CMP Journal 2026-05-26
Statistics
Nature: 1
arXiv: 137
Nature
Bottom-Up Synthesis of Molecular Nanodiamond from Nanographene
Original Paper | Optical properties of diamond | 2026-05-25 20:00 EDT
Jiaxu Liang, Christopher P. Ender, Nancy C. Forero-Martinez, Ilyes Batatia, Jingyi Liu, Xin Yang, Raul Gonzalez Brouwer, Lev Kazak, Rémi Blinder, Leonardo Cancellara, Nadezda V. Tarakina, Yizhi Liu, Tobias Eklund, Mangalika Sinha, Sarah Köster, Shrikant Bhat, Fabian Rohmann, Andreas Tangemann, Kilian Lee Gallo, Rüdiger Berger, Robert Farla, Alexander Kubanek, Katrin Amann-Winkel, Manfred Wagner, Fedor Jelezko, Klaus Müllen, Gábor Csányi, Robinson Cortes-Huerto, Yingke Wu, Tanja Weil
Nanodiamonds hosting colour centres are promising building blocks for quantum technologies, enabling advances in quantum computation1,2, nanoscale NMR spectroscopy3-6, single-spin magnetometry7,8, wide-field quantum imaging9 and single-photon sources10,11. However, the controlled bottom-up synthesis of ultrasmall and structurally uniform nanodiamonds has remained a major challenge, with existing methods producing heterogeneous materials that vary in size, morphology, impurity content and defect quality. Here we show that well-defined, hydrogen-terminated molecular nanographenes serve as chemically confined precursors for high-pressure, high-temperature synthesis of ultrasmall (3-4 nm), monodisperse and highly crystalline molecular nanodiamonds (m-NDs) with only a single sp² surface reconstruction and produced on a milligram scale. The same bottom-up platform also enables a two-component strategy for incorporating silicon- and germanium-based colour centres during synthesis, yielding SiV⁻ and GeV⁻ emitters without ion implantation, irradiation or post-treatment. Because the nanographene precursor defines both the confined carbon framework and the hydrogen content, this approach provides intrinsic, precursor-level control over nanodiamond size and composition, particularly in the low-nanometre regime relevant for biological and quantum sensing. Molecular nanographenes, ultralarge polycyclic aromatic hydrocarbons, therefore establish a scalable and modular route to high-quality molecular and fluorescent nanodiamonds and offer a general design principle for tailored quantum materials and nanoscale devices.
Optical properties of diamond, Nanoparticle synthesis, Quantum optics
arXiv
Towards terahertz excitons in hydrogenated graphene superlattices
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2026-05-26 20:00 EDT
Vasil A. Saroka, Olivia Pulci, Marco D’Alessandro
Carbon nanostructures, such as nanotubes and graphene nanoribbons, exhibit unique electronic and optical properties that make them very promising candidates for terahertz components. However, carbon nanotube and nanoribbon monolithic on-chip integration is challenging because it may results in significant change of their intrinsic properties after an embedment into a substrate. We investigate with first principles theoretical methods the successful routes of such integration and calculate electronic and optical properties of the integrated structures – two-dimensional graphene superlattices, where quasi-metallic and dielectric regions alternate by selective hydrogenation of graphene. It is shown that chemical engineering of the graphene surface can lead to strong and well-isolated excitonic absorption peaks in the far-infrared and possibly even terahertz frequencies.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
10 pages, 4 figures
Supersymmetry Without Time-Reversal Invariance in Model A: A FRG perspective
New Submission | Statistical Mechanics (cond-mat.stat-mech) | 2026-05-26 20:00 EDT
Sankarshan Sahu, Bertrand Delamotte, Adam Rançon, Matthieu Tissier
We show that, contrary to common belief, supersymmetry alone is not sufficient in Model A dynamics to ensure relaxation toward a stationary state satisfying time-reversal invariance (TRI). An additional condition on top of supersymmetry is required for TRI, which we analyze in detail. We explicitly construct a model that is supersymmetric but violates TRI, and argue that, at least perturbatively, TRI nevertheless emerges as an effective large-scale symmetry. Using the functional renormalization group (FRG), we further show that the dynamical effective action, $ \Gamma[\varphi,\tilde\varphi]$ , contains the derivative of the equilibrium effective action, $ \Gamma^{\mathrm{eq}}[\varphi]$ , whose renormalization-group flow is identical to that of the equilibrium theory order by order in the derivative expansion. Finally, extending the same line of reasoning, we show that the probability distribution of the total magnetization in the Ising model can be recovered within the Model A framework.
Statistical Mechanics (cond-mat.stat-mech), Soft Condensed Matter (cond-mat.soft), High Energy Physics - Theory (hep-th)
14 pages
Radiation conduction in polaritonic nanowires
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2026-05-26 20:00 EDT
Livia C. McCormack, Mathieu Francoeur
Phonon polaritons have attracted increasing interest as a means to offset the reduction in phonon thermal conductivity in nanostructures caused by enhanced boundary scattering. However, the interpretation of the limited experimental data on phonon polariton-mediated conduction is hindered by the lack of comprehensive full-wave models for predicting thermal electromagnetic transport in solid-state systems. Here, the radiative thermal conductivity in the diffusive regime along SiO2 nanowires near room temperature is predicted using the fluctuational electrodynamics-based discrete system Green’s function method. At 400 K, for nanowire diameters of 66 nm and 132 nm, modest radiative conductivities of 0.0264 W/m-K and 0.0165 W/m-K, respectively, are obtained, with contributions dominated by surface phonon polaritons. In contrast, the kinetic theory combined with nanowire dispersion relations derived from Maxwell’s equations predicts conductivities that can be nearly two orders of magnitude larger than those obtained from fluctuational electrodynamics, and are largely dominated by bulk phonon polaritons propagating within the nanowire volume. Improved agreement between the kinetic theory and fluctuational electrodynamics for the total radiative conductivity can be achieved by introducing an effective mean free path that accounts for the reduced mean free path of bulk phonon polaritons outside the Reststrahlen spectral bands of SiO2. However, even with this correction, the kinetic theory fails to accurately capture the spectral distribution of radiative conductivity. This work establishes a solid foundation for the development of phonon polariton-based systems for thermal management in micro/nanoelectronic devices.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Computational Physics (physics.comp-ph)
25 pages, 4 figures, 4 supporting figures
Universal classification of continuous phase transitions with two order parameters
New Submission | Statistical Mechanics (cond-mat.stat-mech) | 2026-05-26 20:00 EDT
The continuous phase transition, indicated by the macroscopic order parameter and the occurrence of the spontaneous symmetry breaking, is well illustrated based on the Ginzburg-Landau’s paradigm. In systems described by one order parameter, the phase diagram is only composed of the normal phase and the ordered phase. However, in systems with two or more order parameters, much richer phase diagrams and critical phenomena may emerge. According to coupling terms of the free energy, we classify the systems with two order parameters into several categories, featuring different patterns of phase diagrams and critical scalings respectively. Our work propose the new avenue to studying and evaluating the complex systems only based on the coupling terms in expressions of free energy.
Statistical Mechanics (cond-mat.stat-mech), Quantum Physics (quant-ph)
Pressure and Size Dependence of Roton Emission and Vortex Creation by Moving Objects in He~II in $T \to 0$ Limit: Generalized Nonlocal Gross-Pitaevskii Model
New Submission | Quantum Gases (cond-mat.quant-gas) | 2026-05-26 20:00 EDT
Nicolás Pablo Müller, Ladislav Skrbek, Yuri A. Sergeev, Giorgio Krstulovic
In the framework of generalized, nonlocal Gross-Pitaevskii (GP) model, we study numerically the pressure- and size-dependent mechanisms of roton emission and vortex nucleation by objects moving in superfluid $ ^4$ He. As far as the authors are aware, this is the first attempt to analyze the pressure dependence of these mechanisms and the associated critical velocities within a single theoretical framework. For each of several pressures in the range from 0 to the solidification pressure of $ \approx25$ ~bar, we chose the parameters of the interatomic interaction potential such that the resulting excitation spectrum for the generalized, nonlocal GP equation approximates fairly accurately the pressure-dependent dispersion curve determined experimentally by Godfrin \textit{et al.}, Phys. Rev. B \textbf{103}, 104516 (2021). In the two-dimensional approximation, for circular obstacles (disks) moving in quiescent $ ^4$ He, we calculated two critical velocities – one corresponding to the roton emission and the other to the nucleation of quantized vortices – as functions of pressure and the obstacle’s size. We also comment briefly on three-dimensional simulations of the roton emission and vortex nucleation by moving spherical obstacles.
Quantum Gases (cond-mat.quant-gas)
Controlling spin-$\frac 12$ antiferromagnetic interaction strength in nanographene dimers
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2026-05-26 20:00 EDT
Robiatul Adawia, Pawel Tecmer, Pawel Potasz
We demonstrate that the effective spin-exchange coupling $ J$ in open-shell nanographene dimers can be precisely tuned via tip-induced dehydrogenation of selected carbon atoms. Using the double ionization potential equation-of-motion coupled-cluster singles and doubles (DIP-EOM-CCSD) method, we accurately compute the singlet-triplet gaps, which correspond directly to the exchange coupling $ J$ . We show that the position of the dehydrogenated (or hydrogen-passivated) site in triangulene dimers strongly modulates the singlet-triplet splitting, allowing $ J$ to be tuned over a wide range - from a few meV to several tens of meV. This strategy provides a simple yet powerful route for designing tailored spin models with alternating or spatially patterned spin-exchange couplings.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Other Condensed Matter (cond-mat.other)
8 pages, 7 figures
Electrostatically stabilized surface flat bands in rhombohedral graphite at zero displacement field
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2026-05-26 20:00 EDT
Kryštof Kolář, Andrea F. Young, Cyprian Lewandowski
Rhombohedral (ABC-stacked) multilayer graphene hosts interaction-driven phases enabled by surface flat bands at large displacement fields. In thick flakes, however, strong screening suppresses internal electric fields, raising the question of whether a flat-band regime is accessible within the same experimental paradigm. Here, we show that self-consistent, nonlinear electrostatics provides a robust alternative mechanism: even in the absence of a displacement field, a nonuniform near-surface potential flattens the surface-band dispersion and enhances the density of states. In the strong-coupling limit, electrostatics drives the system toward uniform half-filling at each momentum, yielding an asymptotically flat surface band without any gating. At realistic interaction strengths, surface-band flatness is tuned by the proximal gate, with maximal flatness achieved at hole doping when the band is empty. Combining analytic arguments with fully self-consistent calculations in a realistic model, we map the resulting low-field regime and connect to finite $ N!\sim! 6-15$ layered samples, providing a framework for analyzing the symmetry-broken phases observed in these systems. Our results motivate future experiments in large-$ N$ devices and establish a low-field regime for exploring electrostatically induced flat-band physics.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
Comments are very welcome
Theory of supercooled water
New Submission | Statistical Mechanics (cond-mat.stat-mech) | 2026-05-26 20:00 EDT
Jacobo Troncoso, Claudio A. Cerdeiriña
We introduce a model of water contemplating true supercooled-liquid states that, as such, are metastable with respect to the crystalline-solid ones. Its numerical solutions reproduce from Speedy-Angell’s stability-limit picture to Poole et al.’s metastable liquid–liquid criticality. The real existence of a liquid–liquid critical point is found to gain significant theoretical plausibility from a hitherto unnoticed analogy with the ``inversion thermodynamics’’ of Joule-Thomson gas throttling process and, by extension, with the equivalent phenomenology exhibited by black holes.
Statistical Mechanics (cond-mat.stat-mech)
Anderson Localization: A Floquet operator Krylov space perspective
New Submission | Disordered Systems and Neural Networks (cond-mat.dis-nn) | 2026-05-26 20:00 EDT
The problem of Anderson localization, as well as the single particle localization-delocalizaton transition of the Aubry-André model, is studied employing operator Krylov space methods. It is shown that even when the dynamics is generated by a Hamiltonian, studying the dynamics at stroboscopic rather than continuous times has its advantages. In particular, mapping the dynamics to an effective Floquet problem results in an operator Krylov space description where quantities such as the spectral function can be computed with fewer computational resources, while a moment method exists that allows for the extraction of Krylov parameters directly from the discrete time autocorrelation function. For stroboscopic dynamics, the operator Krylov space corresponds to the dynamics of an edge operator of an inhomogeneous Floquet transverse field Ising model, with the parameters of this effective model generated recursively. The Krylov parameters show disorder-averaged renormalization with their distribution narrowing as the recursion step increases. It is shown that a more physical spectral function is obtained from the Krylov parameters obtained from the disorder-averaged autocorrelation function, rather than the disorder-averaged Krylov parameters. The delocalized (localized) phase is shown to correspond to the appearance (absence) of a Porter-Thomas distribution, a ballistically propagating (localized) wavefront in operator Krylov space, and a smooth (discrete) Berstein-Szegö power-spectrum. The localization-delocalization transition is also demonstrated in operator Krylov space. A Porter-Thomas distribution is also observed at the critical point. The long-time dynamics and the inverse participation ratio at the critical point is shown to exhibit behavior consistent with a multi-fractal scaling with system size.
Disordered Systems and Neural Networks (cond-mat.dis-nn), Quantum Physics (quant-ph)
Signature of spin liquid state in a frustrated 3D antiferromagnet
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2026-05-26 20:00 EDT
Satish Kumar, U. Jena, A. Bandhopadhay, G. B. G. Stenning, D. T. Adroja, S. Petit, P. Khuntia
Frustrated pyrochlore lattices in transition-metal oxides provide an ideal platform for realizing exotic quantum states, including spin liquids with unconventional low-energy excitations arising from the macroscopic ground-state degeneracy of corner-sharing tetrahedral networks. Here, we report the synthesis and comprehensive characterization of ZnCrGaO$ 4$ , a frustrated three-dimensional pyrochlore-like magnet in which intrinsic cation ordering gives rise to unavoidable atomic-site disorder. A Curie–Weiss analysis of the high-temperature magnetic susceptibility yields a large negative Curie–Weiss temperature, $ \theta{\mathrm{CW}} \approx -205$ K, indicating dominant antiferromagnetic exchange interactions ($ J/k_{\mathrm{B}} \sim 55$ K) between Cr$ ^{3+}$ ($ S = 3/2$ ) moments. Despite the presence of strong antiferromagnetic interactions, no signature of long-range magnetic ordering is observed down to 125 mK, as evidenced by specific-heat and ac-susceptibility measurements. Furthermore, the absence of bifurcation between zero-field-cooled and field-cooled dc magnetic susceptibilities measured at 0.01 T indicates the absence of spin freezing, which is further supported by the frequency-independent ac susceptibility down to 250 mK. The presence of broad maxima in the magnetic specific heat and ac susceptibility at low temperatures suggests the development of short-range spin correlations within a dynamic magnetic state. In addition, the low-temperature specific heat follows a power-law behavior below 1 K, indicating the presence of unconventional low-energy excitations and algebraic spin correlations. These results provide compelling evidence for a dynamic correlated ground state in ZnCrGaO$ _4$ , establishing it as a promising platform for exploring highly frustrated $ S > 1/2$ three-dimensional quantum magnets and potential spin-liquid behavior.
Strongly Correlated Electrons (cond-mat.str-el), Materials Science (cond-mat.mtrl-sci)
Charge density wave in a band insulator
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2026-05-26 20:00 EDT
Md Shafayat Hossain, Wenhao Liu, Yuqi Zhang, Qi Zhang, Chao Lei, Nana Shumiya, Kouta Dagnino, Maksim Litskevich, Yu-Xiao Jiang, Jia-Xin Yin, Nikhil Dhale, Zi-Jia Cheng, Byunghoon Kim, Yongkai Li, Tyler A. Cochran, Xian P. Yang, Fan Zhang, Yugui Yao, Zhiwei Wang, Bing Lv, Titus Neupert, Luis Balicas, M. Zahid Hasan
Charge density wave (CDW) implies a periodic modulation of the charge density. Typically observed in metallic systems, CDWs arise from Fermi surface instabilities, resulting in the total or partial gapping of the Fermi surface. Here, we present experimental evidence for a CDW state emerging in a band insulator which has no Fermi surface. The bulk and surface of our material platform, Bi4Br4, is gapped over the entire Brillouin zone. Through topographic and spectroscopic imaging at low temperatures, we unveil an unexpected unidirectional charge modulation in Bi4Br4, breaking the lattice translation symmetry. The CDW develops at temperatures below 40 K and adds an energy gap atop the existing insulating gap of Bi4Br4. Furthermore, our transport measurements reveal nonlinear electrical conduction, a phenomenon conventionally associated with the sliding or phason mode of incommensurate CDWs. These highly unusual observations represent a new type of CDW and demand a new theoretical framework for CDWs.
Strongly Correlated Electrons (cond-mat.str-el), Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Materials Science (cond-mat.mtrl-sci), Applied Physics (physics.app-ph)
nature Communications (2026) in press
Quantized thermal current vortices
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2026-05-26 20:00 EDT
The thermal Hall effect has emerged as a fundamental tool for probing exotic quasiparticles and topological order, particularly in magnetic insulators where electronic conduction is suppressed. Much like skyrmions, which are characterized by their topologically protected spin configurations, the thermal Hall effect is deeply rooted in the geometric properties of the underlying physical space. Although the effect is a well-established experimental phenomenon, current research points toward the existence of its quantum analogue: the quantized thermal Hall effect. In this paper, we provide a theoretical framework for this quantum version based on Sommerfeld’s flux quantization. Furthermore, we demonstrate the potential existence of dissipationless thermal current vortices. We suggest that these vortices may play a crucial role in the stability and dynamics of other topological structures, such as skyrmion lattices, offering a new perspective on the interplay between heat transport and magnetic textures.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Mathematical Physics (math-ph)
11 pages, 4 figures
AB2X4 spinel structures: similarity and difference between the centrosymmetric, Fd-3m, and non-centrosymmetric, F4132, space groups
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-05-26 20:00 EDT
Alla Arakcheeva, Arnaud Magrez, Gervais Chapuis
Many compounds belonging to the spinel AB2X4 structure play an important role due to their wide range of practical applications. Most of them are traditionally assigned to the centrosymmetric space group Fd-3m. However, the physical properties of some spinels are incompatible with centrosymmetry. This discrepancy is often accounted for by reducing the symmetry to the non-centrosymmetric space group F-43m, allowing thus small atomic displacements from their original position in Fd-3m. In this work, we demonstrate that the loss of the inversion symmetry can occur without any atomic displacements, since the centrosymmetric Fd-3m and non-centrosymmetric F4132 space groups are equivalent for structure determination and refinement based on X-ray diffraction data. If consistent with experiment, only the use of an anharmonic model of atomic displacements can distinguish these space groups. This study aims to clarify certain misconceptions regarding the structural symmetry and physical properties of spinel type compounds.
Materials Science (cond-mat.mtrl-sci)
The structure of a melt: The case of liquid bismuth
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-05-26 20:00 EDT
Flor B. Quiroga, Isaías Rodríguez, David Hinojosa, Alexander Valladares, Renela M. Valladares, Ariel A. Valladares
Molecular Dynamics (MD) is performed on supercells of 216 atoms of bismuth, going from 300 K to 573 K in 100 steps and maintaining it in the liquid state, at 573 K, during 500 steps using the Materials Studio (MS) suite of codes. The Pair Distribution Functions (PDFs) and the Plane Angle Distributions (PADs) of the last 1, 10, 25 and 100 steps of the MD have been obtained. Averaging the last 100 steps, as representative of the liquid, Reverse Monte Carlo (RMC) was applied to obtain 4 atomic structures, one for each set of initial random velocities. Then, a detailed structural study of liquid bismuth at 573 K was undertaken; PDFs and PADs are calculated and reported. Two noticeable peaks appear for the PDFs, at 3.25 and 6.55 Å, along with a pseudo peak (shoulder) at 4.6 Å. This shoulder (after the first peak) of the PDFs is found to be related to the third and fourth neighbor peaks of the crystalline Wyckoff structure and also to the diagonal distances in deformed squares in the liquid structure. For completeness J(r)s are also reported. Two prominent peaks in the MS PADs are observed: 53° and 85°; and two for the RMC PADs: 58° and 90°, suggesting the existence of deformed triangles and squares. Less abundant are higher-order geometrical structures.
Materials Science (cond-mat.mtrl-sci), Superconductivity (cond-mat.supr-con)
19 pages, 10 figures
ChatMOSP: A Chemistry-Grounded Mobile Agent for Working-State Catalyst Simulations
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-05-26 20:00 EDT
Sanyang Ye, Rui Qi, Beien Zhu, Yi Gao
Catalytic nanoparticles restructure dynamically under reaction conditions, so their working morphology and activity are governed by temperature, pressure, and gas composition. However, converting experimentally specified environments into physically meaningful morphology-performance simulations remains difficult because the translation of reaction conditions into model-specific energetic, kinetic, and execution parameters requires the specialized knowledge in computational catalysis. Here we report ChatMOSP, a chemistry-grounded mobile scientific agent that translates natural-language and voice-expressed catalytic requests into parameter-validated simulations using the Multi-scale Operando Simulation Package. ChatMOSP maps catalyst identity, temperature, pressure, gas composition, and target observables onto multiscale structure reconstruction and kinetic Monte Carlo tasks, retrieves database parameters or constructs missing inputs from an online literature-retrieval workflow, and executes validated MOSP workflows. Using CO oxidation on Pd nanoparticles as an example, we verify the ChatMOSP simulations capture the temperature-induced transition from faceted to rounded morphologies observed by in-situ TEM experiments either by built-in database or from web-retrieved literature information when the parameters are absent. Moreover, we demonstrate the capability of ChatMOSP to perform end-to-end study at mobile devices to simulate a pressure-coverage-morphology-activity feedback cycle for Pt CO oxidation to interpret the oscillatory CO conversion. These results establish ChatMOSP as a physically constrained mobile agent for accessible and interpretable catalyst working-state simulations.
Materials Science (cond-mat.mtrl-sci), Atomic and Molecular Clusters (physics.atm-clus), Classical Physics (physics.class-ph)
26 pages, 5 figures
Resonant interactions in the $α$-FPUT lattice with site-dependent coefficients
New Submission | Statistical Mechanics (cond-mat.stat-mech) | 2026-05-26 20:00 EDT
Lorenzo Migliorelli, Giovanni Dematteis, Sergio Chibbaro, Miguel Onorato
The wave turbulence framework has proven to be an effective tool for analyzing certain features of nonlinear energy transfer in one-dimensional nonlinear chains. In this work, we extend this approach to the $ \alpha$ -FPUT problem when the spring stiffness $ \chi$ and the nonlinear coefficient $ \alpha$ are site-dependent. Although three-wave interactions are non-resonant for constant coefficients, their spatial modulation gives rise to a non-trivial resonant manifold. In this framework, we derive a new kinetic equation that suggests the possibility of substantially faster thermalization with respect to the constant coefficient case. The new kinetic equation includes also an extra term that can be associated to the Bragg-scattering mechanism, which promotes the isotropization of the wave-action spectral density function.
Statistical Mechanics (cond-mat.stat-mech), Chaotic Dynamics (nlin.CD)
Streaming Molecular Dynamics Simulation Data for On-the-fly Processing and Analysis
New Submission | Statistical Mechanics (cond-mat.stat-mech) | 2026-05-26 20:00 EDT
Amruthesh Thirumalaiswamy, Lawson J. Woods, Heekun Cho, Hugo MacDermott-Opeskin, Jennifer Clark, Irfan Alibay, Yuxuan Zhuang, Oliver Beckstein, Matthias Heyden
Only a small fraction of the data generated in state-of-the-art all-atom multi-microsecond molecular dynamics (MD) simulations is typically analyzed. With femtosecond integration steps, microsecond simulations generate billions of time steps containing atomic positions, velocities, and forces, often corresponding to petabytes of data. Since this exceeds practical storage capacities, only a subset of frames is usually written to trajectory files at intervals of 10-100 ps. While sufficient for ensemble averages and slow dynamics, this approach discards information on fast processes such as molecular vibrations, solvent dynamics, short-lived transition states, and transport phenomena that are directly related to macroscopic properties and experimental observables. Here, we introduce a streaming framework for MD simulations that provides direct access to all data generated during a running simulation. Instead of writing high-frequency output to disk, the framework enables user-defined analysis and processing routines to access simulation data in real time. To achieve this, we extend the Interactive Molecular Dynamics (IMD) protocol and implement an enhanced version, termed IMDv3, in the MD packages GROMACS, NAMD, and LAMMPS. We further introduce the Python package imdclient, which receives IMDv3 data streams and exposes them to external applications. To maximize usability, we add an imdclient-based reader to the MDAnalysis package, enabling streamed simulation data to be analyzed alongside conventional trajectory files. Benchmark results show that streaming can improve performance compared to simulations with high-frequency trajectory output. Example applications include live monitoring of custom variables, evaluation of velocity time-correlation functions with fast fluctuations, and real-time analysis of membrane pore currents.
