo Torres, Renaud Côte, Marc Pachebat, Antonin Coutant
The bulk-boundary correspondence states that topological properties of a bulk material guarantee the existence of protected edge modes, oftentimes associated with the attractive property of backscattering immunity. In this Letter, we consider a time reversal invariant classical system with both translation and chiral, or sublattice, symmetries. We show that when these two symmetries anti-commute, the material exhibits a topological phase protected by the same invariant as type D topological superconductors. We realize such a system experimentally and observe the existence of the associated edge modes in an acoustic network. Our measurements are in excellent agreement with theoretical predictions from discrete lattice models. Finally, we show that these edge modes are immune to backscattering for perturbations consisting in two subsequent identical defects.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Classical Physics (physics.class-ph)
7+4 pages. 4+3 figures
Multichannel Phonon Interconversion Drives 90 Polarization Rotation for Stable Domain Walls in Hafnium Oxide
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-11-10 20:00 EST
Fatoye Sawyerr, Hamoon Fahrvandi, Pawan Kumar, Zekun Zhang, Shuning Lv, Yue Yu, Xuan Gao, Kang Jia, Shifeng Wen, Zheng Wen, Li-Min Liu, Xiaoli Fan, Jun Hee Lee, Tengfei Cao
Polarization rotation is a fundamental mechanism in ferroelectric materials, yet how such rotation arises microscopically in fluorite ferroelectrics and gives rise to distinct domain walls (DW) remains unresolved. Phonon modes offer a microscopic route to such structural transformations, as geometric orientations can modify their frequencies, dispersion relations, and vibrational eigenstates when their characteristic wavelengths become comparable to relevant physical dimensions. Here, by combining condensed phonon mode decomposition with first-principles calculations, we investigate the origin of 90 polarization rotation in the ferroelectric phase of HfO2. Using the cubic parent phase as reference, we show that polarization rotation originates from multiple symmetry equivalent phonon modes of distinct eigenstates at different wavevectors in the Brillouin zone, whose coupling and cooperative reorientation continuously evolve to generate distinct 90 Pca21 variants and switching pathways. Among the 90 variants, the lowest-energy switching pathway through the Pmn21 exhibits an energy barrier comparable to, but slightly lower than, that of the 180 polarization reversal pathway through the P42/nmc phase, indicating that 90 polarization rotation is an energetically accessible alternative switching route. We further analyze 90 DW and find that frustrated phonon modes emerge at the wall center, where the coexistence and competition of condensed modes promote local reconfiguration of the lattice distortions, contributing to the elevated DW energies. Importantly, experimental observations with STEM imaging provide direct evidence of atomic mode distortions in stable 90 DW, consistent with the theoretically identified low-energy DW. These findings provide the fundamental structural mechanism underlying 90 switching dynamics, competing domain-wall physics, and macroscopic ferroelectric behavior.
Materials Science (cond-mat.mtrl-sci)
Defects and Structural Evolution in CrSBr: Machine-Learning Potentials for Atomistic Simulations
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-11-10 20:00 EST
Arsalan Hashemi, Daniil Kruklinskii, Xiaoya Chang, Tapio Ala-Nissila, Mikko Karttunen, Arkady V. Krasheninnikov, Mahdi Ghorbani-Asl
The layered van der Waals semiconductor CrSBr combines intrinsic magnetic order with semiconducting and optical properties, making it a promising material for multifunctional electronic and photonic applications. Understanding how defects and structural transformations affect its properties under experimentally relevant conditions, however, remains challenging for first-principles simulations due to the relevant length and time scales. Here, we develop and benchmark machine-learning interatomic potentials (MLIPs) for the Cr-S-Br system, enabling large-scale atomistic simulations of CrSBr with accuracy approaching that of density functional theory (DFT). The charge-aware variant qNEP achieves near-DFT accuracy in predicting lattice constants, formation enthalpies, vacancy energetics, and the anisotropic pressure response of o-CrSBr. Nudged elastic band calculations reveal that pre-existing S vacancies lower the Cr Frenkel-pair migration barrier by up to 1.1 eV, providing an atomistic mechanism for beam-induced Cr redistribution and structural transformations. Displacement threshold calculations further show that Br is the most susceptible species to electron-beam-induced displacement, identifying the relative ease of removing different atomic species. Together, these results establish a validated computational framework for investigating atomic-scale disorder and structural transformations in CrSBr, providing a basis for defect engineering in materials for future magneto-optoelectronic applications.
Materials Science (cond-mat.mtrl-sci)
Positronium resonance of electric monopoles in quantum spin ice
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2026-11-10 20:00 EST
José Maria Cruz, Hidemaro Suwa, Masafumi Udagawa
Quantum spin ice attracts considerable attention due to its remarkable low-energy properties, described by the effective gauge theory, which mimics the quantum electrodynamics (QED). The effective" QED in quantum spin ice is beyond the real” QED in our universe in many respects. Above all, the effective QED hosts two kinds of gapped particles, the electric monopole, in addition to the magnetic monopole. Among the two monopoles, the electric monopole is of purely quantum origin, and its character has not been well resolved. In this work, we focus on the Rokhsar Kivelson point of the quantum dimer model, as the low-energy description of the quantum XXZ model on a pyrochlore lattice, and address the excitation spectrum of the electric monopoles, by combining the quantum Monte Carlo simulation with the stochastic analytical continuation. Most strikingly, the electric monopole spectrum exhibits clear double-peak structure, corresponding to the bound states and scattering states of electric monopoles. The lower-energy peak is attributed to the exciton-like bound state of an electric monopole pair, a signal of positronium in quantum spin ice. We found that the flippable loop operator serves as a local physical observable to excite a pair of electric monopoles, implying that monopoles can be detected through lattice or optical response.
Strongly Correlated Electrons (cond-mat.str-el)
16 pages, 11 figures
Tuning correlated states in rhombohedral pentalayer graphene with magnetic encapsulation
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2026-11-10 20:00 EST
Cuiju Yu, Yitao Sun, Jose L. Lado
Rhombohedral graphene multilayers provide a flexible platform for correlated physics associated with their flat-band electronic this http URL a variety of correlated states appear in these systems as a function of bias and electrostatic doping, promoting specific correlated flavor symmetry breaking states remains a challenge. Here we show that magnetic encapsulation by CrGeTe$ _3$ achieves this in rhombohedral pentalayer graphene, by using switchable exchange couplings induced by ferromagnetic substrates. We show that correlations in rhombohedral multilayers at charge neutrality strongly renormalize the exchange proximity splitting,giving rise to collective spin modes whose character is switched by the parallel or antiparallel alignment of the encapsulation. We further show that upon doping of the flat bands, spin triplet $ f$ -wave superconducting solutions emerge, whose layer and spin selectivity is controlled by the magnetic encapsulation, hosting in-gap excitations at the edges. Our results establish magnetic alignment as a means to control spin symmetry breaking and unconventional superconductivity in rhombohedral pentalayer graphene.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Materials Science (cond-mat.mtrl-sci)
Ultrafast Liquid Jet X-ray Total Scattering
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-11-10 20:00 EST
Adam F. Sapnik, Philip A. Chater, Dean S. Keeble, Tobias A. Bird, John S. O. Evans, Federica Bertolotti, Antonietta Guagliardi, Norberto Masciocchi, Daniel T. Bowron, Lise J. Støckler, Elodie A. Harbourne, Anders B. Borup, Rebecca S. Silberg, Viktoria A. Kaznelson, Stefanie Punke, Mariia Svyrydenko, Maryna I. Bodnarchuk, Dmitry N. Dirin, Simon C. Boehme, Maksym V. Kovalenko, Bo B. Iversen, Emil S. Bozin, Kirsten M. Ø. Jensen, Gabriele Ansaldi, Karen Appel, Alexander Gierke, Jörg Hallmann, Aliaksandr Leonau, Anders Madsen, Johannes Möller, Jan-Etienne Pudell, Angel Rodriguez-Fernandez, Andreas Schmidt, Roman Shayduk, Cornelius Strohm, Joana Valerio, Ulrike Boesenberg, David A. Keen
X-ray free-electron lasers (XFELs) provide the temporal resolution needed to extend total scattering and pair distribution function (PDF) analysis to investigate structural dynamics on femtosecond-to-picosecond timescales. We recently demonstrated that high-quality total scattering data and PDFs can be obtained from individual XFEL pulses; here, we take the next step towards time-resolved studies of structural dynamics in solution. Using the Materials Imaging and Dynamics (MID) instrument at the European XFEL, we obtain total scattering data up to $ Q_{\max} = 16.4,\mathring{\mathrm{A}}^{-1}$ from both conventional capillary samples and, critically, from samples delivered by a liquid jet. Despite the large air and solvent backgrounds inherent to this setup, PDFs suitable for quantitative structural analysis are recovered from liquid dispersions and molecular clusters in solution. We further demonstrate pump-probe total scattering from $ \mathrm{CsPbBr}_3$ nanocrystals in a liquid jet, resolving a fluence-dependent photoinduced isotropic lattice strain. Additionally, empirical potential structure refinement (EPSR) of XFEL total scattering data from an aqueous Keggin cluster reveals site-specific hydration environments and enables three-dimensional mapping of the surrounding solvent structure. Together, these advances open the door to tracking not only ultrafast structural changes in solution, but also the evolving solvent environments that govern molecular behaviour and reactivity.
