CMP Journal 2026-08-03
Statistics
Nature: 1
Nature Materials: 1
Nature Nanotechnology: 2
Nature Physics: 1
Nature Reviews Materials: 1
arXiv: 85
Nature
Gasdermin D-mediated delivery of caspase inhibitors to suppress pyroptosis
Original Paper | Innate immunity | 2026-08-02 20:00 EDT
Katarzyna M. Groborz, Melissa E. Truong, Irma Stowe, Katherine E. Wickliffe, Bettina Lee, Stefan Bauernfried, Robert S. Jones, Emile Plise, Elizabeth S. Levy, Ponien Kou, Wyne P. Lee, Juan Zhang, Hanna Budayeva, Christopher M. Rose, Julia Nguyen, Malgorzata Kalinka, Marcin Drag, Nobuhiko Kayagaki, Kim Newton, Marcin Poreba, Vishva M. Dixit
Caspase-1, -4, -5, and -11 activate Gasdermin D (GSDMD) pores, causing pyroptotic cell death and the release of interleukin (IL)-1β and IL-18 1. Blocking this pathway holds therapeutic promise for the treatment of inflammatory disorders, but cell permeable caspase inhibitors have not been successful in clinical trials 2. Here, we describe covalent caspase inhibitors that selectively block pyroptosis and IL-1β secretion despite being excluded from healthy cells. These inhibitors did not prevent caspase-driven apoptosis, implying that GSDMD pores facilitated their uptake. Membrane-impermeable dyes entered the cells rescued from pyroptosis, consistent with transient membrane permeabilization by GSDMD pores. Caspase inhibition prevented rather than delayed cell death, consistent with membrane repair mechanisms neutralizing the initial GSDMD pores. Inhibiting caspase-1 and -11 suppressed IL-1β and IL-18 production in a mouse model of endotoxic shock, underscoring the therapeutic potential of exploiting GSDMD pores for targeted caspase inhibition in inflammatory diseases.
Innate immunity, Proteases
Nature Materials
Molecular coordination achieves uniform kesterite absorber film for efficient solar modules
Original Paper | Solar cells | 2026-08-02 20:00 EDT
Bowen Zhang, Menghan Jiao, Xiao Xu, Jiazheng Zhou, Jinlin Wang, Tan Guo, Yuan Li, Jingchen Wang, Shudan Chen, Yiming Li, Jiangjian Shi, Huijue Wu, Yanhong Luo, Dongmei Li, Qingbo Meng
Environmentally benign and earth-abundant kesterite Cu2ZnSn(S,Se)4 (CZTSSe) solar cells have advanced rapidly through solution-based processing. However, scaling from laboratory-scale devices to modules remains a major challenge, largely because complex coordination networks in the precursors hinder the formation of uniform large-area films. Here we show that molecular-level regulation of metal-organic coordination can suppress the formation of cross-linked networks in precursor solutions, promoting efficient solvent removal and uniform selenization and crystallization. This coordination-controlled strategy enables the blade coating of highly homogeneous films over 10 cm2, realizing certified efficiencies of 14.2% for 1 cm2 cells and 13.0% for 10.5 cm2 modules, representing a leap-forward improvement in scalable kesterite photovoltaics. Beyond performance, the provided molecular insights into kesterite solution chemistry facilitate establishing a scalable and low-cost route towards industrial deployment of this thin-film solar technology.
Solar cells
Nature Nanotechnology
Intrinsic plasmon canalization in the biaxial van der Waals crystal MoOCl2
Original Paper | Polaritons | 2026-08-02 20:00 EDT
Farid Aghashirinov, Andrea Mancini, Lin Nan, Giacomo Venturi, Bettina Frank, Harald Giessen, Antonio Ambrosio
Anisotropic polaritons in low-symmetry crystals allow for subwavelength confinement and directional routing of light. The most extreme form of such anisotropy arises at the topological transition between elliptical and hyperbolic dispersion, where the isofrequency contours collapse into parallel lines and polaritons propagate in a diffractionless, beam-like fashion. This canalization regime has previously been accessed through twisted heterostructures or engineered metasurfaces. Here we show that intrinsic canalization can be achieved without any fabrication or structuring by exploiting the intrinsic elliptical-to-hyperbolic transition in the van der Waals crystal MoOCl2 at room temperature. Using near-field imaging, we directly visualize plasmon-polariton canalization emerging at the low-loss Drude crossing point along the [010] crystal axis. Owing to the moderate slope of the Drude permittivity, the resulting polaritons remain highly directional across a broad spectral window. This weak dispersion also enables robust thickness-dependent tuning, and we demonstrate, both experimentally and theoretically, that the canalization wavelength can be adjusted by more than 1 μm simply by varying the flake thickness. This work brings canalized polariton propagation into the 4.5-6 μm range, beyond the frequency limits of phonon-polariton platforms and overlapping with important molecular vibrations, opening new opportunities for mid-infrared nanophotonics and sensing.
Polaritons, Sub-wavelength optics, Two-dimensional materials
Self-assembled contacts for high-yield molecular devices
Original Paper | Molecular electronics | 2026-08-02 20:00 EDT
Sarah O. Spector, Peter F. Satterthwaite, Maxwell Conte, Teddy Hsieh, Eduard O. Bobylev, Kieran Dunn, Weikun Zhu, Jinwoo Sim, Jeremiah A. Johnson, Farnaz Niroui
With their atomic precision and synthetically tailorable properties, molecules offer new possibilities for emerging computing, sensing, optical and quantum technologies. However, the scalable, damage-free integration of molecules into active devices with atomic-scale control remains a critical challenge due to incompatibility with existing top-down fabrication processes. Here we introduce self-assembled contacts, a strategy in which device structures are first fabricated using standard semiconductor manufacturing processes and subsequently transformed through engineered surface interactions to form self-aligned, pristine interfaces with molecules. We validate this approach by fabricating over 1,000 electrically active metal-molecule-metal devices with yields of up to 99% and stable operation over 105 measurement cycles, even for molecular layers thinner than 1 nm. In situ Raman measurements verified the preservation of molecular integrity. Beyond individual devices, the platform supports system-level integration, which we demonstrate through vector-matrix multiplication, a fundamental operation in neuromorphic computing, implemented in a crossbar array of self-rectified molecular memory devices. Our results establish self-assembled contacts as a scalable platform for integrating molecular functionalities into devices, bridging self-assembly and top-down manufacturing.
Molecular electronics, Molecular self-assembly, Techniques and instrumentation
Nature Physics
Altermagnetic photonic crystals
Original Paper | Magnetic properties and materials | 2026-08-02 20:00 EDT
Jianfeng Chen, Yidong Zheng, Zhi-Yuan Li, Cheng-Wei Qiu
Altermagnetism is a magnetic phase that combines zero net magnetization with time-reversal-symmetry breaking and momentum-dependent spin splitting, but it has so far been confined to fermionic systems. Here we report a photonic platform capturing the symmetry features of altermagnetism. Using a magnetophotonic crystal with staggered magnetic bias and controlled structural variation, we observe momentum-dependent polarization splitting, spin-momentum locking and vanishing net magnetization in the photonic band structure. By solving Maxwell’s equations, we show that the momentum-dependent splitting is symmetry governed, rather than a consequence of the momentum-independent gyrotropic effect. These results demonstrate a photonic analogue of altermagnetic behaviour and provide a route towards spin-functional photonic devices without net magnetization.
Magnetic properties and materials, Metamaterials
Nature Reviews Materials
Engineered interfaces in electronic materials for energy-efficient computing
Review Paper | Electronic devices | 2026-08-02 20:00 EDT
Sathvik Ajay Iyengar, Pulickel M. Ajayan, Vincent Meunier, Tahir Ghani, Sayeef Salahuddin, Asir Intisar Khan
The rapid expansion of data-centric technologies has made energy-efficient computing a technological and societal priority. Modern systems consume energy not only through computation but also through data movement between logic and memory, resistive losses in interconnects and heat removal. These energy costs intensify as devices shrink and integration density increases. Architectural strategies such as three-dimensional integration reduce latency and increase functional density by bringing memory and logic closer together. Yet further scaling is progressively constrained by materials functionality at interfaces, rather than by bulk properties. In this Perspective, we argue that transport within the first few atomic layers at material boundaries will determine the efficiency and scalability of future electronic devices. First, we outline four governing principles of interface engineering: electrostatics, electronic hybridization, boundary-dominated transport and thermal and structural stability. We then derive design rules and use representative device examples to show how engineered interfaces control switching energy, electrical conduction, heat dissipation and reliability. Finally, we consider the need for low-temperature materials synthesis, interface-sensitive metrology and uncertainty-aware predictive modelling to facilitate future advances in energy-efficient computing.
Electronic devices, Electronic properties and materials
arXiv
Anomalous Boundary Modes in a Floquet Hyperbolic System
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2026-08-03 20:00 EDT
Ali Fahimniya, Hossein Dehghani, Alicia J. Kollár, Alexey V. Gorshkov
We construct an anomalous Floquet topological phase on a negatively curved hyperbolic lattice. The model is a tight-binding Hamiltonian with a periodically repeated four-color edge-hopping sequence and a sublattice-staggered onsite potential step. The topological regime is reached near the limit in which a single hopping step transfers amplitude completely across an active edge, while the trivial regime is reached near the point where two full hops occur along an active edge during a single hopping step, returning the amplitude to its starting site. In finite open patches, the topological regime is characterized by bulk quasienergy gaps at $ 0$ and $ \pi$ that are populated by in-gap states, in contrast to a trivial regime where these gaps remain empty. Using compact periodic lattices, we map the bulk $ 0$ and $ \pi$ quasienergy gaps and identify the gapped regions connected to the trivial and anomalous open-boundary spectra. We diagnose the in-gap states as chiral boundary modes by their real-space dynamics. Finally, we introduce a small-boundary spectral-flow diagnostic based on punctured periodic hyperbolic lattices, which avoids the ambiguity associated with the extensive outer boundary of finite hyperbolic patches. This puncture-based diagnostic should be useful for studying other topological hyperbolic systems.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Other Condensed Matter (cond-mat.other), Quantum Physics (quant-ph)
15 pages, 11 figures
Enhancement of exciton radius near a band-gap closing through quantum geometry
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2026-08-03 20:00 EDT
Jin-Hyung Choi, Sang-Hoon Han, Young-Kwon Han, Sun-Woo Kim, Jun-Won Rhim, Joshua J. P. Thompson
Exciton engineering traditionally focuses on modifying semiclassical material properties, such as the effective mass and dielectric screening, while largely overlooking the quantum geometry of the underlying electron and hole Bloch states. This approximation is adequate for many materials but breaks down near a topological band-gap closing, where the quantum metric around the band extrema becomes strongly enhanced. In this regime, Bloch states at different momenta become less similar, reducing the projected electron–hole Coulomb matrix elements and consequently weakening exciton binding. We demonstrate this mechanism in a spin–orbit-coupled Lieb-lattice model tuned toward a topological phase transition. The suppressed Coulomb matrix elements narrow the exciton wavefunction in momentum space, leading to an enlarged exciton radius in real space. This increase in exciton size produces an experimentally accessible enhancement of the weak-field diamagnetic response. Our results show that quantum geometry can fundamentally reshape exciton properties near a topological phase transition, revealing a previously underexplored route for engineering excitonic states.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
Meissner Effect and Josephson Radiation in Driven Dissipative Superconductors
New Submission | Superconductivity (cond-mat.supr-con) | 2026-08-03 20:00 EDT
Carl Philipp Zelle, Subir Sachdev
Photo-induced superconducting signatures have been observed in several materials at temperatures far above their equilibrium critical temperatures, including magnetic field expulsion as in the Meissner effect. We propose driven-dissipative condensation of the superconducting order parameter as a mechanism for this phenomenon. In such a theory, optical pumping generates an effective gain (possibly via a parametric resonance) that overcomes the intrinsic damping of the pairing field, and stabilizes a non-equilibrium condensate whose phase rotates at an intrinsic frequency that is generally lower than, and incommensurate with, the drive frequency. We develop a phenomenological continuum theory that couples this slowly rotating order parameter to the conserved charge density and the electromagnetic gauge field. Despite its finite-frequency dynamics, the resulting state exhibits the conventional long-wavelength electromagnetic signatures of superconductivity. In three dimensions, it displays a static Meissner effect and a gapped plasmon generated by the Anderson–Higgs mechanism. In a two-dimensional sheet, it exhibits Pearl screening and the characteristic square-root plasmon dispersion. We further propose a direct experimental test based on a Josephson junction between the driven-dissipative state and an equilibrium superconductor. The junction supports an AC Josephson current at zero applied voltage and emits radiation at the intrinsic rotation frequency of the condensate. Its low, pump-dependent, and generally incommensurate frequency provides a clear signature distinguishing driven-dissipative superconductivity from equilibrium and drive-locked pairing states.
Superconductivity (cond-mat.supr-con), Statistical Mechanics (cond-mat.stat-mech), Strongly Correlated Electrons (cond-mat.str-el)
Gapped Parent Hamiltonians for the Strongly Deformed Toric Code
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2026-08-03 20:00 EDT
Nandagopal Manoj, Zack Weinstein, Jason Alicea
Local non-unitary deformations of topologically ordered wavefunctions can drive transitions into peculiar states that challenge modern perspectives on gapped quantum matter. The strongly deformed toric code offers a curious case, hosting $ m$ anyon condensation alongside perimeter-law scaling of Wilson loops charged under an exact 1-form symmetry—properties that typically do not coexist in gapped ground states. Nevertheless, we rigorously construct local gapped parent Hamiltonians for these strongly deformed toric code states. The Hamiltonians we construct are not strictly finite-range, but contain sums of Wilson loop operators whose coefficients decay exponentially in their diameter. If one adopts standard locality bounds used to define gapped phases—which allow for such exponentially decaying terms—our construction shows that these states realize a trivial gapped phase. Within this locality class, we demonstrate that perimeter-law scaling of Wilson loops does not imply a spontaneously broken 1-form symmetry, and from a dual perspective, that long-range ferromagnetic order and perimeter-law disorder parameter correlations can coexist in a 2D gapped ground state. We evade a recent no-go theorem [Sahay et al., arXiv:2503.01977] by relaxing its assumptions in a manner that we quantify as benign in the thermodynamic limit. More broadly, our results highlight that stronger notions of locality are necessary for prohibiting these counterintuitive properties within a gapped phase.
Strongly Correlated Electrons (cond-mat.str-el), Statistical Mechanics (cond-mat.stat-mech), Quantum Physics (quant-ph)
7 + 25 pages, 1 + 2 figures
Intrinsic Orbital Hall Effect in Degenerate Spin-3/2 Systems driven by the quantum metric
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2026-08-03 20:00 EDT
We show that in rotationally invariant spin-$ 3/2$ systems the orbital Hall effect originates from interband matrix elements of the orbital magnetic moment. The resulting Hall response is governed by the quantum metric, rather than by the Berry curvature, revealing a purely geometric transport mechanism. Conventional intraband contributions associated with the orbital magnetic moment and Berry curvature are shown to vanish identically in degenerate systems. These results identify the quantum metric as the key geometric quantity controlling orbital Hall transport in degenerate multiband systems.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
7 pages, 3 figures
Symmetry Rules for Cavity Materials Engineering with Linearly Polarized Vacuum Fields
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-08-03 20:00 EDT
Jingkai Quan, Chongxiao Fan, Benshu Fan, I-Te Lu, Dante M. Kennes, Angel Rubio
Cavity materials engineering, aiming to manipulate material properties by coupling to vacuum fluctuations inside a cavity, is a rapidly advancing field. Despite significant progress, most studies to date have focused on specific materials and cavity configurations. Here, through a comprehensive group-theoretical analysis, we establish general symmetry rules for cavity materials engineering with linearly polarized cavity photon modes. By analyzing the symmetry of the effective photon-free quantum-electrodynamics Hamiltonian, we provide a complete classification of the symmetry-breaking patterns induced by cavity modes for all crystallographic point groups. The power of this framework is then demonstrated by quantum-electrodynamical density functional theory calculations. In particular, we explain the distinct cavity-induced lifting of band degeneracies in cubic BaTiO$ _3$ for different cavity mode configurations, and the cavity-modified infrared and Raman spectra of monolayer MoS$ _2$ due to symmetry breaking. Our results highlight the central role of symmetry in cavity materials engineering and provide general guidelines for future studies in this field.