Statistical Mechanics (cond-mat.stat-mech)
30 pages, 9 figures, 7 tables
Resonances in Overdamped Odd Materials
New Submission | Soft Condensed Matter (cond-mat.soft) | 2026-05-26 20:00 EDT
Odd viscoelasticity arises in parity-violating nonequilibrium materials, where it leads to unconventional mechanical responses and oscillatory relaxation even in overdamped systems. While many living and active chiral materials present promising candidates to exhibit odd viscoelasticity, there is currently no approach that allows for a rheological inference of the large number of elastic and viscous moduli that even a minimal isotropic odd viscoelastic material can depend on. Generalizing the century-old Papkovich-Neuber ansatz to active materials, our work introduces an odd Papkovich-Neuber (OPN) solution – an analytic solution for any isotropic linear odd fluid or solid, each described by up to 6 independent moduli – that enable us to study the boundary-driven response in geometries that mimic common rheology methods. OPN solutions reveal three physically distinct resonances in odd viscoelastic solids that are characteristic of the underlying material moduli and can all be interpreted within a single geometric framework. Underlying this unification is an equivalent description of overdamped odd viscoelastic materials in terms of damped harmonic oscillators. Resonances appear as the effective damping coefficients of these oscillators vanish, which is facilitated by the activity that powers odd material properties.
Soft Condensed Matter (cond-mat.soft), Biological Physics (physics.bio-ph), Fluid Dynamics (physics.flu-dyn)
10 pages, 4 figures
Ultrafast Magneto-optical Fingerprints of Altermagnetism in MnTe
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-05-26 20:00 EDT
Xu Yang, Xingkai Cheng, Zhuo Deng, Yu-Han Gao, Qing-Lin Yang, Zheng Chang, Peng-Tao Yang, Hong-Mei Feng, Xiang-Qun Zhang, Wei He, Junwei Liu, Zhao-Hua Cheng
Recently identified altermagnets exhibit a distinctive dual-space nature: they possess spin-split electronic bands akin to ferromagnets in momentum space while maintaining the fully compensated magnetization of antiferromagnets in real space. This inherent duality, originating from the same crystal symmetry, gives rise to various intriguing physical phenomena unique to altermagnets. Consequently, a robust and efficient experimental signature capable of revealing this dual character is critically needed. The magneto-optical Kerr and Voigt effects, given their high sensitivity to ferromagnetism and antiferromagnetism, respectively, are ideally suited to probe this duality. Here, using time-resolved pump-probe magneto-optical measurements, we report the coexistence of pronounced Kerr and Voigt effects in the altermagnet MnTe. Combining the magnetization measurement and first-principles calculations, we demonstrate that the Kerr effect originates from the intrinsic Berry curvature of altermagnetism distribution in momentum space, while the Voigt effect arises from an anisotropic permittivity induced by the in-plane Néel order in real space, directly revealing the dual-space nature of altermagnets. Furthermore, the transient Kerr signal exhibits faster relaxation dynamics than the transient Voigt signal, underscoring their distinct origins in Berry curvature and Néel order, respectively. These findings establish transient magneto-optical responses as distinctive fingerprints of altermagnetism and position altermagnets as promising platforms for manipulating magneto-optical phenomena in ultrafast spin optoelectronics.
Materials Science (cond-mat.mtrl-sci)
23 pages, 1 table, 4 figures
Systematic comparison of approximations and functionals in first-principle calculations of aluminum-based III-V ferroelectric nitrides
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-05-26 20:00 EDT
Alejandro Mercado Tejerina, Peng Chen, Keisuke Yazawa, Andriy Zakutayev, Laurent Bellaiche, Charles Paillard
We revisit first-principles predictions of structural, ferroelectric, and electronic properties in aluminum-based III-V nitride alloys, focusing on Al1-xScxN and Al1-xBxN. Using density functional theory within a unified 48-atom supercell framework, we systematically assess the role of chemical disorder and exchange-correlation approximations by comparing the virtual crystal approximation (VCA) and special quasirandom structures (SQS), as well as PBE, PBESol, SCAN, and SCAN+rVV10 functionals. We demonstrate that, even amongst the similar PBE and PBESol functionals, big quantitative and qualitative differences emerge. In particular, the VCA or SQS PBESol (a popular functional) strongly underestimate the stability domain of the ferroelectric wurtzite phase in Al1-xScxN compared to SQS PBE or SQS SCAN. We demonstrate that the 5-fold coordinated hexagonal phase predicted in 2002 by Farrer and Bellaiche [Phys. Rev. B 66, 201203] is a low-energy metastable state between the four-fold coordinated ferroelectric wurtzite phase and the six-fold coordinated rocksalt phase near the transition point upon increasing the Sc content. In contrast, Al1-xBxN shows a much faster destabilization of the wurtzite ferroelectric phase, with bond breaking which strongly distorts the wurtzite structure (with enhanced polarization) and eventually favor a zincblende phase and a threefold coordinated hexagonal layer phase. Our analysis highlights the critical importance of both local disorder and exchange-correlation treatment in predicting the functional properties of III-V nitride ferroelectrics. Overall, SQS combined with SCAN provides the most consistent theoretical framework for understanding and optimizing emerging nitride-based ferroelectric materials.
Materials Science (cond-mat.mtrl-sci)
A helical Rashba–exchange gauge field drives a uniaxial pair density wave in EuRbFe$_4$As$_4$
New Submission | Superconductivity (cond-mat.supr-con) | 2026-05-26 20:00 EDT
The recent discovery of an intrinsic pair density wave (PDW) in the iron-pnictide superconductor EuRbFe$ 4$ As$ 4$ presents a fascinating puzzle. Structurally, the FeAs layers break local inversion symmetry, while the Eu$ ^{2+}$ spins exhibit a period-four helical magnetic order. Here, we demonstrate that the interplay of induced Rashba spin-orbit coupling and the helical exchange field generates a layer-rotating effective $ U(1)$ gauge field for the Cooper pairs. Because this gauge field shares the symmetry of the Fe $ 3d{xz}/3d{yz}$ orbitals, it explicitly induces an intertwined, orbital-selective pairing state. Using a phenomenological Ginzburg-Landau theory, we show this mechanism naturally stabilizes a structurally modulated Bloch superconducting state. This state features a strictly uniaxial (unidirectional) PDW, naturally capturing the phenomenology of recent scanning tunneling microscopy experiments. Furthermore, we predict this PDW is accompanied by spontaneous loop currents between adjacent layers, offering a distinctive signature for future $ \mu$ SR or scanning SQUID experiments.
Superconductivity (cond-mat.supr-con)
Thermodynamics of classifiers
New Submission | Statistical Mechanics (cond-mat.stat-mech) | 2026-05-26 20:00 EDT
The Landauer principle bridges the energetic cost and information processing, showing that irreversible computation inevitably demands energy dissipation. As energy demands from computation continue to rise, approximate computing has attracted considerable attention. Approximate computing is based on the idea that energy consumption can be reduced by sacrificing computational accuracy. This raises a fundamental question about the relationship between error and thermodynamic cost in information processing. In this study, we derive the error-cost trade-off in the binary classifier by considering classification based on Markov processes. We obtain the lower bounds on the Bayes error in terms of thermodynamic costs such as entropy production and dynamical activity. Our results show that when entropy production or dynamical activity vanishes, the Bayes error reaches $ 1/2$ , equivalent to random guessing, while greater thermodynamic costs enable lower error. This establishes a fundamental trade-off between error and cost in information processing by thermodynamic systems. Because the Bayes error provides the lowest achievable error among all possible classifiers, the classification error cannot fall below the obtained bounds given the entropy production or dynamical activity. We also discuss the quantum generalization and show that the Bayes error of the quantum classifier is bounded from below by the variance of the Hamiltonian.
Statistical Mechanics (cond-mat.stat-mech), Quantum Physics (quant-ph)
11 pages, 1 figure
1/9 Magnetization Plateau in a Classical Kagome Ising Ferromagnet with Competing Further-Neighbor Interactions
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2026-05-26 20:00 EDT
Yixin Guan, Kan Zhao, Nvsen Ma
The two-dimensional kagome lattice is a paradigmatic platform for exploring geometrically frustrated magnetism. While the nearest-neighbor ferromagnetic Ising model on this lattice is theoretically trivial, competing further-neighbor interactions can reintroduce severe frustration. In this work, we systematically investigate a classical kagome Ising model with ferromagnetic nearest-neighbor (J1) and antiferromagnetic second- (J2) and third-neighbor (J3) couplings using simulated annealing Monte Carlo methods. We demonstrate that while J2 couplings merely suppress the conventional ferromagnetic order, the inclusion of J3 fundamentally reconstructs the low-temperature phase diagram. This extended geometric frustration stabilizes a novel ordered phase characterized by a robust 1/9 magnetization plateau and a massively enlarged 3 by 3 magnetic supercell. Crucially, this fractional ordered phase manifests as a stability plateau in the phase diagram, where its critical temperature becomes nearly independent of the coupling strength J3. We also calculate the corresponding static spin structure factor, revealing a distinct Z6-symmetric reciprocal-space signature for experimental identification. Our findings reveal that complex fractional magnetic orders can emerge purely from classical geometric frustration induced by competing extended interactions, providing a distinct mechanism for understanding fractionally ordered states in real frustrated magnets.
Strongly Correlated Electrons (cond-mat.str-el), Statistical Mechanics (cond-mat.stat-mech)
Dilute Magnetism and Edge-State Engineering in Monolayer SnO
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-05-26 20:00 EDT
Yuya Fukuta, Souren Adhikary, Kazuhito Tsukagoshi, Katsunori Wakabayashi
Tin monoxide (SnO) is a p-type oxide semiconductor whose electronic properties can be widely modified via atomic-scale engineering. Using density functional theory, we investigate the electronic and magnetic properties of transition-metal (TM = Mn, Fe, Co and W) doped SnO monolayer within a large supercell. We find that all dopants induce finite localized magnetic moments, primarily originating from $ d$ -orbitals of the impurity atoms. We show that these localized magnetic states give rise to nearly
dispersionless bands in the vicinity of the Fermi energy (taking Co doped SnO as an example). In addition, we investigate dimensional effects by constructing nanoribbon geometries of SnO monolayer. The ribbons exhibit intrinsic edge-localized states that are largely independent of ribbon width. For chiral nanoribbons oriented along a low-symmetry direction of the square lattice, we find that oxygen-rich edges are thermodynamically most stable and remain semiconducting, whereas Sn-terminated edges host metallic one-dimensional conduction channels. Our results demonstrate that transition-metal doping and edge engineering provide effective routes to tailor the electronic properties of SnO monolayer, making it a promising candidate for future spintronic and nanoelectronic applications.
Materials Science (cond-mat.mtrl-sci), Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
8 pages; 4 figures
Light-Driven Ferroic Switching Enables Reversible Control of Hydrogen Adsorption Thermodynamics
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-05-26 20:00 EDT
Xueqing Wan, Zhenlong Zhang, Charles Paillard, Jian Zhou, Jinyang Ni, Chuanlu Yang, Zhijun Jiang, Laurent Bellaiche
Reversible ultrafast switching of surface thermodynamics is highly desirable for hydrogen storage and catalysis yet remains elusive at the nanoscale. Here we demonstrate that photoinduced ferroic-order switching in two-dimensional ionic ferroelectric monolayers enables rapid, reversible control of hydrogen binding. In TiGeSe$ _3$ , carrier-density-driven redistribution of transition-metal 3\textit{d} orbital occupations triggers a sequential evolution from the ferroelectric ground state to paraelectric phases with staggered or Zig-Zag antiferromagnetic order. This switch continuously tunes the hydrogen adsorption free energy from 0.33 to 1.11 eV, shifting the interface from near-thermoneutrality to spontaneous desorption. Nonadiabatic dynamics indicate that electron-phonon coupling promotes nonthermal H release, while picosecond carrier recombination rapidly restores the initial ferroic order, closing an ultrafast reversible cycle. Generality is further validated in AgBiP$ _2$ Se$ _6$ and CuInP$ _2$ S$ _6$ , establishing ferroic order as an optically addressable knob for dynamic thermodynamic reconfiguration beyond static design.
Materials Science (cond-mat.mtrl-sci)
21 pages, 6 figures
Colossal Type-II Multiferroic Polarization Driven by Collinear Spin Orders
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-05-26 20:00 EDT
Chengxi Huang, Xinhai Tu, Jintao Jiang, Xiangang Wan, Erjun Kan
Achieving strong magnetoelectric coupling (MEC) together with large ferroelectric polarization remains a central challenge in type-II multiferroics. In conventional spin-driven multiferroics, the induced polarization is usually mediated by spin-orbit coupling (SOC) or spin-lattice coupling (SLC). Since many representative systems are based on 3d transition-metal ions, where SOC is relatively weak and SLC-induced lattice distortions are often limited, their polarizations are typically much smaller than those of proper ferroelectrics. Moreover, electric polarizations in type-II multiferroics are generally induced by spiral spin orders stabilized by competing magnetic interactions, which often leads to relatively low magnetic transition temperatures. In this Letter, using spin-group symmetry, we propose an SOC- and SLC-independent route to MEC in collinear 3d magnetic systems. We show that, even for a noncentrosymmetric lattice structure, different collinear magnetic configurations can either forbid or allow electric polarization, indicating direct magnetic control of polarization and hence strong MEC. The first-principles calculations excluding SOC on monolayer 2H-VS2 support this picture: a collinear stripy antiferromagnetic order induces an in-plane ferroelectric polarization up to 25.00 {\mu}C/cm2, about two orders of magnitude larger than that of typical type-II multiferroics. Furthermore, our microscopic model suggests that the induced polarization originates from SOC-independent p-d hybridization governed by electronic hopping. Our results suggest a possible route toward type-II multiferroics combining strong MEC with large electronic polarization in collinear 3d magnetic systems.
Materials Science (cond-mat.mtrl-sci)
15pages, 3 figures
Spiral and Mixed Plaquette-Dimer Phases in the $S=1$ and $3/2$ Shastry-Sutherland Heisenberg Model
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2026-05-26 20:00 EDT
Han-Qing Wu, Muwei Wu, Shou-Shu Gong
We investigate the ground-state phase diagram of the $ S=1$ and $ S=3/2$ Heisenberg model on the two-dimensional Shastry-Sutherland lattice (SSL) using density matrix renormalization group (DMRG) and cluster mean-field theory (CMFT). Between the dimer phase and Néel antiferromagnetic phases, we identify two intermediate phases: a mixed plaquette-dimer (MPD) phase and a spiral phase. These phases are characterized via bond energies and spin-spin correlation functions; phase boundaries are located from the ground-state energy derivative and entanglement entropy. The MPD phase exhibits strong intradimer correlations and weak tetramerization on the empty plaquettes, and its transitions to the dimer and spiral phases are first order. Combining our results with the known boundaries for $ S=1/2$ and the classical limit $ S\to\infty$ , we construct a global $ S$ -$ g$ phase diagram. This diagram reveals the progressive suppression of quantum effects with increasing $ S$ and offers a theoretical framework for larger-$ S$ SSL materials.
Strongly Correlated Electrons (cond-mat.str-el)
7 pages, 3 figures
Termination-Dependent Surface States and Magnetic Fingerprints of Chiral Helimagnet Cr1/3TaS2
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-05-26 20:00 EDT
Bo Liang, Xue Li, Congcong Le, Zirui Wu, Wenpei Zhu, Neng Cai, Yong-Chang Lau, Xianxin Wu, Jiayu Liu, Zhanfeng Liu, Hongen Zhu, Tongrui Li, Zhicheng Jiang, Yu Huang, Wenchuan Jing, Xun Ma, Qi Jiang, Hang Li, Zhihao Cai, Xuezhi Chen, Gexing Qu, Yiwei Cheng, Bing-Jie Chen, Zhengtai Liu, Dawei Shen, Mao Ye, Shengtao Cui, Zhe Sun, Koji Miyamoto, Taichi Okuda, Kenya Shimada, Yaobo Huang, Zhenhua Chen, Lin Zhao, Baojie Feng, Xinguo Ren, Wenhong Wang, Xingjiang Zhou, Guodong Liu
Chiral helimagnets based on intercalated transition-metal dichalcogenides, characterized by nano-scale spin ordering, provide a powerful route to engineer chiral spin textures (e.g. the topologically protected magnetic solitons) and emergent electronic functionality at reduced dimensions, where surface and interface states often dominate device operation. However, despite growing interest, direct experimental studies of termination-dependent surface electronic structures and their temperature-driven magnetic evolution remain largely unexplored, hindering a microscopic understanding of the electronic states that is crucial for the development of low-dimensional spintronic devices. Here, for the first time, taking Cr1/3TaS2 as a representative example, we systematically investigate the termination-dependent surface electronic states of the chiral helimagnets and uncover their distinct temperature evolution across the magnetic transition (TC~142K) by combining high-resolution ARPES with a micro-focused beam and surface-state-resolved first-principles calculations. The TaS2-terminated surface hosts folded monolayer-like TaS2 bands under the $ \sqrt3\times\sqrt3$ superlattice potential and a shallow triangular electron pocket at the superlattice $ \bar K$ point arising from Cr-Ta orbital hybridization. In contrast, the Cr-terminated surface exhibits reconstructed hole pockets with pronounced magnetic band splitting. This splitting disappears above TC and closely follows the chiral helimagnetic order parameter, providing a direct spectroscopic fingerprint of chiral helimagnetic order. In addition, multiple ultranarrow Cr-d-derived surface flat bands are resolved. These findings establish Cr1/3TaS2 as a model system in which surface electronic states are strongly coupled to chiral magnetism, opening new opportunities for chiral spintronic and valleytronic micro/nanodevices.
Materials Science (cond-mat.mtrl-sci), Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
Superconfined Antiferromagnons on the Two-Dimensional Penrose Lattice
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2026-05-26 20:00 EDT
We find novel confined states in the spin-$ S$ nearest-neighbor antiferromagnetic Heisenberg model on the two-dimensional Penrose lattice. Linear spin waves have massively degenerate eigenstates strictly confined to tricoordinated sites. They contrast with the well-known itinerant analogs in the tight-binding model, where electrons are confined but extended to both tricoordinated and pentacoordinated sites. It is the site potentials in the spin-wave Hamiltonian, originating from Coulomb interactions between electrons, that confine spin waves to minimally coordinated sites only. Confined states in the tight-binding Hamiltonian consist of six types of building blocks, whereas those in the spin-wave Hamiltonian consist of only four of them. Confined spin waves are robust against $ 1/S$ corrections. Emergent $ O(S^{0})$ interactions further confine – superconfine – spin waves into two separate groups within tricoordinated sites.
Strongly Correlated Electrons (cond-mat.str-el), Mathematical Physics (math-ph)
18 pages, 13 figures
Emergence of Triplet Superconductivity from Cavity Vacuum Fluctuations
New Submission | Superconductivity (cond-mat.supr-con) | 2026-05-26 20:00 EDT
Xin-Xin Yang, Shuai Zhang, Kun Ding, Xiaopeng Li
Engineering quantum materials with cavity fields has emerged as a powerful route to manipulate phases of quantum matter in solids. Here we demonstrate that cavity vacuum fluctuations alone can drive the emergence of triplet superconductivity in an otherwise singlet superconductor. The vacuum field renormalizes the electronic band structure in a polarization dependent manner, reshaping the Fermi surface and altering the competition among symmetry allowed pairing channels. As a result, multiple superconducting phases arise from the cavity vacuum fluctuations. Above a critical light matter coupling, the leading instability switches from singlet to triplet pairing, yielding a superconducting state absent in the bare material. This vacuum induced symmetry transition produces distinct modifications of the gap structure and low energy quasiparticle spectrum. Our results establish cavity vacuum engineering as a mechanism for generating unconventional superconducting phases and stabilizing triplet states of potential relevance for topological superconductivity.
Superconductivity (cond-mat.supr-con)
Multi-Source Domain Transfer Learning for Accurate Property Prediction in Two-Dimensional Materials
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-05-26 20:00 EDT
Huiyang Zhang, Xinyu Chen, Qionghua Zhou, Jinlan Wang
Machine learning has revolutionized materials discovery, but data scarcity remains a critical bottleneck for complex functional properties. As emerging systems, two-dimensional (2D) materials possess limited overall data volumes. Evaluating their diverse functional properties requires time-consuming simulations, hindering unified high-throughput screening. Furthermore, restrictions in known structural prototypes lead to highly fragmented data distributions. To address these challenges, we propose a multi-source domain transfer learning framework to extract generalizable and complementary knowledge from diverse crystalline systems. To mitigate data scarcity, the framework employs a shared feature extractor that integrates adversarial transfer learning with maximum mean discrepancy, mapping crystal structures into a domain-invariant latent space while preserving underlying physical correlations. To resolve distribution fragmentation, a sample-adaptive weighted ensemble strategy is subsequently utilized to dynamically aggregate predictions from multiple source domains. Relying solely on crystal structures, the framework predicts 2D carrier mobilities with an R2 score exceeding 0.90. The framework successfully screened 55 novel high-mobility 2D semiconductors, which were validated via first-principles electron-phonon coupling analysis, confirming their exceptional transport properties and stability. This work can potentially accelerate machine learning-assisted materials design and discovery with less data restriction.
Materials Science (cond-mat.mtrl-sci)
The peculiar response of Kelvin-Voigt chains with a free end
New Submission | Statistical Mechanics (cond-mat.stat-mech) | 2026-05-26 20:00 EDT
We exactly solve a model of a heterogeneous chain of overdamped, harmonically coupled particles with momentum-conserving dissipation. Despite being governed by a non-symmetric drift operator, the system admits an analytical diagonalization by use of a forward-difference transformation. In case of one free end, the response matrix shows a peculiar staircase form: the response of particle i to a force acting on particle j is independent of the properties and the length of the chain-part between i and j. For rank-deficient interaction matrices, the state space is decomposed into free and constrained subspaces. We demonstrate that this separation has clear physical consequences: the free subspace governs steady state responses, while the constraint subspace governs the relaxation after cessation of forcing. These results establish a framework for analyzing heterogeneous overdamped dynamics with momentum conservation.
Statistical Mechanics (cond-mat.stat-mech)
12 pages, 7 figures
Techno-economic Analysis of Light Isotope-enriched Elements for Lightweighting Applications
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-05-26 20:00 EDT
Wenbo Bao, Zhihao Yang, Taeyoung Wang, Joseph F. Wild, Yuan Yang
Lightweighting is critical to mass-sensitive applications such as aircraft and space transportation. Conventional lightweight strategies often rely on new designs of materials and structures. An alternative approach is to enrich the lightest stable isotopes in an element to reduce the elements atomic mass while having little effect on structural and chemical properties. However, the economic feasibility of this concept remains unclear. Here we present a techno-economic analysis of light isotope-enriched elements for lightweighting applications by estimating isotope enrichment cost and the economic gain from mass reduction. The enrichment cost is scaled from established large-scale processes. Twelve common aerospace-relevant elements are considered, including Li, B, C, Mg, Cl, Ti, Ni, Fe, Cu, Zn, Mo, and Sn. We find that nine elements, especially Li, B, Zn, Ni, Mo, and Sn, show potentially attractive economic benefit at moderate enrichment levels, whereas C, Mg, and Fe provide little or no benefit. With the optimized enrichment levels, an Airbus A380 is expected to save approximately USD 700 K over a 30-year operational lifetime, a SpaceX Falcon 9 could save USD 516 K, and a SpaceX Starship is expected to save USD 2.37 million over its whole lifetime. While the exact enrichment cost needs to be further investigated, these results provide an initial screening of promising candidate elements and highlight isotopic mass reduction as a potential drop-in lightweighting strategy.