Materials Science (cond-mat.mtrl-sci), High Energy Physics - Experiment (hep-ex), Instrumentation and Detectors (physics.ins-det)
Atomically Sharp Magnetic Domain Walls beyond Micromagnetics
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-11-10 20:00 EST
Atomically narrow magnetic domain walls can arise in ultrathin magnetic films, van der Waals magnets, and systems with reduced effective exchange stiffness due to competing exchange interactions. As their width approaches the atomic lattice spacing, the continuum approximation underlying micromagnetics becomes increasingly unreliable. We investigate the structure and stability of such domain walls in a one-dimensional nearest-neighbor J-K-D spin-lattice model incorporating Heisenberg exchange, uniaxial anisotropy, and Dzyaloshinskii-Moriya interaction (DMI). In the absence of DMI, we demonstrate analytically a continuous transition to an atomically sharp easy-axis wall at the critical exchange-to-anisotropy ratio J/K = 3/2, characterized by the softening of a localized Hessian mode. Atomistic spin-dynamics simulations confirm this transition and reveal that fitting discrete wall profiles with the conventional micromagnetic solution, as commonly done in experimental analyses, underestimates the exchange interaction and overestimates the anisotropy. Finite DMI removes the perfectly collinear wall as a stationary configuration, replacing the transition by a smooth crossover toward a strongly localized but canted wall that approaches the collinear easy-axis configuration only asymptotically in the strong-anisotropy limit. We derive an analytical expression for the DMI-induced canting in this regime and demonstrate its strongly enhanced canting response near the critical ratio. These findings establish the limitations of micromagnetic descriptions of atomically narrow domain walls and suggest opportunities for controlling their structure through anisotropy and DMI.
Materials Science (cond-mat.mtrl-sci)
Ultrafast Inter-Aggregate Energy Transfer Drives Efficient Charge Generation in Organic Homojunctions
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-11-10 20:00 EST
Shanchao Ouyang, Hang Yuen Ho, Sudhi Mahadevan, Ziyao Yue, Haochen Liu, Zhiqiang Guan, Chun-Sing Lee, Shu Kong So, Sai-Wing Tsang
Y6-based homojunction organic photovoltaic devices have recently achieved exceptional power conversion efficiencies, surpassing those of conventional organic photovoltaic materials. Although unusually long exciton diffusion lengths and efficient exciton dissociation have been reported, the fundamental mechanism underlying this outstanding performance remains under debate. Here, we report that structurally distinct aggregates in Y6 thin films exhibit complementary charge-transfer (CT) characters that enable directional energy transfer and enhanced exciton delocalization. Using ultrafast spectroscopy, we identify highly efficient Förster resonance energy transfer (FRET) between Y6 aggregates, with an ensemble-averaged efficiency of 65% occurring on a sub-picosecond timescale (<1 ps). This aggregate-mediated energy-transfer pathway drives long-range energy migration in Y6 thin films and accounts for the remarkable external quantum efficiencies observed in homojunction devices, even in the absence of conventional donor-acceptor bulk heterojunction morphologies and despite substantial fractions of weak-CT components. Here, using Y6 as a model non-fullerene acceptor (NFA) system, we show that structurally distinct aggregates coexisting in NFA thin films possess complementary CT characters, which are expected to enable directional energy transfer and enhanced exciton delocalization. We establish a general multi-component FRET framework that quantitatively links molecular aggregation, CT character, and excited-state dynamics in systems with multiple packing motifs. This work provides insight into the development of next-generation high-performance organic electronic materials and devices.
Materials Science (cond-mat.mtrl-sci)
The role of preparation protocols in the Mpemba effect under time-delayed Newton cooling
New Submission | Statistical Mechanics (cond-mat.stat-mech) | 2026-11-10 20:00 EST
The Mpemba effect depends on both the relaxation dynamics and the protocol used to prepare the initial states. Here, this dependence is investigated using the time-delayed Newton cooling law, comparing protocols in which two samples are exposed to piecewise-constant bath temperatures before being placed in a common final bath. For protocols with at most two quenches and a common waiting time, exact conditions for the occurrence of the effect are derived. They rule out the Pontus protocol within this model and show that the synchronous two-reservoir protocol maximizes the effect magnitude within the class considered. The robustness of this optimum is then examined by allowing asynchronous quenches or an additional quench for one sample. Numerical optimization of these extensions identifies the synchronous two-reservoir protocol as the maximizing limit in the cases studied. This evidence motivates a conjecture that the same protocol remains optimal for more general bath histories, although that broader statement is not proved.
Statistical Mechanics (cond-mat.stat-mech)
17 one-column pages, 10 figures
Kagome Flat Bands from Self-Assembled Water on Non-van der Waals 2D Materials
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-11-10 20:00 EST
Tom Barnowsky, Madeleine Christie, Anastasiia Nihei, Rico Friedrich
The properties of two-dimensional (2D) materials are governed not only by their intrinsic electronic structure but also in particular by their surface chemistry and interactions with the environment. The surfaces of non-van der Waals (non-vdW) 2D materials are intrinsically reactive and may require chemical stabilization under realistic experimental conditions. Here, we perform a systematic first-principles study of water passivation of non-vdW 2D materials and demonstrate that molecular water adsorption is energetically and dynamically favored for a wide range of systems. Rather than dissociating, water molecules frequently remain intact and form adsorbed ordered surface overlayers. These overlayers can adopt a kagome lattice geometry, leading to the emergence of flat electronic bands directly at the valence-band edge. Analysis of the electronic structure reveals a strong intermolecular coupling between neighboring water lone pairs within this kagome topology, while the locked molecular orientations simultaneously produce an electrostatically frustrated surface potential. These findings establish water not only as a stabilizing agent but also as an active element for electronic structure engineering of non-vdW 2D surfaces.
Materials Science (cond-mat.mtrl-sci)
17 pages, 27 figures
Quantum Embedding from Molecular to Crystalline Environments at the Cost of a Gas-Phase Calculation
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-11-10 20:00 EST
We present a direct-space formulation and implementation of quantum density functional theory (DFT) embedding for molecular active subsystems embedded in frozen environments (hosts) of arbitrary dimensionality, from finite molecular hosts to extended systems. The host is computed once without the embedded molecule (the guest) and is represented only by its electron density fitted in an atom-centered auxiliary Gaussian basis together with its nuclear charges with the periodic electrostatics separated into an explicit near-field and a continuous fast-multipole far-field operator. The method allows the removal of host atoms from this representation to create vacancies or other voids without requiring a supercell creation. Analytic nuclear gradients are also implemented, enabling structural relaxation of the active subsystem. We demonstrate the versatility of the approach through applications to adsorbates on periodic surfaces and molecules embedded in bulk solvent environments. For CO on MgO(001), we show that DFT-in-DFT converges rapidly and reproduces the periodic interaction energy within 0.44 kJ/mol while reducing the cost by a factor of 27. Real-time time-dependent embedded DFT (RT-TDDFET) of methylenecyclopropene in periodic water is showcased to produce a ~0.6 eV solvatochromic blue shift, while strong-field propagation of CO2 on hexagonal boron nitride (hBN) yields substrate-induced effects at the cost of a gas-phase propagation. Coupling the embedding scheme to excited-state correlated wave function theory methods such as CC2 yields a solvent shift within 0.01 eV of supermolecular CC2 references, while reducing the computational cost by over 500 times.
Materials Science (cond-mat.mtrl-sci)
Discrete time crystals stabilized by bounded measurement noise
New Submission | Statistical Mechanics (cond-mat.stat-mech) | 2026-11-10 20:00 EST
Pallabi Chatterjee, Tanay Nag, Ranjan Modak
Periodically driven clean interacting systems generically heat up, which destroys discrete time-crystalline order. Here we ask whether continuous weak measurement can stabilize such order. We study a long-range interacting spin chain whose local occupation is continuously monitored. Measurements generally induce a transition from volume-law to area-law entanglement. Yet low entanglement alone is not enough: along typical quantum trajectories, the system still reaches a featureless state with no subharmonic response. In contrast, the most-probable trajectory, obtained by suppressing measurement fluctuations, shows robust period doubling. To connect these limits, we introduce a bounded-noise protocol that restricts measurement fluctuations to a finite window. Narrow windows preserve period doubling. Intermediate windows produce coexisting time-crystalline and non-time-crystalline trajectories. Over time, trajectories leave the time-crystalline group one by one, so the order is long lived but finite. Wide windows destroy the order. Our results establish bounded measurement noise, discarding the large-deviation trajectories, as a route to time-crystalline order in clean systems. They also show that the measurement-induced area-law phase is necessary, but not sufficient, for this order.