Materials Science (cond-mat.mtrl-sci)
Local B-site chemistry controls oxygen-vacancy energetics in Ca-Ce-Ti-Mn perovskites for thermochemical hydrogen production
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-08-03 20:00 EDT
Manish Kumar (1), Natalia Ali (2), Matthew D. Witman (3), Shang Zhai (4), James E. Miller (2), Ivan Ermanoski (2), Ellen B. Stechel (2), Robert B. Wexler (1) ((1) Washington University in St. Louis, (2) Arizona State University, (3) Sandia National Laboratories, (4) The Ohio State University)
Two-step thermochemical water splitting driven by concentrated solar heat is a scalable route to renewable hydrogen, but it requires oxides whose oxygen-vacancy formation energies balance facile reduction with favorable reoxidation. Perovskite solid solutions can tune this balance, but the relationship between bulk stoichiometry and local defect energetics remains poorly understood. Here we map oxygen-vacancy formation energetics across Ca-Ce-Ti-Mn (CCTM) perovskites by combining first-principles calculations with a coverage-constrained special quasirandom structure approach that realizes all fifteen symmetry-distinct oxygen nearest-neighbor environments, an interpretable crystal-feature model whose fitted coefficients directly encode the underlying Born-Haber thermochemistry, and a fine-tuned defect graph neural network. Local B-site chemistry dominates the oxygen-vacancy formation energy $ E_\mathrm{v}$ : varying the nearest-neighbor Mn fraction shifts $ E_\mathrm{v}$ by 1.0-1.5 eV depending on local Ce content, whereas A-site Ce variation contributes a smaller, Mn-dependent shift of 0.2-0.6 eV. Short-range B-site cation order, if it can be established and kinetically retained through processing, is therefore a candidate means of tuning redox performance without changing bulk composition. Composition-space maps identify a Ce/Mn-balanced region ($ X_\mathrm{Ce}$ = 0.29-0.33, $ X_\mathrm{Mn}$ = 0.58-0.67) combining a high fraction of vacancy sites within the targeted $ E_\mathrm{v}$ window with phase stability and solubility, whose predicted redox cycle capacity matches or exceeds the ceria benchmark at 1350 $ ^\circ$ C rather than the roughly 1600 $ ^\circ$ C ceria requires. Measurements on three CCTM compositions show cycle capacity increasing monotonically with Ce content under protocols close to the model conditions. The design rules are expected to transfer to related perovskite families.
Materials Science (cond-mat.mtrl-sci)
16 pages, 6 figures, 3 tables; supplementary information appended (23 pages, 10 figures, 6 tables), 39 pages total. Manish Kumar and Natalia Ali contributed equally. Data and figure-generation scripts at this https URL. VASP inputs and outputs at this https URL
Deriving the second law of thermodynamics and exploring its boundaries
New Submission | Statistical Mechanics (cond-mat.stat-mech) | 2026-08-03 20:00 EDT
The second law of thermodynamics still lacks a general proof applicable to both classical and quantum systems across broad ranges of time scales, interactions, and degrees of nonequilibrium. In this paper, we show that when the macrostate-level probability $ f$ of an isolated system increases monotonically with the number of possible microstates $ \Omega$ (i.e., $ \partial f/\partial \Omega > 0$ ), the second law emerges naturally from the continuity equation of $ f$ in phase space; a special case of $ \partial f/\partial \Omega > 0$ is Boltzmann’s assumption of equal a priori equilibrium probabilities. Based on this finding, the second law can be readily derived for fully chaotic systems. The derivation does not rely on dynamical details, highlighting the statistical nature of entropy increase. In contrast, for a locally nonchaotic system, the positive correlation between $ f$ and $ \Omega$ may break down (i.e., $ \partial f/\partial \Omega \leq 0$ ). Consequently, the conventional framework of thermodynamics does not apply, and entropy can decrease spontaneously without any energetic penalty.
Statistical Mechanics (cond-mat.stat-mech), Classical Physics (physics.class-ph)
33 pages, 7 figures
Disorder induced time crystal in athermal random field Ising model with non-reciprocal interactions
New Submission | Statistical Mechanics (cond-mat.stat-mech) | 2026-08-03 20:00 EDT
A two species random field Ising model with non-reciprocal interactions between the species is studied using the greedy Glauber dynamics. By solving the dynamics exactly on a complete graph, we obtain the phase diagram of the model as a function of the non-reciprocal interaction ($ K$ ) and the variance ($ \sigma$ ) of the quenched random field distribution. The model exhibits a rich phase diagram with the presence of a chaotic time-oscillatory phase for intermediate values of $ K$ and $ \sigma$ . The chaotic phase has stable time oscillations along with the autocorrelation time that diverges with system size on a complete graph and also in three dimensions. We find that the random field disorder along with non-reciprocal interaction alone can produce a time crystal without an external driving. In two dimensions the autocorrelation time does not increase with the system size and the time crystal phase is absent.
Statistical Mechanics (cond-mat.stat-mech)
Statistical Gauge Theory of Structural Glasses: Equilibrium Scenarios and Glass-Forming Ability
New Submission | Disordered Systems and Neural Networks (cond-mat.dis-nn) | 2026-08-03 20:00 EDT
The model primarily concerns structural glasses described by systems of topological defects. We explore the scope of this approach and investigate equilibrium behavior within the mean-field approximation. Our analysis reveals three possible equilibrium scenarios, only one of which exhibits a strong glass-forming ability. These scenarios allow for the phenomenological selection of model parameters based on equilibrium behavior, which can then be used to study dynamics during quenching. We identify an upper temperature limit beyond which quenching into the glassy state becomes impossible.
Disordered Systems and Neural Networks (cond-mat.dis-nn), Statistical Mechanics (cond-mat.stat-mech)
26 pages, 2 figures
Electrical Control over Volatile Mott Switching through Non-Volatile Memory Effects
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-08-03 20:00 EDT
Amihai Kronman (1), Gil Levi (1), Yoav Kalcheim (1) ((1) Department of Materials Science and Engineering, Technion - Israel Institute of Technology, Haifa, Israel)
Vanadium Dioxide (VO2) and Vanadium Sesquioxide (V2O3) are Mott insulators that undergo an Insulator-to-Metal Transition (IMT) at ~340K and ~160K, respectively, manifested as an orders-of-magnitude reduction in their electrical resistance. These transitions provide the physical basis for their Volatile Resistive Switching (VRS) behavior, making them promising candidates for threshold-switching devices. Here, we show that the volatile switching in these materials can be strongly affected by non-volatile processes associated with the creation and annihilation of the conducting filament. These processes give rise to pronounced memory effects in which the initial switching voltage substantially exceeds that of subsequent cycles. We identify two distinct mechanisms underlying this behavior in different thermal regimes. In the phase-coexistence regime, a memory effect is observed in V2O3, arising from the spatial redistribution of metallic and insulating domains. Well below the hysteresis regime, an additional electroforming-like memory effect is observed in both VO2 and V2O3 which is attributed to the formation and/or migration of defects under the influence of a high electric field and a current surge associated with the IMT-driven switching. Using a protective internal resistor and a multi-step writing protocol, this normally destructive process can be harnessed to tune the switching voltage and power over a wide temperature range. These results demonstrate a route toward controlled programming of switching parameters in IMT-based resistive switching devices.
Materials Science (cond-mat.mtrl-sci)
22 pages, 8 figures, 12 supplementary pages, 7 supplementary figures
Open-Shell Molecules as Sensitive Probes of Spin-Orbit-Controlled Surface Electronic Structure
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-08-03 20:00 EDT
Solange Mariel Di Napoli, Alexei Nefedov, María Andrea Barral, Gustavo E. Murgida, Ana María Llois, Christof Wöll, M. Verónica Ganduglia-Pirovano, Verónica Laura Vildosola
Open-shell molecules are highly sensitive probes of correlated oxide surfaces because their partially occupied frontier orbitals strongly amplify subtle changes in adsorbate-substrate hybridization. Combining infrared reflection-absorption spectroscopy with hybrid density functional theory including non-collinear magnetism and spin-orbit coupling, we show that inclusion of spin-orbit coupling is essential to reproduce the vibrational spectrum of NO adsorbed on UO$ _2$ (111) by suppressing an otherwise artificial overhybridization between the NO frontier orbitals and uranium 5f states. While spin-orbit coupling determines the position of the N-O stretching and, dispersion-driven intermolecular interactions account for its asymmetric broadening at monolayer coverage. These results establish open-shell molecules as sensitive probes of spin-orbit-controlled surface electronic structure and identify NO/UO$ _2$ (111) as a stringent benchmark for electronic-structure methods describing open-shell molecule-surface interactions.
Materials Science (cond-mat.mtrl-sci)
Symmetry-assisted computation of the magnetic field at the site of a point dipole
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2026-08-03 20:00 EDT
In this paper, we revisit this concept of the magnetic field at the site of a magnetic dipole using symmetry arguments that are mathematically rigorous yet intuitive enough to be well-suited for upper-level undergraduate courses in electrodynamics and quantum mechanics. Furthermore, we present symmetry-based results that go beyond those discussed in the standard literature, which are directly relevant to fundamental problems in two-dimensional physics.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Other Condensed Matter (cond-mat.other)
18 pages
Exact Results for the Symmetric Dyson Exclusion Process
New Submission | Statistical Mechanics (cond-mat.stat-mech) | 2026-08-03 20:00 EDT
Ali Zahra, Jerome Dubail, Gunter M. Schutz
The symmetric Dyson exclusion process (SDEP) is an exclusion process on the lattice with a long-range logarithmic Coulomb-type interaction. It appears in several equivalent forms: as symmetric random walkers conditioned, in the Doob-transform sense, not to collide; as the maximal-activity limit of a conditioned SSEP; and as a ground-state transform of the spin- 1/2 XX chain. In this work, we exploit this latter representation to obtain exact evolution formulas from deterministic initial configurations. The resulting determinantal kernel is expressed through a finite interpolation expression in terms of Lagrange polynomials, leading to explicit density evolution in finite and infinite lattices. For the melting of a densely packed block, we show that the full hierarchy of density moments is governed by a finite-dimensional polynomial algebra, and we identify Catalan numbers in the leading time coefficients. We also derive the Euler-scale density profile and the arctic curve separating frozen and liquid regions, and show that they coincide with conjectured hydrodynamic results obtained in a previous work.
Statistical Mechanics (cond-mat.stat-mech), Mathematical Physics (math-ph)
Engineering micro-disorder for macro-performance in magnetic nanoparticles
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2026-08-03 20:00 EDT
Jonathan Leliaert, Elizabeth M Jefremovas
Spin disorder, inherent to magnetic nanoparticles, has traditionally been regarded as a detrimental feature, with materials-engineering efforts largely focused on producing ‘’perfect particles’’ containing as few defects as possible. Alongside this pursuit of perfection, however, an alternative framework has emerged in recent years that reframes intra-particle disorder as an ‘’ugly duckling’’ whose functional potential remains to be unlocked. In this Perspective, we review the emerging concept of disorder engineering in magnetic nanoparticles, identify its current challenges, and outline promising future directions. From a theoretical standpoint, progress requires moving beyond the widely used macrospin approximation, which severely restricts the description of intra-particle degrees of freedom. Micromagnetic modelling, in contrast, treats magnetisation as a continuous vector field and thereby enables (i) the explicit representation of intra-particle degrees of freedom, linking microstructural features to internal magnetisation textures, and (ii) direct correspondence with polarized small-angle neutron scattering, an experimental technique that provides quantitative access to ensemble-averaged magnetic correlations on nanometre length scales. The field must now advance towards falsifiable and uncertainty-aware models with structurally motivated parameters and predictions that can be tested against independent experimental observables. The overarching goal is to establish quantitative relationships between particle structure, intra-particle magnetisation textures, and macroscopic functionality, thereby transforming spin disorder from an elusive hidden variable into an engineerable design parameter.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Materials Science (cond-mat.mtrl-sci)
Giant Exfoliation Induced Magnetic Coercivity in Fe$_3$GaTe$_2$
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-08-03 20:00 EDT
Lingrui Mei, PeiYu Cai, Sang-Eon Lee, Yue Li, Shyam Raj Karullithodi, Vadym Kulichenko, Charudatta Pathak, Elton J. G. Santos, Luis Balicas
Permanent magnets with strong anisotropy and high coercivity underpin modern information and energy technologies, yet rare-earth-free alternatives remain limited. Here, we show that thickness engineering via mechanical exfoliation induces hard magnetic behavior in the van der Waals ferromagnet Fe$ _3$ GaTe$ _2$ . Bulk crystals exhibit Curie temperatures above 350 K but negligible room-temperature coercivity. When thinned below 100 nm, the coercive field is dramatically enhanced, reaching nearly 1 T at room temperature for in-plane fields which is comparable to values of conventional hard magnets. Micromagnetic analysis reveals a crossover in magnetization reversal from domain-mediated processes in bulk samples to quasi-coherent rotation in thin flakes, driven by increased effective anisotropy and suppressed domain formation. This thickness-dependent transition enables tuning of magnetic hardness without chemical modification. Combined with high saturation magnetization and robust room-temperature performance, Fe$ _3$ GaTe$ _2$ emerges as a promising rare-earth-free material for spintronic applications. Its layered structure further allows integration into van der Waals heterostructures, where large in-plane coercivity can stabilize magnetic states against perturbations and interlayer coupling, offering potential for high-density nonvolatile memory and domain-wall-based devices.
Materials Science (cond-mat.mtrl-sci), Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
5 figures, plus Supplementary information, including 6 supplementary figures
Advanced Electronic Materials 2026
Ultrafast Nonthermal Lattice Destabilization and Suppression of Polar Optical Scattering in Electronically Excited $α$-SiO$_2$ from First-Principles and Deep Neural Network Potential Modeling
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-08-03 20:00 EDT
Iyyappa Rajan Panneerselvam, Mark Yeung, Charlotte Palmer, Brendan Dromey, Lorenzo Stella
We present a multiscale first-principles-to-machine-learning approach to investigate ultrafast lattice dynamics in electronically excited $ \alpha$ -SiO$ _2$ . Ab initio molecular dynamics (AIMD) based on electronic-temperature-dependent density functional theory (DFT) are used to train electronic-temperature-dependent deep neural network potentials (DNNPs). The use of DNNPs enables atomistic modeling at near-DFT accuracy of large $ \alpha$ -SiO$ _2$ cells with thousands of atoms. In particular, DNNPs allowed us to obtain accurate phonon band structures and molecular dynamics (MD) of $ \alpha$ -SiO$ _2$ excited by a sudden increase in electronic temperature. With increasing electronic temperature, $ T_e$ , pronounced lattice destabilization of $ \alpha$ -SiO$ _2$ is found, as evidenced by violations of elastic stability criteria, substantial volumetric expansion, a sharp reduction of the bulk modulus, and progressive weakening of Si-O bonding due to antibonding-state occupation. From the electronic and phonon band structures, we estimated the Frohlich coupling constant, which decreases as $ T_e$ increases, suggesting a crossover to a nonpolar phase of $ \alpha$ -SiO$ _2$ at elevated electronic temperature. This is corroborated by the Bader charge analysis. We also suggest that polar optical phonon scattering should be strongly suppressed at $ T_e > 2$ eV. From large-cell DNNP-MD simulations, we show that a well-defined thermal equilibrium, as defined by the Maxwell-Boltzmann distribution, is not achieved over the first few hundred femtoseconds. This behavior explains the non-monotonic equilibration of the kinetic temperature after a sudden rise of $ T_e$ . After $ T_e$ is raised to 2.6 eV, Si and O atoms first equilibrate separately at two different temperatures, suggesting an atomic fluid phase, in agreement with recent experimental and theoretical findings.