Materials Science (cond-mat.mtrl-sci)
Main text (19 pages) and Supporting information (17 pages)
Implicit Binarization via Complex Phase Dynamics in Combinatorial Optimization
New Submission | Statistical Mechanics (cond-mat.stat-mech) | 2026-05-26 20:00 EDT
Khen Cohen, Mark Glass, Meir Feder, Yaron Oz
We introduce a physics-inspired continuous relaxation framework that yields substantially improved solutions for NP-hard combinatorial optimization problems, including Quadratic Unconstrained Binary Optimization (QUBO), binary sparse coding, and planted-solution Ising models. By parameterizing discrete binary variables as continuous wave-like states on the complex unit circle, we inherently smooth highly non-convex energy landscapes. We show that representing binary variables as complex phases reveals an implicit regularization mechanism that promotes convergence toward discrete states. Extracting this mechanism yields significant improvements even within standard real-valued optimization frameworks, using this regularizer explicitly. Empirically, this regularization yields vastly higher ground-state convergence rates than standard real-valued alternatives. Our models achieved zero error in large-scale 160x160 QUBO tasks under severe noise (sigma=0.25), and outperformed traditional algorithms (OMP and LASSO) in underdefined sparse coding with perfect recovery at sigma=0.15. The solver’s robustness was further validated by recovering exact ground-state configurations in 8 out of 11 rigorously engineered planted-solution benchmarks.
Statistical Mechanics (cond-mat.stat-mech), Machine Learning (cs.LG), Combinatorics (math.CO), Computational Physics (physics.comp-ph)
27 pages, 5 figures
Strong Eigenstate Thermalization from Mean-Ergodic Non-chaotic Dynamics
New Submission | Statistical Mechanics (cond-mat.stat-mech) | 2026-05-26 20:00 EDT
Avadhut V. Purohit, Harshit Sharma, Udaysinh T. Bhosale
We report an example of a many-body system, derived from the double kicked top (DKT), with non-chaotic yet mean-ergodic dynamics that displays \textit{strong} eigenstate thermalization hypothesis (ETH) in the quantum regime. The analysis addresses a key open question: whether \textit{strong} ETH is a quantum analog of ergodicity (or mean-ergodicity). Despite non-chaotic dynamics, the fluctuations of the diagonal matrix elements of an observable scale as $ D^{-1/2}$ , where $ D$ denotes the Hilbert space dimension. Furthermore, the off-diagonal matrix elements show Gaussian statistics together with a smooth function $ f_O(\bar{E}, \omega)$ that becomes nearly uniform in the large-$ k_\theta$ domain. Our findings show that even mean-ergodic and non-chaotic systems can exhibit \textit{strong} ETH.
Statistical Mechanics (cond-mat.stat-mech), Quantum Physics (quant-ph)
5 pages (two-column) + 5 pages (one-column) + 12 figures. Comments are welcome
Synchronization of Bloch Oscillations in array of parallel Josephson Junctions
New Submission | Superconductivity (cond-mat.supr-con) | 2026-05-26 20:00 EDT
R. Shaikhaidarov, R. Hussain, V.N. Antonov, E. Il’ichev
We demonstrate the synchronization of current quantization in a parallel array of weakly coupled Josephson Junctions operating in the regime of the coherent quantum phase slip. The first quantized current step on the voltage-current characteristic of 69 parallel Josephson junctions, under microwave excitation at a frequency of f = 19.325 GHz, is observed at 426 nA. Experiments show that accuracy of quantization does not degrade with increasing number of combined Josephson junctions. This demonstration addresses the issue of quantized current amplitude requirements adopted for a practical quantum standard, while leaving the question of accuracy for further research. At present, the quantum current standard of accepted metrological accuracy in the triangle of electrical units is under development. The other two, the Volt and Ohm standards based on the Josephson and Quantum Hall effects, respectively, are already well established in metrology.
Superconductivity (cond-mat.supr-con)
5 pages 4 figures
Emergent Dispersive Multipolar Excitations in NaErSe$_{2}$
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2026-05-26 20:00 EDT
Zheng Zhang, Mingfang Shu, Mingtai Xie, Weizhen Zhuo, Yanzhen Cai, Christian Balz, Jianting Ji, Feng Jin, Jie Ma
In most condensed-matter systems, local and collective excitations remain decoupled due to their distinct energy scales. Here, we identify coupled local-collective excitations in the triangular antiferromagnet NaErSe$ 2$ by combining neutron spectroscopy with total angular momentum modeling. The low-lying crystalline electric field (CEF) doublets include a dipolar $ \Gamma_4$ ground state forming stripe-$ x$ order and a $ \Gamma{5,6}$ excited state with dipole-octupole character. High-resolution spectra reveal emergent symmetry-selected dispersions, where magnon branches from the ground state are replicated on higher $ \Gamma_4$ levels but couple with the $ \Gamma_{5,6}$ levels to form a distinct multipolar band. An applied magnetic field reconstructs the CEF wavefunctions and polarizes the system into a multipolar ferromagnet, further reshaping the spectra. This study demonstrates the emergent coupling of local and collective excitations driven by strong spin-orbit coupling and establishes NaErSe$ _2$ as a platform for field-tunable multipolar excitations in frustrated magnets.
Strongly Correlated Electrons (cond-mat.str-el)
7 pages, 4 figures
Phys. Rev. Lett. 135, 256503 (2025)
Nonunitary triplet superconductivity in the Z2 topological metal SrPd2As2
New Submission | Superconductivity (cond-mat.supr-con) | 2026-05-26 20:00 EDT
Aarti, Dibyendu Samanta, Kartik Panda, Devashibhai Adroja, Daloo Ram, Zakir Hossain, Rhea Stewart, Adrian Hillier, Amitava Bhattacharyya, Samar Layek, Sudeep Kumar Ghosh, Vivek Kumar Anand
In Z2 topological metals, nontrivial band topology and strong spin-orbit coupling (SOC) impose symmetry constraints that can stabilize unconventional superconducting states, even when thermodynamic probes indicate an isotropic gap. Here, we investigate the superconducting ground state of such a material, SrPd2As2, using muon spin rotation and relaxation (muSR), first-principles calculations, and Ginzburg-Landau analysis. Transverse-field muSR indicates a fully gapped superconducting state below Tc = 0.94 K, while zero-field muSR detects spontaneous internal magnetic fields below Tc, establishing time-reversal symmetry (TRS) breaking. Electronic structure calculations identify SrPd2As2 as a Z2 topological metal with surface states crossing the Fermi level. Standard anisotropic Migdal-Eliashberg calculations predict a nodal gap and overestimate Tc, indicating that a purely phonon-mediated pairing mechanism is insufficient. We resolve this apparent contradiction by showing that the interplay of SOC, tetragonal symmetry, and an open Fermi surface topology stabilizes a nonunitary triplet superconducting state whose symmetry-imposed nodes lie in momentum-space regions devoid of electronic states. This yields a fully gapped thermodynamic response while naturally breaking TRS. Our results establish SrPd2As2 as a clean platform for bulk nonunitary triplet pairing and a promising candidate for intrinsic topological superconductivity.
Superconductivity (cond-mat.supr-con), Materials Science (cond-mat.mtrl-sci), Strongly Correlated Electrons (cond-mat.str-el)
14 pages, 10 figures, 1 table
Rare events of small-noise Doob conditioned processes
New Submission | Statistical Mechanics (cond-mat.stat-mech) | 2026-05-26 20:00 EDT
Iago N. Mamede, Francesco Coghi
Doob fixed-time conditioning enables the sampling of rare trajectories of Markov processes by modifying the drift so that reaching a prescribed target at a given time is guaranteed. We study the statistics of this conditioned path ensemble through the moment generating function in the weak-noise large deviation regime. Since the Doob drift is rarely available in closed form, we reinterpret the conditioned ensemble as the original process post-selected on the terminal constraint, thereby avoiding explicit construction of the Doob transform. This viewpoint then yields an optimal-control representation for the leading exponential contribution to the generating function, expressed as a variational principle with terminal boundary conditions set by the Doob end-point constraint. We illustrate the framework with two analytical examples and with an application to heat dissipation of a minimal model of biomolecular folding.
Statistical Mechanics (cond-mat.stat-mech), Mathematical Physics (math-ph), Probability (math.PR)
13 pages + Appendices, 4 figures
Manipulation of information flow and thermodynamic performance in nonreciprocal quantum dot information engines
New Submission | Statistical Mechanics (cond-mat.stat-mech) | 2026-05-26 20:00 EDT
Quantum information engines leverage information as a thermodynamic resource to facilitate energy conversion. In the operation of such engines, the information flow between the working substance and the controller is pivotal, however, strategies for its efficient manipulation remain largely unexplored. Here, we investigate an autonomous information engine based on a double-quantum-dot setup, where a downstream dot coupled to two reservoirs acts as the working substance, and an upstream dot coupled to a single reservoir serves as the controller. By extending the second law of thermodynamics to incorporate the effects of nonreciprocal couplings between the dots and their electronic reservoirs, we develop a thermodynamic framework that allows us to demonstrate that nonreciprocity can significantly modulate the inter-dot information flow, thereby providing a robust control mechanism. We show that the influence of nonreciprocity can be equivalently understood through a mapping to an effective reciprocal system upon a reparameterization of chemical potentials and the electron-electron coupling strength. We further analyze the impact of nonreciprocity on the engine’s performance and operation regime. Our findings establish nonreciprocal coupling as an effective control knob for designing and optimizing quantum dot information engines, surpassing the capabilities of conventional reciprocal configurations.
Statistical Mechanics (cond-mat.stat-mech), Quantum Physics (quant-ph)
16 pages, 6 figures, comments are welcome
Application and Performance Assessment of Annealing Methods for Electrostatic-Energy-Based Configuration Search in Mixed Crystals
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-05-26 20:00 EDT
Tack Saquai, Kenta Hongo, Ryo Maezono, Tom Ichibha
In first-principles design of solid solutions and disordered materials, exhaustive evaluation of all possible substitutional configurations is often impractical because the number of site occupations increases exponentially. Here, we develop a framework for pre-screening mixed-crystal configurations using annealing methods, where the Ewald electrostatic energy is used as the objective function. Substitutional occupations are represented by binary variables, allowing the Ewald energy to be mapped onto an Ising-type Hamiltonian and the search for low-energy configurations to be formulated as a combinatorial optimization problem.
We implement this formulation using simulated annealing (SA) and quantum annealing (QA), and benchmark their performance against exhaustive search. For the small-scale system CaYAlO$ _4$ , SA achieved a speed-up of about 30 times, while QA achieved a speed-up of more than 100 times; both methods identified all lowest-energy configurations. For the medium-scale system $ \beta$ -KSbF$ _4$ and the large-scale Ba-doped SiAlON system, SA achieved speed-ups of about 200-300 times while robustly identifying the lowest-energy structures. In contrast, QA was effective for the small-scale case but showed limited speed-up for medium-scale problems and missed some low-energy configurations due to chain breaks.
These results indicate that SA is currently the most robust and general-purpose approach for rapid pre-screening of mixed-crystal configurations based on electrostatic energy. The proposed formulation can be implemented automatically using publicly available libraries and provides a practical route for accelerating candidate-structure generation before first-principles calculations.
Materials Science (cond-mat.mtrl-sci)
Theoretical study of superconductivity in freestanding infinite-layer nickelate membranes under pressure: mitigation of excess correlation enhances $T_c$
New Submission | Superconductivity (cond-mat.supr-con) | 2026-05-26 20:00 EDT
Mahiru Seki, Reo Kono, Naotaka Tanaka, Kensei Ushio, Daiki Nakaoka, Masayuki Ochi, Kazuhiko Kuroki, Hirofumi Sakakibara
We theoretically investigate a freestanding membrane of infinite-layer nickelate Nd$ _{0.85}$ Sr$ _{0.15}$ NiO$ _2$ under pressure by constructing a seven-orbital effective model based on first-principles calculations.
By performing the fluctuation exchange (FLEX) approximation, we demonstrate that the seven-orbital model explains a monotonic increase in $ T_c$ reported in a recent experiment. This enhancement of superconductivity is attributed to the mitigation of excessively strong electron correlations caused by exceptionally low valence of Ni atom. Furthermore, we examine the dynamical stability of the crystal structure under pressure through phonon calculation.
Superconductivity (cond-mat.supr-con), Materials Science (cond-mat.mtrl-sci), Strongly Correlated Electrons (cond-mat.str-el)
9 pages, 5 figures,
Ab-initio Crystal Structure Determination from Powder X-Ray Diffraction
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-05-26 20:00 EDT
Kaixiang Su, Osman Goni Ridwan, Hongfei Xue, Qiang Zhu
Determining crystal structures from powder X-ray diffraction (PXRD) has been a significant challenge in materials science, particularly when experimental data contain noise or the target structure has a high complexity. While recent AI generative models show promise for rapid structure generation, they predominantly employ data-driven approaches to learn direct mappings between PXRD patterns and crystal structures, often failing on complex or out-of-distribution cases. In this work, we present a hybrid ab-initio approach that decomposes structure determination into a two-stage optimization problem: (1) discrete selection of space group symmetry, unit cell parameters, and Wyckoff site combinations; and (2) continuous optimization of atomic coordinates within the selected Wyckoff positions. By integrating AI-based techniques for peak profile analysis, density estimation and energy minimization with physics-informed constraints, our method systematically overcomes limitations of purely data-driven PXRD solvers. We demonstrate that this hierarchical optimization framework enables robust structure determination even for challenging cases with high structural complexity or limited experimental data quality. Our approach provides a principled pathway for incorporating crystallographic knowledge into AI models for more reliable and generalizable crystal structure determination.
Materials Science (cond-mat.mtrl-sci)
8 pages, 4 figures
Quantum Printing: Laguerre-Gaussian Beam Induced Topological Magnetic Textures
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2026-05-26 20:00 EDT
Yuefei Liu, Tien-Tien Yeh, Alexander V. Balatsky
Structured light has become a practical tool for controlling matter by applying tailored, space- and time-dependent electromagnetic fields. We show that Laguerre-Gaussian pulses imprint non-collinear magnetic textures via the spatial structure of optical magnetic field. Our route offers a direct spatial selectivity determined by the optical features without relying on material anisotropic interactions. The proposed printing approach does not require interfacial anisotropy or bulk chirality, current-driven torques, or thermal quenching. We use micromagnetic simulations to demonstrate the potential to create topological charge density emerging during the pulse and reveal control through the optical topological properties and polarization. These results suggest structured-light quantum printing as a viable approach for magnonics and motivate studies toward reconfigurable topological textures enabled by ultrafast THz optics and non-thermal control.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Optics (physics.optics)
13 pages, 8 figures
Redox behaviour of Fe impurities in BaTiO$_3$ based on many-body calculations
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-05-26 20:00 EDT
Zhiyuan Li, Hamza Zerdoumi, Hao Wang, Ruiwen Xie, Hongbin Zhang
Based on detailed electronic structure and spectroscopy obtained using DFT-based many-body techniques, the redox behavior of Fe impurities in BaTiO$ 3$ is investigated. It is observed that Fe impurities exhibit a mixed valence nature, comprising mostly Fe$ ^{2+}$ ($ 3d^6$ ) and Fe$ ^{3+}$ ($ 3d^5$ ) configurations, and such configurations can be tuned via oxygen vacancies which favor Fe$ ^{2+}$ . The origin of such a redox behavior can be attributed to the charge transfer caused by shifting of the $ d{3z^2-r^2}$ orbitals. Furthermore, x-ray photoemission spectroscopy is evaluated by solving the Wannier function-derived local atomic Hamiltonian using the crystal field multiplet approach, with good agreements with recent experimental measurements.
Materials Science (cond-mat.mtrl-sci)
Proton-electron coupled catalyst for ionomer-free electrochemical energy conversion
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-05-26 20:00 EDT
Ao Zhang, Ran Wang, Mohammed O. Bazaid, Shiyi Wang, Ting-Jung Hsiao, Yibo Wang, Antonio Sorrentino, Yang Liu, Yu-Han Joseph Tsai, Boxuan Zhou, Bosi Peng, Zeyan Liu, Xiangfeng Duan, Adam Z. Weber, William A. Goddard III, Seung Soon Jang, Yu Huang
Efficient electrochemical energy devices are vital to renewable energy technology, yet coordinating the effective flow of electrons, ions, and chemical species continues to be a major challenge. In conventional proton-exchange membrane fuel cell (PEMFC) catalyst layers, proton and electron transport are supplied separately through percolating carbon networks and ionomer binders, rendering the catalyst largely passive and imposing fundamental trade-offs between reactant accessibility, ionic conductivity, and catalyst activity. Here, we introduce a one-dimensional proton-electron coupled catalyst (PECC) design, a transport-integrated electrocatalyst architecture in which the catalyst itself simultaneously supplies electronic and protonic transport to catalyst active sites. Using this PECC, PEMFCs can have an ionomer-free cathode catalyst layer (CCL), resulting in a dramatic 95% reduction in non-Fickian oxygen transport and boosting power density by 34% and 85% compared to traditional CCLs, with cathode Pt loadings of approximately 0.090 mg/cm^2 and 0.037 mg/cm^2, respectively. Meanwhile, PECC retains 65% of its mass activity and exhibits 32% higher power density than its ionomer-based CCL counterpart after 30k accelerated stressed test. Similar mass transport improvements have been observed in the electrochemical hydrogen pump (EHP) using PECC in the catalyst layers. Molecular dynamics simulations show the PECC’s proton conductivity is 249% higher than Nafion. This PECC catalyst structure addresses core transport problems in PEMFCs, leading to almost 20% improvement in fuel efficiency and opens up new possibilities for designing high-performance, cost-effective electrochemical devices.
Materials Science (cond-mat.mtrl-sci), Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
Charge dynamics at nitrogen impurities and nitrogen-vacancy centers in diamond
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-05-26 20:00 EDT
Chandan Kumar Vishwakarma, J. K. Nangoi, Mark E. Turiansky, Chris G. Van de Walle
The nitrogen-vacancy (NV) center in diamond is the prototype quantum defect that enables a variety of diamond-based quantum technologies. However, charge-state instability and spectral diffusion, often induced by substitutional nitrogen impurities (N$ _{\rm C}$ ), remain key challenges for device performance. Here, we employ first-principles density functional theory calculations to quantitatively investigate nonradiative carrier capture processes mediated by multiphonon emission at both the NV center and the N$ _{\rm C}$ impurity. For relevant cases, we also compute the rates of radiative and thermal emission processes. For N$ _{\rm C}^0$ $ \to$ N$ _{\rm C}^-$ , we obtain an electron capture coefficient of $ 2.2 \times 10^{-8}$ cm$ ^3$ s$ ^{-1}$ at 300 K. Both the magnitude and temperature dependence are in excellent agreement with experimentally measured capture cross sections. Electron capture at N$ _{\rm C}^+$ is even faster, with a capture coefficient of $ 1.0 \times 10^{-4}$ cm$ ^3$ s$ ^{-1}$ at 300 K. For the NV center, we find that carrier capture rates involving only the ground states of NV$ ^0$ and NV$ ^-$ are negligibly slow. However, capture into the excited states (NV$ ^{0\ast}$ and NV$ ^{-\ast}$ ) is significantly faster. In particular, the capture coefficient for the hole capture process NV$ ^-$ $ \to$ NV$ ^{0\ast}$ is as large as $ 1.8 \times 10^{-7}$ cm$ ^3$ s$ ^{-1}$ and largely temperature-independent. Hole capture at NV$ ^-$ will thus occur via nonradiative capture into an excited state of NV$ ^{0}$ followed by fast radiative decay to the NV$ ^0$ ground state. Similarly, electron capture at NV$ ^0$ will occur via the NV$ ^0$ $ \to$ NV$ ^{-\ast}$ $ \to$ NV$ ^-$ pathway, but with a lower nonradiative capture coefficient ($ 2.1 \times 10^{-9}$ cm$ ^3$ s$ ^{-1}$ at 300 K). Our calculated capture coefficients and rates provide essential information for analyzing charge-state dynamics.
Materials Science (cond-mat.mtrl-sci)
Submitted to Physical Review B
High-fidelity EDSR in Si/SiGe Wiggle Wells
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2026-05-26 20:00 EDT
Hudaiba Soomro, Minyoung Kim, Avani Vivrekar, M. A. Eriksson, Benjamin D. Woods, Mark Friesen
Si/SiGe quantum wells that incorporate Ge concentration oscillations, known as long-period Wiggle Wells, have previously been shown to enhance the Dresselhaus spin-orbit coupling (SOC) of conduction-band electrons. Such intrinsic SOC is desirable when performing spin-qubit gate operations based on electric dipole spin resonance (EDSR) because it eliminates the need for external micromagnets. However, random-alloy disorder plays a key role in the valley physics of this materials system by spatially randomizing the valley phase $ \phi_{s,s}$ , and has not been fully accounted for in recent EDSR analyses. Here, we show that alloy disorder affects EDSR in two main ways. First, the Rabi frequency $ \Omega$ acquires a dependence on the valley phase, given by $ \cos\phi_{s,s}$ , which causes spatial randomization of $ \Omega$ . Despite this variability, we show that fast EDSR can be achieved at most locations across a given sample. Second, a new Rabi driving mechanism emerges, enabled by valley dipoles that result from disorder and the hybridization of ground and excited valley states in response to an EDSR driving field. This mechanism is dominant in regions of low valley splitting. Alloy disorder can therefore strengthen EDSR, but it can also cause gradients in $ \Omega$ that lead to dephasing in the rotating frame. We explore this problem by first identifying “sweet spots,” where EDSR is relatively insensitive to electric-field fluctuations. We then show that high-fidelity Rabi oscillations can be achieved in the presence of realistic charge noise. Our results demonstrate that the Wiggle Well is a promising platform for high-quality, micromagnet-free gate operations.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Quantum Physics (quant-ph)
18 pages
Photoluminescence Identification of Multiple Local Eu3+ Environments in BaTiO3 Ceramics
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-05-26 20:00 EDT
Yutong Cai, Duanting Yan, Hancheng Zhu
BaTiO3 is a model ferroelectric perovskite whose properties are highly sensitive to local structure, defect chemistry, and dopant distribution. However, conventional diffraction mainly probes the average lattice and can miss subtle changes in the local coordination environment. Here we use Eu3+ photoluminescence as a local optical probe for BaTiO3 ceramics prepared at 1250, 1300, and 1350 °C. X-ray diffraction and Raman spectra show that all samples retain the tetragonal BaTiO3 phase within the detection limits of these techniques. Electron microscopy reveals a porous ceramic microstructure with temperature-dependent grain growth, and elemental mapping confirms a spatially distributed Eu signal. The Eu3+ excitation and emission spectra show strong sensitivity to the processing temperature. The sample sintered at 1250 °C gives the highest emission intensity, while higher sintering temperatures change the relative intensity of the charge-transfer band and the 4f-4f transitions. Most importantly, the 5D0 to 7F0 emission contains two reproducible components near 579.5 nm and 582.2 nm. Their relative weights vary with sintering temperature, and double-exponential decay at 612 nm further supports the presence of multiple Eu-related local environments. These results show that Eu3+ luminescence provides a sensitive route to track local structural heterogeneity in BaTiO3 ceramics.