Statistical Mechanics (cond-mat.stat-mech), Quantum Physics (quant-ph)
13 pages, 11 figures
Gate-tunable supercurrent switching in a three-terminal quantum dot transistor
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2026-11-10 20:00 EST
David Novák, Kacper Wrześniewski, Filip Krizek, Wolfgang Belzig, Peter Zalom
We propose and analyze a three-terminal superconducting transistor switch in which a gate-defined quantum dot region interrupts a flux-controlled loop. The output supercurrent is switched off completely when the two loop arms couple to the dot with equal tunneling strengths and half a flux quantum threads the loop. The device then operates as a symmetric SQUID at half flux. The condition follows from a single geometric factor $ \chi$ , which reduces the three-terminal problem to an equivalent two-terminal Anderson impurity model and makes the switching mechanism independent of the Coulomb interaction, the dot level position, the total hybridization and temperature. These enter only through a prefactor and thus decide how tolerant the device is to imperfect barrier tuning. Numerical renormalization group calculations across the full coupling parameter space show that the resonance is embedded in a broad region of elevated switching ratio at intermediate hybridization $ \Gamma \approx \Delta$ , while both weaker and stronger coupling reduce it to a thin isolated line. Finite temperature smooths the underlying singlet-doublet transition and lowers the supercurrent amplitude, but affects the open and closed states comparably and leaves the switching ratio largely intact. Within a zero-bandwidth two-level model, a second dot level is shown to open a leakage channel that grows as the two levels approach in energy. Raising the output barrier and the realistic presence of inter-level Coulomb repulsion, however, suppress the leakage.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
Lattice dynamical properties and interatomic force constants of transition metal oxide perovskite superlattices
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-11-10 20:00 EST
Xiao-Lin Chen, Jin-Zhu Zhao, Philippe Ghosez
In this study, we investigate the construction of efficient model potentials for perovskite heterostructures by transferring relevant dynamic quantities from bulk systems and short-period superlattices. Through first-principles calculations, we provide a comprehensive analysis and comparison of the dynamical properties of different perovskite-based superlattice structures, including (PbTiO3 )n /(SrTiO3 )m superlattices, (ATiO3 )n /(AO) 2 superlattices, and An+1 Tin O 3n+1 Ruddlesden-Popper phases, where A can be Sr, Ba, or Pb. We demonstrate that as the thickness of these structures increases, the dynamical properties of the perovskite blocks converge rapidly towards their bulk counterparts. We discuss this convergence in terms of phonon density of states in reciprocal space and inter-atomic force constants in real space. Our findings suggest a straightforward strategy for developing transferable model potentials that accurately capture the dynamics of layered oxide compounds with progressively thicker layers.
Materials Science (cond-mat.mtrl-sci)
Deriving Tsallis Entropy from First Principles
New Submission | Statistical Mechanics (cond-mat.stat-mech) | 2026-11-10 20:00 EST
The kinetic approach for q-distribution is extended through a “bottom-up” procedure to the corresponding entropic formula. In this way, the validity of Tsallis’ formula, S_q(W) = k_B ln_q(W), is established from first principles. The resulting q-entropy is additive and the zeroth law of thermodynamics is automatically satisfied because the conventional identification beta = 1/(k_B T) remains valid. Entropy, energy, and all relevant quantities for both discrete and continuous cases are evaluated using standard (linear) averages. The “bottom-up” and “top-down” approaches yield the same q-distribution for velocities. The standard results are naturally recovered in the limit q -> 1.
Statistical Mechanics (cond-mat.stat-mech), Plasma Physics (physics.plasm-ph)
5 pages
Real Topology on Symmetry-Invariant Loops Enforces Superconducting Pairing Zeros
New Submission | Superconductivity (cond-mat.supr-con) | 2026-11-10 20:00 EST
Normal-state topology can obstruct superconducting pairing and give rise to gapless nodes in the quasiparticle spectrum. However, existing pairing-obstruction mechanisms largely rely on Fermi-surface topology or global Bloch-band topology. Here, we establish a new and general mechanism: one-dimensional (1D) real topology, defined on antiunitary-symmetry-invariant loops, enforces pairing zeros without requiring Fermi-surface or global Bloch-band topology. We derive sufficient conditions and lower bounds for pairing zeros across diverse pairing channels, for both zero and finite Cooper-pair momenta. The theorems apply to systems of arbitrary spatial dimensions without requiring the pairing bands to be globally isolated. We further show that such topologically enforced pairing zeros, if isolated, necessarily carry odd vorticity and can give rise to Bogoliubov-de Gennes nodes and zero-energy boundary modes, as demonstrated in a minimal two-orbital model. Our results reshape the understanding of how normal-state topology can obstruct the superconducting order, highlight the significant role of 1D real topology beyond single-particle band phenomena, and provide a general framework for identifying candidate materials hosting nodal superconductivity.
Superconductivity (cond-mat.supr-con), Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Strongly Correlated Electrons (cond-mat.str-el)
Revealing laser-induced modification of weak ferromagnetism through a spin-reorientation phase transition in iron borate Fe$_3$BO$_6$
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-11-10 20:00 EST
A. V. Kuzikova, S. N. Barilo, R. A. Lanovsky, A. V. Sadovnikov, R. V. Pisarev, A. M. Kalashnikova
In the iron oxide Fe$ _3$ BO$ _6$ weak ferromagnetism stems from competing contributions from two-site Dzyaloshinskii-Moriya interactions (DMI) and from on-site anisotropies at the two $ 4c$ and $ 8d$ types of nonequivalent Fe$ ^{3+}$ sites. As a result, spin reorientation (SR) transition $ \Gamma_2$ $ \rightarrow$ $ \Gamma_4$ in Fe$ _3$ BO$ _6$ uniquely comprises 90$ ^\circ$ spin switching and a 35% change of weak ferromagnetic moment. We explore ultrafast kinetics of such a transition as a proxy for weak ferromagnetism contributions modified by femtosecond laser pulses. Using magneto-optical pump-probe technique we reveal that the SR transition is triggered by an abrupt decrease of the weak ferromagnetic moment in the $ \Gamma_2$ phase, and relate it to the laser-induced modification of the DMI and anisotropy contributions to the spin canting. By tuning the pump pulse phonon energy between different optical absorption ranges, we show that laser-driven impact on spin canting possesses a nonthermal character and is achieved through the charge-transfer transitions $ 2p\rightarrow3d$ within Fe$ ^{3+}$ O$ ^{2-}_6$ octahedra rather than by localized $ 3d\rightarrow3d$ transitions at Fe$ ^{3+}$ . The decreased weak ferromagnetic moment controls the threshold and the latency of the SR transition, as well as a final state. The latter is achieved via the precessional switching to the $ \Gamma_4$ phase activated by the laser-induced heating. Final state is found to be a coexistence of $ \Gamma_4$ and $ \Gamma_2$ phase with modified spin canting persisting even at hundreds of picoseconds.
Materials Science (cond-mat.mtrl-sci), Strongly Correlated Electrons (cond-mat.str-el)
16 pages, 9 figures
Giant Diffusion at Flocking Transitions
New Submission | Statistical Mechanics (cond-mat.stat-mech) | 2026-11-10 20:00 EST
Sohini Chatterjee, Wasim Akram, Subir K. Das
We simulate dynamics in two-dimensional aligning active-matter models exhibiting order-disorder transitions in the velocity field. Analysis reveals that the single-particle diffusivity, $ D_s$ , exhibits strong enhancements at criticality which we quantify via a finite-size scaling method. This dynamical behavior at nonequilibrium flocking transitions is fundamentally different from that at the criticality of equilibrium systems, where diffusivities either vanish or remain non-critical. Furthermore, $ D_s$ exhibits pronounced finite-size effects throughout the ordered phase, which also are absent in equilibrium settings. We interpret these counterintuitive transport anomalies within the framework of a flocking theory. Our results suggest that enhanced diffusion generates effective long-range interactions. This relaxes the constraints of the Mermin-Wagner theorem that otherwise prevents order-disorder transitions in two dimensions for systems possessing continuous symmetry. These results are of much experimental relevance and have important implications in formulating quantitative theories for nonequilibrium transports.
Statistical Mechanics (cond-mat.stat-mech)
10 pages, 5 figures
Scalable operating currents in amorphous W-N/FePt superconducting rectifiers
New Submission | Superconductivity (cond-mat.supr-con) | 2026-11-10 20:00 EST
S. Russo, A. Sanson, Yeonkyu Lee, Jeehoon Kim, N. Haberkorn
We demonstrate high-efficiency, field-free superconducting diode behavior in W-N/FePt bilayers fabricated entirely by sputtering at room temperature. The devices combine amorphous W-N superconducting thin films with a 48-nm-thick FePt layer exhibiting remanent stripe-domain magnetization. We used lithographically patterned microbridges to compare W-N/FePt bilayers with single-layer W-N reference films at three nominal W-N thicknesses (18, 24, and 28 nm). The bilayers exhibit superconducting transition temperatures of approximately 4.1-4.3 K. At zero applied magnetic field, the current-voltage (I-V) characteristics exhibit pronounced nonreciprocity, controlled by the orientation of the in-plane remanent FePt magnetization relative to the transport current. The diode response is maximized for perpendicular alignment, reverses polarity upon magnetization reversal, and is strongly suppressed when the magnetization is aligned with the current. This behavior is consistent with asymmetric vortex entry and motion governed by the magnetic stray fields generated near the bridge edges. At 3 K with the remanent magnetization perpendicular to the current, increasing the W-N thickness from 18 to 28 nm widens the current interval between the dissipation thresholds for opposite polarities from about 0.3 to 1.55 mA. All three bilayers exhibit diode efficiencies of approximately 75-80% in this configuration.