Materials Science (cond-mat.mtrl-sci), Computational Physics (physics.comp-ph)
49 pages, 12 figures, and 4 tables, including Supplemental Material
An End-to-End Differentiable Forward Model for High-Energy Diffraction Microscopy
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-08-03 20:00 EDT
Hemant Sharma, Nina Andrejevic, Simon Zhang, Mathew Cherukara
High-Energy Diffraction Microscopy (HEDM) recovers crystallographic orientation, strain, and grain position from rotating-crystal X-ray diffraction patterns. Existing forward models in far-field (FF), near-field (NF), and point-focused (pf) HEDM are not differentiable, which forecloses gradient-based joint parameter refinement, physics-informed regularisation, and Bayesian uncertainty quantification. We present the first end-to-end differentiable HEDM forward model covering all three geometries, implemented in PyTorch with pixel-exact agreement against the established MIDAS reference simulators (162/162 FF, 2304/2304 NF including a non-zero detector-tilt sweep, and 1088/1096 pf-HEDM spots matched). Three demonstrations validate the framework: joint orientation-strain-position recovery in NF-HEDM at ~6 nm precision; round-trip refinement on a real 214-grain alpha-Ti FF-HEDM dataset reaching 100% grain recovery from a 1.5 degree initial perturbation with residuals matching the production fit to 0.3%; and joint refinement of all per-detector geometry parameters and per-grain state on a synthetic four-panel FF-HEDM setup, recovering panel rotations about the beam axis to ~10 mu-rad and a global rotation-axis wedge to ~26 mu-rad. The framework is released as the open-source midas-diffract package (pip install midas-diffract).
Materials Science (cond-mat.mtrl-sci)
Automating the analysis of micron-scale synchrotron diffraction data on inhomogeneous polycrystalline samples: a solid oxide electrolysis cell case study
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-08-03 20:00 EDT
Liam A. V. Nagle-Cocco, Christopher A. Crain, Michael J. Dzara, Mathias A. Kiefer, Madeline G. Port, Tolga Han Ulucan, Madeline Van Winkle, Oscar Hathaway, Nicholas A. Strange
A novel approach to post mortem characterisation of electrochemical and photovoltaic devices is spatially-resolved diffraction using a hyper-focused, micron-width x-ray beam to examine the distribution of degradation products and strain, a technique called $ \mu$ -XRD. Aside from the experimental difficulties associated with beam focusing and sample preparation, which are themselves non-trivial, the analysis of resulting data is complex and challenging, with full Rietveld analysis rarely attempted in literature. The difficulty lies in the size of the data, which may consist of hundreds or even thousands of diffraction patterns with very different crystallographic phase compositions depending on position within the device, and the difficulty in fitting the data due to the presence of many phases at the same position, including possible degradation products which may be difficult to index and assign to known phases. In this paper, we present a fully-automated open access Python routine for performing phase identification and Rietveld analysis on 2D datasets of diffraction pattern taken at micron-scale positions, measured over the cross-section of a chemically inhomogeneous device with polycrystalline phases. Solid oxide electrolyser cells are a promising technology for green hydrogen production which can utilise waste heat to split water at higher efficiencies than low-temperature electrolysis techniques such as polymer electrolyte membranes, but exhibit many degradation modes due to the high operating temperatures. We present a case study using our analysis protocol on an SOEC fragment encompassing the air electrode, cation diffusion barrier, electrolyte, and fuel electrode. With modification, this protocol could be applied to other devices such as all-solid-state batteries, wet-electrolyte battery electrodes, solid oxide fuel cells, photovoltaic devices, and metal-oxide pseudocapacitors.
Materials Science (cond-mat.mtrl-sci), Other Condensed Matter (cond-mat.other), Accelerator Physics (physics.acc-ph)
In review
Knudsen-Controlled Switching of Thermal Conductivity Response by Targeted Phonon Excitation
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-08-03 20:00 EDT
Shixian Liu, Tianhao Li, Fei Yin, Yu He, Alexander A. Barinov, Han Meng, Nuo Yang
Targeted phonon excitation offers a route to dynamically control heat conduction, yet no general principle predicts whether a spectrally selective nonequilibrium phonon population will enhance or suppress thermal transport. A Knudsen-controlled competition between the increased contribution of long-mean-free-path phonons and excitation-enhanced intrinsic scattering governs the sign of the thermal-conductivity response. First-principles three-phonon scattering rates combined with phonon-tracking Monte Carlo simulations are used to examine Ge, Si, and 3C–SiC from bulk crystals to confined nanofilms. In bulk systems, excitation-enhanced scattering dominates and thermal conductivity is predominantly suppressed. In nanofilms, by contrast, low-frequency excitation can increase the contribution of quasi-ballistic heat-carrying channels and enhance thermal conductivity, whereas higher-frequency excitation is predominantly suppressive. At fixed background temperature and excitation strength, these opposite responses are organized in a frequency–Knudsen map based on the normalized target frequency, $ \omega_{\mathrm t}/\omega_{\mathrm D}$ , and the Knudsen number, $ \mathrm{Kn}$ . The resulting framework provides a general physical basis for controlling nonequilibrium heat transport beyond static phonon engineering.
Materials Science (cond-mat.mtrl-sci)
11 pages, 4 figures
Molecular beam epitaxy synthesis of ternary nitride PrTaN$_2$ and its crystal structure determination
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-08-03 20:00 EDT
Kosuke Takiguchi, Yoshiharu Krockenberger, Eisuke Magome, Yoji Kunihashi, Hideki Yamamoto
We report the discovery of a novel ternary nitride PrTaN$ _2$ synthesized as a thin film using molecular beam epitaxy. The combination of e-beam evaporation for refractory elements and a radio-frequency nitrogen radical source enables growth under a highly nitriding environment, providing access to phases not readily obtained in bulk synthesis. Structural characterization by X-ray diffraction and high-angle annular dark-field scanning transmission electron microscopy reveals that the compound crystallizes in an orthorhombic structure and grows with a well-defined orientation on YAlO$ _3$ substrates, while remaining essentially strain-free. To determine the crystal structure from limited thin-film diffraction data, we developed a fitting procedure based on structure factors. By combining extinction rules with constraints from Wyckoff positions, the number of fitting parameters is significantly reduced, enabling reliable structure determination. Systematic exclusion of alternative candidate phases in the Pr-Ta-N system, together with structure factor fitting, identifies the space group as $ P222$ and determines the atomic coordinates. The present results demonstrate that thin-film growth with molecular beam epitaxy can stabilize previously unexplored ternary nitrides, and establish a practical approach for structural determination in such systems. This work provides a pathway for the exploration of new complex nitride materials.
Materials Science (cond-mat.mtrl-sci), Other Condensed Matter (cond-mat.other)
Symmetry selection rule for the band-edge shift current in two dimensions
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2026-08-03 20:00 EDT
Felipe Pérez Riffo, Matías Castro, Leonor Chico, L.E.F. Foa Torres. Eric Suárez Morell
The shift current is the intrinsic bulk photovoltaic response of a crystal without an inversion center. In graphene multilayers, recent calculations report large band-edge shift currents that reverse sign under a gate or displacement field, a behavior that neither the quantum metric nor the Berry curvature captures. We show that this behavior follows from a symmetry principle: at the absorption edge of an inversion-broken, two-dimensional gapped Dirac-like system, an emergent low-energy rotational symmetry forbids the response, and the trigonal warping, which reduces this emergent symmetry to the lattice’s three-fold rotation, switches the current on linearly in its strength. We formulate this as an exact angular selection rule that unifies the band-edge responses of multilayer graphene and of the kagome lattice. In the multiband structures, the released current is governed by a signed, detuning-weighted three-point Bargmann invariant of the Bloch states: the optical amplitude remains fixed while the sign alignment of the Bargmann triangles grows with the warping, a phase-coherence effect captured by a bounded coherence factor and invisible to any positive-definite figure of merit, the quantum metric included. In bilayer and trilayer graphene, a gate voltage alone drives the sign reversal, making the band-edge shift current a parameter-free, gate-switchable bulk photovoltaic response.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
16 pages, 8 figures. Code and data: this https URL
Covariance-Driven Momentum Rectification at Liquid-Vapor Interfaces Near Wetting Transitions
New Submission | Soft Condensed Matter (cond-mat.soft) | 2026-08-03 20:00 EDT
Nelson Bolívar, Gabriel Abellán, Ivaylo Vasilev
Zero-mean forcing can generate directed transport when a medium responds in a spatially structured way and the relevant symmetries are broken. Liquid-vapor interfaces are a useful setting for this problem because surface-tension gradients, wetting dynamics, vapor exchange, capillary and acoustic waves, electro-ionic screening, thermal noise, and boundary compliance can all carry momentum. We develop a conservative continuum model in which the central object is the covariance between a local response field and a zero-mean tangential drive, $ \langle Mf\rangle-\langle M\rangle\langle f\rangle$ , embedded in an explicit momentum ledger. In a minimal diffuse-interface realization, this covariance gives the phase-selective drift law $ U\propto\epsilon_h\Theta\sin\varphi$ for a Marangoni-driven liquid-vapor interface above a structured wall, with exact nulls when the symmetry is restored. Wetting susceptibility then acts as a bounded gain factor: first-order spinodal conditions provide the useful amplification regime, critical wetting saturates because interfacial unbinding removes the short-range drive, and bulk criticality suppresses the channel as the interface disappears. Additional reservoirs - phase change, waves, thermal transport, electro-ionic coupling, compliance, and fluctuations - are treated as compensating channels to be isolated by sign reversals, scaling laws, and budget closure. The result is neither a new microscopic force nor an apparatus-level claim, but a symmetry-constrained accounting scheme for rectified momentum transfer in water-based interfacial systems. Reduced numerical calculations illustrate the phase-selection rules, bounded spinodal gain, momentum-budget closure, transverse chirality, and grid convergence.
Soft Condensed Matter (cond-mat.soft), Statistical Mechanics (cond-mat.stat-mech), Fluid Dynamics (physics.flu-dyn)
17 pages, 4 figures. Submitted to Physical Review E. Numerical code and reference results are archived at this https URL
Generalized Holstein-Primakoff transformation with optimizable bosonic truncation
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2026-08-03 20:00 EDT
Yang Liu, Jia-Wei Mei, Rong Yu, Z. Y. Xie, Hong-Gang Luo, Jize Zhao
Spin-wave theory provides a quasiparticle description of excitation spectra in quantum spin systems. In this theory, the spin operators are usually bosonized by the Holstein-Primakoff transformation or the Dyson-Maleev transformation. In practical calculations, the bosonized Hamiltonian has to be truncated, and thus the resulting excitation spectra depend on the choice of bosonic representation. Here, we introduce a generalized Holstein-Primakoff transformation that continuously interpolates between the conventional Holstein-Primakoff and Dyson-Maleev transformations through a single parameter. The formulation naturally extends to the SU(N) algebra and provides a flexible framework for optimizing bosonic truncations beyond harmonic order. As an application, we investigate the spin-1 bilinear-biquadratic model on the square lattice. By combining the generalized Holstein-Primakoff transformation with continuous similarity transformations, we obtain excitation spectra in excellent agreement with tensor-network calculations. Our results demonstrate that optimizing the bosonic representation substantially reduces truncation errors and provides quantitatively reliable descriptions of both quasiparticle dispersions and multi-boson continua.
Strongly Correlated Electrons (cond-mat.str-el)
Critical Phases of the extended isotropic $XY$ chain with four-spin interaction
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2026-08-03 20:00 EDT
Nika Kurdadze, Giorgi Gogabedashvili, G.I. Japaridze
Using the Jordan-Wigner transformation we calculate exactly the ground state and low-temperature thermodynamic properties of the spin $ S=1/2$ isotropic $ XX$ chain with four spin interaction. In terms of the equivalent spinless fermion (SF) representation the system is viewed as a lattice fermion gas with nearest-neighbor ($ J$ ) and next-next-next-neighbor ($ J^{\ast}/4$ ) hopping. It is shown that with the increase of four spin coupling, at $ J^{\ast}_{c} = 4J/3$ the system experiences the Lifshitz type topological phase transition characterized by the tripling of Fermi points. The quantum phase transition (QPT) point marks transition from a gapless spin-liquid phase of standard $ XX$ chain into again a gapless spin-liquid phase with different character of power-low decay of spin correlations. At the transition point the free fermion dispersion relation shows flattering at Fermi points, what determines singular character of density of states $ \rho(\omega)\sim (\omega/J)^{-2/3}$ and as a consequence unconventional temperature dependence of heat capacity of the system $ C\sim (T/J^{\ast})^{1/3}$ , and singular magnetic susceptibility of the system $ \chi(H)\sim (H/J^{\ast})^{-2/3}$ .
In the case of alternating magnetic field the system is characterized by the rich ground state phase diagram which contains fully polarized (ferromagnetic), gapped antiferromagnetic (AFM) and spin liquid phases. At the transition point from the gapped AFM phase into the gapless polarized spin liquid phase the system shows rapid increase of magnetization $ m\sim(H-H_c)^{1/6}$ and magnetic susceptibility a singular behavior as $ \chi(H)\sim (H-H_c)^{-5/6}$ .
Strongly Correlated Electrons (cond-mat.str-el), Other Condensed Matter (cond-mat.other)
Mechanism-Dependent Descriptors Enable Predictive Design of Oxygen Capacity in Perovskite Oxides
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-08-03 20:00 EDT
Shuiping Gong, Yi Li, Jie Su, Zhenhao Zhou, Xiaobo Liao, Jian Deng, Chris Wolverton, Tao Deng, Jiangang He, Runxia Cai, Chaochao Dun, Zhenpeng Yao
Perovskite oxides can reversibly accommodate substantial changes in oxygen stoichiometry, making them attractive for clean-energy technologies including chemical looping and oxygen storage. Despite extensive efforts to optimize their redox properties, predictive descriptors capable of assessing oxygen capacity across diverse compositions remain under development. Here, we combine experiments and first-principles calculations to establish composition and oxygen-capacity relationships in the model perovskite series LnxSr1-xCoO3. We confirm that increasing Sr2+ content promotes the formation of high-valence Co4+, expanding the cationic redox reservoir available during oxygen release and thereby enhancing oxygen capacity. In this regime, oxygen-vacancy formation energy captures the observed trend because oxygen release is primarily compensated by Co4+/Co3+/Co2+ redox. Across the rare-earth series, however, oxygen capacity decreases from La to Lu despite progressively lower oxygen-vacancy formation energies. We reveal that this counterintuitive behavior originates from an alternative charge-compensation pathway, in which lattice oxygen is partially oxidized to O1- -like species during oxygen removal. Heavy rare-earth compositions (Tb-Lu) preferentially stabilize these oxygen-hole species through distinct local bonding environments, with charge compensation involving both oxidized lattice oxygen and reduced rare-earth and cobalt cations, thereby suppressing net oxygen release despite favorable vacancy thermodynamics. We further identify average metal-oxygen bond strength, quantified by integrated crystal orbital Hamilton population, as a physically meaningful descriptor for oxygen capacity when anionic redox becomes dominant.
Materials Science (cond-mat.mtrl-sci)
19 pages, 4 figures
Charge discreteness and the energy efficiency of information erasure in dynamic random-access memory cells
New Submission | Statistical Mechanics (cond-mat.stat-mech) | 2026-08-03 20:00 EDT
Takase Shimizu, Kouki Yamamoto, Kensaku Chida, Gento Yamahata, Katsuhiko Nishiguchi
A dynamic random-access memory (DRAM) cell stores information as an integer number of electrons on a capacitor, and whether this discreteness is thermodynamically relevant depends on the competition between the charging energy and thermal fluctuations. This competition is quantified by the ratio $ \kappa$ of the single-electron charging energy to the thermal energy, and here we investigate how $ \kappa$ affects the energy efficiency of information erasure in a DRAM cell. Using a stochastic-thermodynamic model of a DRAM cell, we show that the nonquasistatic heat released during the discharge step is suppressed as $ \kappa$ increases, whereas the quasistatic heat of the charge step approaches the Landauer cost. As a result, the energy efficiency increases monotonically with $ \kappa$ and approaches the Landauer limit where the effect of charge discreteness is maximal and the cell is effectively reduced to two charge states. The parameter $ \kappa$ thus connects two thermodynamic regimes: a multilevel single-well memory, whose nonequilibrium initial state prevents quasistatic erasure, and an effective two-level memory that can attain the Landauer limit. These results identify $ \kappa$ as the parameter that controls the fundamental efficiency ceiling of transistor–capacitor memory circuits.