Materials Science (cond-mat.mtrl-sci), Optics (physics.optics)
9 pages, 9 figures
Native defects and erbium impurities in CaWO4
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-05-26 20:00 EDT
Minseok Choi, Mark E. Turiansky, BaiQing Zhao, Jeff D. Thompson, Chris G. Van de Walle
We perform hybrid density functional calculation to study the energetics, electronic properties, optical transitions, and migration barriers of native defects in CaWO$ 4$ . Oxygen and calcium vacancies are most likely to form in the absence of doping, but interstitials could also incorporate. Tungsten-related defects are unlikely to be present. The positively charged $ V{\rm O}$ and the negatively charged $ V_{\rm Ca}$ are likely to form complexes. Calculated optical transition levels indicate that experimentally observed absorption and emission peaks can be attributed mainly to oxygen-related defects. Calculations of migration barriers allow us to conclude that Ca$ i^{2+}$ , $ V{\rm O}^{2+}$ and O$ i^{2-}$ are highly mobile, even below room temperature. We have also examined Er dopants, finding that erbium easily substitutes on the Ca site in a positive charge state. Erbium can form complexes with $ V{\rm Ca}$ and O$ _i$ , which would deactivate the Er. If Er is introduced by implantation, Er interstitials are likely present, which will produce emission that is prone to spectral diffusion and blinking. Our calculated properties of Er$ _i$ explain why annealing at modest temperatures allows the interstitials to move into substitutional sites and point defects to move away, resulting in stable emission.
Materials Science (cond-mat.mtrl-sci)
Analytic Origin of Green-Function Compression in the Intermediate Representation
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2026-05-26 20:00 EDT
Information compression plays a central role in diverse fields of modern science and technology, from communication theory to machine learning. In condensed-matter physics, the intermediate representation (IR) basis has recently been developed as an efficient method for compressing imaginary-time Green functions, which are fundamental quantities for describing quantum many-body systems. This compression relies on the rapid decay of the singular values with the basis index and the unusually weak growth of the effective rank with inverse temperature. Because of these useful features, the IR basis is now widely used as a standard method in quantum many-body calculations. However, the analytic origin of its compression capability has remained unclear. Here we uncover a finite-Laplace-transform structure underlying the IR kernel, which reveals that the eigenfunctions of the IR kernel admit a natural expansion in terms of classical special functions, the oblate spheroidal wave functions. This finite-Laplace-transform structure also enables us to analytically clarify the compression mechanism of the IR basis. Our results provide a mathematical foundation for the compression of imaginary-time Green functions, connecting quantum many-body physics with theories of information compression and finite integral transforms.
Strongly Correlated Electrons (cond-mat.str-el), Mathematical Physics (math-ph)
8 pages, 2 figures
Prediction of 1:1 kagome metals with superconductivity and band topology
New Submission | Superconductivity (cond-mat.supr-con) | 2026-05-26 20:00 EDT
Na Jiao, Shu-Xiang Qiao, Pan Zhou, Hong-Yan Lu, Ping Zhang
Kagome superconductors featuring topologically nontrivial band structures have attracted extensive research interest. FeSn and CoSn is a new kind of kagome material with intrinsic magnetism, which suppresses the emergence of superconductivity. Here, we theoretically predict a new kind of 1:1 kagome MSn (M=transition metal), which exhibit intrinsic superconductivity and nontrivial band topology by first-principles calculations. Among twenty-seven candidates, MSn (M= Mo, Hf, Nb, Ta, W, Ti) are theoretically identified as both dynamically and thermodynamical stable. And, five non-magnetic MSn (M= Mo, Hf, Nb, Ta, W) exhibit phonon-mediated superconductivity. Especially, the d orbitals bands display Dirac points and van Hove singularities near the Fermi level, which contribute to the emergence of topology and the electron-phonon coupling (EPC). More interestingly, MoSn, HfSn and NbSn show nontrivial topological band structure at the Fermi level. Thus, the predicted MSn establish a platform integrating superconductivity and topological order.
Superconductivity (cond-mat.supr-con)
Tuning quantum tunneling in WSe$_2$ via strain engineering
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2026-05-26 20:00 EDT
Rachid El Aitouni, Hasna Chnafa, Clarence Cortes, David Laroze, Ahmed Jellal
We present a comprehensive theoretical study of strain-engineered quantum transport in monolayer tungsten diselenide (WSe$ _2$ ) in the presence of an electrostatic scalar potential. By incorporating strain effects within a low-energy Dirac framework, we analyze their impact on spin- and valley-resolved transmission, conductance, and polarization. The applied potential barrier partitions the system into three distinct regions, allowing for an analytical derivation of the wave functions in each domain. Enforcing continuity conditions at the interfaces yields exact expressions for the transmission and reflection amplitudes. The transmission probability is evaluated from the corresponding current densities, while the conductance is obtained using the Landauer-Büttiker formalism, enabling a quantitative determination of spin and valley polarizations. Our numerical analysis reveals that strain acts as a powerful tuning parameter that reshapes the electronic dispersion and strongly modifies transport characteristics. In particular, the transmission and conductance exhibit pronounced oscillatory behavior driven by quantum interference and resonant tunneling mechanisms. More importantly, both spin and valley polarizations display substantial and highly controllable variations as functions of strain, barrier height, and incident energy. These results demonstrate that strain and electrostatic engineering provide an efficient and versatile platform for manipulating spin-valley degrees of freedom in WSe$ _2$ . The ability to tailor polarization and interference effects suggests promising opportunities for the design of next-generation spintronic, valleytronic, and optoelectronic devices based on two-dimensional transition-metal dichalcogenides.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Quantum Physics (quant-ph)
11 pages, 7 figures. Version to appear in Physica E 2026
Revisiting spin Hamiltonian parameters in a Kitaev material via Bayesian optimization of magnetization curves
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2026-05-26 20:00 EDT
Takahiro Misawa, Ryo Tamura, Kazuyoshi Yoshimi, Youhei Yamaji
Determining the spin Hamiltonian of a magnetic compound is crucial for understanding its magnetic properties. A standard approach is to derive model parameters from $ ab$ $ initio$ calculations based on the crystal structure. However, the resulting Hamiltonian can depend sensitively on methodological details of the $ ab$ $ initio$ procedure. This issue is particularly evident in $ \alpha$ -RuCl$ _3$ , a candidate Kitaev material. Here, we present an alternative, data-driven approach to determine the spin Hamiltonian parameters of $ \alpha$ -RuCl$ _3$ by Bayesian optimization of experimental magnetization curves along the $ b$ - and $ c$ -axis directions. We optimize five parameters, namely the Kitaev interaction $ K$ , off-diagonal interactions $ \Gamma$ and $ \Gamma’$ , the Heisenberg interaction $ J$ , and the $ c$ -axis $ g$ -factor $ g_c$ . The parameter set that minimizes the cost function is $ (K,\Gamma,\Gamma’,J,g_c)=(-6.0,,7.5,,-0.3,,-1.75,,2.3)$ , where the exchange couplings are in meV. We find that the cost function is insensitive to the absolute value of the Kitaev coupling $ K$ . Thus, the magnetization data alone do not determine its energy scale. The cost function also depends only weakly on $ \Gamma’$ and $ J$ , while the optimization favors a large positive $ \Gamma$ . By computing the static spin structure factor, magnetic susceptibility, and specific heat, we show that these quantities favor the large-$ \Gamma$ scenario over the small-$ g_c$ scenario and that the parameter set that minimizes the cost function yields good agreement with experiment. The combination of Bayesian optimization and accurate low-energy solvers provides an effective approach for determining parameters of spin Hamiltonians. This methodology opens a systematic route to determining spin Hamiltonians in quantum magnets from experimental data.
Strongly Correlated Electrons (cond-mat.str-el), Materials Science (cond-mat.mtrl-sci)
13 pages, 7 figures
Edge Dislocation Mediated Anomalous Charge Transfer in Face Centered Cubic High Entropy Alloys
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-05-26 20:00 EDT
Gautam Anand, Swarnava Ghosh, Suman Chabri, Markus Eisenbach
Charge transfer in concentrated alloys governs their structural stability and functional response, and can be strongly perturbed by lattice defects. In high-entropy alloys, the interaction between edge dislocations and volume misfit plays a central role in solid-solution strengthening models; however, the influence of dislocations on the local charge transfer has not been explicitly investigated. In this work, large-scale ab initio calculations are employed to examine the dislocation-mediated charge transfer in CoNi, CoCrNi and CoCrFeMnNi alloys. The calculations reveal an anomalous charge redistribution near edge dislocation cores, including deviation from the conventional electronegativity trend. The observed behavior is shown to originate from collective electronegativity equalisation effects rather than simple pairwise atomic interactions. Furthermore, the asymmetric atomic volume response within the compressive and tensile regions of the dislocation field is rationalised in terms of anomalous magneto-volume fluctuations. These results establish a direct coupling between dislocation-induced electronic redistribution and local volumetric response in chemically complex alloys. The demonstrated coupling between dislocation-mediated charge transfer and atomic volume fluctuations provides a pathway toward electronically informed solid-solutions strengthening models and defect-aware alloy design strategy for chemically complex alloys. These findings further suggest that local electronic redistribution near dislocation-cores can play a critical role in governing the deformation behavior and defect-enbergetics in high-entropy alloys.
Materials Science (cond-mat.mtrl-sci)
Strong Correlation Effect and In-gap State in the Doped Electron-Hole Two-Band Hubbard Model Based on the Dynamical Mean-Field Theory
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2026-05-26 20:00 EDT
Masashi Akiyama, Yusuke Inokuma, Yoshiaki Ono
We investigate the strong correlation effect in the spinless electron-hole two-band Hubbard model using the dynamical mean-field theory. At half filling, both the renormalization factor $ Z$ and the number of conduction electrons (valence holes) $ n_c$ decrease with increasing the interband Coulomb interaction $ U$ down to $ Z\sim 0.15$ and $ n_c\sim 0.1$ for $ U_c \sim \mbox{bandwidth}$ at which the first-order Lifshitz transition occurs from a correlated semimetal with a large effective mass $ m^\ast/m=Z^{-1}$ to a band insulator with a finite gap due to the Hartree shift. A slight hole doping $ x$ in the band insulator with a large $ U>U_c$ yields a remarkable correlated semimetal with $ Z\sim 0.1$ at $ x\sim 0.01$ , where in-gap states emerge above the valence band top and those weights increase with increasing $ x$ together with the increase in $ Z$ similar to the in-gap states observed in doped Mott insulators.
Strongly Correlated Electrons (cond-mat.str-el)
4 pages, 6 figures
Efficient cooling by ferroelectric or ferromagnetic hysteresis loops
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-05-26 20:00 EDT
An efficient cooling effect is put forward, by means of external electric or magnetic fields along hysteresis loops. A simplified model of hysteresis is used for numerical illustration. The model is based upon a second-order expansion of the energy in powers of polarization and external field. The electrocaloric effect along hysteresis loops is discussed for comparison.
Materials Science (cond-mat.mtrl-sci)
11 pages, 1 Figure
Processing-Controlled Structural Uniformity and Oxide-Ion Conduction in Na0.52Bi0.47TiO3 Ceramics Probed by Eu3+ Photoluminescence
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-05-26 20:00 EDT
Zhouyang He, Xiaoou Sun, Xinyue Wang, Duanting Yan
Sodium bismuth titanate (NBT) is a promising oxide-ion conductor,but its electrical conductivity is highly sensitive to small changes in A-site stoichiometry and processing this http URL sensitivity can reduce sample-to-sample this http URL we examine how precursor mixing controls structural uniformity and ionic transport in Na0.52Bi0.47TiO3 this http URL grinding,wet grinding with ethanol,and ball milling were compared by X-ray diffraction,electron microscopy,energy-dispersive spectroscopy,Eu3+ photoluminescence excitation spectroscopy,and electrochemical impedance this http URL processed powders and ceramics form the perovskite NBT phase within the detection limit of this http URL,the microstructure,surface A-site cation ratio,Eu3+ excitation spectra,and electrical response change strongly with the mixing this http URL monitoring of Eu3+ excitation spectra at different emission wavelengths reveals different distributions of local Eu3+ this http URL spectral-shape variations are consistent with lower structural uniformity and stronger local this http URL-ground samples show higher bulk conductivity than wet-ground samples,whereas wet-ground samples show much lower grain-boundary this http URL 600 \u2103,the dry-60 min sample reaches a bulk conductivity of 13.54 mS cm-1,while wet-30 min shows the highest grain-boundary conductivity of 13.72 mS this http URL results suggest a processing-driven trade-off between bulk defect generation and grain-boundary this http URL on this processing understanding,Ca was introduced at the A site in this http URL x=0.04 sample reaches 8.35 mS cm-1 at 500 \u2103 and 18.98 mS cm-1 at 600 \u2103.
Materials Science (cond-mat.mtrl-sci), Optics (physics.optics)
Rheotaxis of microswimmers in colloid-laden channel flow
New Submission | Soft Condensed Matter (cond-mat.soft) | 2026-05-26 20:00 EDT
Margam Ramprasad, Shubhadeep Mandal, Pallab Sinha Mahapatra
Microswimmers are often found in heterogeneous and crowded environments within narrow conduits under external flow conditions, enabling them to perform interesting translational and rotational maneuvers, such as swimming in the upstream direction, following walls, and oscillatory motion. Studying such systems helps us understand the motility behaviors of microswimmers (pushers, pullers, or neutrals) and develop applications such as targeted drug delivery. To study the motion of microswimmers in a channel flow with the presence of hard, monodisperse spherical colloids, we adopted the spherical squirmer model to represent the microswimmers, along with a mesoscale simulation framework, multi-particle collision dynamics (MPCD), to represent the background fluid. In the absence of colloids, a squirmer in a microchannel flow develops an increased probability of moving away from the walls and oscillates between the walls as the flow speed increases compared to the squirmer speed, with a dominant upstream orientation near the walls. However, the presence of the colloids makes the pusher swim towards the center of the channel and upstream direction, and the puller swim away from the center of the channel at low flow speeds. At high flow speeds, the flow carries all the squirmers, resulting in a dominant upstream direction in the channel center. We observe that this leads to a decrease in the local velocity of the squirmer in the flow direction for pusher, neutral, and puller-type squirmers. We also observe that, for a constant colloidal packing fraction, the local velocity magnitude of the puller along the flow direction is less than that of the pusher.
Soft Condensed Matter (cond-mat.soft), Fluid Dynamics (physics.flu-dyn)
Programmable dipolar interaction geometry selects stripe-family order in a molecular lattice quantum simulator
New Submission | Quantum Gases (cond-mat.quant-gas) | 2026-05-26 20:00 EDT
Microwave-dressed polar molecules offer a route to lattice quantum simulators in which the angular form of long-range dipolar interactions, not only their overall strength, can be engineered. We study this setting in a minimal hard-core Bose lattice model on a square optical lattice, with particles interacting through a sign-changing non-axisymmetric dipolar tail \mathcal V(\mathbf r)\propto (x^2-y^2)/(x^2+y^2)^{5/2} that is repulsive along one lattice axis and attractive along the other. Using worm-algorithm path-integral quantum Monte Carlo simulations, supported by a hard-core spin mapping and a Gutzwiller soft-mode diagnostic, we find two regimes controlled by t/V: at larger t/V the system remains superfluid but develops a pronounced directional stiffness anisotropy, while at smaller t/V it forms a stripe solid selected in the (q,0) axial family, corresponding to real-space stripes parallel to y. The leading ordering wave vector remains in this axial family but reorganizes with filling, showing that the robust ordered object is a family of stripe states rather than one fixed commensurate Bragg peak. Near the closure of the stripe lobe, averaged observables can mimic a narrow supersolid signal; measurement-resolved stripe structure-factor histograms instead reveal first-order switching between superfluid and stripe-solid sectors. NaCs lattice estimates place the relevant V/t window within reach of modest effective dressed dipole moments, linking the predicted stripe-family order and its experimental diagnostics to accessible molecular quantum-simulation scales.
Quantum Gases (cond-mat.quant-gas)
14 pages, 8 figures
Target-Distribution-Guided Cross-Functional Fine-Tuning of Machine-Learning Interatomic Potentials
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-05-26 20:00 EDT
Yuki Nagai, Bo Thomsen, Motoyuki Shiga
Cross-functional fine-tuning of machine-learning interatomic potentials (MLIPs) is often treated as a relabeling problem, where configurations generated at one density-functional level are relabeled using a higher-fidelity target functional. However, the resulting training data may be drawn from the wrong equilibrium distribution, because the statistical weights of configurations change across exchange–correlation functionals. Here we address this distribution mismatch using a target-distribution-guided workflow based on self-learning hybrid Monte Carlo (SLHMC), in which trial configurations are proposed by a machine-learning potential and accepted or rejected using target-functional density-functional-theory energies. Using rutile TiO$ _2$ as a test system, we fine-tune the MACE-MP-0 foundation potential toward PBE, r$ ^2$ SCAN, and HSE06 target functionals. The resulting adapted potentials reproduce target-anchored nearest-neighbor Ti–O distributions, radial distribution functions, and the NPT cell metrics examined here more accurately than the foundation-model and off-target relabeling controls considered in this work. In particular, HSE06-guided fine-tuning improves structural and thermodynamic properties that are difficult to access with direct hybrid-functional molecular dynamics because of the computational cost of exact exchange. These results indicate that target-distribution coverage is an essential component of cross-functional MLIP transfer, and that accurate target-level labels alone may be insufficient when the configurational distribution is mismatched.
Materials Science (cond-mat.mtrl-sci), Computational Physics (physics.comp-ph)
23 pages, 9 figures
Lateral Shift as a Control Knob for Localization Transitions in a Quasiperiodic Ladder
New Submission | Disordered Systems and Neural Networks (cond-mat.dis-nn) | 2026-05-26 20:00 EDT
Bing Shao, Guangjie Zhang, Longwen Zhou, Jiangbin Gong, Weiwei Zhu
This work reports rich localization-delocalization transitions in a quasiperiodic ladder, of which the two legs are subject to the same quasiperiodic onsite potential but can be shifted laterally relative to each other. It is found that the lateral shift between the two legs effectively generates a magnetic flux in the reciprocal momentum space. The lateral shift thus offers a control knob, allowing us to access and simulate rich phenomena including magnetic-flux-enhanced localization, magnetic-flux-suppressed localization, and magnetic-flux-induced reentrant localization transitions. The underlying physical mechanisms as well as the phase boundaries separating localized, mixed, and extended phases are both qualitatively and quantitatively understood, based on a band-structure analysis that employs a commensurate approximation to the quasiperiodic potential, requiring only unit cells of small to modest sizes. Our work provides a highly tunable platform for exploring localization physics with promising applications such as quantum switching, and a broadly applicable approach for understanding localization-delocalization transitions in quasiperiodic systems.
Disordered Systems and Neural Networks (cond-mat.dis-nn), Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Quantum Physics (quant-ph)
8 pages, 4 figures
Superconductivity in Al-based high-entropy alloys TiHfNbTaAl and TaNbHfZrAl
New Submission | Superconductivity (cond-mat.supr-con) | 2026-05-26 20:00 EDT
Junjin Huang, Wenbo Sun, Longfu Li, Shuangyue Wang, Jingjun Qin, Rui Chen, Zaichen Xiang, Yucheng Li, Lingyong Zeng, Huixia Luo
Since the first report of a high entropy alloy (HEA) superconductor in 2014, HEAs have continued to captivate the interest of superconducting researchers. Owing to the significant degree of disorder inherent in these systems, they serve as exemplary models for examining the properties of materials that exist in states intermediate between crystalline and amorphous structures. Here we present the superconductivity properties and crystal structure of TaNbHfZrAl and TiHfNbTaAl HEAs, which both have the VEC of 4.2 and body centered cubic (BCC) structure. Through resistivity, magnetic, and specific heat measurements, we prove that both samples are the bulk type-II superconductors with a critical temperature Tc of 5.5 K for TaNbHfZrAl and Tc of 3.2 K for TiHfNbTaAl. The Tc of HEA superconductors is influenced by the VEC and the element composition. And the incorporation of Al in high disorder HEA superconductors causes a more crystallinelike Tc dependence.
Superconductivity (cond-mat.supr-con)
22 pages, 5 figures
Superconductor Science and Technology, 2026
Assessment of a GW-BSE approximation scheme on an asymmetric two-dimensional interacting electron system in a perpendicular magnetic field
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-05-26 20:00 EDT
A GW-BSE approximation scheme is assessed by applying it to a model of asymmetric two-dimensional (2D) interacting electron system. The model is assumed to have a parabolic band characterized by two independent effective mass parameters. A perpendicular magnetic field is applied to the asymmetric 2D electron system, and the well-known Kohn’s theorem is still valid, i.e., the cyclotron resonance is not affected by the electron-electron interaction. This theorem imposes a constraint on the approximation scheme employed in the treatment of electron-electron interaction. In the present study, the Green’s function is calculated in the self-consistent Hartree-Fock approximation. The electron density correlation function is calculated by solving a Bethe-Salpeter equation (BSE) in the ladder diagram approximation. It is found that, the excitation frequency near the cyclotron resonance frequency approaches a value that is lower than the cyclotron resonance frequency at small wave vectors, when two effective masses are different. When two effective masses are the same, the excitation frequency approaches the cyclotron resonance frequency at small wave vectors as required. Our findings suggest that the approximation scheme used in this theoretical investigation fails to satisfy the requirement due to the Kohn’s theorem, and one should go beyond this approximation scheme.
Materials Science (cond-mat.mtrl-sci)
Topological metal-insulator transitions in one-dimensional non-Hermitian quasicrystals: beyond PT-symmetry
New Submission | Disordered Systems and Neural Networks (cond-mat.dis-nn) | 2026-05-26 20:00 EDT
Guangjie Zhang, Bing Shao, Longwen Zhou, Jiangbin Gong, Weiwei Zhu
One-dimensional non-Hermitian quasicrystals with parity and time-reversal (PT) symmetry can simultaneously exhibit localization-delocalization transition, topological phase transition, and PT-symmetry-breaking transition. This motivates this work to investigate how the absence of PT symmetry impacts topological metal-insulator transitions in non-Hermitian quasicrystals. We propose a non-Hermitian quasiperiodic model that generally does not preserve PT symmetry and demonstrate that, in most parameter regions, such a system supports triple phase transitions that encompass localization, topology, and degeneracy-breaking. The system may also exhibit a particular type of localization-delocalization transition analogous to the Hermitian case, namely, without activating topological phase transitions or degeneracy-breaking transitions. Our work extends the topological metal-insulator transitions previously studied in PT-symmetric systems to a more general class of non-Hermitian setting, and further reveals that non-Hermitian systems can host distinct types of localization behavior.
Disordered Systems and Neural Networks (cond-mat.dis-nn), Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Quantum Physics (quant-ph)
8 pages, 6 figures
Cascaded Four-Wave Mixing on Quantum Paraelectrics for On-chip Cryogenic Microcombs
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2026-05-26 20:00 EDT
Harikrishnan Sundaresan, Prasad Muragesh, Madhu Thalakulam
Here, we demonstrate an on-chip cryogenic microwave frequency-comb on a planar superconducting resonator fabricated on Strontium titanate(STO), a quantum paraelectric material. The material’s Kerr-type nonlinearity arising from the quantum paraelectric phase, an underexplored state, enables pronounced resonance shifts, Duffing-like bifurcations and comb generation via cascaded foure-wave mixing. Our results establish STO resonators as a low power, cryogenically compatible platforms for nonlinear microwave photonics, with applications in scalable quantum control and on-chip frequency synthesis.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Optics (physics.optics)
18 pages
Intrinsic Topological Control of the Orbital Hall Effect in Buckled Dirac Materials
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2026-05-26 20:00 EDT
Madiha Zia, Muzamil Shah, Kashif Sabeeh, Gao Xianlong, Reza Asgari
We study the orbital Hall response in buckled two-dimensional Dirac materials using a unified framework that includes an antiferromagnetic exchange field, a perpendicular electric field, and intrinsic spin-orbit coupling. We show that the orbital Hall conductivity is considerably boosted around band-inversion points and shows different signatures across multiple electronic phases using a low-energy massive Dirac model in conjunction with Berry-curvature-based linear response theory. We find a series of quantum spin Hall, valley Hall, and anomalous Hall regimes by methodically adjusting external fields, and demonstrate how the evolution of the orbital response is controlled by the redistribution of Berry curvature between spin and valley sectors. We examine the impacts of finite temperature in more detail and find that although the response s size is suppressed by thermal broadening, the distinctive phase-dependent features remain robust. Our findings demonstrate that orbital Hall conductivity offers a sensitive band topology probe in Dirac systems and emphasize buckled two-dimensional materials as a flexible platform for engineering tunable orbital currents for orbitronic applications.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
Orbital-Engineered Altermagnetism in Two-Dimensional Square Lattices
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-05-26 20:00 EDT
Yixuan Che, Peibo Xu, Haifeng Lv, Xiaojun Wu, Jinlong Yang
Altermagnetism is characterized by even-parity spin-momentum locking in spin-split bands despite zero net magnetization and negligible spin-orbit coupling. Here, we formulate a microscopic framework that links altermagnetic splitting in two-dimensional (2D) square lattices to orbital character. Using tight-binding models and symmetry analysis, we show that, within the minimal antiferromagnetic square-lattice model, single-orbital lattices remain spin-degenerate, whereas interwoven dual-orbital configurations lift Kramers degeneracy and generate d-wave or g-wave altermagnetic states. The spin-splitting originates from orbital anisotropy in the same-spin hopping channels. Guided by this framework, we identify M-TCNX (M = Cr, Mn, Fe; TCNX = TCNE, TCNQ) metal-organic framework monolayers with mcm topology as candidate g-wave altermagnets. Our work provides a symmetry-explicit wavefunction-level design framework for orbital-controlled altermagnetism in 2D square lattices.