Superconductivity (cond-mat.supr-con), Applied Physics (physics.app-ph)
10 pages, 7 figures, 1 table. S. Russo and A. Sanson contributed equally to this work
Schottky barrier height modulation and memristive behavior in a mechanically exfoliated $MoS_2$ flake with multiple lateral electrodes
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-11-10 20:00 EST
Gabriel Caballero, Ramón Bernardo-Gavito, Mariela Menghini, Daniel Granados
Van de Waals materials possess great potential as core active materials for novel electronics, optoelectronics, and sensing applications. In particular, transition metal dichalcogenides (TMDs) and other low-dimensional materials, such as hexagonal boron nitride and binary oxides exhibit memristive behavior, making them attractive candidates as building blocks for resistive memories and neuromorphic computing devices. In this work, we investigate two-terminal lateral memristors based on mechanically exfoliated few layer $ MoS_2$ flakes. We study the influence of the Schottky barrier height (SBH) as a function of the contact area. We report different SBHs from 60 meV up to 208 meV in the same $ MoS_2$ flake and analyze the effect of the SBH in the memristive-like $ J-V_{DS}$ curves and the observed non-volatile/volatile resistance switching. Our results highlight the importance of contact engineering to obtain different memristive properties in $ MoS_2$ -based devices.
Materials Science (cond-mat.mtrl-sci), Other Condensed Matter (cond-mat.other)
To be published in Advanced Electronic Materials
Holonomy, Spectral Topology, and Detailed Balance in Classical and Open Quantum Systems
New Submission | Statistical Mechanics (cond-mat.stat-mech) | 2026-11-10 20:00 EST
Band topology and non-Hermitian spectral theory are now applied to mechanical metamaterials, chiral active fluids, stochastic networks, and open quantum systems. We give a tutorial synthesis organized by holonomy and by one question: what can the spectral data of a linear generator reveal about detailed balance? Three holonomies recur: the Berry phase of a band, the Burgers vector of a dislocation (the integrated torsion of the defect geometry), and the cycle affinity of a Markov network (the holonomy of the connection $ \ln(W_{ij}/W_{ji})$ ). We rederive the Chern numbers $ C_m=m(\mathrm{sgn},\Omega+\mathrm{sgn},\nu_o)$ of a compressible odd-viscous fluid and restate the dislocation zero-mode count of Paulose, Chen, and Vitelli as a pairing of integrated torsion with topological polarization. Our central message is that spectral topology can obstruct detailed balance but does not determine the magnitude of dissipation. Detailed balance is self-adjointness in the inner product fixed by the stationary state, so a non-real eigenvalue, an exceptional point (EP), or a nonzero point-gap winding number of a Markov generator rules it out and forces entropy production $ \sigma>0$ , with $ \sigma\ge k_B j^2/D$ for any current, whereas a real, diagonalizable spectrum does not in general certify it. In the Hatano-Nelson ring, which is normal yet has complex spectrum, $ \sigma$ sweeps $ (0,\infty)$ at fixed winding number. EPs need a separate assessment of the dynamics: with generalized detailed balance including time-reversal parity, an EP is compatible with equilibrium only through time-reversal-odd dynamics, as at critical damping of a Langevin oscillator, whereas an EP of a system with only even variables, such as an odd elastic medium, certifies a nonequilibrium steady state; in both cases $ \sigma$ is analytic across the EP. We propose benchtop tests for each statement.
Statistical Mechanics (cond-mat.stat-mech), Soft Condensed Matter (cond-mat.soft), Quantum Physics (quant-ph)
16 pages, 3 figures, 2 tables. Verification scripts (Wolfram Language and Python) are included as ancillary files
Topological states in fractals through a self-similar tensor network encoding
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2026-11-10 20:00 EST
Zebedeus F. Osseweijer, Jagoda Malag, Jose L. Lado, Tiago V. C. Antão, Anouar Moustaj
Tensor network methods have been instrumental in addressing exponentially large many-body problems. Most recently, these techniques have also been applied to single-particle tight-binding Hamiltonians, allowing observables to be evaluated on exponentially large lattices. Here, we show that the scale-separated nature of these methods allows for a natural encoding of self-similar structures, such as the Sierpiński gasket, a scale-invariant fractal with Hausdorff dimension $ \log 3/\log 2 \approx 1.58$ , yielding an exact and compact representation of Hamiltonians on such lattices. Using this encoding, we study a Chern insulator, the flux kagome model, confined to this fractal geometry, and develop methods to investigate its topological states within a tensor network framework. This allows us to reach much higher fractal generations than would otherwise be possible with dense-matrix methods, resolving the density of states of a deep fractal with over 100 million sites. Furthermore, the larger structures allow us to resolve topology in smaller gaps, suggesting that these methods could be instrumental in understanding the interplay between topology and non-integer dimensionality.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Quantum Physics (quant-ph)
10 pages, 4 figures
Memory in biological Lévy walks from the dynamic-entropy formalism
New Submission | Statistical Mechanics (cond-mat.stat-mech) | 2026-11-10 20:00 EST
Lévy walks are recognized by the histogram of their flight lengths, while the renewal hypothesis on which the textbook model rests, that every flight is drawn afresh, is seldom tested. We test it with the dynamic-entropy formalism. Maximizing the causal entropy of a sequence of logarithmic flight lengths at fixed lagged correlations yields a chain of continuous spins on a compact interval, whose depth, selected by the data, tells a renewal walker from a Markovian one and from one with a longer memory. With one lag the chain is exactly solvable. A duality that exchanges long and short flights locates a first-order condensation of the flights at the upper cutoff, with the logarithmic range of the flights in the role of system size, and a positive memory makes the histogram heavier-tailed than the rule that generates each flight. For groups, the same construction separates the memory of each individual from delayed interactions and from drives common to all units, which an analysis of the group average confounds, and it gives the collective speed a critical point. On open data, renewal is rejected in seven of ten conditions of Drosophila larvae and in every termite, whose memory reaches a few flights back and lowers the exponent of the histogram by more than half a unit below that of the one-step rule. Wild baboons align with where their nearest neighbors, those ahead above all, were heading 10 to 30 s earlier, and homing pigeons are coupled across their small flocks. Zebrafish T cells, a negative control, remember their own speed, but no delayed coupling between the speeds of different cells survives the controls.
Statistical Mechanics (cond-mat.stat-mech), Biological Physics (physics.bio-ph)
21 pages, 9 figures. Code available at this https URL
Direct imaging of vortex lattices across fractional fillings in two-dimensional Josephson junction arrays
New Submission | Superconductivity (cond-mat.supr-con) | 2026-11-10 20:00 EST
Cequn Li, Austin R. Kaczmarek, Omri Lesser, Maciej W. Olszewski, Katja C. Nowack
Josephson junction arrays are predicted to host a rich sequence of commensurate vortex lattices. However, direct imaging of these configurations remains limited, while transport measurements cannot resolve the underlying vortex arrangements or how order breaks down. Using scanning superconducting quantum interference device (SQUID) microscopy, we resolve individual vortices and directly image this long-predicted hierarchy spanning filling factors $ f$ = 1/8 to 1/2 in two-dimensional Au-Nb Josephson junction arrays, including several states with no discernible transport signatures. At $ f$ = 1/4, two structurally distinct vortex orders with 4$ \times$ 4 and 2$ \times$ 4 unit cells coexist, consistent with their energetic degeneracy in the frustrated XY model. Away from commensurate filling, we resolve defect structures tied to the underlying vortex-lattice order: the $ f$ = 1/2 checkerboard retains its order around isolated excess vortices and vacancies, whereas the $ f$ = 1/3 staircase fragments into domains separated by domain walls. These results reveal how frustration, competing configurations, and defects shape the spatial coherence of commensurate vortex order in engineered superconducting lattices.
Superconductivity (cond-mat.supr-con), Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
7 pages, 4 figures, with Supplemental Material. Comments are welcome
Resolving the backbone of multiscale interactions through mutual information rates
New Submission | Statistical Mechanics (cond-mat.stat-mech) | 2026-11-10 20:00 EST
Alberto Raiola, Giorgio Nicoletti, Daniel Maria Busiello
Natural systems are often composed of processes evolving on multiple timescales and coupled through complex interaction networks. Inferring such networks is especially challenging when timescales are widely separated, since resolving the fastest processes while accurately sampling the slowest ones is generally prohibitive. In this work, we propose a framework to reconstruct a multiscale interaction tree by combining a rescaled version of the mutual information rate, its conditional counterpart, and the ordering of timescales. We derive an exact theory for stationary Gaussian processes, finding that these measures identify directly connected processes, with the asymptotic mutual information rate distinguishing fast-to-slow from slow-to-fast couplings. We show that this reconstruction can be achieved from the spectral matrix and illustrate its robustness to finite trajectory lengths, moderate timescale separation, and weak nonlinearities. Our work paves the way for exploiting the presence of multiple timescales in real-world systems as a source of structural identifiability rather than an obstacle to network inference.