Statistical Mechanics (cond-mat.stat-mech)
7 pages, 6 figures
One-Step Epitaxial Access to Rhombohedral Graphene Flat-Band States on Step-Bunched SiC
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-08-03 20:00 EDT
Hao Zhong, Xingzhe Wang, Hanbin Deng, Tianyu Yang, Haixuan Cao, Renzhe Li, Qiang Wan, Shangkun Mo, Keming Zhao, Shuming Yu, Dingkun Qin, Guang Zhu, Yifan Zhou, Jianping Shi, Shuangfeng Jia, He Zheng, Jia-Xin Yin, Nan Xu
Rhombohedral graphene multilayers provide a moiré-free platform for correlated and topological flat-band physics, but direct, transfer-free epitaxial access to thickness-tunable multilayers remains limited. Here we report a one-step graphitization route on 4$ ^\circ$ off-axis 4H-SiC, in which high-temperature flash annealing simultaneously drives self-organized step bunching and multilayer graphene formation. Atomic-resolution cross-sectional scanning transmission electron microscopy identify local ABC registry and distinguish rhombohedral from Bernal stacking. The thickness is tuned from bilayer to more than twenty layers by varying single parameter, the annealing temperature. Angle-resolved photoemission spectroscopy directly tracks the thickness-dependent evolution from interface-dominated low-energy states toward pronounced near-Fermi-level flat-band spectral weight in thick multilayers. Low-temperature scanning tunneling microscopy and spectroscopy on a 17-layer film further reveal a 13.4 meV low-energy spectral reconstruction and a $ \sqrt{3} \times \sqrt{3}$ Kekulé-like modulation, providing microscopic signatures consistent with an intervalley-mixed electronic texture. This one-step, transfer-free approach establishes step-bunched SiC as an epitaxial platform that links stacking engineering with moiré-free correlated flat-band electronic states.
Materials Science (cond-mat.mtrl-sci), Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Strongly Correlated Electrons (cond-mat.str-el)
First-principles carrier mobility and optical absorption of strained ZnO with self-consistent Hubbard interactions
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-08-03 20:00 EDT
Hong-Guk Min, Wooil Yang, Sabyasachi Tiwari, Feliciano Giustino, Young-Woo Son
Carrier mobility and optical absorption are key performance parameters of oxide semiconductors in transparent and flexible displays. We use a newly developed density-functional perturbation theory with a self-consistent Hubbard correction (DFPT+U) to study phonon-limited electron transport and phonon-assisted optical absorption in strained zinc oxide (ZnO). This parameter-free approach accounts for electron-phonon interactions and on-site correlation effects simultaneously. Electronic structures and phonon dispersions are computed under three distinct uniaxial strain directions. Uniaxial tensile strain up to 4.8% along [\bar110] is found to increase the room-temperature electron mobility by 19% while leaving visible-range optical absorption essentially unchanged. These results demonstrate that moderate strain can selectively enhance carrier transport without degrading optical transparency, and establish DFPT+U as an effective framework for predicting strain-dependent transport and optical properties in wide-band-gap oxides with implications for strain-engineered display and optoelectronic applications.
Materials Science (cond-mat.mtrl-sci), Strongly Correlated Electrons (cond-mat.str-el)
12 pages, 9 figures
Emerging network model in a twisted monolayer-rhombohedral graphene
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2026-08-03 20:00 EDT
Juyoung Song, Jeyong Park, Jinhong Park
We investigate the coexistence of localized states and propagating one-dimensional (1D) modes in graphene moiré systems. We first show within a minimal model that a spatially varying scalar potential can confine localized states, while sign changes of a staggered potential generate 1D modes along the resulting domain walls. These two types of states can coexist within the same finite energy window and form a hybrid network. We then demonstrate a microscopic realization of this mechanism in twisted monolayer-rhombohedral N-layer graphene. Band structures, energy contours, and Bloch wave functions obtained in a realistic parameter regime reveal the coexistence of localized nearly flat-band states and propagating quasi-1D modes. Our results establish twisted monolayer-rhombohedral graphene as a promising platform for realizing hybrid electronic networks with coexisting states of distinct effective dimensionalities.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Strongly Correlated Electrons (cond-mat.str-el)
9 pages, 3 figures
Charge-Density-Wave Phase Selection by Janus-Induced Intrinsic Strain in Monolayer NbSSiAs$_2$
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-08-03 20:00 EDT
Chun-Jie Zhang, Bing Zhang, Dongliang Mao, Yapeng Wu, Xiao-Ping Li, Lei Wang
Controlling phase selection among competing charge-density-wave (CDW) instabilities remains challenging in two-dimensional materials. Here, first-principles calculations show that Janus-induced intrinsic tensile strain redirects the off-M soft-mode tendency of NbS$ _2$ to the M point in NbSSiAs$ _2$ , selecting a $ 2\times2$ CDW reconstruction. Electron-phonon coupling analysis identifies momentum-selective coupling between Nb-derived states and a longitudinal acoustic mode as the origin of the M-point instability. The reconstructed phase hosts two nearly degenerate Nb-trimerized configurations whose relative stability is tuned by biaxial strain. Both configurations retain phonon-mediated superconductivity on the 6-7 K scale, indicating the coexistence of CDW order and superconductivity. Compressive strain favors the 1+3-hollow configuration and induces a band-inverted, $ Z_2$ -nontrivial state while preserving superconductivity. Together, these results identify Janus-induced intrinsic strain as an internal structural route for CDW phase selection, whereas external strain provides access to a regime in which CDW order, topology, and superconductivity coexist.
Materials Science (cond-mat.mtrl-sci)
13 pages,5 figures,1 table
Optomechanical tuning of nonlinearity in graphene resonators
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2026-08-03 20:00 EDT
Alberto Martín-Pérez, Peter G. Steeneken, Farbod Alijani
Graphene resonators exhibit unique mechanical and electrical properties, making them promising candidates for next-generation sensing applications. Here, we introduce an optomechanical approach that enables active, reversible, in situ tuning of the nonlinear nanomechanical response of graphene resonators. By exploiting photothermal heating and the resulting optomechanical interaction between the mechanical oscillations and the optical cavity formed by a graphene membrane suspended over a reflective substrate, we achieve dynamic control over both the linear restoring force and the nonlinear dynamic response of the resonator. We show that the strength and sign of the Duffing nonlinearity can be continuously tuned through the optical probe power and cavity depth, enabling transitions between hardening and softening behavior as well as near-complete suppression of geometric nonlinearities. Our results establish a versatile platform for on-demand engineering of nonlinear dynamics in graphene resonators and provide a general strategy for active control of the mechanical response of two-dimensional nanoelectromechanical systems.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
A low-temperature ultra-high-vacuum scanning probe microscope with in situ electronic transport capabilities: from macro to nano in 10 minutes
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2026-08-03 20:00 EDT
Diego Exposito (1, 2 and 3), Oscar Custance (4), Ivan Brihuega (1, 2, and 3) ((1) Departamento de Fisica de la Materia Condensada, Universidad Autonoma de Madrid, (2) Condensed Matter Physics Center (IFIMAC), Universidad Autonoma de Madrid, (3) Instituto Nicolas Cabrera (INC), Universidad Autonoma de Madrid, (4) National Institute for Materials Science (NIMS))
We have developed a low temperature (LT), ultra-high-vacuum (UHV) system that combines two complementary techniques, scanning probe microscopy (SPM) and electrical transport measurements, within a single platform. By providing simultaneous access to the atomic-scale surface landscape and the macroscopic device response of the same sample, the setup enables direct correlations between local structural/spectroscopic signatures and global electronic transport behavior in two-dimensional (2D) devices. The system allows experiments where atomic-scale modifications or controlled manipulations are performed while continuously monitoring their impact on device-scale performance. The setup consists of two interconnected UHV chambers: a dedicated preparation chamber and a separate measurement chamber that houses a liquid-helium cryostat and the SPM/transport stage. Base pressure is 1x10^-11 Torr. A key feature is direct optical access to the sample, enabling rapid and reliable tip positioning with an accuracy of 5 microns x 5 microns within 10 minutes. The SPM, operated using custom-built electronics, can track the exact same sample region across a temperature range from 2.9 K to 400 K, with mechanical stability below 1 pm. System performance is demonstrated on graphene devices, and bulk Pb is used to determine energy resolution. Using superconducting tips, scanning tunneling spectroscopy measures the superconducting gap with an energy resolution of 30 microV. Transport measurements track the temperature dependence of both resistivity and critical current across the superconducting transition of an in-situ prepared Pb nanowire.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Materials Science (cond-mat.mtrl-sci), Superconductivity (cond-mat.supr-con), Instrumentation and Detectors (physics.ins-det), Quantum Physics (quant-ph)
19 pages, 10 figures
The stability of electronic Poiseuille flow in two-dimensional materials
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2026-08-03 20:00 EDT
Marine Bastida, Alvaro Meseguer, Iacopo Torre
Motivated by the experimental observation of electronic Poiseuille flow in graphene [J.A. Sulpizio et al. Nature 576, 75 (2019)] we analyze the linear stability of plane-Poiseuille flow of electrons in a two-dimensional material using a modified Orr-Sommerfeld equation. We calculate the critical current needed to make the flow unstable as a function of the experimental parameters and characterize the most favorable situation, that is the one needing the lowest current density, to observe flow instability. We predict the streamwise wavenumber and frequency at which the instability occurs and discuss the difficulties of an experiment aimed at probing this phenomenon.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Fluid Dynamics (physics.flu-dyn)
11 pages, 4 multi-panel figures
Successive Electronic Topological Transitions in the Antiferromagnet UPd$_2$Al$_3$
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2026-08-03 20:00 EDT
Adrien Gourgout, Gaël Bastien, Dai Aoki, Gabriel Seyfarth, Ilya Sheikin, Andrey Varlamov, Gertrud Zwicknagl, Jacques Flouquet, Georg Knebel, Alexandre Pourret
We report successive anomalies at low temperature in the magnetic field dependence of the thermoelectric signal in the heavy fermion compound UPd$ {2}$ Al$ {3}$ inside the antiferromagnetic state up to the metamagnetic transition at $ H\text{M} =18$ ~T. Based on renormalisation perturbation theory and the partitioning of the $ f$ orbitals into localized and delocalized parts, our analysis attributes these anomalies to complex topological changes of the Fermi surface driven by Zeeman effect. The observation of a sudden change of sign both in the thermoelectric power and in the Hall coefficient at $ H\text{M}$ in addition to the appearance of large quantum oscillations in the thermoelectric power above $ H_\text{M}$ indicate a strong Fermi surface reconstruction at the metamagnetic transition due to the unfolding of the electronic bands.
Strongly Correlated Electrons (cond-mat.str-el), Superconductivity (cond-mat.supr-con)
14 pages, 12 figures
Domain-Selective Enhancement of Second Harmonic Generation in Monolayer MoS$_2$ via Ferroelectricity-Controlled Photodoping
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-08-03 20:00 EDT
David Hernández-Pinilla, Line Jelver, María Jesús Martínez-Morillo, César Hernando-Fuente, Miquel Cherta, Guillermo López-Polin, Joel D. Cox, Luisa E. Bausá, Mariola O Ramírez
Hybrid heterostructures combining two-dimensional semiconductors with ferroelectric materials offer a versatile route to actively control light-matter interactions at the nanoscale. Here, we report all-optical, light-induced domain-selective control of second-harmonic generation (SHG) in monolayer molybdenum disulfide (MoS$ _2$ ) integrated with periodically poled lithium niobate (LiNbO$ _3$ ). Spatially resolved SHG imaging reveals a pronounced modulation of the nonlinear optical response of monolayer MoS$ _2$ governed by the ferroelectric domain pattern of the underlying substrate. A strong SHG contrast is observed between domains of opposite polarization, with a marked dependence on both the excitation wavelength and the incident optical power. The comparison between ferroelectric domains that either enable or do not exhibit light-driven photodoping in the MoS$ _2$ monolayer provides a direct assessment of the role of carrier density in the nonlinear optical response. We find that ferroelectric-polarization-controlled photodoping at the MoS$ _2$ /LiNbO$ _3$ interface enhances the effective second-order susceptibility, $ \chi^2$ , producing an increase in SHG intensity of up to ~70% under resonant excitation conditions. Ab initio calculations corroborate that charge doping modifies the electronic band structure of MoS$ _2$ and strongly affects $ \chi^2$ in the resonant regime, providing microscopic support for the experimentally observed modulation. The results highlight the combination of light intensity and ferroelectricity as a powerful knob for band-structure modulation in 2D materials and reconfigurable nonlinear optical responses, opening pathways toward programmable frequency conversion, smart light modulators, and advanced nonlinear photonic functionalities in integrated hybrid platforms.
Materials Science (cond-mat.mtrl-sci), Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Optics (physics.optics)
Origins of microwave losses in superconducting circuits made with silicon-on-insulator substrates
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2026-08-03 20:00 EDT
Simon Messelot, Nicolas Aparicio, Kazi Rafsanjani Amin, Eric Eyraud, Bruno Fain, Mikaël Cassé, Guillaume Jourdan, Fabrice Nemouchi, Sébastien Hentz, Frédéric Gustavo, François Lefloch, Nicolas Roch, Jérémie J. Viennot, Julien Renard
Silicon-on-insulator technology is widely used to fabricate silicon based devices, from advanced transistors to photonic circuits or nanomechanical systems. Integrating low loss superconducting quantum circuits with silicon-on-insulator substrates enables to couple the advantages offered by the mature silicon technology to the exquisite sensitivity of superconducting circuits. The natural approach, inherited from research in superconducting microwave devices, is to use a substrate made with highly resistive silicon, known for its low level of microwave losses. In this work, using superconducting microwave resonators, we show that counterintuitively, standard resistivity silicon-on-insulator substrates perform better than high resistivity silicon-on-insulator substrates at cryogenic temperatures. In the latter case, the presence of a parasitic sheet conduction at the interface between bulk silicon and silicon oxide acts as the dominant loss mechanism. This parasitic sheet can be suppressed using substrates with intentionally induced traps. In such substrates, losses are ultimately limited by the dielectric losses of the silicon oxide layer. These substrates offer interesting perspectives for the development of superconducting nanoelectromechanical systems. First, the release, i.e. the removal of the silicon oxide, could be limited to the moving parts, thereby maintaining the mechanical integrity of the rest of the device. Additionally, such structure would enhance heat evacuation into the bulk of the substrate which is an issue in current devices such as microwave-to-optics converters.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Quantum Physics (quant-ph)
25 pages, 4 figures
Strength-degradation phase-field regularization of cohesive fracture: the antiplane case
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-08-03 20:00 EDT
Blaise Bourdin, Corrado Maurini
Phase-field approaches to fracture, initially designed as regularization of the Griffith model of brittle fracture, are now commonly viewed as gradient-damage models whose regularization length becomes a material property driving crack nucleation. One weakness of this approach is that the strength surface cannot be arbitrary: its shape is dictated by the elastic energy, and its magnitude by the regularization length. We focus on the antiplane version of the model introduced by Bourdin, Marigo, Maurini and Zolesi (arXiv:2506.22558), which handles crack propagation along unknown paths and nucleation governed by an arbitrary convex strength surface by degrading the strength instead of the stiffness. It can be interpreted as a regularization of softening plasticity in which localization bands obey an equivalent cohesive law set by the strength domain and the toughness, while the role of the regularization length, when small compared to the elasto-cohesive length, is purely numerical. Strength, stiffness, and toughness thus become independent material data, and limit analysis, perfect plasticity, cohesive fracture, and brittle fracture merge into a single variational framework. We derive closed-form solutions for a simple shear problem, propose a numerical scheme combining alternate minimization and conic programming, and numerically verify the equivalent cohesive law, its independence of the regularization, and the size effect governed by the elasto-cohesive length. A “surfing” simulation highlights the structure of the propagating crack while a re-entrant V-notch is used to show how the model bridges small-scale yielding, cohesive fracture, and brittle fracture without a priori hypotheses.
Materials Science (cond-mat.mtrl-sci), Mathematical Physics (math-ph), Classical Physics (physics.class-ph)
43 pages, 18 figures, 1 table. Submitted to Comptes Rendus. Mecanique
Photoemission insights into lanthanide-based crystals
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2026-08-03 20:00 EDT
Dmitry Yu. Usachov, Georg Poelchen, Vasily S. Stolyarov, Kristin Kliemt, Cornelius Krellner, Denis V. Vyalikh
The interplay of strongly localized 4$ f$ electrons with itinerant spd-valence states gives rise to a wide range of correlated phenomena and properties that place lanthanide materials at the focus of considerable research efforts. Beyond the bulk, their surfaces are of particular interest, where the reduced coordination, a modified crystal electric field, broken inversion symmetry in combination with strong spin-orbit coupling, and the emergence of surface states and resonances considerably reshape 4$ f$ -driven electronic and magnetic properties. This, in turn, enables novel functionalities of particular relevance for low-dimensional systems and their applications. This review summarizes how advances in photoelectron spectroscopies, together with improved crystal growth, have enabled detailed insights into bulk and surface phenomena of lanthanide-based crystals. After a brief overview of key developments from the 1970s to the 1990s, we discuss recent progress, focusing on systematic studies by the authors and collaborators that form a coherent line of research. These include the unveiling of $ k$ -resolved $ f-spd$ hybridization, the formation and evolution with temperature of $ f$ -derived Fermi surface in Kondo lattices, layer-dependent 4$ f$ magnetic anisotropy, the emergence of ferromagnetically ordered surfaces in systems with non-magnetic bulk ground state. This coherent line of research addresses core questions in the physics of 4$ f$ systems and opens opportunities for engineering novel lanthanide-based architectures, including heterostructures and supramolecular complexes with novel physical properties and functionalities.