Materials Science (cond-mat.mtrl-sci), Chemical Physics (physics.chem-ph)
7 pages, 4 figures
A particle-resolved rheological study of chirality transfer and odd transport
New Submission | Statistical Mechanics (cond-mat.stat-mech) | 2026-05-26 20:00 EDT
Rémi Goerlich, Alexander P. Antonov, Kristian Stølevik Olsen, Lorenzo Caprini, Christian Scholz, Hartmut Löwen, Yael Roichman
Chirality, or the breaking of mirror symmetry, appears across all scales in nature, from molecular conformations to the dynamics of bacterial collectives. Environments composed of such symmetry-breaking constituents can give rise to emergent physical phenomena, particularly in the transport and response of embedded tracers. Yet it remains unclear how chiral environments influence such tracers and through which microscopic mechanisms anomalous responses emerge. Here, we present a particle-resolved study of these systems, demonstrating chirality transfer and odd transport of an object embedded in a chiral active bath. In a rheological experiment, a symmetric passive tracer is driven through collisions with the particles of a non-equilibrium chiral bath. Combining table-top experiments, many-body simulations, and a reduced coarse-grained theory, we demonstrate that local collisions transfer chiral active dynamics to the tracer, which displays circular trajectories. We show that the same mechanism gives rise to a systematic transverse drift under a constant pulling force. Crucially, we identify nonlinear friction as an essential factor that rectifies these transferred chiral active fluctuations into a macroscopic odd response. Our results reveal a microscopic mechanism for odd transport in chiral active matter and provide general insights into transverse transport in driven non-equilibrium systems.
Statistical Mechanics (cond-mat.stat-mech), Soft Condensed Matter (cond-mat.soft)
First-principles finite-size correction schemes for point defects of Cu$_3$N
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-05-26 20:00 EDT
Abdul M. Reyes, Sebastian E. Reyes-Lillo, Eduardo Menéndez-Proupin
Point defects play a key role in determining semiconductor properties, such as electrical conductivity and photoluminescence, and often enable functional behavior. Accurate first-principles supercell simulations of point defects require reliable finite-size corrections. In this study, we combine PBE+U structural relaxations with HSE hybrid-functional calculations to determine defect formation energies and thermodynamic transition levels of Cu$ _3$ N. Finite-size trends are quantified using $ \Gamma$ -point calculations in supercells containing 256, 864, and 2048 atoms. We assess and extend the Makov-Payne and Lany-Zunger correction schemes by introducing additional $ 1/L^n$ terms, together with core-level potential alignment and defect-specific scaling models. Using Cu$ _3$ N as a case study, we show that charged vacancies with strongly localized defect states are accurately described by the Makov-Payne-type scaling ($ 1/L + 1/L^{3}$ ), whereas interstitial defects with shallow or weakly localized electronic character are better captured by a hydrogenic impurity model that accounts for defect-band dispersion. Residual trends for neutral or weakly localized defects are described by higher-order polynomial fits in $ 1/L^{3}$ and $ 1/L^{4}$ . Hybrid-functional energetics corrected using PBE+U-based finite-size trends confirm the intrinsic $ p$ -type character of Cu$ _3$ N under the conditions considered and demonstrate that no single finite-size correction can be transferred across all defect types.
Materials Science (cond-mat.mtrl-sci)
13 pages, 10 figures
Unfrustrated Self-Morphing of Bulk Liquid Crystal Elastomers
New Submission | Soft Condensed Matter (cond-mat.soft) | 2026-05-26 20:00 EDT
Precise manipulation of shape-morphing responsive materials is crucial for applications in soft robotics and adaptive structures. While notable precision has been achieved in thin two-dimensional sheets, an accurate volumetric shape-morphing remains a major challenge due to geometric frustration, which inevitably generates complex, residual elastic stresses. In this work, we extend the geometric approach used for thin sheets to bulk Liquid Crystal Elastomers (LCEs). By examining their reference Ricci curvature, we formulate the minimal set of conditions required for a three-dimensional nematic director field to undergo stress-free, frustration-free deformations upon actuation. Through this mathematical framework, we identify two distinct classes of geometrically compatible bulk systems. The first class comprises twistless director fields that remain frustration-free across all temperatures, leading to holographic design principles demonstrated through “Planar” and “Smectic” LCE subfamilies. The second class features twisted configurations that exhibit unique, temperature-selective compatibility, leading to non-monotonic accumulation of internal elastic stresses that relax completely at a predefined target temperature. Our framework establishes a firm mathematical foundation for robust forward and inverse design protocols in bulk LCEs.
Soft Condensed Matter (cond-mat.soft)
11 pages, 3 figures, 5 SI pages
Light-Driven Intrinsic Perfect Superconducting Diode Effect
New Submission | Superconductivity (cond-mat.supr-con) | 2026-05-26 20:00 EDT
Makoto Ichikawa, Youichi Yanase
We demonstrate the perfect superconducting diode effect (SDE) – unidirectional supercurrent with 100% diode efficiency – in light-driven nonequilibrium systems. Although the perfect SDE is difficult to achieve in equilibrium, monochromatic light induces the perfect SDE in systems lacking inversion and time-reversal symmetries. More strikingly, multi-frequency light enables the perfect SDE even in centrosymmetric systems via dynamical symmetry breaking. Our results establish a general principle for realizing unidirectional superconducting transport based on nonequilibrium control and symmetry engineering.
Superconductivity (cond-mat.supr-con)
7 pages, 4 figures, Supplemental Material (12 pages, 3 figures)
Lattice polarons with extended interactions
New Submission | Quantum Gases (cond-mat.quant-gas) | 2026-05-26 20:00 EDT
Enrique I. Ramírez-Juárez, Genaro Lopez-Olivera, Luis A. Peña Ardila, Arturo Camacho-Guardian
Lattice impurities have recently emerged as a platform in which polarons unveil new quantum many-body states absent in free space and can serve to probe strongly correlated matter. In this work, we investigate two-dimensional lattice polarons with strong on-site repulsion and tunable nearest-neighbor interactions using a variational approach including up to one excitation of the medium. We show that extended interactions qualitatively modify the quasiparticle structure beyond the conventional attractive and repulsive polaron picture. A direct analysis of the eigenvalue spectrum reveals the presence of dark impurity states, orthogonal to the bare impurity and therefore spectroscopically dark. These states exhibit nontrivial internal structure, including dipolar symmetries in real space. Our results demonstrate that long-range interactions generate multiple quasiparticle excitations with distinct symmetry properties, highlighting the crucial role of interaction range and lattice geometry. This work opens new avenues for probing hidden quasiparticle states in lattice systems through spectroscopic and wave-function-resolved measurements.
Quantum Gases (cond-mat.quant-gas), Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
16 pages including references and one Appendix. 6 Figures, comments are very welcome. To be submitted to SciPost. Physics
First-passage time distribution of a Brownian particle harmonically confined in a viscoelastic bath
New Submission | Statistical Mechanics (cond-mat.stat-mech) | 2026-05-26 20:00 EDT
Brandon R. Ferrer, Juan Ruben Gomez-Solano
We investigate theoretically and experimentally the first passage-time properties of a spherical Brownian particle that is harmonically trapped at thermal equilibrium in a fluid at constant temperature. By using the overdamped version of the generalized Langevin equation, we derive a general expression for the probability density function of the time that the particle takes to reach for the first time the minimum of the potential starting from an arbitrary position. We show that such a first-passage time distribution can be implicitly expressed in terms of the friction memory kernel that encodes the interaction of the particle with its surroundings, and correctly reduces to previously found expressions in the case of a Markovian viscous bath. We validate our theoretical results by measuring the first-passage time of colloidal beads optically trapped in non-Markovian baths such as viscoelastic polymer and micellar solutions, as well as in a viscous glycerol/water mixture and water, which behave as Markovian media, having quantitative agreement with the derived expressions. In particular, we find that the mean first-passage time in a viscoelastic bath can surpass that in a viscous medium of the same zero-shear viscosity due to the emergence of slowly decaying tails in the first-passage time probability density of the former.
Statistical Mechanics (cond-mat.stat-mech), Soft Condensed Matter (cond-mat.soft)
8 figures
Exploring Multi-Transition-Metal NASICON Frameworks as High-Performance Cathodes for Sodium-Ion Batteries
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-05-26 20:00 EDT
Santosh Behara, Achinthya Krishna Bheemaguli, Gopalakrishnan Sai Gautam
The search for sustainable, high-performance cathodes has driven a growing interest in sodium superionic conductor (NASICON)-type phosphates for sodium-ion batteries (SIBs). To identify promising NASICONs containing earth-abundant transition metals (TMs) and to systematically examine the role of multiple TMs in influencing the various properties of NASICON cathodes, we employ density functional theory calculations to investigate nine NASICON compositions containing Mn, Cr, and/or Fe, and spanning unary, binary, and ternary combinations. Our calculations reveal that unary systems, in terms of their Na intercalation phase behavior, exhibit well-defined stabilization at intermediate Na contents ($ x$ in Na$ _x$ TM$ _2$ (PO$ _4$ )$ _3$ ), while binary and ternary systems display more complex phase behavior, with some systems showing a shift of thermodynamic minima from $ x$ = 3 to 2. Intercalation voltages highlight the dominant role of Fe$ ^{4+}$ /Fe$ ^{3+}$ redox activity in elevating average voltages ($ \sim$ 4.0 V), while Mn and Cr introduce intermediate-to-low voltage redox activity. Electronic structure data demonstrate non-systematic changes in the band gap, especially in systems containing multiple TMs. Na$ ^+$ mobility results identify mixed-TM frameworks as favorable, achieving Na$ ^+$ migration barriers in the 0.3-0.4 eV range. Importantly, we identify Na$ _x$ MnFe$ _{0.5}$ Cr$ _{0.5}$ (PO$ _4$ )$ _3$ to be a promising ternary composition for subsequent experimental validation, offering an optimal intersection of phase stability, voltages, thermodynamic (meta)stability, and Na$ ^+$ migration barriers. Together, our study provides fundamental insights into the interplay between compositional complexity, thermodynamic stability, electronic structure, and ionic transport in NASICONs, and offers actionable design principles for utilising multi-TM NASICONs as high performance SIB cathodes.
Materials Science (cond-mat.mtrl-sci)
Dynamical susceptibility and quantum Fisher information in the Su-Schrieffer-Heeger model with Hatsugai-Kohmoto interactions
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2026-05-26 20:00 EDT
Sepide Mohamadi, Jahanfar Abouie
We investigate the dynamical spin and charge susceptibilities and the associated quantum Fisher information in a class of interacting lattice models, with a primary focus on the Su-Schrieffer-Heeger model in the presence of Hatsugai-Kohmoto interactions. To provide a rigorous analytical benchmark, we contrast the response properties of the SSH-HK system with those of the single-band Hubbard and SSH-Hubbard models, treated within the random-phase approximation. While standard Hubbard-type interactions typically suppress excitation strength, we demonstrate that the SSH-HK model displays qualitatively distinct physical behavior arising from the interplay between SSH dimerization and the momentum-diagonal nature of the HK interaction. Leveraging the exact solvability of the HK term, we derive closed-form expressions for the dynamical susceptibility, revealing unique filling-controlled characteristics such as a finite response at zero wave vector and a pronounced restructuring of spectral weight across integer and fractional filling sectors. We show that the quantum Fisher information, defined as the frequency integral of the imaginary part of the susceptibility, serves as an efficient probe of these filling sectors, exhibiting distinct piecewise behavior that distinguishes integer from fractional fillings. Notably, our results indicate that the quantum Fisher information remains insensitive to topological transitions within uniform-density regimes, highlighting the limitations of standard dynamical response functions in characterizing band topology. These findings establish the SSH-HK model as a powerful analytical platform for exploring the competition between topology and strong correlations, demonstrating how dynamical susceptibilities and the quantum Fisher information provide complementary, experimentally accessible probes of many-body physics.
Strongly Correlated Electrons (cond-mat.str-el)
15 pages, 18 figures
Composition-Driven High-Entropy Alloys with Enhanced Magnetocaloric Properties
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-05-26 20:00 EDT
Nishant Tiwari, Juan Rafael Gomez Quispe, Noorbasha Bhavani Sai, Saikat Talapatra, Pedro Alves Da Silva Autreto, Varun Chaudhary, Chandra Sekhar Tiwary
High entropy alloys (HEAs) are promising magnetocaloric materials with tunable operating temperature conditions using compositional modifications. Here, we combine experiments and first principles based spin modelling to engineer magnetocaloric response in single-phase cubic HEAs consisting of earth-abundant elements such as Fe, Ni, Co, Cr, and Cu. An equiatomic (Fe20Ni20Co20Cr20Cu20) and a Fe and Co rich non equiatomic (Fe34Ni17.7Co24.8Cr15.2Cu8.3) show a continuous ferromagnetic to paramagnetic transition with Curie temperature (TC)=110 K and TC=420 K for non equiatomic. Under the 1.6 Tesla magnetic field, the investigated alloy shows the entropy change =1.24 J per kgK with relative cooling power (RCP) =92 J per kg due to a broader effective cooling span. Density functional theory simulations reveal that reducing Cu enhances the spin-polarized Fe, Co, or Ni, 3d weight near fermi level, consistent with stronger ferromagnetic exchange. Exchange couplings mapped onto a classical Heisenberg model and solved by atomistic Monte Carlo to theoretically predict TC of both the investigated alloys. A controlled theoretical Cu sweep in equimolar further confirms that increasing Cu monotonically dilutes the magnetic sublattice and lowers TC, providing a quantitative design guideline to tune magnetocaloric operating temperatures in transition metal HEAs.
Materials Science (cond-mat.mtrl-sci)
24 Pages, 6 Figures
Imaging Surface Magnetization in Altermagnetic MnTe Films
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-05-26 20:00 EDT
Ling-Jie Zhou, Senlei Li, Zi-Jie Yan, Yufei Zhao, Hongtao Rong, Zelong Xiong, Yiran Zhao, Pu Xiao, Lok Kan Lai, Hyeonhu Bae, Haoyu Liu, Chao-Xing Liu, Binghai Yan, Cui-Zu Chang, Hailong Wang, Chunhui Rita Du
Altermagnets with pronounced spin-splitting band structure, unconventional magnetic and crystal symmetries, and exotic magneto-transport properties have received immense interest in cutting-edge spintronics, materials science, and condensed matter physics research. Microscopic imaging of spontaneous magnetic domains and phases in altermagnets constitutes an important step for investigating their underlying material properties, mechanisms, and spin behaviors. Taking advantage of scanning-probe quantum microscopy, here we report nanoscale quantum sensing of a prototypical altermagnet candidate $ \alpha$ -MnTe. We visualize evanescent magnetization and the associated magnetic domains in epitaxial MnTe films, which allows external magnetic fields to control the intrinsic altermagnetic order and configurations. By evaluating a series of MnTe films with different thicknesses down to the atomic scale, we further present evidence for the interfacial origin of the observed weak magnetization and show its correlation with the anomalous Hall effect in MnTe film. Our results advance the current understanding of emergent altermagnetism, providing insights into future material design of altermagnet-integrated spintronic devices.
Materials Science (cond-mat.mtrl-sci), Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
Non-local low energy neutral excitations in a strongly disordered triangular Mott magnet Cr$_3$Se$_2$Br$_5$
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2026-05-26 20:00 EDT
Wenhao Liu, Dechen Zhang, Yuanqi Lyu, Lebing Chen, Lifang Hu, Keith M. Teddei, Yuting Zhang, Steve Shelton, Moon Kim, Xiqu Wang, Michael A. Susner, James G. Analytis, Dung-Hai Lee, Lu Li, Bing Lv, Robert J. Birgeneau
Understanding if low-energy excitations can remain itinerant in the presence of strong disorder remains a central challenge in frustrated quantum magnets, where disorder is generally expected to localize excitations through Anderson-like mechanisms. Here we report the emergence of charge-neutral itinerant excitations in a van der Waals compound Cr$ _3$ Se$ _2$ Br$ _5$ , a strongly disordered $ S = 3/2$ Mott insulator with a frustrated triangular lattice. Structural analysis reveals substantial intrinsic disorder arising from Cr-site deficiency and Se/Br-site mixing, which appear to be fixed and cannot be readily tuned. No long-range magnetic order or conventional glassy behavior is observed. In addition to its highly insulating nature, the magnetic specific heat C_mag/T and thermal conductivity \k{appa}_xx/T both exhibit linear temperature dependencies with substantial finite intercepts. In particular, a sizeable field-independent residual term $ \kappa/T \approx 0.03~\mathrm{W,m^{-1},K^{-2}}$ is observed, providing compelling evidence of itinerant low-energy excitations that carry entropy without charge. These findings conceptually advance our understanding of quantum matter by demonstrating a rare regime where the interplay of disorder, frustration, and electronic correlations actively reshapes the nature of low-energy excitations, allowing itinerant neutral excitations to coexist with strong intrinsic disorder.
Strongly Correlated Electrons (cond-mat.str-el), Materials Science (cond-mat.mtrl-sci)
18 pages, 4 figures
Thermal PBE in warm dense matter: Does it matter and is it accurate?
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-05-26 20:00 EDT
Kushal Ramakrishna, Mani Lokamani, Zhandos A. Moldabekov, Tobias Dornheim, Kieron Burke, Attila Cangi
Conditional probability density functional theory has recently been used to derive the temperature dependence of the Perdew-Burke-Ernzerhof (PBE) generalized gradient approximation (GGA) for the exchange-correlation (XC) free energy. We implement and systematically benchmark thermal PBE within Kohn-Sham density functional theory calculations of warm dense matter. Comparisons with the local density approximation (LDA) and PBE functionals, as well as thermal LDA, show that thermal PBE significantly improves the description of warm dense matter properties, including energies, forces, pressures, and electronic charge densities. In particular, thermal PBE exhibits close agreement with path integral Monte Carlo (PIMC) reference data at negligible additional computational cost. This work demonstrates the practical utility of thermal PBE as an accurate semilocal functional for simulations in the warm dense regime.
Materials Science (cond-mat.mtrl-sci), Chemical Physics (physics.chem-ph), Plasma Physics (physics.plasm-ph)
Anomalous Subsurface Vacancy Stabilization Dictated by Geometry-Electronic Decoupling on Metal Surfaces
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-05-26 20:00 EDT
Vacancy formation energetics fundamentally govern the structural integrity and catalytic behavior of metal surfaces. Contrary to conventional coordination-dependent broken-bond models, we identify an anomalous thermodynamic inversion on close-packed surfaces across Ir, Pt, Au with face-centered cubic (FCC) lattice and Be, Zn, Cd with hexagonal close-packed (HCP) lattice, where subsurface vacancies are intrinsically more stable than surface ones. Using high-throughput DFT calculations and machine learning force fields, we demonstrate that the physical origins of this anomaly are fundamentally decoupled between the two crystal systems. For the FCC trio, pronounced surface relaxation and a profound real-space electronic localization induce directional, covalent-like intralayer bonding, materializing a “geometry-electronic decoupling” mechanism. Crucially, this unconventional thermodynamic hierarchy enables a dynamic “self-healing” mechanism on Pt(111) that preserves an intact topmost layer and prevents catalytic degradation during hydrogen evolution and oxygen reduction reactions. It also successfully decoding the critical defect threshold (~8%) for lifting the Au(100) surface reconstruction. Our work challenges classical scalar defect models and provides a fresh paradigm for engineering catalyst surface integrity.
Materials Science (cond-mat.mtrl-sci)
25 pages, 5 figures
Effects of Band Symmetry on Spin-Dependent Transport in Noncollinear Antiferromagnetic Tunnel Junctions
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-05-26 20:00 EDT
Mohamed Elekhtiar, Ding-Fu Shao, Evgeny Y. Tsymbal
Antiferromagnetic tunnel junctions (AFMTJs) can exhibit large tunneling magnetoresistance (TMR), making them promising candidates for ultrafast and field-robust spintronic devices. Here, we elucidate the role of band symmetry in governing spin-dependent transport in AFMTJs. Using first-principles density-functional theory combined with quantum-transport calculations, we investigate Mn3NiN/LaAlO3/Mn3NiN (001) junctions based on the noncollinear $ \Gamma_{4g}$ antiferromagnetic phase of Mn3NiN. Although Mn3NiN exhibits a large momentum-dependent spin polarization due to broken $ PT$ symmetry, we show that the tunneling conductance is critically controlled by band symmetry of the electrode Bloch states and their symmetry-selective coupling to evanescent states in the LaAlO3 barrier. Orbital-symmetry selection rules suppress interband transmission in the parallel configuration, whereas the antiparallel configuration enables symmetry-compatible interband tunneling along the diagonal directions of the two-dimensional Brillouin zone. These additional transmission channels enhance the antiparallel conductance and reduce the TMR relative to predictions based solely on spin polarization. Nevertheless, the TMR remains exceptionally large, exceeding 2000%, while band symmetry controls the attainable magnitude of TMR in AFMTJs. Our results establish band-symmetry filtering as an essential ingredient of spin-dependent tunneling in AFMTJs.
Materials Science (cond-mat.mtrl-sci)
Non-Hermitian Twisting Theory under the open boundary condition
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2026-05-26 20:00 EDT
Chen-Hao Zhao, Jia-Rui Li, Yuping Tian, Wei-Jiang Gong
The non-Hermitian skin effect (NHSE) is a hallmark of non-Hermitian system, yet its generalized Brillouin zone (GBZ) description is restricted to periodic systems. We develop a site-resolved theory via a local scaling transformation (LST), introducing local twisting $ T_n$ to quantify metric operator $ \xi$ nontriviality. This elucidates the NHSE’s origin and uncovers the generalized multiple-channel skin effect (MCSE). Exploiting $ T_n$ ‘s translational independence, we define the Zahlen-Brillouin Zone (ZBZ), extending non-Hermitian band theory to nonperiodic and disordered lattices. Furthermore, we unify the $ \xi$ with GBZ Riemannian geometry, establishing the metric and state correspondence (MSC) as the principle for real-space localization. With a global skin index $ \mathbf\Gamma$ for phase transitions, our results provide a universal paradigm for non-Hermitian physics in both crystalline and amorphous media.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Quantum Physics (quant-ph)
6 pages, 3 figures, 1 table
Microfluidic Actuation by Einstein-de Haas Spin Torque
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2026-05-26 20:00 EDT
We propose spin-current microfluidic actuation of a sealed liquid metal. Spin angular momentum injected from Pt contacts enters the liquid as an Einstein-de Haas torque and is converted through micropolar angular-momentum balance into viscous flow without pressure drive, moving walls, magnetic fields, Lorentz forces, or charge flow through the liquid. The dc velocity obeys universal spin-diffusion scaling, and the finite-frequency spin-mechanical admittance resolves viscous momentum diffusion, spin transport, microrotation relaxation, and interface transparency of the liquid-metal channel.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Fluid Dynamics (physics.flu-dyn)
15 pages, 3 figures
Beyond Local Detailed Balance: Microscopic Rates Reshape Nonequilibrium Phase Behavior
New Submission | Statistical Mechanics (cond-mat.stat-mech) | 2026-05-26 20:00 EDT
Takahiro Kanazawa, Kyogo Kawaguchi, Kyosuke Adachi
Local detailed balance (LDB) is a central guiding principle for modeling nonequilibrium stochastic dynamics, yet it only constrains the ratio of forward and backward transition rates and does not fix the steady state. Although the functional form of rates under the same LDB has been shown to affect correlation properties in weakly interacting systems, whether it can reshape phase behavior in strongly interacting systems remains unclear. Here, for a two-dimensional driven lattice gas with attractive nearest-neighbor interactions, we consider hopping rates with a parameter that preserves the same LDB but tunes asymmetry along the driving force. We find that this parameter controls qualitative phase behavior: in the homogeneous phase, it reverses the sign of the structure-factor discontinuity and hence the anisotropy in long-range density correlations; in the phase-separated regime, it switches the orientation of anisotropic patterns and their long-time stability. Both effects are coherently captured by an approximate fluctuating hydrodynamic equation. The results demonstrate that, in contrast to equilibrium systems, nonequilibrium phase behavior depends on specific dynamical rules even when following the same LDB.