Statistical Mechanics (cond-mat.stat-mech)
Quotient Index for Symmetry-Protected Zeros and the Tenfold Way in Mackey’s Construction of Super Corepresentations
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2026-11-10 20:00 EST
Symmetries that anticommute with a Hamiltonian can protect zero modes by obstructing their removal through symmetry-compatible perturbations. We formulate this obstruction as a quotient of the additive group of symmetry representations by the image of the map that forgets a compatible representation grading. To compute the quotient, we use Mackey’s method to construct all irreducible super corepresentations of finite graded symmetry groups, allowing antiunitary operations and projective factor systems. Starting from the unitary Hamiltonian-preserving normal subgroup, this construction yields two complex and ten real structural types, characterized by residual Altland–Zirnbauer symmetry algebras. The residual and induced graded modules have isomorphic graded commutants, and their represented symmetry algebras share a graded Morita class that is super opposite to that of the commutant. We derive character criteria that identify these types. Exhaustive enumeration of the restriction relations gives independent sector contributions $ 0$ , $ Z$ , or $ Z_2$ , with only integer factors in the purely unitary case. In the finite semisimple setting, the complete index vanishes if and only if all zero modes can be lifted by a symmetry-compatible perturbation. Applications to one-dimensional end states and interpolation cylinders of disordered boundary Dirac theories recover protected multiplet counts and connect the quotient to bulk topology and sigma-model topological terms using bulk–boundary correspondence, texture-index theorems, and fermion-phase calculations.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
36 pages
Quantum benchmarks for magnetic energies and transition temperatures
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-11-10 20:00 EST
Mojtaba Alaei, Ilia Mikhailov, Alireza Qaiumzadeh, Artem Oganov
Predicting magnetic ordering temperatures requires accurate exchange interactions and an appropriate treatment of spin thermodynamics. Here we assess these requirements through complementary quantum Monte Carlo benchmarks. For five insulating antiferromagnets, we compare ferromagnetic-antiferromagnetic energy differences from diffusion Monte Carlo (DMC) and density functional theory with references reconstructed from inelastic neutron scattering (INS) exchanges. DMC underestimates these references but achieves a mean absolute error comparable to the best-performing functionals tested. Separately, we directly test the previously proposed (S+1)/S rescaling of classical Monte Carlo temperatures against quantum stochastic series expansion simulations for 17 compounds using corresponding INS-derived Heisenberg Hamiltonians. Rescaling reduces the mean absolute classical-quantum temperature difference from 81.7 to 8.2 K, with a mean absolute percentage difference of 5.9 %. These results establish a direct quantum benchmark for the rescaling within the tested models and emphasize that improvements in electronic magnetic energy scales should be accompanied by attention to quantum spin thermodynamics.
Materials Science (cond-mat.mtrl-sci)
12 pages, 6 figures
Contrasting one- and two-particle excitations in cuprate strange metals
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2026-11-10 20:00 EST
Falk Röder. Roman Schuster, Martin Knupfer, Axel Lubk, Jörg Fink
In unconventional superconductivity, the pairing mechanism remains one of the central unresolved problems in solid-state physics. Moreover, the normal state shows strong deviations from conventional Fermi-liquid behavior, most notably a scattering rate that is linear in energy and temperature. Here we study the momentum dependence of the energy and damping of collective excitations in optimally doped cuprates in the normal state. In particular, we analyze existing Electron Energy Loss Spectroscopy (EELS) data of Bi2Sr2CaCu2O8 [Phys. Rev. B 44, 7155 (1991)] and new analogous optical plasmon data of Bi2Sr2Ca2Cu3O10. Furthermore, we reanalyze similar Resonant Inelastic Xray Scattering (RIXS) acoustic plasmon data [Phys. Rev. R 6, 043184 (2024)] of La1.84Sr0.16CuO4 and La1.84Ce0.16CuO4. We contrast these two-particle excitation results with one-particle excitations measured by Angle-Resolved Photoemission Spectroscopy (ARPES). Most of the plasmon behavior can be described well by combined self-energies of a hole and an electron. The dispersion of optical plasmons at high energy is only weakly determined by correlation effects, indicating resilient quasiparticles. The damping of the optical plasmons at low energy, however, is strongly influenced by the reduced scattering rates described in the marginal Fermi liquid model for “strange-metal” behavior. In addition, the same model describes the linear-in-energy damping of acoustic plasmons. Contrary to some theoretical predictions, we see no overdamped optical plasmons below the classical Lindhard critical wave vector.
Strongly Correlated Electrons (cond-mat.str-el), Superconductivity (cond-mat.supr-con)
Nonlinear integral equations for stress-controlled rheology: Collocation methods for Volterra equations with functional kernels
New Submission | Soft Condensed Matter (cond-mat.soft) | 2026-11-10 20:00 EST
Stephan Domann, Thomas Voigtmann
We present a class of numerical collocation methods to solve a typical inverse problem that arises in the stress-controlled rheology of complex fluids with pronounced history-dependent response, where the relation between stress and flow rate is given by an integral constitutive equation as the material law. We demonstrate the method by calculating the creep response of a nontrivial model of a shear-thinning viscoelastic fluid where a stress overshoot in rate-controlled startup flow leads to ``sudden yielding’’ in stress-controlled creep. Our method is able to address the long-time behavior of the model, distinguishing the amorphous solid from the stress-induced yielded fluid, and from the in-between case of infinite deformation that never achieves a stationary shear rate (proper creep). To this end, we implement a method with flexible time-stepping, and prove uniqueness of the solution and convergence of the methods for a broad class of highly viscoelastic non-linear rheological laws in integral form.
Soft Condensed Matter (cond-mat.soft), Numerical Analysis (math.NA)
45 pages, 5 figures, for an implementation that also has been used to create the figures see this https URL
Spin-valve effect through electrostatic coupling
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2026-11-10 20:00 EST
Jan Phillips, Joaquín Fernández-Rossier
We propose a spin-valve effect in which an insulating magnetic van der Waals multilayer controls the conductance of an adjacent non-magnetic conductor by electrostatic coupling, without transport-electrons entering the magnetic layers. The coupling is induced by the variations of the electronic structure when the relative orientation of the magnetization of adjacent monolayers changes from parallel to antiparallel, modifying both the dielectric constant and band alignment. We consider two types of coupling and device concepts: charge transfer to a graphene monolayer and capacitive coupling in a single-electron transistor. We use density functional calculations to assess the magnitude of the effect in various materials, including CrI$ _3$ , CrBr$ _3$ , CrCl$ _3$ and NiBr$ _2$ . We predict magnetoresistance ratios in the range of 1.14-1.20 for the charge-transfer device and up to $ 10^3$ in the single-electron transistor.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Applied Physics (physics.app-ph)
11 pages, 6 figures
Harmonic origin of local symmetry breaking in PbTe revealed using machine-learned potentials
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-11-10 20:00 EST
Seongjoo Jung, Nicola A. Spaldin
We use machine-learned interatomic potentials combined with higher-order interatomic force constant models to show that finite-range polar correlations in PbTe are driven by long-range harmonic interactions rather than lattice anharmonicity. Our molecular dynamics simulations reveal a spatial polar correlation range exceeding 50 Å at low temperatures and decreasing with increasing temperature. Selective interatomic force constant mapping demonstrates that crystal anharmonicity usually associated with the formation of polar nanoregions suppresses polar correlations. Instead, long-range harmonic interactions extending to 13 Å are necessary to reproduce the spatial coherence of local dipoles. In reciprocal space, these extended harmonic interactions correspond to high curvature of the transverse optical (TO) phonon branch at the $ \Gamma$ point. Comparison with isostructural NaCl connects these extended interactions to local underscreening of predominantly Coulombic forces. Our results provide a key microscopic description of finite-range polar correlations and a framework for understanding local symmetry breaking in centrosymmetric materials.
Materials Science (cond-mat.mtrl-sci)
GibbScope: interactive calculation and visualization of phase diagrams in the browser
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-11-10 20:00 EST
Ramya Ramachandran, Zhuocheng Huang, Jiayang Wang, Marat I. Latypov
Phase diagrams are a constant work in progress as Gibbs-energy models are fitted, revised, and disputed in the light of an endless stream of experimental and computational data. Yet, phase diagrams are still largely communicated as static figures, in much the same way as a century ago. We present GibbScope, a web-based framework for interactive calculation and visualization of binary phase diagrams. Written in Rust and compiled to WebAssembly, the new CALPHAD engine recomputes a complete phase diagram in the browser in a fraction of a second with zero installation on the user or server side. The high speed allows new ways of interacting with phase diagrams and underlying assessments. Validation against well-established CALPHAD software shows agreement to within 0.01 K for invariant temperatures and within 1e-6 for tie-line compositions for most databases. GibbScope offers interactive CALPHAD parameter adjustments, overlays of different assessments and point-by-point misfit to experimental data, which makes the diagram a live, working object. In addition, GibbScope provides convenient access to 2745 thermodynamic databases from the SGTE collection (Hallstedt, 2025) and their live adjustment. For over 1200 of these databases, all phases are modeled in full with the current implementation.