Strongly Correlated Electrons (cond-mat.str-el)
Mesoscience & Nanotechnology, 1, 2026
Scalar curvature density as a new invariant in thermodynamic geometry: metric dependence and critical exponents
New Submission | Statistical Mechanics (cond-mat.stat-mech) | 2026-08-03 20:00 EDT
José Torres-Arenas, Jaime Jaramillo-Gutiérrez, Juan Becerra-Zamudio
We compare two Ruppeiner metrics constructed under fixed volume and fixed particle number conditions ($ g_{V}$ and $ g{V}$ ) by analyzing the scalar curvature $ R$ and introducing the scalar curvature density $ \mathcal{R} = \sqrt{|g|},R$ as a complementary geometric invariant. Three fluid models of increasing physical realism are considered: van der Waals, Lennard-Jones, and argon described by a multiparameter equation of state that correctly reproduces non-mean-field critical behavior consistent with the Ising universality class. We find that $ R$ and $ \mathcal{R}$ exhibit distinct critical scaling: $ R \sim t^{-d\nu}$ is governed by the correlation length exponent, whereas $ \mathcal{R} \sim t^{-(1+\beta)}$ scales solely with the order parameter exponent $ \beta$ , a result that follows analytically from hyperscaling and the Rushbrooke relation independently of the universality class. The $ N$ -metric consistently outperforms the $ V$ -metric in reconstructing the vapor-liquid coexistence curve away from criticality, and the four Widom lines defined by the minima of $ R{V}$ , $ R{N}$ , $ \mathcal{R}{V}$ , and $ \mathcal{R}{N}$ display a characteristic fourfold structure reproduced across all three models. The loci where both representations yield identical geometric descriptions define two new objects: the Curvature Equality Curve (CEC, $ R{V} = R{N}$ ) and the Curvature-Density Equality Curve (CDEC, $ \mathcal{R}{V} = \mathcal{R}{_N}$ ), with the CDEC enclosing a substantially larger region of the phase diagram in all cases. These results establish $ \mathcal{R}$ as a meaningful complement to $ R$ in thermodynamic geometry and highlight the nontrivial role of metric choice in the description of phase transitions and supercritical behavior.
Statistical Mechanics (cond-mat.stat-mech)
Polariton-Assisted Inelastic Tunneling through a Quantum Well
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2026-08-03 20:00 EDT
Théophile Seck, Yanko Todorov, Guido Pupillo, David Hagenmüller
We investigate electronic transport through a doped quantum well strongly interacting with a photonic mode confined in a double-metal cavity. Using a nonequilibrium Green’s function formalism, we derive compact expressions for the current valid for arbitrary collective light–matter coupling strengths exceeding the relevant loss rates. We show that cavity polaritons leave observable transport signatures when the carrier injection rate is smaller than the cavity-induced electronic broadening. In this regime, the current–voltage characteristics exhibit inelastic sidebands associated with resonant and anti-resonant polariton emission, which are strongly enhanced under resonant illumination. Our results provide a realistic route to detecting cavity-induced modifications of charge transport in semiconductor heterostructures.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
Curvature-amplified angular localization of radially localized states
New Submission | Disordered Systems and Neural Networks (cond-mat.dis-nn) | 2026-08-03 20:00 EDT
We study a continuum Schrödinger particle on a surface of constant curvature subject to a radial random potential and a weaker angle-dependent perturbation. Exact angular-momentum decomposition reduces the rotationally symmetric problem to independent one-dimensional random radial channels. A positive radial Lyapunov exponent distinguishes radial Anderson localization from the circular probability profile imposed by symmetry. Projection of a narrow radial mode produces a disordered one-dimensional ring. For angular disorder that is stationary in physical arc length, the ring localization length grows as the inverse square of the perturbation amplitude. Equating this length with the geodesic circumference yields a shell-breaking radius that grows algebraically in flat space but as $ 2a\ln(1/\varepsilon)+O(1)$ on a hyperbolic surface of curvature radius $ a$ and angular-disorder amplitude $ \varepsilon$ . Transfer-matrix and finite-ring calculations determine the crossover coefficient. Direct polar-grid calculations at the same angular energy as the ring model use unbiased tracking of the degenerate angular-momentum subspace across six independent radial-disorder realizations and quantify the validity of the single-mode projection. The noncommuting weak-disorder and flat-curvature limits establish a curvature-amplified crossover for this deliberately anisotropic disorder ensemble, rather than a generic metal–insulator transition on the hyperbolic plane.
Disordered Systems and Neural Networks (cond-mat.dis-nn)
13 pages, 9 figures
Coalescence-induced alignment of anisotropic particles in drying sessile droplets
New Submission | Soft Condensed Matter (cond-mat.soft) | 2026-08-03 20:00 EDT
Johannes Schöttner, Qingguang Xie, Jens Harting
Alignment of anisotropic particles strongly governs the functional properties of printed materials, yet most studies have focused on particle alignment in single evaporating droplets. In droplet- based printing, however, neighboring droplets can coalesce, generating rapid capillary flows that redistribute material and markedly affect the final morphology. Here, we use mesoscale simulations to investigate how droplet coalescence and subsequent evaporation jointly determine alignment and redistribution in sessile droplets with different contact angles and volumes. During the early stages of coalescence, the mean nematic order along the coalescence direction increases for all combinations of contact-angle and volume asymmetries of the droplets. At later times, the mean nematic order either continues to increase or decreases, depending on the droplet geometry. We derive a geometric scaling based on curvature and volume asymmetry and show that the simulation results collapse onto a master curve, identifying an effective geometric asymmetry parameter that governs the mean nematic order at the end of coalescence. During evaporation, the contact angle strongly influences how the coalescence-induced orientational structure is transferred to the final deposit. For small contact angles, the contact line remains pinned for a longer duration, better preserving alignment. In contrast, larger contact angles promote contact-line motion, which weakens alignment, as reflected by a reduced mean nematic order, while simultaneously generating stronger concentration gradients in the final deposit.
Soft Condensed Matter (cond-mat.soft), Fluid Dynamics (physics.flu-dyn)
15 pages,6 figures
Quadratic piezoelectricity from stacking-engineered interference in multilayer sliding ferroelectrics
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-08-03 20:00 EDT
Jiaxuan Fan, Yuexing Zhao, Xiao-Ping Li, Yurong Yang, Xing-Qiu Chen, Lei Wang
Designing nonlinear piezoelectricity requires suppressing the linear piezoelectric coefficient without extinguishing higher-order electromechanical response, yet a general and reconfigurable route remains lacking. Here we introduce stacking-engineered piezoelectric interference as such a mechanism in multilayer sliding ferroelectrics. Combining first-principles calculations with a generalized Ginzburg–Landau framework, we show that each interlayer gap acts as a local piezoelectric channel whose sign and magnitude are determined by stacking. Constructive interference between same-signed channels produces a linear-dominated response, whereas destructive interference between oppositely signed channels suppresses the linear coefficient while preserving a finite quadratic response. Representative MoS$ _2$ and NiTe$ _2$ multilayers approach the parabolic limit, with BAAC-stacked MoS$ _2$ reducing the linear-to-quadratic crossover strain by a factor of 25 relative to CBA-stacked MoS$ _2$ . Experimentally accessible tetralayer MoS$ _2$ sliding pathways further connect linear-dominated, quadratic-dominated and sign-inverted states. Here, we identify stacking-engineered interference as a design principle for programmable nonlinear electromechanics in layered materials.
Materials Science (cond-mat.mtrl-sci)
9 pages, 4 figures; 16-page Supplementary Information included as an ancillary file
Weak-electrolyte diffusiophoresis for rigid colloids
New Submission | Soft Condensed Matter (cond-mat.soft) | 2026-08-03 20:00 EDT
We develop a model for the diffusiophoresis of a chemically inert, rigid spherical colloid with fixed surface charge in a monovalent weak electrolyte, in which a neutral solute reversibly dissociates into ions. A weak far-field gradient is imposed in the neutral-species concentration. In the fast-reaction limit, local mass action and bulk electroneutrality determine the far-field ionic gradients, while the bulk zero-current condition determines the diffusion-potential gradient. We solve the coupled Nernst-Planck, Poisson and Stokes equations for arbitrary double-layer thickness, linearising in the gradient strength while retaining the nonlinear Poisson-Boltzmann equilibrium. In the Debye-Hückel limit, the mobility consists of one half of the matched fully dissociated response and a finite-double-layer correction due to neutral-ion coupling; the correction vanishes in both the Hückel and Smoluchowski limits. Beyond this limit, numerical solutions for the representative systems reveal a branch-selective response as the surface potential magnitude increases. When the counterion is slower than the co-ion, dissociation-association weakens a retarding concentration-polarisation layer, allowing the mobility to exceed the fully dissociated value. When the counterion is faster, the response remains close to the one-half scaling set by mass action. This reaction-polarisation coupling cannot be reproduced by adjusting only the bulk ionic strength, and hence the Debye length, in a fully dissociated model.
Soft Condensed Matter (cond-mat.soft), Fluid Dynamics (physics.flu-dyn)
Beyond Stoner-Wohlfarth: Machine-Learning Models and Symbolic Regression of Hard-Magnet Properties
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2026-08-03 20:00 EDT
Samuel J. R. Holt, Christina Winkler, Timoteo Colnaghi, Martin Lang, Swapneel A. Pathak, Andrea Petrocchi, Michael Adams, Thomas Schrefl, Andreas Marek, Hans Fangohr
Predicting the extrinsic properties from hysteresis loops of a magnetic grain, namely the coercive field, remanent magnetisation, and maximum energy product, from its intrinsic micromagnetic parameters is a central problem in permanent-magnet modelling. Established analytical models provide useful estimates but often neglect nonuniform magnetisation processes, whereas direct micromagnetic simulations are computationally expensive. In this work, we train machine-learning models on 12012 micromagnetic simulations of an idealised cubic grain, spanning broad ranges of the saturation magnetisation, exchange constant, and uniaxial anisotropy constant. Benchmarked against the analytical models on identical held-out data, the machine-learning models predict all three extrinsic properties with substantially lower errors. Symbolic regression recovers the Kronmüller form of the coercive field, with an effective demagnetising factor that depends on the material, and finds new closed-form expressions for the remanence and maximum energy product. Each law contains at most two fitted constants yet approaches the accuracy of the machine-learning models. We also investigate the inverse problem of recovering the intrinsic parameters from the three extrinsic properties. The saturation magnetisation and anisotropy constant are recovered accurately, whereas the exchange constant is not, because it influences the extrinsic properties only weakly. The trained models are released through the mammos-ai Python package, enabling thousands of candidate parameter sets to be screened in seconds rather than the hours or days required by direct micromagnetic simulation.
Strongly Correlated Electrons (cond-mat.str-el), Materials Science (cond-mat.mtrl-sci)
14 pages, 9 figures, 3 tables. Supplementary material (8 pages, 11 figures, 8 tables) included as an ancillary file
Mechanical isotropy of heterogeneous octahedral materials
New Submission | Soft Condensed Matter (cond-mat.soft) | 2026-08-03 20:00 EDT
Jehoon Moon, Seunghwan Lee, Gisoo Lee, Jeongun Lee, Hansohl Cho
An octahedral network has been widely used as a fundamental building block for diverse architected materials. Here, we demonstrate that heterogeneous octahedral materials can achieve complete elastic isotropy at a critical constituent volume fraction, nearly independent of the constituent stiffness ratio. The anisotropy ratio, a, transitions from a > 1 to a < 1 at the critical constituent volume fraction, due to a change in the dominant deformation modes. Microstructural analysis reveals that the geometry and connectivity of the heterogeneous octahedral materials are very similar to those of heterogeneous materials constructed on combined simple cubic (SC) and body-centered cubic (BCC) lattices exhibiting opposite elastic anisotropy. More importantly, we demonstrate that varying the constituent volume fractions in the octahedral materials governs elastic anisotropy, similarly to tuning the BCC-to-SC composition ratio in the SC-BCC materials widely employed for designing mechanically isotropic architected materials. The mechanical isotropy of the heterogeneous octahedral materials is further assessed using 3D-printed prototypes.
Soft Condensed Matter (cond-mat.soft), Materials Science (cond-mat.mtrl-sci)
21 pages, 9 figures (7 in the main text, 2 in the appendix), 2 tables
Phoretic flow in a three-dimensional wedge geometry
New Submission | Soft Condensed Matter (cond-mat.soft) | 2026-08-03 20:00 EDT
Abdallah Daddi-Moussa-Ider, Semyon Yakubovich, Maciej Lisicki
Understanding how chemically induced surface transport generates fluid motion in confined geometries is essential for the rational design of microscale pumping devices and active microfluidic systems. Here we develop a theoretical framework for chemically driven phoretic flows in a three-dimensional wedge geometry in the diffusion-dominated regime. We formulate both the diffusion and hydrodynamic problems using a Fourier-Kontorovich-Lebedev spectral representation, exploiting the translational invariance and radial structure of the wedge. Green’s functions for the concentration field are derived for reflecting and mixed reflecting-absorbing boundaries, reducing to finite image-like sums or closed-form expressions for commensurate wedge angles. The resulting slip velocity is then used to construct the three-dimensional Stokes flow through the Papkovich-Neuber representation, yielding explicit spectral solutions for the velocity field. These results establish a Green’s-function framework for phoretic pumping in wedge-shaped confinement and provide analytical benchmarks for numerical simulations of chemically driven transport in confined microfluidic systems.
Soft Condensed Matter (cond-mat.soft), Fluid Dynamics (physics.flu-dyn)
24 pages, 5 figures
Emergence of Propagating Exciton-Polaritons in Hybrid Waveguide-van der Waals Heterostructures
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2026-08-03 20:00 EDT
Alina Schubert, Karoline Becker, Andreas Thies, Rico Schwartz, Takashi Taniguchi, Kenji Watanabe, Henije Stolz, Alexander Szameit, Matthias Heinrich, Tobias Korn
Integrating few-layer materials into photonic circuits is a promising concept for novel on-chip photonic applications. We incorporate transition metal dichalcogenides (TMDs) with femtosecond-laser-written surface waveguides, which are embedded in fused silica chips. Our novel low-temperature optical spectroscopy setup enables coupling to the waveguide and simultaneous focus from the top to the TMD layer for a distinct excitation and collection of micro-photoluminescence ($ \mu$ PL) signals in several measurement geometries. Along these lines, we observe spectral changes of the A exciton for encapsulated TMD monolayers when capturing the $ \mu$ PL signal propagating through the waveguide. Depending on the thickness of the encapsulation with hexagonal boron nitride (hBN), these changes manifest as energetic redshifts of the A exciton, or even a splitting of the A exciton into two components. We attribute this behavior to strong coupling of the waveguide mode and the exciton in the sample, giving rise to the formation of propagating exciton-polaritons. Our interpretation is supported by calculations for a simplified model of a slab waveguide in the vicinity of an exciton by using the transfer matrix method. Having proven to be a highly adaptable framework for the study of propagating polaritons, our experimental platform likewise holds great promise for harnessing the unique properties of exciton-polaristons in integrated photonic circuits.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Optics (physics.optics)
Potential-defect-driven collective modes of one-dimensional two-component quantum droplets
New Submission | Quantum Gases (cond-mat.quant-gas) | 2026-08-03 20:00 EDT
Harsimranjit Kaur, Kuldeep Suthar
We examine a one-dimensional binary mixture of ultradilute quantum droplets in the presence of a central potential defect. The properties of the potential strength and the number of atoms exhibit distinct polarization transitions and low-lying ollective excitation spectra. The balance of (attractive) Lee-Huang-Yang quantum fluctuations and repulsive mean-field interactions results in a self-bound quantum droplet in a potential well. However, the potential barrier causes the polarization transition with the number of atoms, which is reflected in the excitation spectrum as a discontinuity and softening of the quasiparticle modes. We reveal that the critical number of atoms for the transition decreases as the attractive intercomponent interaction increases. Finally, the quench time dynamics of the interaction in potential barrier and well show the localization and diffusive fragmented droplets of two-component systems.