Statistical Mechanics (cond-mat.stat-mech), Soft Condensed Matter (cond-mat.soft)
9 pages, 6 figures
Three-Dimensional Atomic-Scale Structural Transformation in a SrTiO3 Grain Boundary
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-05-26 20:00 EDT
Xiaoyue Gao, Jiake Wei, Bo Han, Junpin Luo, Ruilin Mao, Xiaowen Zhang, Xiaomei Li, Ryo Ishikawa, Bin Feng, Naoya Shibata, Yuichi Ikuhara, Peng Gao
Grain boundaries (GBs) in complex oxides play critical roles in governing their functional properties, which are intrinsically linked to their three-dimensional (3D) atomic configurations and local chemical environments that can deviate markedly from those of the bulk. However, the 3D atomic structures of GBs remain poorly understood due to the projection limitations of conventional (S)TEM. Here, using multislice electron ptychography, we resolve the 3D atomic structure of a {\Sigma}13(510)/[001] tilt GB in SrTiO3 with simultaneous visualization of both cation and oxygen columns. Depth-resolved reconstruction reveals pronounced structural inhomogeneity along the GB, uncovering a transition from the canonical symmetric configuration (STR1) to an asymmetric configuration (STR2) that is hidden in conventional projection imaging. Quantitative analysis of atomic-column intensities demonstrates that these two GB configurations possess distinct local chemical and vacancy distributions. By further mapping the atomic displacement fields, we reveal that the transformation between STR1 and STR2 proceeds via local atomic shuffling at the GB core and collective shear displacement in the adjoining grains, mediated by the step and dislocation character of the junction, respectively. Moreover, analysis of oxygen octahedral rotations reveals a strong dependence on the local atomic structure with pronounced asymmetry around the STR2 region. These findings establish a direct link among the 3D atomic structure, local chemical composition, and lattice order parameters at the GB, underscoring the critical importance of depth-resolved characterization in understanding and engineering GB-mediated functionalities in complex oxides.
Materials Science (cond-mat.mtrl-sci)
Experimental and computational diffusion analysis in Ni-X binary and Ni-Al-X (X = Cr, Mo, Ta, W, Re) ternary systems
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-05-26 20:00 EDT
Ankur Srivastava, Suman Sadhu, Satyam Kumar, Ujjval Bansal, Raju Ravi, Saswata Bhattacharyya, Gopalakrishnan Sai Gautam, Aloke Paul
An extensive diffusion analysis is presented for binary Ni-X and ternary Ni-Al-X (X = Cr, Mo, Ta, W, Re) systems, which play a crucial role in microstructural evolution and phase stability in Ni-Al-based superalloys. Specifically, we highlight changes in the diffusion coefficients of X in the presence of Al and compare diffusional interactions across systems considered. First-principles calculations, combined with activation energies derived from temperature-dependent experiments, reveal consistent trends in Ni-X systems, with variations in activation energies largely attributed to differences in migration energies. In ternary systems, diffusion coefficients estimated from intersecting diffusion profiles show that the main interdiffusion coefficient of X is comparable to its binary counterpart, with similar activation energies. However, cross-diffusion coefficients are shown to significantly influence fluxes, either enhancing or reducing diffusion lengths depending on the relative directions of diffusing elements. For Ni-Al-Re, a single-profile method is employed to overcome uncertainties in estimating composition gradients at the near-end-member intersecting composition. The diffusion coefficients obtained correlate well with the nature of diffusion paths when represented on Gibbs triangles. To extend these findings, a physics-informed neural network (PINN) optimization method is applied to extract composition-dependent diffusion coefficients across the full composition range. The analysis demonstrates the necessity of incorporating experimentally estimated diffusion coefficients as equality constraints, without which optimization reliability is compromised. Overall, the results establish a robust framework for diffusion studies in Ni-Al-X systems, highlighting the critical role of cross-diffusion effects and constraint-enhanced numerical methods.
Materials Science (cond-mat.mtrl-sci)
Disentangling the contributions of individual cations to magnetic order in a spinel high entropy oxide
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-05-26 20:00 EDT
Mario Ulises González-Rivas, Chun-Fu Chang, Martin Bluschke, Jessica Freese, Peter Bencok, Ronny Sutarto, Teak D. Boyko, Robert J. Green, George A. Sawatzky, Liu Hao Tjeng, Alannah M. Hallas
High entropy oxides (HEOs) can possess long-range ordered magnetic states despite their extreme chemical disorder. Very little is known about how the different chemical constituents in HEOs contribute to the emergence of these magnetic states. In this work, we leverage element-specific magnetometry attained via x-ray magnetic circular dichroism (XMCD) to understand how magnetic order is driven in two ferrimagnetic spinel-structured HEOs with compositions (Cr,Mn,Fe,Co,Ni)$ _3$ O$ _4$ and (Cr,Mn,Fe,Co,Ni)$ _{2.4}$ Ga$ _{0.6}$ O$ _4$ . We find that while the magnetic transition is simultaneous for all chemical species, the rate at which their magnetic moments grow is strongly cation dependent. This behavior is explained by the varying $ \textit{3d}$ crystal field level fillings of the magnetic cations, which in turn determine their ability to participate in the different magnetic exchange pathways available in the spinel structure. Dominant $ A$ -$ B$ sublattice exchange enables some species to harden rapidly ($ \textit{e.g.}$ tetrahedral Fe$ ^{3+}$ and octahedral Ni$ ^{2+}$ ) while others exhibit a sluggish transition due to frustration from competing interactions ($ \textit{e.g.}$ octahedral Fe$ ^{3+}$ and Cr$ ^{3+}$ ). Non-magnetic substitution suppresses these differences, introducing broken magnetic linkages that relieve frustration. Tailoring the magnetism of HEO spinels therefore requires detailed knowledge of both their site selectivities and their exchange pathways.
Materials Science (cond-mat.mtrl-sci)
Local Structural Signatures of Shear Bands in Metallic Glasses via Electron Nanodiffraction
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-05-26 20:00 EDT
Huyen T. Pham, Daniel East, Chunguang Tang, Matteo Baggioli, Alessio Zaccone, Timothy C. Petersen, Amelia C. Y. Liu
Structural changes in a glass due to deformation are subtle and difficult to quantify using conventional imaging and diffraction techniques. Additionally, transmission electron microscopy (TEM) sample preparation using energetic ions often causes structural modifications that are challenging to detect in disordered materials. By preparing inverted cross-sectional transmission electron microscopy lamellae of shear bands formed during bending, and employing cryogenic ion polishing to minimize preparation artefacts, we preserve the intrinsic atomic structure. Using sensitive, new parameters derived from electron nano-diffraction, we directly probe the local nano-scale structure in the plastic zone beneath surface shear steps in metallic glasses. Mapping of local centrosymmetry and strain reveals nanoscale, stripe-like regions oriented at 45 degree to the applied strain where strain has localized. These regions exhibit a high density of local atomic structures that have transformed to configurations with reduced centrosymmetry and increased magnitudes of shear and normal strain. Our results demonstrate that plastic deformation in metallic glasses arises from coordinated nanoscale structural transformations, providing direct experimental insight into a long-standing problem.
Materials Science (cond-mat.mtrl-sci)
Non-equilibrium pathway to mesoscale ordering in ethanol-water binary liquid
New Submission | Soft Condensed Matter (cond-mat.soft) | 2026-05-26 20:00 EDT
Xinyue Jiang, Yating Shang, Jianhui Li, Zhaoyong Zou, Yanxia Zuo, Yuqun Xie
Ethanol-water mixtures are a classic example of thermodynamic non-ideality, yet the structural origin of their pronounced anomalies, such as volume contraction and a large negative excess entropy, has remained a long-standing puzzle. Here, we demonstrate these anomalies are not equilibrium properties but calorimetric fingerprint of an arrested phase transition. By imposing periodic thermal oscillations, we drive a 50% (v/v) ethanol-water system along a complete hierarchical self-assembly pathway that progressed from ethanol clusters to water-containing droplets, then to acicular flakes, and finally to micron-scale ordered ethanol aggregates. Fluorescence spectroscopy, two-dimensional correlation analysis and nuclear magnetic resonance revealed the underlying non-equilibrium molecular mechanism: a periodic perturbation of the water-dominated hydrogen-bond network initiates a ethanol-water coexistence intermediate, ultimately leading to the stable ordered assembly of an ethanol-rich phase. Our finding demonstrated that periodic physical perturbations capable drive spontaneous ordering across multiple length scales in a simple binary mixture, providing a kinetic perspective on the structural origin of solution non-ideality, and carry general implications for self-assembly strategies in soft matter.
Soft Condensed Matter (cond-mat.soft), Atomic Physics (physics.atom-ph)
AI-Driven SERS for Non-invasive and Label-Free Extracellular Vesicle Detection Across Cellular Origins in Tears and Sweat
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2026-05-26 20:00 EDT
Yang Li, Xiaoming Lyu, Ling Xia, Kuo Zhan, Haoyu Ji, Lei Qin, Seppo J. Vainio, Jian-An Huang
Wearable sensing technology capable of point-of-care, continuous and non-invasive analysis of exosomes in biofluid such as tears and sweat is an essential part for future personalized medicine. Major detection and identification methods of cell secreted Extracellular Vesicles (EVs) often require labeling and are time-consuming, resulting in low efficiency in EV mechanism research and disease diagnosis. While the label-free Surface-enhanced Raman spectroscopy (SERS) has been combined with deep learning model for EV identification in blood, their application to non-invasive detection of EVs in tears and sweat are missing. Here, we filled this gap by developing an artificial intelligence (AI)-assisted Surface-enhanced Raman spectroscopy (SERS) method based on salt-induced nanoparticle aggregation for fast EV identification in tears and sweat with high accuracy. Significantly, our label-free detection and AI differentiation of EVs from 6 cell lines (HepG2, Hela, 143B, LO-2, BMSC, H8) achieved the identification of EVs in tear fluids from 7 different disease sources with accuracies >92%. Our results showed that this platform can not only distinguish EVs from multiple cell sources but also generate highly reproducible and selective EV signals in tear fluids without a need for chemical labeling or separation steps. Molecular dynamics simulations revealed that silver atoms (Ag) form electrostatic interactions with oxygen atoms of multiple amino acid residues in proteins, suggesting a high affinity. This strategy realizes ultra-sensitive and anti-interference detection of EVs, providing a new idea for the rapid diagnosis of clinical diseases.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Data Analysis, Statistics and Probability (physics.data-an), Optics (physics.optics), Quantitative Methods (q-bio.QM)
7 figures, 26 pages
Spin layer groups and their corepresentations
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-05-26 20:00 EDT
Zeying Zhang, Gui-Bin Liu, Mu Tian, Run-Wu Zhang, Zhi-Ming Yu, Yugui Yao
Spin layer groups are the crystallographic symmetry groups with a periodic plane, and their symmetry operations are inherited from three-dimensional (3D) spin space groups. However, the direct application of 3D symmetry groups to two-dimensional systems is often inadequate due to anisotropic axes and dimensional reduction. In this work, we systematically classify inequivalent spin layer groups and analytically derive their irreducible corepresentations. This classification establishes a foundational framework for investigating symmetry-protected properties and novel quantum states in low-dimensional magnetic materials.
Materials Science (cond-mat.mtrl-sci)
10 pages, 0 figures
Transition from Homogeneous to Domain-Wall-Mediated Polarization Switching in BaTiO3: A Machine-Learning Molecular Dynamics Study
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-05-26 20:00 EDT
Po-Yen Chen, Teruyasu Mizoguchi
Polarization switching in ferroelectric BaTiO3 can proceed through fundamentally different mechanisms - yet the conditions that determine which pathway is realized remain poorly understood. Using machine-learning potential-based molecular dynamics with the MACEField model, we systematically vary supercell size to reveal a clear transition from homogeneous polarization switching to domain-wall-mediated switching, accompanied by a coercive field increase of over 50%. Shannon entropy analysis demonstrates that this transition is driven by size-dependent polarization fluctuations that promote 180 degree domain-wall nucleation - establishing a direct, quantitative link between local configurational disorder and macroscopic switching behavior. Furthermore, the switching pathway and hysteresis response are shown to depend critically on supercell geometry and the relative orientation of applied stress and electric field. These findings reveal that homogeneous and domain-wall-mediated switching are distinct physical regimes in BaTiO3, and that atomistic simulations must account for system size to correctly capture the operative switching mechanism.
Materials Science (cond-mat.mtrl-sci)
12 pages, 13 figures, submitted to Physical Review B
Magnetoelastic effects in the metallic frustrated antiferromagnet CrB$_2$
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2026-05-26 20:00 EDT
Tadataka Watanabe, Mai Watanabe, Sakurako Suganuma, Andreas Bauer, Christian Pfleiderer
Hexagonal chromium diboride CrB$ _2$ is a metallic frustrated antiferromagnet with a Néel temperature $ T_N \sim$ 88 K. In CrB$ _2$ , Cr 3$ d$ electrons not only give rise to localized magnetic moments but also contribute to metallic conduction. We perform ultrasound velocity measurements on a single crystal of hexagonal CrB$ _2$ to determine its elastic properties. The temperature dependence of the $ ab$ -plane shear elastic modulus exhibits Curie-type softening upon cooling from $ \sim$ 120 K down to $ T_N$ . This behavior is interpreted as a precursor to a symmetry-lowering lattice distortion at $ T_N$ , indicating that magnetic frustration is relieved via transverse magnetoelastic coupling. In addition, the $ a$ -axis and $ c$ -axis compressive elastic moduli show unusual softness and their suppression upon cooling, which are naturally explained by Fermi-surface nesting and its suppression upon cooling. The present results suggest that, in CrB$ _2$ , longitudinal magnetoelastic coupling suppresses Fermi-surface nesting and enhances frustrated exchange interactions, while transverse magnetoelastic coupling plays a key role in relieving the frustration.
Strongly Correlated Electrons (cond-mat.str-el), Materials Science (cond-mat.mtrl-sci)
9 pages, 7 figures
Sensitivity to perturbations in the three-dimensional Anderson model
New Submission | Disordered Systems and Neural Networks (cond-mat.dis-nn) | 2026-05-26 20:00 EDT
Piotr Tokarczyk, Lev Vidmar, Anatoli Polkovnikov, Patrycja Łydżba
We investigate the fidelity susceptibility, which quantifies the sensitivity of single-particle eigenstates to perturbations, in the three-dimensional Anderson model. As a function of disorder strength $ W$ , it exhibits two distinct peaks. The first peak signals a crossover at weak disorder strength from plane-wave states to single-particle quantum chaos, and its position shifts toward $ W\to 0$ in the thermodynamic limit. The second peak emerges, to high numerical accuracy, at the critical disorder strength associated with the Anderson localization transition. We further show that the divergence of the first peak is maximal, scaling as the square of the inverse frequency cutoff, whereas the divergence of the second peak is submaximal. We relate the latter suppression to the fractal structure of single-particle eigenstates at criticality. We discuss two distinct scenarios that give rise to the peaks in the fidelity susceptibilities. Moreover, studying the scaling of typical fidelity susceptibilities above the Anderson transition, we find evidence of two distinct regimes of nonergodic behavior.
Disordered Systems and Neural Networks (cond-mat.dis-nn), Statistical Mechanics (cond-mat.stat-mech), Quantum Physics (quant-ph)
Nitrogen-doped W0.75Re0.25 Superconducting Nanowire Single Photon Detectors
New Submission | Superconductivity (cond-mat.supr-con) | 2026-05-26 20:00 EDT
F. Colangelo, Abhishek Kumar, H. Wang, F. Avitabile, C. Attanasio, I. Esmaeil Zadeh, C. Cirillo
Nitrogen-doped Tungsten-Rhenium superconducting alloys were recently proposed as a promising material platform for superconducting nanowire single-photon detectors (SNSPDs), offering a favorable balance between high normal state resistivity and tunable superconducting properties. In this work, we report on the fabrication and characterization of SNSPDs based on ultrathin W0.75Re0.25 films deposited by reactive DC magnetron sputtering in a mixed Ar/N2 atmosphere. Meander detectors with 70 nm linewidth exhibit saturated internal detection efficiency up to 1310 nm at 2.5 K, with sub-nanosecond rise times, decay times of the order of a few nanoseconds, and timing jitter of 73.2 ps measured with room temperature amplifiers.
Superconductivity (cond-mat.supr-con)
A sweeping twist defect as a topological flagellum that drives colloid motion
New Submission | Soft Condensed Matter (cond-mat.soft) | 2026-05-26 20:00 EDT
Qi Xing Zhang, Claire Dore, Mojtaba Rajabi, Edward B. Steager, Kathleen J. Stebe
Nematic liquid crystals can dramatically reconfigure under dynamic forcing, providing exciting opportunities in active matter. Here, we study a hybrid disk colloid rotated by an external field which generates a dynamic companion topological defect. The disk moves faster when the defect sweeps across the disk’s face. We identify the defect as a non-singular twist wall, characterize the twist energy landscape, and identify the sweeping motion as a topological instability. As the defect sweeps, it reverses the handedness of twist and lowers the free energy in the fluid in the gap above the disk. Landau-de Gennes modeling shows that the sweeping wall behaves as a propagating director texture: the director field is nearly stationary in the wall frame, while nematogens rotate locally as the wall passes. The nematogens’ rotation generates a viscous stress on the surface of the disk that hastens its propulsion. Thus, the defect acts as a flagellum that powers colloid swimming, providing an example of a dissipative topological structure whose dynamics can be harnessed to perform useful work.
Soft Condensed Matter (cond-mat.soft)
37 pages, 5 figures, Supplementary Information included, 15 supplementary figures, 8 ancillary movies
On the Relation Between String Order Parameters, Entanglement, and Dynamical Quantum Phase Transitions in Topological Dynamics
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2026-05-26 20:00 EDT
Sirshendu Bhattacharyya, Szczepan Głodzik, Nicholas Sedlmayr
Topological order is defined by topological invariants, rather than symmetries and local order parameters. Nonetheless some topological phases can be characterized by string order parameters and entanglement. In this article we study how string order parameters and entanglement spectra behave out-of-equilibrium following quenches in one dimensional topological models with $ \mathbb{Z}$ invariants. Previously it has been suggested that string order parameters could serve as an experimental probe of dynamical quantum phase transitions. Despite the existence of clear zeroes in the order parameters at critical times, we show that in general there is no exact quantitative or qualitative connection with the critical times of dynamical quantum phase transitions. Another possible connection is of dynamical string order parameter zeroes and dynamical crossings at the center of entanglement spectra. Here we see that there can sometimes be a connection, but it is not typical. Again there is no general quantitative or qualitative connection. Each dynamical form of criticality behaves independently, though we do see that critical times tend to be of the same order of magnitude and give an argument for why this is the case. We also find that a string order parameter which labels one topological phase can undergo non-trivial dynamics even following a quench between \emph{other} topological phases. We elucidate where connections can be made, and where they result from a consideration of insufficiently general models. These results cast doubt on the idea of genuine dynamical phases following quenches in such models.
Strongly Correlated Electrons (cond-mat.str-el), Statistical Mechanics (cond-mat.stat-mech)
The evolution of pairing correlation with $3d_{z^{2}}$ electron filling in a bilayer two-orbital model for La$_3$Ni$_2$O$_7$
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2026-05-26 20:00 EDT
Y. F. Chen, Y. Shen, X. J. Qian, G. M. Zhang, M. P. Qin
The discovery of high-$ {T_c}$ superconductivity in pressurized bilayer nickelate La$ 3$ Ni$ 2$ O$ 7$ presents a new arena for exploring unconventional pairing mechanisms. A pivotal yet unresolved issue is the specific role of the $ 3d{z^{2}}$ orbital of Ni. While its inter-layer super-exchange antiferromagnetic coupling is widely considered crucial for superconductivity, the role of its itinerancy remains undetermined. Early studies showed that the superconductivity is accompanied by the emergence of a small Fermi pocket of the $ 3d{z^{2}}$ orbitals. However, recent experiments show controversial results on the role of the $ 3d{z^{2}}$ Fermi pocket on superconductivity. Motivated by these experimental results, we investigate an effective bilayer two-orbital model for La$ _3$ Ni$ 2$ O$ 7$ using density-matrix renormalization group (DMRG) on a minimal one-dimensional geometry. By systematically varying the $ 3d{z^{2}}$ orbital filling from $ 1/12$ doping to half-filling, we observe a pronounced suppression of superconducting correlations near half-filling. Our results demonstrate the itinerancy of $ 3d{z^{2}}$ orbital is favorable for the pairing in the bilayer two-orbital model for La$ _3$ Ni$ _2$ O$ _7$ . Moreover, we observe that the pairing correlation is enhanced in regions where charge fluctuations are large, suggesting a competition between charge order and superconductivity in the model.
Strongly Correlated Electrons (cond-mat.str-el), Superconductivity (cond-mat.supr-con)
10 pages, 11 figures
Analysis of Critical Points in a Permutation Model on Hierarchical Lattices by Real-Space Renormalization Group
New Submission | Statistical Mechanics (cond-mat.stat-mech) | 2026-05-26 20:00 EDT
Ryuki Ito, Taisei Matsuo, Masayuki Ohzeki
The permutation model is a classical spin system where elements of the symmetric group interact with one another. The partition function of this model is directly related to the entanglement structure of random quantum circuits and random tensor networks. In these contexts, the entanglement entropy undergoes a transition between area-law and volume-law scaling, depending on the model parameters. This transition point has attracted considerable attention. In the present work, we investigate the ferromagnetic-paramagnetic phase transition of the permutation model, which corresponds to the entanglement entropy transition. Using exact real-space renormalization group calculations on self-dual hierarchical lattices, we numerically determine finite-replica critical points for (q=mn=2,…,6). We compare the results with the duality prediction based on the Fourier transform of the symmetric group and then extrapolate the b=3 data toward the replica limit $ mn\to0$ , where the effective dimension is two. The comparison supports the duality-based estimate while also clarifying the systematic uncertainty associated with the extrapolation formula.
Statistical Mechanics (cond-mat.stat-mech), Disordered Systems and Neural Networks (cond-mat.dis-nn), Quantum Physics (quant-ph)
7 pages, 4 figures
Near-Room-Temperature Antiferromagnetic Ordering in the Quadruple Perovskite Sr4NaRu3O12
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2026-05-26 20:00 EDT
Subham Naik, Biswajit Singh, Hiranmayee Senapati, Akshay K. U., Ramesh C. Nath, Soumyojit Chatterjee, Rahul Sharma, Thomas Doert, Walter Schnelle, Manfred Reehuis, Thomas C. Hansen, Michael Ruck, Gohil S. Thakur
We report the synthesis, structure and magnetic properties of two 1:3 ordered quadruple perovskites Sr4MRu3O12 (M = Li and Na). Sr4NaRu3O12 crystallizes in the centrosymmetric space group R-3 and Sr4LiRu3O12 appears to be isostructural to the Na compound based on the PXRD data. In Sr4NaRu3O12, both Na and Ru are predominantly ordered at the B sites (here Na/Li and Ru) and the structure contains only corner-connected RuO6 and NaO6 octahedra. This atomic ordering also leads to a rather large unit cell with a = 11.25 Å and c = 27.6 Å compared to the basic 12R structure (a = 5.5 Å and c ~ 27 Å). Magnetic measurements reveal that Sr4NaRu3O12 undergoes a magnetic transition to an antiferromagnetic state below TN ~ 265 K which is confirmed by DSC and neutron diffraction. The Ru moments show a collinear antiferromagnetic spin alignment along the hexagonal c axis with a propagation vector k = (0, 0, 1.5). Interestingly, those Ru moments lying on the three-fold roto-inversion do not significantly contribute to the magnetic order, since they are located between antiferromagnetically coupled Ru atoms and are therefore probably highly frustrated. Band structure calculations on Sr4NaRu3O12 complement the observed magnetic ground state and a semiconducting behavior in the compound. Sr4LiRu3O12 shows a magnetic anomaly below 110 K, possibly associated with competing ferromagnetic and antiferromagnetic interactions.