Materials Science (cond-mat.mtrl-sci)
Web application is accessible at this https URL
Compensation Domain Walls in Ferrimagnets as Spin-Torque Oscillator Candidates
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2026-11-10 20:00 EST
Matteo Fettizio, Can Onur Avci
Spin-torque nano-oscillators are promising nanoscale microwave sources, yet their performance is often limited by narrow operational ranges and sensitivity to device parameters. Here, we numerically investigate the dynamics of compensation domain walls in ferrimagnetic systems driven by spin-transfer torque as a microwave source candidate. These walls arise in structures with adjacent regions of different compensation character, where the competition between exchange and Zeeman energies under an applied magnetic field stabilizes a distinct magnetic texture. We demonstrate steady current-driven rotation of compensation domain walls over a broad range of current densities within the model. To elucidate the underlying mechanism, we develop a collective-coordinate model and derive an analytical expression for the oscillation frequency, which quantitatively reproduces the dependence on current and magnetic field observed in micromagnetic simulations. Our results identify compensation domain walls as a candidate platform for tunable spin-torque nano-oscillators with intrinsic field-induced confinement.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Other Condensed Matter (cond-mat.other)
A Hierarchy of Fast and Strong Signatures for Vertex Orbits
New Submission | Statistical Mechanics (cond-mat.stat-mech) | 2026-11-10 20:00 EST
Joe Germany, Mohamad Al Sayed, Rana Dbouk, Amer E. Mouawad, Sara Najem
The defining features of a physical system are its symmetries and its invariants. For a network, the symmetries are the automorphisms, and the invariants are the vertex orbits they define. Two vertices of a graph may appear structurally indistinguishable without being interchangeable under any graph automorphism. Distinguishing apparent similarity from genuine symmetry lies at the heart of the vertex-orbit partition problem. In this work, we develop a hierarchy of increasingly expressive, automorphism-invariant signatures that draw on the spectral properties of the graph Laplacian and the Dirac operator to reveal subtle structural differences. Guided by a sequence of counterexamples, we progressively strengthen these signatures, ultimately incorporating probing techniques, which are temporary structural perturbations, that expose the hidden distinctions in the original unperturbed graph. We evaluate our approach across diverse benchmark families, recovering exact orbit partitions in challenging instances, including graphs that resist low-dimensional Weisfeiler–Leman refinement. We also examine the computational and numerical limitations of our constructions, distinguishing empirical success from theoretical completeness. Our findings highlight the potential of spectral and probing-based methods for uncovering the structural distinctions that define vertex orbit.
Statistical Mechanics (cond-mat.stat-mech), Computational Physics (physics.comp-ph)
Higher tensor network states in two spatial dimensions: fundamental theorem for open boundary conditions
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2026-11-10 20:00 EST
We introduce a class of two-dimensional tensor network states obtained by categorifying matrix product states. This procedure leads us to consider bond spaces provided by a 2-vector space associated with the 2-cells of the underlying lattice. Tensor network representations are then defined as module categories over the free monoidal category on a monoidal signature encoding the lattice geometry. We prove a fundamental theorem stating that two representations generating the same states with suitable open boundary conditions are equivalent as module categories. Finally, we introduce a notion of 2-injectivity, a categorified analogue of the injectivity condition for matrix product states.
Strongly Correlated Electrons (cond-mat.str-el), Mathematical Physics (math-ph), Quantum Physics (quant-ph)
Ground-state phase diagram of the spin-1/2 Heisenberg zigzag ladder with anisotropic $Γ$ term revisited
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2026-11-10 20:00 EST
Toshiya Hikihara, Nobuya Maeshima, Kouichi Okunishi
We study the spin-1/2 Heisenberg antiferromagnet with an anisotropic $ \Gamma$ term on a zigzag ladder, which can be exactly mapped to the spin-1/2 XYZ zigzag ladder by a spin rotation. This model has recently attracted considerable interest as an effective model for the quasi-one-dimensional magnetic semiconductor YbCuS$ _2$ . For the model, the ground-state phase diagram was previously proposed by Saito and Hotta [Phys. Rev. Lett. 132, 166701 (2024); Phys. Rev. B 110, 024409 (2024)]. We systematically reexamine the phase diagram through complementary numerical and analytical approaches, including exact diagonalization, the density-matrix renormalization group method, and low-energy effective theories. We thereby demonstrate that when the anisotropic $ \Gamma$ term is present, the model exhibits the Néel, dimer, ferromagnetic, and double-Néel phases, all of which have a finite excitation gap. The gapless Tomonaga-Luttinger-liquid (TLL) phase appears only in the isotropic case where the $ \Gamma$ term is absent. We also confirm that the transitions between the Néel and dimer phases and between the Néel and ferromagnetic phases are continuous transitions governed by Gaussian criticality with central charge $ c=1$ . The TLL parameter characterizing the critical states at the Gaussian transitions is estimated numerically.
Strongly Correlated Electrons (cond-mat.str-el)
13 pages, 12 figures
Renewal Bias in Parallel Simulations of Absorbing Processes
New Submission | Statistical Mechanics (cond-mat.stat-mech) | 2026-11-10 20:00 EST
Sandro M. Reia, José F. Fontanari
Asynchronous parallel simulations of stochastic processes with absorbing states can exhibit systematic sampling bias when trajectory durations depend on their eventual absorbing outcomes. Workers that continuously restart upon absorption preferentially record rapidly terminating trajectories within a fixed computational budget, distorting the observed ensemble statistics. We investigate this effect using a minimal renewal model with two absorbing states and state-dependent exponential durations. Renewal theory yields exact expressions for the expected number and composition of completed trajectories, showing that the resulting bias decreases algebraically with execution time but persists as the number of parallel workers increases at fixed budget. We compare continuous sampling with First-Trajectory Filtering, which retains only the initial trajectory attempted by each worker. Although finite execution deadlines introduce residual censoring bias, this bias decreases exponentially with the computational budget. An analytical mean-squared error calculation reveals budget-dependent crossover worker allocations beyond which First-Trajectory Filtering becomes more accurate despite collecting fewer trajectories. We also examine the limitations of statistical inference under severe censoring when the absorbing-state probabilities and characteristic durations are unknown. Finally, simulations of the Axelrod model near its nonequilibrium transition demonstrate the preferential sampling of rapidly absorbing fragmented configurations, illustrating the relevance of the renewal mechanism in a spatially interacting system. Our results show that increasing computational throughput does not necessarily improve statistical accuracy and highlight the importance of accounting for trajectory-duration heterogeneity in parallel simulations of absorbing processes.
Statistical Mechanics (cond-mat.stat-mech), Computational Physics (physics.comp-ph)
Spin Shuttling Through Quantum-Dot Based Chiral Molecular Bridges: Gauge Constraints, Holonomy, and Quantum Gates
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2026-11-10 20:00 EST
Amitoj S. Miglani (1), Rajdeep R. Dwivedi (2), Balsant S. Tiwari (3), Vishvendra S. Poonia (2) ((1) Department of Physics, Indian Institute of Technology Roorkee, India (2) Department of Electronics and Communication Engineering, Indian Institute of Technology Roorkee, India (3) University of Birmingham, United Kingdom)
Chiral molecular bridges between silicon quantum dots can provide novel two-qubit entangling resources via the chirality-induced spin-selectivity (CISS) effect. We evaluate this using Makhlin invariants. Modeling a phase-coherent bridge as an $ \mathrm{SU}(2)$ -valued hopping between two spins, a Schrieffer-Wolff reduction yields a twisted exchange interaction $ J \mathbf{S}_1 \cdot \mathbf{R} \mathbf{S}_2$ , whose Dzyaloshinskii-Moriya and symmetric anisotropic parts are fixed by a single bridge angle $ \alpha$ . Using the Kaplan-Shekhtman-Entin-Wohlman-Aharony (KSEA) gauge argument, we prove this interaction is locally equivalent to isotropic exchange; thus, a single chiral bond does not constitute a new entangling class. Breaking this gauge symmetry reveals genuine chiral utility: chiral exchange converts a uniform transverse field into a synthetic gradient, bringing the two-qubit propagator within $ 7\times10^{-4}$ of the CNOT class in invariant space 4.7 times faster than an equivalent orthogonal gradient. Shuttling a spin through bridges with non-collinear axes implements a non-Abelian $ \mathrm{SU}(2)$ holonomy, yielding rotationally non-reciprocal transport and closed-loop geometric gates that suppress dynamical-phase noise to second order. To address the unsettled microscopic origin of CISS, we introduce a unified transport channel combining coherent rotation, a direction-reversing spin filter, and pointer-basis dephasing. This model obeys an exact $ \tanh$ composition law for pumped polarization and a closed-form transverse decay law, yielding four observables that experimentally over-determine the bridge’s coherent fraction $ F_c$ . Finally, we quantify silicon-specific hardware constraints, establishing the Landau-Zener valley-adiabaticity window ($ E_v \geq 2.1\sqrt{\hbar v}$ ) and charge-noise limit ($ \sigma_J/J \leq 3%$ ) required for $ 99%$ gate fidelity.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Quantum Physics (quant-ph)
Out-of-plane interference effects in the angle-resolved photoemission of epitaxial graphene
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-11-10 20:00 EST
E. Favorite, P. Krüger, Ph. Rosenzweig, R. Joshi, S. Williams, B. Matta, K. Küster, M. Hashimoto, U. Starke, H. Nakamura
The epitaxial growth of monolayer graphene by Si sublimation of 6H-SiC(0001) is one of the most effective ways of producing large-scale monocrystalline graphene samples of high quality. However, graphene is left interacting with a reconstructed carbon buffer layer known as zerolayer graphene (ZLG) and the SiC substrate underneath. Beyond the mere creation of Dirac cone replicas, the effect of this interaction on photoemission measurements is poorly understood. We utilized synchrotron radiation for photon-energy-dependent angle-resolved photoemission spectroscopy (ARPES) to investigate the complex final-state interactions of photoelectrons within the heterostructure of monolayer graphene, ZLG, and SiC. We identify multiple resonances in the photoemission intensity of the Dirac cone as a function of photon energy that originate from interlayer interference, confirmed with a multiple scattering model. We also demonstrate for the first time that the relative intensity of the replica bands induced by the $ (6\sqrt{3} \times 6\sqrt{3})\text{R}30^\circ$ reconstruction scales with the electron kinetic energy. Finally, we resolved four nondispersing electronic states, which originate from the ZLG. Our findings show that the three-dimensional (3D) structure of SiC and ZLG manifests itself in the photoemission from two-dimensional (2D) epitaxial graphene. By revealing how 3D substrate architecture dictates the photoemission of a 2D layer, this work establishes a crucial framework for investigating the electronic structure of complex heterostructures via ARPES.