Quantum Gases (cond-mat.quant-gas)
10 pages, 9 figures
Diode Effect in Nonlinear High-Kinetic-Inductance Transmission Line Resonators
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2026-08-03 20:00 EDT
Niklas Gaiser, Ciprian Padurariu, Björn Kubala, Nadav Katz, Joachim Ankerhold
High-kinetic-inductance (HKI) transmission lines provide a promising platform for compact nonlinear superconducting microwave devices. Existing theoretical descriptions are typically based on the slowly varying envelope approximation, which becomes inadequate for strongly nonlinear resonant structures with pronounced spatial field variations. Here, we develop a theoretical framework for single-frequency nonlinear wave propagation in HKI transmission lines by formulating the problem as a boundary value problem that retains the full spatial dependence of the electromagnetic fields. Applying the method to resonant transmission-line geometries, we demonstrate power-dependent resonance shifts, bistable transmission solutions, and strongly direction-dependent transport arising from asymmetric impedance barriers, yielding transmission contrasts of up to $ 93%$ without magnetic bias fields. The framework is further extended to a three-port stub geometry, where nonlinear interference produces shifted anti-resonances and Duffing-like spectral distortions. Our approach provides a versatile tool for the analysis and design of strongly nonlinear superconducting microwave devices.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Superconductivity (cond-mat.supr-con)
9 pages, 12 figures
Quasiparticle modes across soliton transition with density-dependent gauge field in optical lattices
New Submission | Quantum Gases (cond-mat.quant-gas) | 2026-08-03 20:00 EDT
Poorava Kumar Meena, Kuldeep Suthar
Tunneling of ultracold bosons confined in a one-dimensional optical lattice results in a nontrivial gauge field depending on density-difference between the sites involved. The density dependent tunneling (DDT) causes a first-order quantum phase transition from the Bose-Einstein condensate to the localized soliton. Here, we examine the low-lying quasiparticle mode evolution across the transition in the weakly-interacting limit. To this end, we employ the discrete Bogoliubov theory and dispersion curves to reveal an increase in the quasiparticle energies of dipole (and higher) excitations with DDT in the soliton phase while preserving the zero-energy mode. This is due to the decrease in effective tunneling, resulting in a larger energy cost to move the soliton, and causes faster dipole oscillations. The repulsive on-site atomic interaction further shifts the critical gauge field of DDT to a larger value by stabilizing the lattice soliton. The latter is corroborated by a phase diagram in the complex gauge field plane and mode energy gap of quasiparticles. We further show that the soliton does not exhibit Bloch oscillations as the effective momentum becomes density-dependent and deforms its internal structure. The dynamical response of the trap quench does not excite the width of localized wave-packet, and the breathing oscillations are suppressed. The latter two dynamical properties of the condensate uniquely contrast the soliton state due to the density-dependent gauge field.
Quantum Gases (cond-mat.quant-gas)
10 pages, 8 figures
Savi-Bhransha: Graph-Theoretic Dislocation-Loop Characterization in Crystals
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-08-03 20:00 EDT
Dislocation loops govern the properties of crystalline materials, but extracting their detailed characteristics from atomistic simulations is difficult when loops are fragmented or embedded in compact defect debris. We present Savi-Bhransha, a graph-theoretic method that reconstructs interstitial and vacancy loops directly from local defect-displacement motifs, without constructing a global interface mesh. The method identifies Burgers-vector family, habit plane, loop size, segment-wise edge/screw character, and boundary and bulk defect populations for BCC, FCC, and HCP crystals. We apply it to single-cascade simulations over a range of energies in BCC W and HCP Zr, and to successive collision cascades in BCC W and FCC FeNiCr. We benchmark the method against the Dislocation Extraction Algorithm (DXA). Total dislocation lengths remain strongly correlated between the two methods, while Savi-Bhransha returns more stable loop-level objects in complex environments where DXA returns fragmented, overlapping open segments. Savi-Bhransha also better resolves mixed-morphology defects and dislocations near other defects, including vacancy clusters. Median runtime speedups are 6.34x for BCC W and 8.86x for HCP Zr, with peak-memory reductions up to 7.77x. In successive W cascades, the resolved boundary-defect concentration brackets transient-grating-spectroscopy measurements and the predicted Burgers-vector fraction agrees with room-temperature TEM. In FCC FeNiCr, the method resolves Heidenreich-Shockley dissociation, with a Shockley-pair signature in about 91% of surviving <110>-family interstitial clusters. Savi-Bhransha therefore enables efficient, topology-resolved analysis of large radiation-damage simulations and direct comparison with experimentally accessible observables.
Materials Science (cond-mat.mtrl-sci), Computational Physics (physics.comp-ph)
Resolving competing distortions in Ca0.4Sr0.6TiO3 using complementary electron and X-ray techniques
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-08-03 20:00 EDT
Robin Sjökvist, Catriona A. Crawford, Richard Beanland, Mark S. Senn
We present a study of the perovskite Ca0.4Sr0.6TiO3 using variable temperature transmission electron microscopy (TEM) and powder X-ray diffraction (PXRD). At room temperature and below, PXRD shows that the material adopts an orthorhombic Pbcm structure analogous to the P-phase of NaNbO3. Above 380 K the material transforms to a tetragonal I4/mcm phase. The structural distortions of these phases can be described as a combination of modes and order parameters associated with the M, T, $ {\Delta}$ and R-points of the Brillouin zone, each of which can be associated with a different set of superstructure reflections visible in X-ray and electron diffraction patterns. For the I4/mcm phase only the expected R-point reflections are observed in PXRD while both M and R- reflections are observed in electron diffraction. Using $ {\Delta}$ and R dark field TEM images we show that the phase transition proceeds by a loss of coherence of TiO6 octahedral tilting along the c-axis, leading to a microstructure of thin nanoscale platelets with a different local symmetry to the macroscopic structure. These persist well above the phase transition temperature and are probably responsible for the long-standing discrepancy between Raman spectroscopy and diffraction measurements in this materials system, as well as other secondary effects.
Materials Science (cond-mat.mtrl-sci)
11 pages, 6 Figures
Controlling Electron-Beam-Induced Charging in Colloidal Quantum Dots
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2026-08-03 20:00 EDT
Sven Ebel, Alina Myslovska, Stefano Vezzoli, Iwan Moreels, Sergii Morozov
Colloidal quantum dots (QDs) are attractive nanoscale emitters, yet their cathodoluminescence (CL) response remains poorly understood and often unstable under electron-beam excitation, limiting CL spectroscopy and electron-beam-based device processing. Here, we investigate the CL mechanism and strategies to improve its stability using highly photostable, structurally homogeneous giant-shell CdSe/CdS QDs combined with in situ CL and photoluminescence (PL) measurements. By identifying distinct signatures of excited states in both lifetime and spectral measurements, we demonstrate that the CL response is governed by electron-beam-induced charging. Charge accumulation drives multiexciton generation even at relatively low currents, leading to a pronounced blueshift, shorter average lifetimes, and rapid cathodobleaching. To test this further, we employ indirect excitation to reach sub-pA currents beyond the limits of typical electron beams, showing that neutral-exciton emission can be partially recovered and cathodobleaching mitigated, although charging cannot be fully suppressed. Furthermore, by replacing long insulating ligands with shorter ones, we improve charge drainage and strongly suppress biexciton formation. Together, these results show that biexciton formation can be controlled by limiting charge accumulation, providing a practical route toward stable CL for spectroscopy, imaging, and electron-beam-compatible photonic devices.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Other Condensed Matter (cond-mat.other)
Sound attenuation and velocity shift in antiferromagnetic spin-1/2 chains
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2026-08-03 20:00 EDT
Edmond Orignac, Emeric Caprani, Roberta Citro
We investigate ultrasound attenuation and sound velocity shift in antiferromagnetic spin-1/2 XXZ chains in magnetic field. We relate the sound velocity shift to derivatives of the free energy with respect to exchange interactions, permitting its calculation with integrability techniques at any temperature. Using bosonization, we predict the sound velocity shift exhibits a quadratic temperature correction at low temperatures in the Tomonaga-Luttinger liquid phase. Close to the fully polarized phase, a universal behavior associated with z=2 quantum criticality is found. In the Tomonaga-Luttinger liquid phase, ultrasound attenuation obeys a scaling law as a function of wavelength and temperature. An enhancement of attenuation is obtained near the fully polarized phase.
Strongly Correlated Electrons (cond-mat.str-el)
12 pages, 6 PDF figures, RevTeX 4
Layer- and Field-Dependent Magnetic Order in 2D CrSBr Revealed by Pulsed Nanocalorimetry
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-08-03 20:00 EDT
Hugo Gomez-Torres, Roop K. Mech, Alessandra Canetta, Llibertat Abad, Carles Navau, Daniel G. Chica, Xavier Roy, Pascal Gehring, Kenji Watanabe, Takashi Taniguchi, Aitor Lopeandia, Javier Rodriguez-Viejo
Understanding the evolution of magnetic order in the two-dimensional limit remains a central challenge in van der Waals magnets, where thermodynamic measurements are constrained by the femtogram-scale mass of exfoliated flakes. Here, we use microsecond pulse-heating nanocalorimetry to measure the heat capacity and magnetic entropy of CrSBr flakes down to the monolayer limit. The measurements reveal the entropy landscape associated with magnetic ordering, uncovering a reduction of the interlayer transition temperature and an entropy-derived effective magnetic moment approaching the monolayer limit. Thermodynamic anomalies capture a crossover from bulk-like interlayer antiferromagnetism to a regime dominated by intralayer ferromagnetic correlations. A pronounced layer-parity effect further emerges, with odd-layer samples displaying an additional high-temperature contribution associated with uncompensated magnetic layers. Under in-plane magnetic fields applied along the easy axis, antiferromagnetic order is progressively suppressed, allowing extraction of a thickness-dependent critical field reflecting weakened interlayer exchange coupling. Entropy analysis further reveals an extended regime of magnetic fluctuations persisting well above the interlayer ordering transition. Together, these results establish nanocalorimetry as a powerful thermodynamic probe of low-dimensional magnetism, providing direct access to magnetic entropy, exchange interactions, and dimensional crossover in atomically thin van der Waals magnets.
Materials Science (cond-mat.mtrl-sci), Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
31 pages, 8 figures. Main text and Supplementary Information included
A versatile generalized digital twin for Electron Microscopy
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-08-03 20:00 EDT
Thomas W. Pfeifer, Andrew R. Lupini, Eric R. Hoglund
Development of specialized imaging and spectroscopy states in transmission electron microscopy is needed for novel applications, such as flexible momentum-resolved high energy-resolution spectroscopy. This task is complicated by the need to align and configure many different lenses, and by ambiguity as to the locations of various imaging and diffraction planes, which are often not well documented. Here we develop a versatile digital twin for simulating the electron beam trajectory throughout an electron microscope. Our code package contains simple tools for modeling the microscope column, and we present multiple procedures for dialing in precise lens locations and calibrating lens models. This enables use of the model as a predictive tool, allowing the user to quickly and easily determine the correct lens values for setting up new condenser or projector modes. Automatic procedures to change lens settings and measure the resulting changes can be used to close the loop. With the accelerating development of machine learning and artificial intelligence tools, we also believe a physically-informed model of the microscope can serve as a valuable tool for automated microscopy and AI/ML integration.
Materials Science (cond-mat.mtrl-sci)
Boundary Kerr Signatures of the Interband-Coherence Hall Effect
New Submission | Disordered Systems and Neural Networks (cond-mat.dis-nn) | 2026-08-03 20:00 EDT
We identify a Hall response carried by optically induced interband coherence rather than by a non-equilibrium band population. In a weakly doped zinc-blende semiconductor, a longitudinal dc field drives a transverse flux of the conduction–valence coherence created by near-gap light. Angular averaging eliminates the homogeneous coherence density, while a lateral boundary converts the transverse flux into an antisymmetric, edge-localized, helicity-odd polarization. The resulting Kerr signal requires neither spin-orbit coupling nor a spin, valley, or orbital accumulation within an individual band. Within the eight-band Kane model, we derive the boundary kinetic equation and obtain a complex propagation length controlled by optical detuning and interband dephasing. The edge profile is monotonic at optical resonance and develops damped spatial oscillations away from it. The response is enhanced by electron–hole asymmetry and by strong interband mixing, making narrow-gap semiconductors especially favorable to observe the effect. These results establish dc-driven Kerr microscopy as a direct probe of an interband-coherence Hall effect and of multiband quantum kinetics in real space.
Disordered Systems and Neural Networks (cond-mat.dis-nn), Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Materials Science (cond-mat.mtrl-sci)
8 pages, 4 figures
Entropy production of active matter systems as indicator for computing performance
New Submission | Statistical Mechanics (cond-mat.stat-mech) | 2026-08-03 20:00 EDT
Patrick Egenlauf, Hannes A. Kröninger, Arnulf Kung, Mario U. Gaimann, Miriam Klopotek
Physical systems can process information through their natural dynamics, offering alternatives to conventional digital computing. Reservoir computing offers a basic framework by using a nonlinear substrate to map inputs into rich dynamical states read out by a simple linear layer. Active matter substrates are striking examples; they continuously consume energy and produce entropy. Theoretically, entropy production (EP) can describe the irreversibility and distance from equilibrium. But it remains unclear whether it can track computational capabilities. We address this conceptual gap by analyzing a driven swarm reservoir model. The system EP is computed from phase-space contraction and the bath EP from heat flow, separately, and put in direct association to prediction performance on a Lorenz-63 task. Via force parameter scans, we show that dynamical regimes with the strongest response to a driver as well as dissipation coincide with peak performance. Therein, the dynamical discrepancy between innate (minimal dissipation) and driven transferred heat (maximal dissipation) is sharpest. Generally, driver work and relative differences of driven and undriven EP closely mirror the performance landscape. The system EP, derived from a generalized Liouville-equation estimator, and heat flow provide complementary diagnostics and metrics, which are most robust in the best-performing regime. These results extend prior expectations that dissipation matters for computation by identifying when and how it becomes predictive. They also relate inference power to innate dynamics, pointing to generic principles for physical computing and where EP offers a screening metric for reservoirs and other base substrates.
Statistical Mechanics (cond-mat.stat-mech), Adaptation and Self-Organizing Systems (nlin.AO), Chaotic Dynamics (nlin.CD), Computational Physics (physics.comp-ph)
Optimal Navigation on Simplicial Complexes
New Submission | Statistical Mechanics (cond-mat.stat-mech) | 2026-08-03 20:00 EDT
Diego Febbe, Duccio Fanelli, Gianluca Peri, Timoteo Carletti
The navigation time and optimal search strategies deriving from random dynamical processes on binary graphs have been extensively explored and analyzed, being of prominent interest in the network science field. In this work, we study an extension of these topological measures for simplicial complexes: a specific type of geometric and algebraic structures that encapsulates higher-order interactions. Here, the explorability analysis of simplicial complexes has been conducted in terms of the mean first passage times between nodes, i.e. the 0th-order simplices, with the inclusion of a long-range stochastic teleportation term modulated with respect to the local random walk hopping across the various dimensions. We also provide a perturbative approximation scheme recovering the modulation parameter between pure random walk and teleportation mode (for higher-order setting) acting as the expansion parameter.
Statistical Mechanics (cond-mat.stat-mech)
A Unified Symmetry Framework For In-plane Anomalous Hall effect
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-08-03 20:00 EDT
Xun-Jiang Luo, Yong-Ting Shi, Ding-Fu Shao, Ping Zhang, Ning Hao, Mingliang Tian
The in-plane anomalous Hall effect (IPAHE), driven by an in-plane net magnetization or an applied magnetic field, challenges the conventional anomalous Hall paradigm. Despite growing interest, a unified symmetry principle governing these phenomena has remained elusive. Here, we establish a comprehensive symmetry framework that bridges the spin space group, which dictates the magnetic geometry, with the magnetic space group, which governs the anomalous Hall response. We show that spontaneous IPAHE can emerge in ferromagnets when spin-orbit-coupling-induced spin-group symmetry breaking permits additional net magnetization directions. For field-induced IPAHE, we analyze how an applied magnetic field reduces the symmetries of all 122 magnetic point groups and identify 54 groups that support IPAHE. Our framework naturally predicts IPAHE in a broad class of unconventional magnets, including altermagnets and odd-parity magnets. In particular, symmetry analysis reveals characteristic one-, two-, or three-fold angular harmonics of the Hall conductance under an in-plane rotating field, providing a symmetry-resolved fingerprint for unconventional magnetism. Using this framework, we screen the MAGNDATA database and identify candidate materials supporting spontaneous or field-induced IPAHE, encompassing ferromagnets, antiferromagnets, and unconventional magnets. Finally, we validate the symmetry predictions through first-principles calculations for two representative materials.