Strongly Correlated Electrons (cond-mat.str-el), Materials Science (cond-mat.mtrl-sci)
38 pages, including supporting information
Chain conformations in adsorbed layer during polymer capillary imbibition
New Submission | Soft Condensed Matter (cond-mat.soft) | 2026-05-26 20:00 EDT
Tao Liang, Li Peng, Xianbo Huang, Jiajia Zhou
We conducted molecular dynamics simulations to investigate chain conformations in adsorbed layers during polymer capillary imbibition. While the imbibition length adheres to the classical Lucas-Washburn equation, a notable deviation in mobile bead density emerges under strong confinement, consistent with \emph{in situ} dielectric spectroscopy experiments. The proportion of loop structures within adsorbed layers progressively increases during capillary infiltration, attributed to the relaxation of initially stretched chains toward equilibrium configurations. Furthermore, systematic analysis revealed that chain relaxation dynamics exhibit length-dependent retardation, especially under high confinement. The characteristic desorption time demonstrates chain-length dependence in quantitative agreement with scaling predictions.
Soft Condensed Matter (cond-mat.soft)
29 pages, 18 figures
J. Chem. Phys. 162, 224901 (2025)
Alignment-free ultra-broadband parametric frequency conversion in lead-halide perovskites
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-05-26 20:00 EDT
Abhishek Shiva Kumar, Dusan Lorenc, Ayan A. Zhumekenov, Osman M. Bakr, Zhanybek Alpichshev
Lead-halide perovskites were demonstrated to exhibit some of the largest known optical nonlinearities, yet their potential for frequency conversion remains largely untapped. Here we demonstrate ultra-broadband four-wave mixing of near- and mid-infrared femtosecond pulses in thick single-crystal LHPs, generating bright, coherent, and highly collimated emission across an exceptionally wide continuous tuning range without phase-matching engineering, angular alignment, or dispersion optimization. Time resolved measurements reveal that the emission originates near the crystal surfaces, where phase-matching constraints are relaxed, while the unusually large intrinsic $ \chi^{(3)}$ response preserves efficient and directional frequency conversion despite the strongly localized interaction volume. These results position LHPs as a powerful bulk platform for ultra-broadband nonlinear photonics, opening a pathway toward compact, alignment-free architectures for ultrafast frequency conversion.
Materials Science (cond-mat.mtrl-sci), Applied Physics (physics.app-ph), Optics (physics.optics)
kikuchipy: an open-source toolbox for analysis of EBSD patterns
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-05-26 20:00 EDT
Håkon W. Ånes, Phillip Crout, Lars Andreas Lervik, Ole Natlandsmyr, Tina Bergh, Jarle Hjelen, Antonius T. J. van Helvoort, Knut Marthinsen
We present kikuchipy, an open-source toolbox for analysis of electron backscatter diffraction patterns, written in Python. The software is capable of both Hough and dictionary indexing and orientation and/or projection center refinement of patterns stored in file formats from all major vendors. Indexing results can be validated using maps independent of indexing and by visually comparing experimental and simulated patterns. By leveraging scientific packages in the Python ecosystem, emphasis is put on making the indexing workflow flexible and improve results through fast iteration. The software’s capabilities are demonstrated on three application examples: analysis of orientation relationships in a super duplex stainless steel, phase differentiation of aluminium and silicon in a cast modified Al-Si alloy, and phase differentiation of particles in an Al-Mn alloy as Al6Mn or alpha-AlMnSi. The diffraction patterns and analysis workflows are made publicly available. kikuchipy was created and is developed as a resource for the electron microscopy community, allowing anyone to improve the software or include it into their own analysis workflows or softwares.
Materials Science (cond-mat.mtrl-sci)
The Remodeling of Fiber Distributions in Biological Tissues: Rotation without Rotation
New Submission | Soft Condensed Matter (cond-mat.soft) | 2026-05-26 20:00 EDT
Christian Cherubini, Marcello Vasta, Filippo Recrosi, Alessio Gizzi
Collagen remodeling in living tissues exhibits anisotropic orientation patterns commonly described by Von Mises distributions, yet the physical origin of such nonequilibrium organization remains unresolved. In the present work, we demonstrate analytically that the combined action of Malthusian growth dynamics and the introduction of linear relations governing mechanical remodeling naturally gives rise to generalized bimodal Von Mises distributions as emergent states of living matter. The theory reveals a {\it rotation without rotation} mechanism, in which fibers progressively reorient in the absence of angular mechanical coupling via selective deposition and removal along preferred directions. The resulting analytical solutions quantitatively reproduce experimentally observed distributions and establish a direct mechanobiological origin for directional statistics in biological tissues. By interpreting the evolving normalized fiber density as a probability distribution function, we formulate a dynamical Shannon entropy framework that captures the temporal emergence of microstructural organization. The theory further yields closed-form expressions for the drift of the associated Fokker–Planck equation, enabling the corresponding stochastic differential equation to be derived, thus revealing that tissue remodeling is the collective outcome of noisy single-fiber dynamics. These results establish a minimal theoretical framework that connects biomechanics, stochastic processes, and nonequilibrium statistical organization in living matter.
Soft Condensed Matter (cond-mat.soft)
Spectral properties of non-Hermitian real random matrices with long-range correlations
New Submission | Disordered Systems and Neural Networks (cond-mat.dis-nn) | 2026-05-26 20:00 EDT
We investigate the spectral properties of non-Hermitian real random matrices whose entries exhibit long-range correlations decaying as$ |r-r’|^{-\alpha}$ . We find a progressive breakdown of the circular law, controlled by the decrease of$ \alpha$ . In all cases, the radial eigenvalue density decreases away from the origin. At$ \alpha>1$ , an effective radius, reminiscent of the circular law, is retrieved, while instead, for$ \alpha<1$ , the eigenvalue distribution broadens with matrix size and its spectral radius grows like a power law, with exponents numerically close to the exponents controlling the magnitude of fluctuations in the extended central limit theorem. The case~$ \alpha=1$ appears as a case with self-similar eigenvalue density, and slowly growing spectral radius. Long-range correlations also enhance clustering of real eigenvalues and slow the resorption of the Saturn effect. These results reveal a correlation-driven transition and suggest the emergence of a new universality class for correlated non-Hermitian random matrices.
Disordered Systems and Neural Networks (cond-mat.dis-nn), Statistical Mechanics (cond-mat.stat-mech), Probability (math.PR)
7 pages, 6 figures, accepted at Phys. Rev. E
Collective deformation of anisotropic particles with internal pulsation
New Submission | Soft Condensed Matter (cond-mat.soft) | 2026-05-26 20:00 EDT
Luca Casagrande, Alessandro Manacorda, Etienne Fodor
Capturing the emergence of deformation waves in contractile living tissues is a challenge that has recently been tackled with models of actively deformable particles. Inspired by the anisotropic deformation of cardiomyocytes in cardiac tissues, we examine how the pulsation of elliptical particles affects their collective properties in dense assemblies. We introduce two types of deformation where the eccentricity of each particle is subject to a periodic drive, and examine the interplay between nematic order and synchronized deformation via a systematic phase diagram. We derive a hydrodynamic description through a coarse-graining procedure, and show that it qualitatively captures the main collective states of the microscopic dynamics. Overall, our model provides key insights into how an active anisotropic deformation yields waves that self-organize into various dynamical patterns.
Soft Condensed Matter (cond-mat.soft), Statistical Mechanics (cond-mat.stat-mech)
Topological fragility and bilinear magnetoelectric resistance in gapless edge states
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2026-05-26 20:00 EDT
Cosimo Gorini, Matthieu Bard, Sophie Gueron, Hélène Bouchiat, Giovanni Vignale
In time-reversal symmetric systems such as topological and higher-order topological insulators, 1D spin-momentum locked edge and hinge states are theoretically perfectly conducting'', being immune to backscattering by non-magnetic disorder. Here, we reveal a fundamental topological fragility’’: these states exhibit a bilinear magnetoelectric resistance significantly larger than in 2D systems. This effect requires two ingredients: (i) spin-momentum locking, which maximizes time-reversal symmetry breaking in the non-linear regime, and (ii) random spin-orbit interaction – the same mechanism behind Elliott - Yafet spin relaxation in heavy elements. Together, these generate a robust backscattering channel when a modest external magnetic field is applied. Our theory requires no gap opening or complex many-body effects, offering a simple and general mechanism that quantitatively explains recent observations in Bismuth hinge states.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
Equivalent-neighbor $k$-core percolation in two dimensions
New Submission | Statistical Mechanics (cond-mat.stat-mech) | 2026-05-26 20:00 EDT
Qiyuan Shi, Ming Li, Youjin Deng
We perform large-scale numerical simulations to investigate the critical behavior of $ k$ -core percolation in two dimensions with an extended interaction range $ r$ . By systematically varying both the core index $ k$ and the interaction range $ r$ , we construct a comprehensive phase diagram in the $ (k,r)$ plane. In contrast to $ k$ -core percolation in infinite dimensions, no hybrid transition is observed in two dimensions: the phase diagram contains only a continuous transition regime and a strictly first-order regime, separated by a tricritical or critical-end point $ (k_s,r_s)$ . For $ k<k_s$ and $ r<r_s$ , the transition is continuous and belongs to the universality class of standard two-dimensional (2D) percolation. For $ k>k_s$ and finite $ r>r_s$ , the transition is discontinuous, with no hybrid features or critical singularities. In this first-order regime, the pseudocritical point approaches the critical point as $ 1/\ln L$ , where $ L$ is the linear system size, distinct from the $ L^{-d}$ scaling typical of conventional thermodynamic first-order transitions in $ d$ dimensions. This logarithmic finite-size drift is consistent with a nucleation-driven mechanism, in which rare voids trigger the collapse of the finite-range $ k$ -core. These results demonstrate that geometric constraints can fundamentally alter the nature of $ k$ -core percolation found in finite dimensions.
Statistical Mechanics (cond-mat.stat-mech)
Dealloying by peritectic melting
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-05-26 20:00 EDT
Peritectic melting of Ti–Ag has been shown experimentally to form bicontinuous structures, but the mechanism remains unclear. Here we use phase-field simulations to show that these structures arise from a morphological instability of liquid film migration in three dimensions: a Ti-rich solid growing through an Ag-rich liquid film develops a branched seaweed or dendritic structure whose side branches coalesce to form handles, generating a high-genus bicontinuous topology. A sharp-interface theory predicts a solidification-front velocity and an initial ligament width that are constant in time, in contrast to liquid metal dealloying; subsequent $ t^{1/3}$ coarsening reproduces the experimentally observed final ligament width.
Materials Science (cond-mat.mtrl-sci)
Hybridization of Ferromagnetic and Cyclotron Resonances in a Two-Dimensional Electron System on a Ferromagnetic Film
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2026-05-26 20:00 EDT
A. A. Zabolotnykh, I. V. Zagorodnev, A. A. Matveev, D. A. Rodionov, O. Yu. Arkhipova, D. V. Kalyabin, A. R. Safin, S. A. Nikitov
The microwave response of a two-dimensional (2D) electron system located on a dielectric ferromagnetic film, which in turn lies on a conducting metal (gate), has been theoretically studied. The entire system has been placed in the perpendicular static magnetic field. It has been found that the ferromagnetic resonance of the film and the cyclotron resonance of the electrons of the 2D system interact in the magnetic field, leading to their repulsion (‘anticrossing’). It has been revealed that the anticrossing region is characterized not only by the modification of resonance frequencies compared to the cyclotron resonance in the 2D system without the ferromagnetic substrate and the ferromagnetic resonance in the film without the 2D system, but also by a strong change in the resonance linewidths.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
5 pages, 3 figures
JETP Lett. 123, 271-276 (2026)
Cluster moves with an entropic reservoir accelerate low-temperature simulations of three-dimensional spin glasses
New Submission | Disordered Systems and Neural Networks (cond-mat.dis-nn) | 2026-05-26 20:00 EDT
Claudio Chilin, Enzo Marinari, Víctor Martín-Mayor, Giorgio Parisi, Juan J. Ruiz-Lorenzo, David Yllanes
We present an algorithm for the simulation of three-dimensional spin glasses deep in the low-temperature phase: Parallel Tempering enhanced with Houdayer moves and with an entropic reservoir (PTHR). Although differences with the standard Houdayer algorithm are small, PTHR allows us to equilibrate a large number of samples of $ L=16$ lattices with Gaussian couplings for temperatures $ T\geq 0.2$ . We show that the computational complexity displays better size scaling than standard Parallel Tempering. For finite sizes, our method outperforms other cluster algorithms by a speedup factor of around 64. In close analogy with standard Parallel Tempering, PTHR’s computational complexity strongly relates to temperature chaos.
Disordered Systems and Neural Networks (cond-mat.dis-nn), Statistical Mechanics (cond-mat.stat-mech), Computational Physics (physics.comp-ph)
24 pages, 6 figures
Scaling features for the stress fluctuations in the OFC model
New Submission | Statistical Mechanics (cond-mat.stat-mech) | 2026-05-26 20:00 EDT
Naveen Kumar, Rahul Chhimpa, Avinash Chand Yadav
We consider the Olami-Feder-Christensen (OFC) model on a square two-dimensional lattice with open boundary conditions. The model exhibits self-organized criticality and explains the Gutenberg-Richter law observed for earthquakes. A parameter $ \alpha$ controls the level of local dissipation: $ \alpha < 0.25$ corresponds to locally dissipative and $ \alpha = 0.25$ marks locally conservative dynamics. The avalanche size distribution follows a decaying power-law, with a non-universal critical exponent. Here, we examine the probability distribution of the difference between avalanche size and area. This quantity remains unexplored despite being of significant interest in earthquakes. We find a power-law with a scaling exponent close to one in the conservative OFC model. The scaling feature vanishes even for the physically relevant case $ \alpha = 0.21$ . To examine the robustness of such features, we also examine the same quantity in the BTW and Manna sandpile models on a square lattice. We find that the power-law behavior survives for these systems due to locally conservative dynamics. We further examine the local and total stress fluctuations in the OFC model for both locally conservative and dissipative dynamics. The finite-size scaling analysis of the power spectra for the stress fluctuations reveals qualitatively the same but quantitatively significantly different behavior. The dynamic exponent describing the divergence of the correlation time with system size changes from nearly ballistic in the conservative to diffusive behavior in the locally dissipative dynamics with $ \alpha = 0.21$ . The local stress also exhibits a signature of nearly canonical $ 1/f$ noise in the intermediate regime, and $ 1/f^2$ -type scaling dominates the high-frequency regime.
Statistical Mechanics (cond-mat.stat-mech)
14 pages, 9 figures
Superconductivity and electronic structure evolution in the enforced semimetal Fe-doped ZrTe$_2$
New Submission | Superconductivity (cond-mat.supr-con) | 2026-05-26 20:00 EDT
L. M. Ishikura, C. F. Schuch, A. Faé Rabello, F. F. Nogueira, L. E. Corrêa, L. R. de Faria, J. Larrea Jiménez, L. T. F. Eleno, A. J. S. Machado
ZrTe$ _2$ is an outstanding layered semimetal due to the topologically nontrivial electronic structure. In this work, we present an investigation of the electronic evolution of ZrTe$ _2$ in the presence of Fe intercalation, namely Fe$ _{x}$ ZrTe$ _2$ ($ x= 0 - 0.25$ ), scrutinized by both experimental measurements and \textit{ab} initio calculations. While the first reveals a superconducting state with a maximum critical temperature $ T_c = 2.74$ K ($ x=$ 0.03), the latter indicates that the topological features of the pristine ZrTe$ 2$ is sensitive to the distance between Te atoms and Zr layers. Also, the intercalation of Fe does not modify the non-trivial electronic band structure unlike the band crossings are now shifted slightly below $ E{F}$ . In particular, a van Hove singularity near the Fermi level for a Fe content of $ x=0.125$ is observed in the density of states, indicating that the superconducting order may be associated with features of the unfolded band structure and the concomitant enhancement of the density of states at $ E_F$ . Finally, our results reveal that the new compound with inclusion of Fe intercalation preserves the enforced semimetal classification.
Superconductivity (cond-mat.supr-con), Materials Science (cond-mat.mtrl-sci)
Benchmarking Transparent Conductors
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-05-26 20:00 EDT
Transparent conducting oxides (TCOs) are central to optoelectronic technologies, yet their design is often guided by popular figures of merit that are disconnected from the electrical requirement of actual devices. As a result, widely used metrics guide material design under conditions that can be impractical for devices. Here, we introduce a benchmarking framework to guide TCO development, in which transparent conductors are evaluated at fixed, application-relevant sheet resistance $ (R_S)$ . The resulting metric, $ T_{app}(R_S)$ , anchors comparison to device requirements, asking instead: What optical transparency can be obtained at the sheet resistance required by a given application? This approach provides a directly interpretable measure of performance, enabling materials to be benchmarked in terms of absolute transparency gains at a specified $ R_S$ . Applied to representative conventional and emerging TCOs, the framework defines the sheet-resistance landscape relevant to each application and maps how different materials perform within it. In doing so, it provides an application-rooted guide to material development and selection. More broadly, this approach establishes a general strategy for evaluating materials under fixed operational constraints, bridging the gap between materials design and device integration.
Materials Science (cond-mat.mtrl-sci)
Substitution modulated transition from semimetal to superconductor in ZrTe$_{2-x}$Se$_x$ with coexistence of nontrivial electronic topology
New Submission | Superconductivity (cond-mat.supr-con) | 2026-05-26 20:00 EDT
V. M. Fim, C. F. Schuch, L. R. de Faria, F. A. Santos, M. S. da Luz, S. S. Tsirkin, L. T. F. Eleno, A. J. S. Machado
This study explores the emergence of superconductivity in high-quality ZrTe$ _{2-x}$ Se$ _x$ crystals, grown via the isothermal chemical vapor transport (ICVT) technique. Resistive, structural, and thermal measurements reveal that substituting Te with Se in the ZrTe$ _2$ matrix induces a superconducting state at low temperatures. The critical temperature ($ T_c$ ) exhibits a clear dependence on the selenium concentration, peaking at $ x=0.15$ with a $ T_c$ of $ 4.8$ K. Calorimetric data indicates that even a low Se substitution range is capable of modifying both the electronic contribution and the vibrational modes of the crystal lattice. Combined with ab initio calculations and Wannier Hamiltonian interpolation between ZrTe$ _2$ /ZrSe$ _2$ , we established an extensive phase diagram mapping the transition from charge density wave (CDW) to the state with coexistence between the Dirac semimetal and superconductivity (SC), up to the semiconductor phase. This coexistence suggests that ZrTe$ _{1.85}$ Se$ _{0.15}$ could be a candidate platform for topological superconductivity, as it hosts a nontrivial $ \mathbb Z_2$ invariant, with nonvanishing surface states in its $ (001)$ planes.
Superconductivity (cond-mat.supr-con), Materials Science (cond-mat.mtrl-sci)
Mutual Friction in Dissipative Gross-Pitaevskii Thermal Counterflow Turbulence
New Submission | Other Condensed Matter (cond-mat.other) | 2026-05-26 20:00 EDT
Kyo Yoshida, Hideaki Miura, Yoshiyuki Tsuji
We report numerical simulations of the dissipative Gross-Pitaevskii equation for a bulk region of thermal-counterflow turbulence. Quasistationary states are obtained over a range of forcing, damping, and healing-length parameters. The mutual-friction acceleration exhibits cubic scaling with the mean relative velocity between the superfluid and normal-fluid components, and the coefficient of this scaling is linked to the phenomenological damping parameter. The intervortex spacing follows the expected dimensional scaling in the weak-forcing regime. Comparison with a straight-vortex-line model suggests that the vortex-line orientations are nearly isotropic.
Other Condensed Matter (cond-mat.other), Fluid Dynamics (physics.flu-dyn)
5 pages, 4 figures
Freezing of the tetrahedral amorphous network in supercooled water triggers crystallization towards LDA ice
New Submission | Statistical Mechanics (cond-mat.stat-mech) | 2026-05-26 20:00 EDT
Ashutosh Srivastava, Pankaj A. Apte
In this work, we provide mechanistic insight into the initial stages of formation of ice across the limit of stability of supercooled water. Such an analysis is particularly important since crystal nucleation is not a relevant mechanism under these conditions. Using molecular dynamics simulation with the TIP4P/2005 potential, water is cooled at a constant pressure with cooling rates of 5 to 10 K per nanosecond. As the liquid is cooled across the temperature of maximum density (T_0 = 277 K), we find that there is a continuous increase in the tetrahedrality of the system. As the cooling continues across the limit of stability of water (T_s $ \approx$ 235 K), large scale thermal fluctuations dissipate while the thermal equilibration is achieved through small scale fluctuations. This phenomenon, known as the dynamical crossover [Goutam et. al. in J. Stat. Phys., 168: 1302–1318 (2017)], ends the existence of the liquid state. Subsequently, we find that the tetrahedral network drives the decrease of energy and density. This process terminates when the network undergoes `freezing’ (i.e., the bonds of the network acquire sufficient rigidity), due to which the network evolution, as a whole, stops. This triggers a qualitative change in the relaxation mechanism: subsequent relaxation occurs through crystallization, i.e., an increase in the structural order. In particular, we find that the cubic and hexagonal crystalline motifs, which possess medium range order, increase rapidly across the freezing point. In the resulting LDA ice states, cubic ice is found to have a significant contribution in the overall extent of crystallization, which is consistent with the experimental findings. Overall, our work provides the specific mechanism by which crystallization (leading to LDA ice) is initiated across the limit of stability of supercooled water.
Statistical Mechanics (cond-mat.stat-mech)
6 pages, 6 figures
Exact Single-Scale Outer Solution of the Abrikosov Vortex in the Extreme Type-II Limit
New Submission | Superconductivity (cond-mat.supr-con) | 2026-05-26 20:00 EDT
We determine the exact outer structure of the Abrikosov vortex in the extreme type-II limit, which occurs when the Ginzburg-Landau parameter $ \kappa$ diverges. In this limit, Ginzburg-Landau theory simplifies, outside a shrinking core, to a closed nonlinear theory for the superfluid velocity subject to an algebraic density constraint. The resulting solution is asymptotically exact everywhere outside the vanishing vortex core, demonstrating that both magnetic field and superconducting density vary on the length scale of the London penetration depth. This establishes that the conventional two-length-scale picture of the vortex does not hold in the $ \kappa\gg 1$ limit.
Superconductivity (cond-mat.supr-con), Exactly Solvable and Integrable Systems (nlin.SI)
4 pages, 2 figures
Generalized field mixing for endpoint criticality with marginal flow: resolving the four-state Potts endpoint in the square-lattice $J_1$–$J_2$ Ising model
New Submission | Statistical Mechanics (cond-mat.stat-mech) | 2026-05-26 20:00 EDT
Identifying the asymptotic criticality of a critical endpoint is challenging, as pseudo-first-order signatures persist over accessible system sizes and mask its underlying critical nature. This ambiguity is amplified at endpoints controlled by a marginally irrelevant scaling field, where logarithmic flow delays the onset of asymptotic scaling. Here we develop a generalized field-mixing framework for endpoint criticality governed by one relevant scaling field together with a marginally irrelevant one, a setting that lies outside the conventional two-relevant-field formulation. By constructing a finite-size pseudocritical manifold, the framework removes the normal relevant detuning and exposes the residual marginal drift, enabling controlled histogram- and Binder-based finite-size analyses. We apply this approach to the frustrated square-lattice $ J_1$ –$ J_2$ Ising model, where the location and even the nature of the stripe-ordering endpoint have remained controversial for decades. The endpoint is isolated directly as a distinct singular point, rather than inferred from where the phase boundary appears most Potts-like, and its asymptotic criticality is shown to follow four-state Potts universality with logarithmic corrections. This identification is independently supported by direct comparison with the Potts point of the Ashkin–Teller model and by consistent Binder scaling in both the magnetic and nematic sectors. Our results resolve a longstanding numerical ambiguity in a paradigmatic frustrated Ising system and establish a general framework for extracting asymptotic endpoint criticality in the presence of marginal flow.