Materials Science (cond-mat.mtrl-sci)
Catalysis-induced phase separation of enzymes via diffusivity contrast
New Submission | Soft Condensed Matter (cond-mat.soft) | 2026-11-10 20:00 EST
Marie Jardat, Jacques Fries, Vincent Dahirel, Jaime Agudo-Canalejo, Pierre Illien
Catalysis can drive phase separation by coupling local chemical composition to molecular transport, even in the absence of attractive interactions. Here, we demonstrate such catalysis-induced phase separation in a microscopic particle-based model of enzymes catalyzing the interconversion of substrate and product molecules with different diffusivities. We derive an analytical instability criterion in the dilute limit, showing that a homogeneous mixture becomes unstable when the nonequilibrium chemical drive and the diffusivity contrast are sufficiently large, and the substrate and product concentration exceeds a threshold set by the enzyme volume. Brownian-dynamics simulations confirm the predicted instability and reveal macroscopic coexistence of enzyme-rich and enzyme-poor phases, including in regimes where equilibrium depletion interactions cannot account for demixing. Finally, we show that, upon eliminating the fast chemical degrees of freedom, the reactive ternary mixture maps onto an effective binary mixture nonreciprocal interactions. Our results establish an explicit microscopic mechanism for catalysis-induced phase separation and connect chemically driven phase separation to the physics of motility-regulated and nonreciprocal matter.
Soft Condensed Matter (cond-mat.soft), Biological Physics (physics.bio-ph), Chemical Physics (physics.chem-ph)
Finite temperature and pressure structural relaxations including zero-point motion and anharmonicity
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-11-10 20:00 EST
Henricus R.A. ten Eikelder, Florian Knoop, Florian Trybel
At finite temperature and pressure, the equilibrium structure of a crystal minimizes the Gibbs free energy rather than the static Born-Oppenheimer energy. We present WARP (Wyckoff-constrained Anharmonic Relaxations at Pressure and temperature), a symmetry-constrained, variable-cell relaxation based on the stochastic temperature-dependent effective potential method, including anharmonicity and zero-point motion. Every position update is projected onto Wyckoff positions and every strain onto symmetric strains, so a relaxation can raise the symmetry but never lower it. For aluminum, the thermal expansion follows measurements at cryogenic temperatures, including the quantum plateau below 50 K. For lanthanum hydrides at megabar pressures, equations of state agree with phonon-based and path-integral calculations, and LaH$ _{10}$ relaxes from its rhombohedral static minimum to the observed cubic phase, also with a machine-learned potential fine-tuned on 150 supercells. For brucite, Mg(OD)$ _2$ , lattice parameters, bond distances and thermal expansion agree with neutron diffraction, and the O-D isotope effect is captured.
Materials Science (cond-mat.mtrl-sci), Other Condensed Matter (cond-mat.other), Computational Physics (physics.comp-ph), Geophysics (physics.geo-ph), Space Physics (physics.space-ph)
Universal semiclassical drift velocity of magnetic edge channels
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2026-11-10 20:00 EST
Ekaterina R. Sleptsova, Alexey A. Sokolik
Magnetic edge channels, arising at the edge of a two-dimensional electron gas in a magnetic field, are topologically protected and propagate unidirectionally along the edge. Their group velocities at the Fermi level, being averaged harmonically, result in drift velocity, which is related to the edge density of states, quantum capacitance, and the velocity of edge magnetoplasmons. Using semiclassical quantization of electron skipping orbits, we show that the drift velocity equals 1/2 of the electron Fermi velocity in the limit of a large number of edge channels crossing the Fermi level. This result, being universal for a hard edge and for isotropic dispersion, is checked numerically for massive electrons and for massless electrons in graphene. The drift velocity at smooth electrostatically defined edges lacks such universality. In the case of anisotropic dispersion, the semiclassical drift velocity at the hard edge reduces to a coordinate-velocity correlation along the cyclotron orbit.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Quantum Physics (quant-ph)
9 pages, 4 figures
Ambient-pressure superconductivity in bulk single crystals of La$_5$Ni$4$O${10}$
New Submission | Superconductivity (cond-mat.supr-con) | 2026-11-10 20:00 EST
R. Zhang, P. Reiss, A. Krajewska, M. Isobe, H. Takagi, P. Puphal
Superconductivity in the Ruddlesden-Popper (RP) nickelates has so far been confined either to multilayer compounds under high pressure or to square-planar infinite-layer-type films stabilized by epitaxial strain. Here we report the high-pressure high-temperature (HPHT) growth of bulk single crystals of the quadruple-layer RP nickelate La$ _5$ Ni$ _4$ O$ _{13}$ ($ n=4$ ) and reproduce the quintuple-layer La$ _6$ Ni$ _5$ O$ _{16}$ ($ n=5$ ) synthesis, two members of the series that had previously been accessible only as thin films. Topotactic reduction of La$ _5$ Ni$ _4$ O$ _{13}$ single crystals with CaH$ _2$ yields the square-planar phase La$ _5$ Ni$ 4$ O$ {10}$ , which we show to be a bulk, ambient-pressure superconductor with $ T\mathrm{c}^\mathrm{onset} \approx 18,\mathrm{K}$ , a shielding fraction above 60%, and a specific-heat jump that confirms a bulk pairing transition. All crystals show besides superconductivity a coexistence with a density-wave or metal-insulator transition. The upper critical field shows a small anisotropy, $ \gamma \approx 2.4$ , which remains finite as $ T \to T_c$ , indicating three-dimensional superconductivity with substantial coupling between the four-layer blocks. These results identify the square-planar nickelates $ R{n+1}$ Ni$ _n$ O$ _{2n+2}$ as a bulk platform in which the layer number alone tunes the nickel valence into the superconducting regime, without chemical substitution, pressure, or epitaxial constraint.
Superconductivity (cond-mat.supr-con), Strongly Correlated Electrons (cond-mat.str-el)
High Pressure Material Phase Identification with Gaussian Kernel Neural Networks
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-11-10 20:00 EST
Cameron Ryan, Yasantha Pasindu Hetti Kankanamalage, Shuai Zhang
Phase identification is a computational task involving the classification of material structure using the positions of atoms. Using data from Molecular Dynamics (MD) simulations, our task is to identify the material phase of a set of atoms, based on how the simulations predict their positioning relative to each other. By leveraging existing research on mechanistic neural network theory, particularly Neural Tangent Kernels (NTK), we develop a new and efficient method for classifying simulated material samples. Our method involves defining a set of “atom detectors” that are given positions around the origin in cartesian coordinates. The sum of Gaussians centered at each atom is calculated at each atom detector, and is used as the input to a neural network. We present theoretical and experimental evidence to show that this method is highly effective and efficient at the task. Our method obtains better or similar accuracy scores to commonly used methods while having a major computational speedup.
Materials Science (cond-mat.mtrl-sci)
Enhancing valley splitting in Si/SiGe Wiggle Well quantum dots through integrated stressor-gate architectures
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2026-11-10 20:00 EST
E. S. Joseph, Talise Oh, D. E. Savage, D. S. Stone, DeAnna Campbell, Benjamin D. Woods, Mark Friesen, M. A. Eriksson
Engineering large and reproducible valley splittings is essential for the scalable operation of silicon spin qubits. In Si/SiGe quantum dot devices, valley splitting arises predominantly from atomic-scale disorder and is therefore inherently random, motivating approaches that introduce a large deterministic contribution. Strain-assisted Wiggle Wells provide a route to deterministic valley splitting by combining an oscillatory Ge concentration in the Si well with shear strain; however, generating the required strain in a manner compatible with large-scale architectures remains a challenge. Here, we propose patterned stressed thin films as a scalable approach for generating shear strain in the quantum well of Si/SiGe quantum dot devices. Finite-element simulations show that compressively stressed TiN films can generate shear strains exceeding 0.1% at the quantum well, sufficient for deterministic valley splittings of hundreds of $ \mu \text{eV}$ in strain-assisted Wiggle Wells. We show that this strain can extend across multiple quantum dots and is maintained in realistic gate geometries, providing a fabrication-compatible approach for scaling deterministic valley splitting to quantum dot arrays.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Quantum Physics (quant-ph)
13 pages, 7 figures
Tetragonal-to-orthorhombic distortion in CeRh${2}$As${2}$
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2026-11-10 20:00 EST
P. Khanenko (1, 2), M. Pfeiffer (2, 3), K. Semeniuk (2, 4), E. Hassinger (2, 4), P. Thalmeier (2), J. Wosnitza (1, 3), A. M. León (5), G. Zwicknagl (6, 2), C. Geibel (2), S. Khim (2), M. Brando (2) ((1) Hochfeld-Magnetlabor Dresden (HLD-EMFL) and Würzburg-Dresden Cluster of Excellence ctd.qmat, Helmholtz-Zentrum Dresden-Rossendorf, Dresden, Germany, (2) Max Planck Institute for Chemical Physics of Solids, Dresden, Germany, (3) Institute for Solid State and Materials Physics, Technical University Dresden, Dresden, Germany, (4) Institute for Quantum Materials and Technologies, Karlsruhe Institute of Technology, Karlsruhe, Germany, (5) Departamento de Física, Facultad de Ciencias, Universidad de Chile, Santiago, Chile, (6) Institute for Mathematical Physics, Technische Universität Braunschweig, Braunschweig, Germany)
CeRh$ {2}$ As$ {2}$ is best known for its two superconducting phases, which are observed when a magnetic field is applied along the $ c$ axis of its tetragonal unit cell. The emergence of superconductivity, with $ T{c} \approx 0.31$ K, is preceded by an ordered state (phase I), with an ordering temperature $ T{0} \approx 0.46$ K. The precise nature of the order parameter in phase I is still unknown, although evidence of dipolar ordering was found. To investigate a possible symmetry breaking at $ T_{\textrm{0}}$ , we conducted longitudinal thermal-expansion measurements along the crystallographic [100], [010], [110], and [1$ \overline{1}$ 0] directions on a single-crystalline sample cut into an octagonal shape. Our results demonstrate the breaking of the fourfold in-plane symmetry below $ T_{\textrm{0}}$ , evidencing a small tetragonal-to-orthorhombic distortion (orthorhombicity $ \delta \sim 10^{-7}$ ). The breaking of the tetragonal symmetry at $ T_{\textrm{0}}$ might imply that the superconducting order parameter that develops within phase I cannot be multi-component. More generally, the distortion places restrictions on the possible order parameters for phase I.