Materials Science (cond-mat.mtrl-sci)
53 pages, 2 figures, 13 tables
Tuneable magnetic behaviour, electronic structure and nitrogen vacancy formation in Gd${x}$Sm${1-x}$N
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-08-03 20:00 EDT
Omri Porat, Elma Joshy, Jackson Miller, Simon Granville, William Holmes-Hewett
The rare earth nitrides are the only series of intrinsic ferromagnetic semiconductors where the interplay of spin and unquenched orbital angular momentum provides access to a range of magnetic behaviour. Furthermore, the magnetic properties can be finely tuned through the combination of multiple lanthanide ions in the nitride. Here we present a combined computational and experimental study on the electronic and magnetic properties of Gd$ _x$ Sm$ _{1-x}$ N and discuss the effect of cation substitution on the internal exchange field and band structure. We find that as the coercive field of Gd$ _x$ Sm$ _{1-x}$ N changes over orders of magnitude via cation substitution the internal exchange field changes by $ \sim$ 20%. Control of these material properties is vital in the field of superconducting spintronics. Finally, motivated by an enhanced concentration of nitrogen vacancies in films with higher Sm content, we investigate computationally the formation of nitrogen vacancy defects in Gd$ _x$ Sm$ _{1-x}$ N finding that the formation energy is significantly reduced for vacancy sites adjacent to Sm ions rather than Gd ions.
Materials Science (cond-mat.mtrl-sci)
Copyright 2024 American Physical Society. This is the accepted manuscript of the following article: Porat, O., Joshy, E., Miller, J.D., Granville, S. and Holmes-Hewett, W.F., “Tuneable magnetic behavior, electronic structure, and nitrogen vacancy formation in Gd${x}$Sm${1-x}$N”. Physical Review Materials, 8(11), p.116201, (2024). DOI: this https URL
Physical Review Materials, 8(11), p.116201, (2024)
Dissipation-enhanced vortex clustering in a compressible quantum fluid
New Submission | Quantum Gases (cond-mat.quant-gas) | 2026-08-03 20:00 EDT
P. Comaron, M. Matuszewski, D. Sanvitto, D. Ballarini, A. S. Lanotte
Vortex clustering is commonly associated with conservative two-dimensional quantum-fluid dynamics. Therefore, particle loss is mainly expected to limit clustering by shortening the time available for vortex correlations to develop. Here we show instead that particle loss can enhance transient vortex clustering beyond the conservative evolution. We numerically study freely decaying, confined two-dimensional condensates initialized with random distributions of vortices and antivortices, and find a pronounced nonmonotonic dependence of the maximum clustering on particle lifetime. The enhancement is strongest at intermediate particle-loss rates, where loss-induced background rarefaction and incompressible kinetic energy relaxation occur on comparable timescales. Our results identify a finite dynamical window, selected by linear particle loss, in which a confined compressible quantum fluid develops stronger same-sign vortex correlations than in the conservative limit.
Quantum Gases (cond-mat.quant-gas)
7 pages main doc., 7 pages supp. mat
Substrate contact angle governs microgel shape, stiffness and deposition pattern
New Submission | Soft Condensed Matter (cond-mat.soft) | 2026-08-03 20:00 EDT
M. Friederike Schulte, Sebastian S. Meyer, Timon Kratzenberg, Simon Schog, Jesco M. Schönfelder, Silke Klein-Kormelink, Tim Blinzer, Matthias Karg, Walter Richtering, Marcel Rey
Soft microgels are widely used as deformable building blocks for two-dimensional assemblies, yet solid substrates are often treated as passive supports after interfacial deposition. Here, we show that substrate wettability mechanically preconditions soft microgels before drying. Using in-liquid force-volume atomic force microscopy, we find that the same microgels adopt markedly different hydrated shapes and stiffness profiles depending on substrate contact angle: hydrophobic substrates induce spreading, flattening, and internal stiffening, whereas hydrophilic substrates preserve taller, softer microgels with smaller contact areas. These single-microgel states can explain how Langmuir-Blodgett-deposited monolayers respond during drying. On hydrophilic substrates, the observed assemblies are consistent with soft and weakly immobilized microgels rearranging under immersion-capillary forces, producing distinct corona-corona and core-core contact states and an apparent isostructural transition. On hydrophobic substrates, the flattened and stiffened microgels are more strongly immobilized, likely suppressing capillary-driven rearrangements and largely preserving the transferred interfacial assembly structure. These findings establish substrate-controlled microgel mechanics as the missing link between interfacial self-assembly and the final structures observed after transfer and drying.
Soft Condensed Matter (cond-mat.soft)
Valley- and Orbital-Controlled 2D Chern Insulators Without Spin-orbit Interaction
New Submission | Other Condensed Matter (cond-mat.other) | 2026-08-03 20:00 EDT
J. Benkaida, O. Benhaida, L. B. Drissi, E. H. Saidi
We present a theoretical study of orbital-induced topological phase transitions in a two-dimensional lattice model with staggered potential $ (\Delta)$ and orbital coupling $ (\lambda)$ competing with the hopping strength. By tuning these parameters, two gap-closing mechanisms emerge: valley closure at $ \mathbf{K}$ and $ \mathbf{K’}$ for $ \lambda=\pm\Delta$ , and a $ \mathbf{\Gamma}$ -point closure at $ \lambda=\pm\sqrt{\Delta^2+9t_0^{2}}$ . Their interplay defines a topological window in which the Berry curvature localizes near a single valley, yielding a quantized anomalous Hall conductivity ($ \sigma_{xy}=e^{2}/h$ ) and Chern number ($ C=1$ ). These results demonstrate orbital-driven Chern insulating behavior without spin-orbit coupling. The resulting phase diagram captures the transition from trivial to topological phases and suggests practical routes for orbital engineering in tunable lattice systems.
Other Condensed Matter (cond-mat.other)
8 pages, 5 figures. This manuscript has been transferred from Physics Letters A (Elsevier) for consideration in the arXiv submission
J. Benkaida, O. Benhaida, L.B. Drissi, E.H. Saidi, Physics Letters A 592 (2026) 131979
Delayed Formation of Landau Polaritons in Phase-Resolved THz Spectroscopy
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2026-08-03 20:00 EDT
Noureddine Charrouj, Yurii Ivonyak, Dmitriy Yavorskiy, Vladimir Y. Umansky, Jerzy Lusakowski, Wojciech Knap, Marcin Bialek
Strong light-matter coupling gives rise to polaritons through coherent and periodic energy exchange between electromagnetic cavity fields and material excitations. While this interaction is typically inferred from spectral mode splitting, its dynamics remain largely unexplored. Here, using phase-resolved terahertz time-domain spectroscopy, we observe Rabi oscillations of Landau polaritons formed by coupling the cyclotron resonance in a GaAs/Al$ _{0.36}$ Ga$ _{0.64}$ As two-dimensional electron gas with Fabry-Perot cavity modes. By employing cross-polarized spectroscopy and magnetic-field differential, we resolve the temporal beating of the cyclotron resonance oscillations. Remarkably, we find that the Rabi oscillations do not start immediately after excitation of the cyclotron resonance, but after a delay corresponding to one cavity round-trip time. This demonstrates that the strong-coupling regime sets up only after the formation of the cavity mode field. Our results provide direct insight into the dynamics of hybrid light-matter states in the THz regime.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Quantum Physics (quant-ph)
Ordered-to-disordered transfer learning with graph neural networks for formation-energy and HOMO-LUMO gap prediction in high-entropy perovskite oxides
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-08-03 20:00 EDT
Panupol Untarabut, Narjes Jomaa, Sylvian Cadars, Olivier Masson, Samuel Bernard, Assil Bouzid, Santanu Saha
High-entropy perovskite oxides (HEPOs) represent a chemically complex class of materials with promising functional properties, yet their vast compositional space and, chemical/structural disorder pose significant challenge for accurate property prediction. Graph neural networks (GNNs) enable rapid exploration of materials space but are often limited by the availability of representative training data. Here, we investigate ordered-to-disordered transfer learning using GNNs for formation-energy and HOMO-LUMO gap prediction in HEPOs by transferring knowledge learned from chemically ordered perovskites. Four representative GNN models, including CGCNN, GATGNN, ALIGNN and M3GNet are evaluated to understand the role of structural representations, spanning pairwise two-body and angular three-body interactions in transfer performance. We find strong property-dependent transfer behavior: formation-energy prediction transfers effectively to disordered HEPOs, whereas HOMO-LUMO gap prediction shows limited transferability due to its sensitivity to local chemical environments. Incorporating a small HEPO-specific training dataset substantially improves HOMO-LUMO gap prediction. Representation-level analysis using UMAP further highlights the importance of encoding three-body geometric information such as in ALIGNN for capturing complex structure-property relationships and improving transferability.
Materials Science (cond-mat.mtrl-sci), Other Condensed Matter (cond-mat.other), Machine Learning (cs.LG)
19 pages, 9 figures
Elastodynamics from Eulerian Poisson-bracket formalism: application to chiral odd solids
New Submission | Soft Condensed Matter (cond-mat.soft) | 2026-08-03 20:00 EDT
Cheng-Tai Lee, Tomer Markovich
The Poisson-bracket (PB) formalism is widely used to derive dynamics of coarse-grained (CG) fields to capture large-scale physics, extending the role of PBs in classical particle mechanics to macroscopic fields. It has been applied to fluctuations in critical phenomena, hydrodynamics of liquid crystals, liquid crystal elastomers, tissues, and the emergence of odd viscosity from spinning particles. The PB formalism can be formulated in either the Lagrangian framework, using reference space, or the Eulerian framework, using real space. Conventionally, the Lagrangian formulation is used for elastic solids, and the Eulerian one for fluids. However, growing interest in Eulerian descriptions of solids has emerged for phenomena naturally defined in real space, such as viscoelastic responses, moving interfaces, and field-induced structural changes in particles. Here we develop a systematic formulation for applying the Eulerian PB formalism to elastic systems with potentials typically written in Lagrangian space, and clarify its consistency with the Lagrangian counterpart. We show that the Eulerian formulation generates additional nonlinearities absent in the Lagrangian framework. Such nonlinearities originate from CG volume changes under coordinate transformation and from particle flow across neighboring CG volumes. They must be retained when nonlinear effects are important. To illustrate, we study chiral active solids of finite-sized particles, where active torques drive internal particle rotations and generate geometric nonlinearities. These nonlinearities give rise to the odd elastic modulus, which non-reciprocally couples two different shear modes in stress-strain response. By recovering this modulus directly from the Eulerian PB formalism, we demonstrate its ability to capture emergent nonlinear elastic behavior in driven active solids, whose stresses are naturally measured in real space.
Soft Condensed Matter (cond-mat.soft), Biological Physics (physics.bio-ph), Fluid Dynamics (physics.flu-dyn)
17 pages, 3 figures
Exponential Capacity in Multilayer Hetero-Associative Neural Networks
New Submission | Disordered Systems and Neural Networks (cond-mat.dis-nn) | 2026-08-03 20:00 EDT
Elena Agliari, Adriano Barra, Andrea Ladiana, Andrea Lepre
Exponential Hopfield networks store a number of patterns that grows exponentially with the number of neurons, and in their classical formulation they are auto-associative: they complete a corrupted copy of a memory into the memory itself. Many of the tasks one wants such a network to perform are instead hetero-associative, mapping a cue to a different target. We introduce and analyse an exponential neural network of $ L$ layers of $ N$ binary neurons, each layer carrying its own dataset, whose energy is an exponential of the product of the per-layer Mattis overlaps, so that it is minimised precisely when every layer retrieves the pattern of the same index; the stored association must be a surjective function of the cue, and we show why nothing else can be stored at all. A cavity/signal-to-noise analysis, made exact at leading order by a large-deviation evaluation of the noise, shows that the aligned hetero-associative state is a fixed point of the zero-temperature dynamics up to a number of stored patterns $ P_c\sim e^{N\rho_L}$ , exponential in the layer size, with an explicit rate $ \rho_L$ that grows like $ L\log 2$ ; enlarging the basins of attraction lowers the rate but never destroys its exponential character. Comparing the theory with structured data we find that the exponential capacity and the predicted basins survive correlated, many-to-one patterns: the network is a near-perfect content-addressable memory. The same closed forms describe, without refitting, a synthetic manifold, real T-cell-receptor/epitope triples and natural-language intent data, so the mechanism is domain-universal. Generalisation to unseen cues, though significantly above chance, stays below memorisation, and it is the geometry of the encoding, rather than the data domain, that sets how far above chance it reaches. In this family, exponential storage and strong generalisation are distinct capabilities.
Disordered Systems and Neural Networks (cond-mat.dis-nn), Machine Learning (stat.ML)
Hidden chiral signatures in ferroaxial K2Zr(PO4)2
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-08-03 20:00 EDT
Nora Taufertshöfer, Awadhesh Narayan, Nicola A. Spaldin
We use first-principles calculations and multipole analyses to demonstrate the relationship between ferroaxiality and chirality in the prototypical ferroaxial material K2Zr(PO4)2. Using the atomic-site electric toroidal monopole as a measure of electronic chirality in real space, we show that, while the paraxial phase of K2Zr(PO4)2 is non-chiral, the ferroaxial phase is antiferro-chiral. By applying an electric field, we induce a ferri-chiral state with net electronic chirality which is opposite for opposite underlying ferroaxial domains and can be tuned by the direction and strength of the electric field. Associated with the real-space induced chirality, we find a distinct response in momentum space, with induced non-zero components in the Berry curvature dipole tensor that switch sign between opposite ferri-chiral domains. Our findings therefore reveal hidden chirality in ferroaxial materials in both real and momentum space.
Materials Science (cond-mat.mtrl-sci)
7 pages, 6 figures
Spindrift: Learning quantum degeneracy from thermal purity in restricted path integral Monte Carlo
New Submission | Statistical Mechanics (cond-mat.stat-mech) | 2026-08-03 20:00 EDT
Restricted path integral Monte Carlo (RPIMC) sidesteps the fluctuating Fermion sign problem by confining paths within nodal pockets of a trial density matrix, thereby recovering polynomial scaling. However, this nodal surface must be provided from elsewhere; unless it is exact, it introduces a fixed-node energy error.
Here we introduce \textsc{Spindrift}, a Variational Density Matrix approach that learns the many-body Fermionic density matrix from a regularised Bloch residual, evaluated on samples drawn by a restricted Worm algorithm. Motivated by the observation of the `purity’ of quantum mechanics at high temperature (where kinetic energy dominates), we train the density matrix along a temperature (imaginary time) curriculum, learning increasingly large \emph{corrections} to the initial free-particle reference. We parametrise our model with a permutation-equivariant continuous normalising flow to generate quasi-particle backflow trajectories, modulated by a symmetric Jastrow factor. This architecture guarantees exact Fermionic antisymmetry and spatial symmetry throughout training.
Simulating $ N=3$ interacting Fermions in a two-dimensional harmonic trap, we demonstrate stable curriculum training. The learnt velocity field smoothly deforms the nodal structure away from the free-particle reference. Open-Worm G-sector trapping provides a natural diagnostic for nodal accuracy.
Although the current lack of a nodal action in our estimator precludes absolute benchmarking, \textsc{Spindrift} lowers the restricted thermodynamic energy relative to the free-particle reference at each temperature, establishing a stable, physics-informed framework for finite-temperature quantum Monte Carlo where the nodal structure is learnt self-consistently.