Statistical Mechanics (cond-mat.stat-mech), Strongly Correlated Electrons (cond-mat.str-el)
9 pages, 7 figures. Comments are welcome!
Anomalous Hall Effect in Silicon-Compatible Altermagnetic alpha-MnTe Thin Films
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-05-26 20:00 EDT
Rajib Sarkar, Subhransu Kumar Negi, Arindom Das, Arijit Mandal, Pankaj Bhardwaj, Sohini Guin, Aryaman Das, Naresh Shyaga, Laxmipriya Nanda, B. R. K. Nanda, Dhavala Suri
Integrating spin-dependent functionality with mainstream semiconductor technology is a central goal of modern spintronics, yet most candidate materials remain incompatible with silicon-based platforms. Here, we report the direct epitaxial integration of alpha-MnTe thin films on Si(111) via molecular beam epitaxy and demonstrate a robust anomalous Hall effect (AHE) in this silicon-compatible altermagnetic system. Despite the absence of net magnetization, the films exhibit a pronounced hysteretic Hall response, providing clear evidence of finite Berry curvature generated by symmetry breaking in the thin-film geometry. High resolution structural and spectroscopic characterization confirms phase-pure, epitaxial growth with hexagonal NiAs-type symmetry, while magnetotransport measurements reveal correlated hysteresis in both transverse and longitudinal channels with systematic temperature evolution. First-principles calculations reveal substantial uncompensated Berry curvature arising from the spin-split band structure consistent with altermagnetic symmetry and the origin of the observed Hall response. These results establish MnTe/Si(111) as a silicon-compatible altermagnetic platform and chart a concrete pathway for embedding Berry-phase-driven functionalities into scalable semiconductor device architectures.
Materials Science (cond-mat.mtrl-sci)
Trimerized Spin-$1/2$ Chain: Emergent Low-Energy Hamiltonian, Higher-Energy Excitations, and Magnetic and Thermodynamic Responses
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2026-05-26 20:00 EDT
Snehasish Sen, Sudhansu S. Mandal
We investigate a spin-1/2 antiferromagnetic chain with trimerized exchange couplings relevant to Na$ _2$ Cu$ _3$ Ge$ _4$ O$ _{12}$ . We show that the low-energy Hilbert space maps onto an effective Heisenberg chain of composite spin-1/2 trimer degrees of freedom with positive coupling, enabling an exact spinon excitations via the Bethe ansatz. To access higher-energy dynamics, we develop a self-consistent Jordan-Wigner mean-field theory that yields three fermionic bands reflecting the underlying trimer structure. Remarkably, this approach reproduces the exact low-energy spinon continuum while predicting two additional higher-energy excitation bands consistent with the experimental observations and previous numerical simulations. The theory further captures the 1/3 magnetization plateau under an applied magnetic field, and provides testable predictions in magnetic susceptibility and specific heat. Our results establish a unified framework connecting low- and high-energy excitations in trimerized quantum spin chains.
Strongly Correlated Electrons (cond-mat.str-el)
7 pages, 5 figures
Excess entropy scaling of the transverse sound speed in simple fluids
New Submission | Soft Condensed Matter (cond-mat.soft) | 2026-05-26 20:00 EDT
A calculation of the transverse sound velocity as a function of excess entropy is presented for several simple fluids, including the Lennard-Jones, Yukawa, one-component plasma, inverse-power law (soft sphere) and hard sphere models. A quasi-universal character of this dependence is established, extending Rosenfeld’s excess-entropy scaling of transport coefficients to the transverse sound velocity. The results are discussed in terms of the soft- to hard-sphere crossover and the Frenkel crossover between gas-like and liquid-like dynamics.
Soft Condensed Matter (cond-mat.soft)
6 pages, 1 figure
Physics of Fluids 38, 057124 (2026)
Light-Induced Transient Polarization Reversal in Rhombohedrally Stacked Bilayer Transition-Metal Dichalcogenides via an Electronic Mechanism
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-05-26 20:00 EDT
Xiangzhou Zhu, Stefano Mocatti, Matteo Calandra
Light-induced sliding ferroelectricity in two-dimensional van der Waals materials enables polarization control via relative layer motion. However, polarization switching occurs on the time scale of shear modes (tens of ps) and requires very large fluences, potentially damaging the samples. Here, using constrained density functional theory and many-body real-time simulations, we demonstrate an ultrafast electronic reversal of the total out-of-plane polarization sign in the photoexcited state, without requiring interlayer sliding, in rhombohedrally stacked transition-metal dichalcogenide bilayers. The polarization changes sign relative to its initial ground-state value at moderate fluences and within 200 fs, about 50 times faster than the typical shear-mode period. The ultrafast switching is driven by a rearrangement of localized dipoles around the tungsten sites. We establish a novel general mechanism for electronic control of low-dimensional ferroelectrics common to all polar multilayers having type II band alignment. Our work has direct implications for ultrahigh-speed volatile optical memory operating on sub-ps time scales.
Materials Science (cond-mat.mtrl-sci)
Boltzmann Distribution from Invariance of Coarse-Graining-Scale and Energy-Shift
New Submission | Statistical Mechanics (cond-mat.stat-mech) | 2026-05-26 20:00 EDT
Weicheng Fu, Yisen Wang, Yong Zhang, Hong Zhao
We present a concise derivation of the Boltzmann form for single-particle energy distributions in classical many-body Hamiltonian systems. The derivation relies on two physical facts: coarse-graining-scale invariance of the empirical distribution and invariance under a uniform shift of the energy zero. These conditions uniquely yield the Boltzmann factor, whose parameter is fixed by the mean energy per particle. For separable Hamiltonians, the equilibrium weight factorizes into kinetic and configurational contributions sharing the same parameter, identified from the kinetic part as the inverse kinetic temperature. The principle extends to any physical quantity with a stationary distribution and translational invariance. It is illustrated in a one-dimensional diatomic hard-core gas and a nonlinear lattice chain, where it predicts velocity, energy, spacing, collision-time, and pressure-dependent displacement distributions in agreement with simulations. The lattice model further shows how harmonic elasticity, anharmonic corrections, internal pressure, and thermal expansion emerge from the same exponential equilibrium weights. Finally, the relationships among different ensembles are briefly discussed.
Statistical Mechanics (cond-mat.stat-mech), Physics Education (physics.ed-ph)
9 pages; 3 figures
Beyond Gaussian Statistics in Polymer Melts: Statistical Masking of Persistent Local Constraints
New Submission | Soft Condensed Matter (cond-mat.soft) | 2026-05-26 20:00 EDT
Short polymer chains exhibit clear deviations from Gaussian end-to-end distance statistics, yet the molecular mechanism by which Gaussian behavior is recovered in long chains remains unestablished. Atomistic molecular dynamics simulations of polyethylene melts reveal that conformational heterogeneity persists at the Kuhn scale across all chain lengths, consisting of a mosaic of slow-relaxing, extended aligned chain segments (ACS) and coiled segments – random conformational sequences (RCS) and chain ends (CE). We show that the end-to-end distance distributions for both unentangled and entangled chains are accurately described by a $ q$ -Gaussian function, with the entropic index $ q$ increasing systematically from $ 0.67$ (C50) to $ 0.99$ (C500). This evolution tracks the emergence and accumulation of RCS segments, which are absent in short chains, establishing $ q$ as a quantitative ``heterogeneity index’’. The $ q < 1$ values are a signature of non-extensive statistics, with the ratio of Tsallis to Boltzmann-Gibbs entropy ($ S_q/S_1$ ), computed directly from simulation data without fitting, decreasing from $ 1.80$ (C50) to $ 1.03$ (C500). Crucially, we demonstrate that Gaussian recovery does not result from the erasure of Kuhn-scale heterogeneities, as ACS domains persist in all chain lengths above the critical mass ($ \approx 35%$ ). Instead, the transition to Gaussian statistics is a statistical masking effect, where the accumulation of independent RCS segments progressively obscures the non-Gaussian signatures of the persistent ACS domains.
Soft Condensed Matter (cond-mat.soft), Statistical Mechanics (cond-mat.stat-mech), Biological Physics (physics.bio-ph)
submitted to the Journal of Chemical Physics
Demagnetization effect on magnetic noise measurements in spin ice materials
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2026-05-26 20:00 EDT
F. Morineau, C. Paulsen, G. Balakrishnan, D. Prabhakaran, K. Matsuhira, S. R. Giblin, E. Lhotel
Magnetic noise spectroscopy provides direct access to spontaneous time-dependent magnetization fluctuations in correlated magnetic systems, including spin liquids, spin ices, and spin glasses. Here we investigate how demagnetizing fields shape the magnetic noise spectra measured in spin ice. By combining magnetic noise and ac susceptibility measurements on single-crystal spin ice samples with different sizes and shapes, we show that magnetic noise, like linear response, is strongly renormalized by sample geometry. As a consequence, measured noise spectra do not directly yield the intrinsic fluctuation spectrum, and demagnetization corrections cannot in general be determined from noise data alone. Instead, sample geometry must be treated as a central experimental control parameter for accessing intrinsic dynamics. These results establish the role of boundary conditions in fluctuation spectroscopy and provide a framework for quantitatively comparing noise measurements with microscopic theories of spin dynamics.
Strongly Correlated Electrons (cond-mat.str-el)
12 pages, 12 figures (main text: 9 pages, 7 figures)
Topology of pulsating active matter: Defect asymmetry controls emergent motility
New Submission | Soft Condensed Matter (cond-mat.soft) | 2026-05-26 20:00 EDT
Luca Casagrande, Alessandro Manacorda, Etienne Fodor
In pulsating active matter, topological defects are motile despite the absence of any macroscopic flows and microscopic self-propulsion. We reveal that this motility arises from a ratchet effect: the mechanochemical coupling between local oscillations and repulsive interactions breaks both spatial and time-reversal symmetries, thus leading asymmetric rotating defects to drift under fluctuations. This mechanism regulates a crossover between spiral waves connecting slow defects and fiber-like waves connecting fast defects, in analogy with the onset of heart rhythm disorder in cardiac tissues. We rationalize this crossover in terms of a fluctuating hydrodynamics that captures how motile defects spontaneously nucleate and move within an ordered background.
Soft Condensed Matter (cond-mat.soft), Statistical Mechanics (cond-mat.stat-mech)
Liquid-Liquid Phase Separation in a Minimal Explicit-Solvent Lattice Model Mimicking Protein Solutions
New Submission | Soft Condensed Matter (cond-mat.soft) | 2026-05-26 20:00 EDT
Siddhartha Roy, Rakesh S. Singh
Biomolecular condensates play essential roles in cellular processes, and recent efforts have focused on understanding their assembly and rational design principles. In this study, we have employed an explicit-solvent minimal statistical mechanical model based on the lattice-gas Hamiltonian with quenched disorder – which mimics crowders – to investigate how protein-solvent and protein-crowder interactions influence condensate phase behavior and morphology. The computed phase diagrams reveal rich behavior, including upper critical solution temperature (UCST), closed-loop, and reentrant type transitions under varying protein-solvent interactions at both equilibrium and out-of-equilibrium conditions. We elucidated the origin of these phase behavior changes and examined the role of protein-crowder interactions in modulating condensed phase morphology and stability. We further extended this model to binary protein mixtures where we studied the phase behavior in the presence and absence of quenched disorder. Without disorder, the system exhibits diverse phase-separated morphologies – partially wetted, fully wetted, segregative, and associative – with phase boundaries delicately sensitive protein-solvent interactions. The introduction of quenched disorder (or crowder) leads to a broader spectrum of complex morphologies, dictated by the interplay among protein-protein, protein-solvent, and protein-crowder interaction parameters. In general, this work underscores that protein-solvent and protein-crowder interactions, together with protein-protein interactions, can act as key regulatory parameters for modulating condensate morphology. These insights may guide future computational and experimental studies of liquid-liquid phase separation in biomolecular systems aimed at designing stimuli-responsive condensates.
Soft Condensed Matter (cond-mat.soft)
Magnetic ground state of a prototype quasicrystal approximant: a candidate for octahedral spin ice physics
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2026-05-26 20:00 EDT
Leonie Woodland, Farid Labib, Dmitry Khalyavin, Pascal Manuel, Fabio Orlandi, Hubertus Luetkens, Ryuji Tamura
Magnetic ordering in quasicrystals has recently emerged as a fertile ground for discovering unconventional magnetic states beyond the framework of periodic crystals. However, elucidating the microscopic origin of such states remains challenging due to the intrinsic aperiodicity of quasicrystals. Here, we address this issue by investigating the prototypical Tsai-type quasicrystal approximant Cd6Tb, which preserves the essential local geometry and connectivity of icosahedral quasicrystals while allowing detailed structural and magnetic characterization due to its translational periodicity. Using neutron diffraction measurements, we find a noncoplanar multi-k magnetic ground state composed of Ising-like Tb moments arranged on a network of corner-sharing octahedra, the ingredients required to host octahedral spin-ice physics. Remarkably, only one third of the Tb moments develop long-range magnetic order, whereas the remaining moments display strongly reduced static order accompanied by persistent spin dynamics on microsecond timescales, as evidenced by muon spin rotation. This coexistence of ordered and fluctuating moments constitutes a potential realization of magnetic fragmentation - a key prediction of octahedral spin-ice physics - in a quasicrystal-related material.
Strongly Correlated Electrons (cond-mat.str-el), Materials Science (cond-mat.mtrl-sci)
7 pages, 4 figures (main text) + 14 pages, 6 figures (supplementary material)
Nuclear-Electron Hyperfine Coupling of the Shallow States Associated with Vacancies in Gallium Nitride
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-05-26 20:00 EDT
Joseph Sink, Michael E. Flatté
We use multiband real space Green’s functions computed using open-boundary conditions for clean GaN to exactly solve the potential-scattering Dyson equation to obtain the electronic structure of single nitrogen and gallium vacancies. From these vacancy solutions, we compute the local density of states as well as the Fermi contact and anisotropic contributions to the hyperfine field in the vicinity of the defect. These quantities directly affect electrically-detected magnetic resonance signals, which can be used to identify these defects when present in GaN devices.
Materials Science (cond-mat.mtrl-sci)
Effect of slow bonds on current fluctuations in the symmetric simple exclusion process
New Submission | Statistical Mechanics (cond-mat.stat-mech) | 2026-05-26 20:00 EDT
Soumyabrata Saha, Sandeep Jangid, Kapil Sharma, Tridib Sadhu
The symmetric simple exclusion process (SSEP) is a paradigmatic model of classical non-equilibrium dynamics. Exact results for large deviations of particle current in the SSEP have been obtained in various settings using integrability-based methods. In this Article, we discuss how these results are modified in the presence of localized slow bonds. We consider three conventional geometries: (a) a finite one-dimensional lattice weakly coupled to unequal reservoirs at its boundaries, (b) a semi-infinite one-dimensional lattice weakly coupled to a boundary reservoir, and (c) an infinite one-dimensional lattice with localized slow bonds near the origin. For each case, we present exact expressions for the large deviation function of current and validate them through rare-event simulations based on the cloning algorithm. In connection with our results, we present an elementary derivation of the exact large deviation function for the current in the semi-infinite SSEP, complementing recent results obtained through more elaborate techniques.
Statistical Mechanics (cond-mat.stat-mech), Mathematical Physics (math-ph)
23 pages, 7 figures
Theory of Electrically Detected Magnetic Resonance of Silicon Vacancy-Related Spin Pairs in Silicon Carbide
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-05-26 20:00 EDT
David A. Fehr, Corey J. Cochrane, Stephen R. McMillan, Nicholas J. Harmon, Patrick M. Lenahan, Michael E. Flatté
We present a quantitative theory for simulating the electrically detected magnetic resonance (EDMR) of silicon vacancy-related spin pairs in silicon carbide using steady-state Lindblad master equations. In our theory, we consider V1a and V2a deep level silicon vacancies near the (0/-) charge state transition level in proximity to a previously identified nitrogen-related complex, the incomplete K-center, due to the hyperfine, spin structure, and Landé g factor of the shallow state. Our theory describes recent room temperature measurements attributed to V1a silicon vacancies, with reasonable extracted parameters for defect spin coherence times and electrical transport rates. At lower temperatures we predict that the shallow level hyperfine structure may be spectrally resolvable. Finally, we predict the EDMR spectrum of V2a silicon vacancy-related spin pairs and predict that two-photon, double quantum transitions of the silicon vacancy’s negative charge state can be electrically read-out for enhanced magnetic field sensing.
Materials Science (cond-mat.mtrl-sci), Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
Magneto-optic phonon resonances in magnetic topological EuCd2As2 via helical Raman spectroscopy
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-05-26 20:00 EDT
Jin Ho Kang, Liangbo Liang, Ioannis Petrides, Kai-Chi Chang, Subhajit Roychowdhury, Chandra Shekhar, Claudia Felser, Prineha Narang, Chee Wei Wong
EuCd2As2 materials have two magnetic ordering states: antiferromagnetic (AFM) and ferromagnetic (FM) when their chemical tunability is utilized. While AFM-EuCd2As2 has a nonzero magnetoelectric response due to its symmetry breaking with spin configuration, FM-EuCd2As2 is an ideal candidate for studies of Weyl physics because of its minimum number of Weyl points with opposite chirality. In this article, we examine cryogenic low-frequency Raman spectroscopy of phonon modes in FM-EuCd2As2 crystals using circular polarization configurations, with support from density functional theory calculations, and investigate in-plane magneto-anisotropy by linear polarization configuration below the Curie temperature (Tc = 26 K). We attribute the anomalous enhancements in Raman intensities below the Curie temperature are due to spin-phonon coupling. Furthermore, we see that A-mode peaks can be distinguished by magneto-helical Raman spectroscopy through the magneto-optic effect and that the degree of circular polarization (DCP) of 12.5 meV peak reaches 60% at 4.2 K and becomes saturated. We also examine AFM-EuCd2As2 below Néel temperature (TN = 9 K) to compare with FM-EuCd2As2, but we hardly observe spin-phonon coupling and find negligible DCP values due to almost zero net magnetization. Our results contribute to the understanding of the phonon dynamics and the interplay between topology and magnetism in FM-EuCd2As2, through helical light and external magnetic fields. This lays the foundation for utilizing state-of-the-art Weyl systems for applications in thermoelectrics, phononic devices, and topological quantum computing.
Materials Science (cond-mat.mtrl-sci)
20 page, 4 figures
Observation of the Optical Phonons in α-MnTe films
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2026-05-26 20:00 EDT
Himanshu Sheokand, Arun K Kumay, Mazharul Islam Mondal, Milo Sprague, Ravinder Sharma, Jayan Thomas, Dariusz Kaczorowski, Andrzej Ptok, Madhab Neupane
The altermagnetic materials have emerged as model systems for studying spin split electronic structures, yet controlled epitaxial growth on technologically relevant substrates remains challenging. Among the known candidates, MnTe stands out as a prominent altermagnetic material owing to its layered structure and high Neel temperature. Here, we report the molecular beam epitaxy (MBE) growth of high quality alpha MnTe thin films on GaAs(111)B substrates and provide a comprehensive analysis of the growth evolution and structural properties. Raman spectroscopy reveals multiple vibrational features of alpha MnTe including modes near 121, and 140 1/cm. Combined with first principles phonon calculations, these features are identified as the Raman-active phonons of the hexagonal NiAs type lattice. Our results show that the high crystalline quality of MBE grown alpha MnTe enables the complete experimental resolution of all symmetry allowed Raman active phonon modes, highlighting epitaxial alpha MnTe as a robust thin film platform for investigating altermagnetism and its lattice coupled excitations.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Materials Science (cond-mat.mtrl-sci)
6 pages, 4 figures
Characterizing emergent multi-scale dynamics in colloidal nanoparticle gels
New Submission | Soft Condensed Matter (cond-mat.soft) | 2026-05-26 20:00 EDT
William D. Brackett, Zachary M. Sherman, Felix Lehmkühler, Thomas M. Truskett, Delia J. Milliron
Colloidal gels assembled from nanoparticles (NPs) are a versatile class of soft network-based materials capable of rich dynamic, mechanical, and even optical or magnetic responses to stimuli. Understanding how their hierarchically organized processes relate to macroscopic network properties remains a broad and unresolved problem in soft matter physics. The mechanisms of gel formation can depend sensitively on the pathway and the nature of NP interactions, thus far preventing a unified theoretical bridge between nanoscopic interactions and structural evolution and network dynamics. Indirect measurement of dynamics using light-scattering techniques provides an experimental means to quantify underlying particle and network motion. X-ray photon correlation spectroscopy (XPCS) has emerged as a powerful tool for probing nanoscopic motion in nanoparticle gels, but alone cannot resolve the full spatiotemporal spectrum of dynamics that drive gelation, aging, and network mechanical properties. While in situ rheo-XPCS enables simultaneous probing of nanoscale and bulk mechanical responses, complementary light scattering, microscopy, or simulations can extend spatiotemporal characterization and, consequently, understanding of NP gel network physics. Implementing a modular model platform with tunable primary nanoparticle features allows systematic variation of nanoscopic characteristics that drive emergent gel responses and inform the development of theoretical models for a wide range of soft, dynamic, nanostructured materials. The rapid expansion of XPCS capabilities at fourth-generation light sources, combined with complementary tools and robust model systems, positions the field to move beyond descriptive fundamental studies toward the design of nanoparticle gels with adaptive and programmable behaviors.
Soft Condensed Matter (cond-mat.soft), Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Materials Science (cond-mat.mtrl-sci), Statistical Mechanics (cond-mat.stat-mech)
77 pages, 7 figures, Perspective for Physical Review E (accepted for publication)
Response of a dipolar BEC to Laguerre-Gaussian beam driven STIRAP
New Submission | Quantum Gases (cond-mat.quant-gas) | 2026-05-26 20:00 EDT
Deepu Singh, Hari Sadhan Ghosh, Arpana Saboo, Soumyadeep Halder, Sonjoy Majumder
Coherent light-matter coupling via STIRAP can offer a versatile route to nucleate quantized vortices in Bose-Einstein condensates, yet its efficacy in dipolar condensates remains an open question. Can the orbital angular momentum of a Laguerre-Gaussian beam be coherently transferred to a dipolar BEC via STIRAP? We investigate this for a quasi-two-dimensional trapped dipolar condensate using co-propagating Gaussian and Laguerre-Gaussian laser beams. The interplay between long-range dipole-dipole interactions and short-range contact interactions enables access to three interaction-driven phases: superfluid, droplet, and supersolid. We find that the amount of angular momentum transferred from the optical field to the dipolar condensate, along with the nucleation and persistence of vortices, depends strongly on the underlying phases of the dipolar BEC. In the superfluid, STIRAP achieves near-complete population transfer and nucleates a stable, long-lived quantized vortex. In the droplet phase, although the vortex remains pinned within the density profile, the angular momentum is partially retained and oscillatory, accompanied by droplet fragmentation and recombination. In the supersolid phase, when the external magnetic field is oriented perpendicular to the LG beam’s propagation direction, the emergence of a modulated density distribution along with a slight reduction in inter-droplet coherence leads to vortex delocalization and eventually expels it along the field direction, yielding a vanishing average angular momentum. However, reorienting the magnetic polarization along the beam propagation direction restores efficient angular momentum transfer and stabilizes the vortex within the supersolid phase. Overall, our results demonstrate a versatile route to engineer vortex states and probe collective excitations in dipolar Bose gases via coherent light-matter coupling.
Quantum Gases (cond-mat.quant-gas)
14 pages, 7 figures