Strongly Correlated Electrons (cond-mat.str-el)
8 pages 5 figures in the main paper, 4 pages, 4 figues in the supplemental material
Research Square
Polymerization of Porphyrins by Indenyl Coupling
Article | Scanning probe microscopy | 2026-11-09 19:00 EST
David Ecija, Alba Garcia-Frutos, Ana Barragán, Ana Monteiro, Tianchen Qin, Jesús Bello-García, Rubén Canales, Alberto Martínez-Bajo, Koen Lauwaet, Pablo Merino, José Ignacio Urgel, Dolores Pérez, Borja Cirera, Jose Martinez, Aurelio Gallardo, Diego Peña
Porphyrin polymers merge the photophysical, electrochemical, sensory and catalytic properties of porphyrins with the processability and robustness of polymeric materials, offering versatile and synergetic platforms for optoelectronics and catalysis. Here we report an on-surface strategy for the atomically precise polymerization of porphyrins via regioselective indenyl coupling. Deposition of an indenyl-functionalized porphyrin on Au(111) and sequential annealing drives a stepwise transformation: cyclodehydrogenation at 100 °C planarizes the precursor into π-extended porphyrins, while annealing above 125 °C triggers carbon-carbon homocoupling through five-membered moieties, forming short oligomers. Heating to 150 °C promotes chain growth into one-dimensional polymers with a 1.1 eV bandgap and extended π delocalization, alongside a minor fraction of cyclic trimers featuring a 1.1 eV HOMO-LUMO gap with both local and global aromaticity. The methodology also proceeds for Co-metallated precursors, confirming that indenyl coupling is also compatible for metalloporphyrins, establishing a general route to design π-extended porphyrin polymers.
Research Square:rs-11614027 (2026)
Posted on Research Square and Under Review at Nature Portfolio
Physical sciences/Chemistry/Surface chemistry/Scanning probe microscopy, Physical sciences/Chemistry/Surface chemistry/Surface spectroscopy, Physical sciences/Chemistry/Polymer chemistry/Conjugated polymers, Physical sciences/Physics/Condensed-matter physics/Electronic properties and materials
Toward a Perfect Lens: Automated Design of GRIN Double-Freeform Systems for Broadband Aberration and Chromaticity Correction
Article | Applied optics | 2026-11-09 19:00 EST
Donglin Ma, Rongqi Shang
In conventional optical design, the inability of a single lens to simultaneously correct high-order geometric and chromatic aberrations over a broad spectral range constitutes a persistent physical bottleneck limiting the development of ultracompact imaging systems. This fundamentally arises from severely restricted degrees of freedom in traditional lenses, which rely solely on interfacial modulation and the intrinsic dispersion of homogeneous media. Here, we propose a global inverse design framework based on gradient-index (GRIN) dual-freeform optics to overcome single-lens constraints. By introducing a wavelength-inclusive extended phase space, the complex ray-tracing evolution is rigorously transformed into an analytical algebraic reconstruction process. This framework reveals a physical mechanism for chromatic aberration compensation: exploiting the three-dimensional spatial dispersion gradient within the GRIN medium induces an anomalous negative chromatic aberration effect. This globally and precisely cancels the intrinsic positive chromatic dispersion introduced by freeform refractions. As methodological validation, we inversely designed an objective singlet lens with a demanding half field of view of 50 degrees. Quantitative evaluations demonstrate that across the entire visible spectrum, the full-field root-mean-square (RMS) spot radius is strictly controlled within 8 nm. This achieves broadband aberration-free and achromatic imaging well within the diffraction limit. This work provides a rigorous theoretical methodology and an implementable pathway for designing ultracompact imaging optics, substantially reducing the reliance on manual experience and iterative numerical optimization in advanced freeform design.
Research Square:rs-9332818 (2026)
Posted on Research Square
Physical sciences/Optics and photonics/Applied optics, Physical sciences/Optics and photonics/Optical techniques, Physical sciences/Optics and photonics/Optical materials and structures/Metamaterials
Non-Contact with Photochromism Strong-Coupling Modulation for a Miniaturized Computational Spectrometer
Article | Optical spectroscopy | 2026-11-09 19:00 EST
Fan Wang, Shuang Zhang, Menghan Tian, Zina Zhao, Zelin Lu, Xiaolan Zhong
Miniaturized computational spectrometers capable of high-resolution spectral measurement are increasingly in demand for on-chip and portable systems. Dynamic modulation can improve spectral resolution by increasing the number and diversity of spectral responses without enlarging the filter footprint. However, existing electrical and thermal modulation schemes often require complex electrode structures and multistep fabrication processes, increasing device complexity and limiting integration. Developing a non-contact modulation strategy that simplifies device architecture and eliminates complex electrodes is therefore key to realizing lightweight, highly integrated spectrometers. Here, we exploit strong coupling between photochromic molecules and a Fabry-Pérot cavity mode to achieve non-contact dynamic modulate of the filter’s transmission spectrum, enriching the spectral sampling information and thereby improving the resolution of spectral reconstruction. With optical modulation, the proposed spectrometer reduces the mean FWHM reconstruction error from 0.50 nm to 0.27 nm and resolves spectral features with an FWHM of 3 nm across 400-700 nm. More importantly, we verified the filter’s spatially selective modulation capability. By independently tuning the strong-coupling response in different filter unit through localized illumination, diverse spectral response channels can be dynamically constructed. Even with only four filter units, the system enables spectral reconstruction with good resolution. This non-contact dynamic modulation strategy requires neither structural modification nor complex electrical driving and supports spatially selective control for on-demand spectral channel configuration, enabling compact, low-cost, and reconfigurable spectrometers for on-chip integration, portable sensing, and spectral analysis across diverse applications.
Research Square:rs-11474805 (2026)
Posted on Research Square and Under Review at Light: Science & Applications
Physical sciences/Optics and photonics/Optical techniques/Optical spectroscopy, Physical sciences/Optics and photonics/Optical techniques/Imaging and sensing
Topological exceptional points bound in the continuum
Article | Topological matter | 2026-11-09 19:00 EST
Yong Li, Jiachen Meng, Ruizhi Dong, Yihuan Zhu, Xu Wang
The deliberate manipulation of symmetries has driven the discovery of exotic wave phenomena, most notably robust topological edge states (TESs), hypersensitive exceptional points (EPs), and zero-leakage bound states in the continuum (BICs). While pairwise combinations of these concepts have expanded the frontiers of wave control, unifying all three into a single hybrid state has remained elusive. Here, we conceptually and experimentally demonstrate a topological exceptional point bound in the continuum (TEP-BIC) utilizing an active acoustic metamaterial, uniquely governed by the fusion of crystalline, parity-time (PT), and local orthogonal spatial symmetries. By inducing PT modulation to an acoustic lattice, we not only concurrently regulate band structure of distinct subspaces, decoupled from each other by mode orthogonality, but also drive paired TESs in one subspace to coalesce into an EP that is embedded within the extended bulk continuum of the other subspace. We experimentally demonstrate that these physical ingredients (TES, EP, and BIC) remain individually accessible even after being fused into a single state, uncovering its multifaceted nature that manifests as contrasting responses under different perturbations. This unity of topology, non-Hermitian degeneracy, and zero-leakage resonance unlocks a hybrid physical regime for wave manipulation, providing a promising pathway for ultra-sensitive, low-loss sensing devices.
Research Square:rs-11630306 (2026)
Posted on Research Square
Physical sciences/Physics/Condensed-matter physics/Topological matter, Physical sciences/Physics/Applied physics/Acoustics