Statistical Mechanics (cond-mat.stat-mech), Disordered Systems and Neural Networks (cond-mat.dis-nn)
12 pages, 3 figures
Superselectivity as a Receptor-Fluctuation Response
New Submission | Soft Condensed Matter (cond-mat.soft) | 2026-08-03 20:00 EDT
Superselective multivalent binding enables sharp receptor-density discrimination in targeting and sensing, but what its logarithmic response measures microscopically remains unclear. Here, we derive an exact response decomposition of the selectivity into receptor-state reweighting and a direct occupation response. In the dilute quenched Poisson limit, the direct term vanishes and selectivity is exactly the mean receptor excess beneath bound particles, which can be measured at a single density from a sufficiently large co-registered receptor-particle image. Beyond Poisson statistics, the excess is normalized by the Fano factor for a linear count response, while changes in distribution shape require the full count-resolved response. Lattice simulations verify these relations across distinct receptor statistics, while off-lattice simulations show that particle crowding enters through the direct term. These results establish a fluctuation-response framework linking multivalent selectivity to the local receptor fluctuations preferentially sampled by adsorption.
Soft Condensed Matter (cond-mat.soft), Statistical Mechanics (cond-mat.stat-mech), Biological Physics (physics.bio-ph)
6 pages, 3 figures; Supplemental Material: 10 pages, 3 figures
Nonlinear Meissner States, Vortex Sheets, and Laminar Structures in Extreme Type-II Superconductors
New Submission | Superconductivity (cond-mat.supr-con) | 2026-08-03 20:00 EDT
A recently derived nonlinear velocity theory of extreme type-II superconductors is shown to possess an exactly solvable one-dimensional sector. Its solutions include nonlinear Meissner states exhibiting universal tails, vortex sheets, and periodic laminar structures. The thermodynamic critical field emerges from a marginal Meissner profile equivalent to the normal-superconducting boundary and may be viewed as a half-soliton. The vortex sheet is a soliton characterized by a discontinuity of the velocity field, a continuous and localized magnetic field and vanishing superconducting density at its center, and may be interpreted as the coarse-grained limit of a dense row of Abrikosov vortices. Periodic solutions describe laminar states that may be interpreted as coarse-grained rectangular vortex lattices.
Superconductivity (cond-mat.supr-con), Mathematical Physics (math-ph)
4.7 pages, I figure
Tunable two-component ultracold molecular gases with vibrational shielding
New Submission | Quantum Gases (cond-mat.quant-gas) | 2026-08-03 20:00 EDT
We propose a method to realize stable, tunable two-component quantum mixtures of ultracold polar molecules. First, we show that a pair of polar molecules in two distinct rovibrational states exhibits a repulsive interaction, thereby leading to collisional shielding without requiring any external field. We refer to this as “vibrational shielding”. This intercomponent interaction is tunable by an external static electric or a microwave field, with the latter stabilizing both inter- and intracomponent interactions in a two-component bulk mixture. Additionally, we show that two microwave fields can independently tune the interactions of the individual components. Our findings thus open the door to the experimental realization of tunable quantum mixtures using polar molecules, analogous to tunable magnetic Feshbach resonances in two-component atomic quantum gases.
Quantum Gases (cond-mat.quant-gas)
9 pages, 7 figures, and 1 table
Unwithered Majorana fermions in the bulk of a quantum chain
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2026-08-03 20:00 EDT
The proposal is to probe Majorana modes in the system when its parameters are tuned to bring it into a disentangled ground state, which occur on the parametric curves known as disorder lines (DL). In such state certain correlation functions do not depend on separation. The exact results are presented for the XY spin chain in transverse field, also called the Kitaev chain in the Majorana representation. The single Majorana modes are shown to be localized near the ends of the chain, as in the states off the DL, while the disentangled $ n$ -particle Majorana modes ($ n \geq 2$ ) penetrate into the bulk without attenuation. The predicted bulk-edge effects can be detected in the specially engineered optical chains and lattices.
Strongly Correlated Electrons (cond-mat.str-el), Mathematical Physics (math-ph), Quantum Physics (quant-ph)
6 pp. main text + 2 appendices
Pairing near the boundary of a box-shaped trap in the BEC-BCS crossover
New Submission | Quantum Gases (cond-mat.quant-gas) | 2026-08-03 20:00 EDT
Kelly R. Patton, Daniel E. Sheehy
We study pairing of attractively interacting fermions confined to a box-shaped trap. In contrast to the infinite translationally-invariant case, where the local pairing order is spatially uniform and undergoes the Bose-Einstein Condensate to Bardeen-Cooper-Schrieffer (BEC-BCS) crossover as interactions are varied, in this case the local pairing is expected to vary rapidly near the edge of the box. We address this problem in the limit of a semi-infinite superfluid, finding that the nature of the edge pairing depends sensitively on the coupling. The local pairing exhibits Friedel-like oscillations in the weak coupling BCS regime that are suppressed with increasing coupling strength towards the BEC regime.
Quantum Gases (cond-mat.quant-gas)
16 pages, 14 figures
Temperature-driven transition between momentum-resolved and disordered averaged Coulomb drag in 1D systems
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2026-08-03 20:00 EDT
Mingyang Zheng, Rebika Makaju, Rasul Gazizulin, Alex Levchenko, Sadhvikas J. Addamane, Dominique Laroche
Advancing the understanding of electron-electron interactions in one-dimensional systems remains one of the central challenges in low-dimensional physics, especially for Coulomb-coupled Tomonaga-Luttinger liquids. Notably, the difficulty of reliably extracting one-dimensional system parameters, combined with the presence of disorder, has hindered the interpretation of 1D Coulomb drag experiments. Here, we present a self-consistent experimental determination of the relative Luttinger liquid interaction parameters through 1D Coulomb drag measurements, and achieve quantitative agreement with theoretical predictions. Utilizing vertically coupled GaAs-AlGaAs quantum wires, we fully characterize the one-dimensional parameters through magnetic depopulation. Coulomb drag exhibits a systematic evolution with magnetic field, reflecting the successive depopulation of 1D subbands and the suppression of disorder effects. Two distinct temperature regimes are identified, marking the boundary between momentum-resolved and disordered-averaged Coulomb drag. The observed scaling, peak broadening, and nonlinear current-voltage characteristics establish a unified and quantitative framework for probing electron-electron interactions in 1D systems.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
22 pages, 5 figures
Continuous Tuning of the Charge-Phase Uncertainty in a Josephson Junction
New Submission | Superconductivity (cond-mat.supr-con) | 2026-08-03 20:00 EDT
Irena Padniuk, Xianzhe Zeng, Juan Carlos Cuevas, Joachim Ankerhold, Klaus Kern, Christian R. Ast
Quantum mechanics constrains conjugate observables from being simultaneously measurable with arbitrary precision. In a Josephson junction, these are the transferred electric charge and the quantum-mechanical phase difference between the superconducting domains. Which of them fluctuates determines the supercurrent: a dissipative trickle of single Cooper pairs in one limit, a coherent dissipationless flow in the other. Bridging both regimes in one device remained elusive because the Josephson and charging energies are fixed at fabrication. Here, we use the tunable tunnel junction of a scanning tunneling microscope at millikelvin temperature to vary their ratio continuously over many orders of magnitude. In this way, we monitor the smooth transition between incoherent and coherent Cooper pair flow in a single junction, revealing the quantum-to-classical transition in a controlled way.
Superconductivity (cond-mat.supr-con), Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
16 pages, 5 figures, including supplementary information
Structure, Diffusion, and Relaxation in a Charge-Neutral ProTalpha-Histone H1 Condensate
New Submission | Soft Condensed Matter (cond-mat.soft) | 2026-08-03 20:00 EDT
Condensates formed by oppositely charged intrinsically disordered proteins provide model systems for understanding how transient electrostatic interactions govern structure and dynamics in biomolecular assemblies. Here we investigate a nearly charge-neutral condensate composed of 50 Prothymosin alpha (ProTalpha) and 40 Histone H1 molecules using a single-bead-per-residue coarse-grained model combining the HPS hydropathy model for disordered regions with a Go model for the globular domain of Histone H1 under NPT conditions at pressures from 2 to 12 bar. We find that chain dimensions, including the radius of gyration (Rg), end-to-end distance (Ree), and their ratio R, are insensitive to pressure, indicating that chain conformations remain largely unchanged over the pressure range studied. Histone H1 exhibits systematically larger values of R than ProTalpha because of its globular-core plus disordered-tail architecture. Translational diffusion coefficients decrease monotonically with pressure, from approximately 0.22 to 0.06 nm^2/ns, with substantial chain-to-chain heterogeneity comparable to the mean diffusion coefficient. Chain relaxation follows a stretched exponential with beta less than 1 that decreases with pressure. ProTalpha relaxation times of approximately 12 to 40 ns obey Rouse scaling, whereas Histone H1 deviates because of the internal constraint imposed by its globular domain. ProTalpha-Histone H1 contact lifetimes of approximately 0.43 to 0.56 ns are much shorter than the Rouse relaxation time, placing the system firmly in the fast-exchange regime where transient electrostatic contacts renormalize chain friction rather than acting as permanent cross-links, consistent with the moderate stretching exponent beta of approximately 0.55 to 0.70 observed across all pressures.
Soft Condensed Matter (cond-mat.soft)
Study of the Anomalous Hall effect by tuning the spin orientation in the Altermagnetic material CrSb
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2026-08-03 20:00 EDT
Sreedevi Chintalapudi, Upasana Agrawal, Suvadip Das
Recent development in the field of altermagnetism, and increased demand for the search of applications of anomalous hall effect have ushered in a new era for novel quantum phases in materials. Quantum materials previously anticipated to be scientifically predictable have unfolded novel properties that brought them into the spotlight. These manifestations have led us to rethink our understanding of existing classification of magnetic materials and preexisting notions about anomalous hall effect in the light of topologically nontrivial phases of matter. One such recent de- velopment lies in the novel class of alter-magnetic materials with prospect for quantum computing. In this article, we delineate the spin and orbital resolved electronic spectrum, mode-decomposed phonon dispersion relations, geometrical berry curvature and topological surface states and their implications on anomalous Hall conductivity in the promising altermagnetic compound CrSb. We further utilize first principles calculations coupled with computationally efficient maximally localized wannier states of numerous magnetic configurations of the altermagnet to simulate the effect of external fields and elucidate the fact that the linear behaviour of anomalous hall conductivity with magnetization does not necessarily hold true for all magnetic classes, such as altermagnets.
Strongly Correlated Electrons (cond-mat.str-el), Materials Science (cond-mat.mtrl-sci)
10 pages, 8 figures
Revealing the Spin Hydrodynamics of a Spin-Imbalanced Unitary Fermi Gas
New Submission | Quantum Gases (cond-mat.quant-gas) | 2026-08-03 20:00 EDT
DeChao Zhang, Johannes Lang, J. E. Thomas
Hydrodynamics governs diverse collective phenomena in nature, from the expansion of a quarkgluon plasma to viscous electron flow in quantum materials. In strongly interacting hydrodynamic fluids, the transport of spin remains poorly understood. Here, we investigate spin transport in the hydrodynamic regime of a spin-imbalanced unitary Fermi gas confined in a uniform optical box. By quenching a spatially periodic optical potential that modulates both the density and spin polarization, we observe the relaxation of the many-body system, which determines both the spin diffusivity and the spin Seebeck/Peltier coefficients in a homogeneous quantum gas. Our measurements provide parameter-free benchmarks for microscopic theories and establish an ultracold atom platform for studying spin caloritronics in strongly correlated matter.
Quantum Gases (cond-mat.quant-gas)
23 pages, 8 figures
Non-reciprocal torques guide self-assembly of active particles into clusters with controllable function
New Submission | Soft Condensed Matter (cond-mat.soft) | 2026-08-03 20:00 EDT
Till Welker, Yukino Fujiya, Holger Stark
Self-assembly of constituents determines structure formation in the microscopic world. Attractive forces can assemble active particles into colloidal machines, but they do not fix the particles’ orientations, which limits control over the machine’s function. We demonstrate that non-reciprocal turn-towards torques not only assemble active particles into clusters, without requiring attractive forces, but also link particle orientations to the cluster configuration. Symmetry then dictates whether the cluster is static, rotates, or translates. In small systems, the particle number uniquely determines the stable configuration and function. In larger systems, there are multiple stable configurations with distinct functions, and tuning the torque strength allows us to bias towards the desired function, such as a run-and-tumble motion. Because the interactions driving assembly can be switched on and off, the clusters self-assemble when needed. For such a “just-in-time” self-assembly to be practical, fast assembly is necessary. We show that stochastic resetting, implemented by briefly turning off propulsion and torque, significantly speeds up self-assembly by avoiding slow pathways. Together, our findings demonstrate that non-reciprocal torques can rapidly assemble active particles into colloidal micromachines with controllable function.
Soft Condensed Matter (cond-mat.soft), Statistical Mechanics (cond-mat.stat-mech)
10 pages, 7 figures
A Simple Necessary and Sufficient Condition for Yang–Baxter Integrability
New Submission | Statistical Mechanics (cond-mat.stat-mech) | 2026-08-03 20:00 EDT
Mizuki Sanatani, Naoto Shiraishi, Fuga Ishii
Quantum integrability is a cornerstone of the exact theory of interacting quantum spin chains. In its standard formulation, however, one starts from R-matrices satisfying the Yang–Baxter equation, rather than from the Hamiltonian itself. It has therefore remained unclear how Yang–Baxter solvability can be characterized directly at the Hamiltonian level, and how it is related to the existence of local conservation laws. Here we prove that, in a broad standard setting, the Reshetikhin condition is not only necessary but also sufficient for Yang–Baxter integrability, thereby reducing the hidden algebraic structure of integrability to a Hamiltonian-level conservation law. Since the Reshetikhin condition is equivalent to conservation of the total energy current, this Hamiltonian-level criterion is also experimentally accessible. This result establishes a quantum counterpart of the Liouville–Arnold theorem for isotropic spin chains, stating that Yang–Baxter solvability is equivalent to an infinite hierarchy of local conserved quantities. Our result also simplifies substantially the search for integrable spin chains by replacing the search for R-matrices with a direct criterion on local Hamiltonians.
Statistical Mechanics (cond-mat.stat-mech), High Energy Physics - Theory (hep-th), Mathematical Physics (math-ph), Exactly Solvable and Integrable Systems (nlin.SI), Quantum Physics (quant-ph)
11 pages, 4 figures, 1 table; Supplemental Material included (23 pages). Code available at this https URL and archived at this https URL
Magnetic properties of a quasi-two-dimensional spin-1/2 antiferromagnet Y2CuGe4O12
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2026-08-03 20:00 EDT
J. Khatua, Changhyun Koo, Suyoung Kim, Eundeok Mun, Yugo Oshima, V. K. Sahu, Heung-Sik Kim, B. Koteswararao, Kwang-Yong Choi, P. Khuntia
Competing magnetic interactions and frustration-induced quantum fluctuations in spatially anisotropic low-dimensional magnets often give rise to exotic magnetic phenomena, including field-induced phases. Here, we present crystal structure, magnetic susceptibility, specific heat, and electron spin resonance (ESR) measurements on polycrystalline Y$ 2$ CuGe$ 4$ O$ {12}$ , supported by density functional theory (DFT) calculations. In this compound, the Cu$ ^{2+}$ ions form a distorted triangular lattice with competing intraplanar ferromagnetic ($ J_1 \approx 0.138$ K and $ J_2 \approx 0.01$ K) and antiferromagnetic ($ J_3 \approx -3.22$ K) exchange interactions, together with a weaker interplanar antiferromagnetic coupling ($ J_4 \approx -1.56$ K). These interactions account for the small Curie–Weiss temperature, $ \theta{\rm CW}=-1.8$ K. Despite the dominant antiferromagnetic interactions, no signature of long-range magnetic ordering is observed down to 0.4 K. Instead, broad maxima in both the magnetic susceptibility and magnetic specific heat reveal the development of short-range spin correlations, further supported by the critical ESR linewidth broadening characteristic of low-dimensional frustrated magnets. Application of an external magnetic field progressively suppresses the broad maximum in the magnetic specific heat, reflecting competition between the Zeeman and exchange energy scales, and drives the system into a field-polarized state above the saturation field, $ \mu_0H_{\rm s}=2.6$ T. In this regime, the magnetic specific heat exhibits an exponential temperature dependence, consistent with gapped magnon excitations. These results establish Y$ _2$ CuGe$ 4$ O$ {12}$ as a rare distorted triangular-lattice magnet in which further-neighbor exchange interactions dominate the magnetic behavior, providing a promising platform for exploring frustration-driven quantum phenomena.
Strongly Correlated Electrons (cond-mat.str-el), Materials Science (cond-mat.mtrl-sci)