CMP Journal 2026-08-24
Statistics
Nature Materials: 2
Nature Nanotechnology: 1
Nature Physics: 2
arXiv: 79
Research Square: 3
Nature Materials
Electrical manipulation and detection of perpendicular altermagnetic order via a proximitized Dirac semimetal
Original Paper | Magnetic properties and materials | 2026-08-23 20:00 EDT
Zhaohui Li, Wenqing He, Hua Bai, Yang Wang, Alexander J. Grutter, Guoyi Shi, Xiwen Zhang, Christy Kinane, Andrew Caruana, Hui Ru Tan, Yuchen Pu, Chenhui Zhang, Yongxi Wang, Hanbum Park, Anjan Soumyanarayanan, Lei Shen, Hyunsoo Yang
Altermagnets, which combine antiferromagnetic-like magnetic compensation with ferromagnetic-like broken time-reversal symmetry, hold great promise for high-density and ultrafast spintronic applications. However, the detection and switching of perpendicular altermagnetic order are fundamentally constrained by magnetic symmetry, restricting both fundamental studies and practical implementation. Here we demonstrate the robust electrical reading and deterministic switching of perpendicular altermagnetic order by designing a Dirac semimetal/altermagnet heterostructure of PtTe2/CrSb. This engineered interface enables anomalous Hall read-out via the altermagnetic proximity effect and delivers efficient spin-orbit torque for manipulating the epitaxial perpendicular Néel vector in CrSb. These findings substantially broaden the functional scope of altermagnetic heterostructures and pave the way for scalable altermagnetic memory.
Magnetic properties and materials, Spintronics
Flux-mediated ligand exchange restructures metal-organic framework glasses
Original Paper | Magnetic materials | 2026-08-23 20:00 EDT
Jan-Benedikt Weiß, Lorena Fritsch, Michele Tricarico, Anke Schoch, Soma Salamon, Wen-Long Xue, Chinmoy Das, Pascal Kolodzeiski, Heiko Wende, Jin-Chong Tan, Matthias Bauer, Sebastian Henke
Melt-quenched glasses derived from metal-organic frameworks (MOFs) combine the processability of glasses with the modularity and microporosity of MOFs, yet remain structurally and functionally less diverse than crystalline analogues. Here we show that the chelating ligand 1,10-phenanthroline acts as an organic flux that lowers the glass transition temperature of selected MOFs and induces ligand exchange during melting, thereby enabling control over local coordination and global topology in MOF glasses. In Co2+-based systems, phenanthroline coordinates to the metal nodes, increases the coordination number and reduces network connectivity by forming terminal ligands. This coordination sphere engineering affords a level of structural control not readily achievable in conventional inorganic or organic glasses. Crucially, the lower processing temperature suppresses thermal decomposition, enabling the synthesis of Co2+-based MOF glasses free of magnetic impurities. These glasses exhibit antiferromagnetic coupling and represent unique examples of magnetic MOF glasses formed by melt quenching. Finally, we extend the strategy to otherwise non-meltable carboxylate-based MOFs, establishing flux-mediated ligand exchange as a versatile route to hybrid glasses with tailored connectivity and properties.
Magnetic materials, Mechanical properties, Metal-organic frameworks
Nature Nanotechnology
Cryogenic energy storage enabled by dipole glass with unit-cell-level polar disorder
Original Paper | Batteries | 2026-08-23 20:00 EDT
Yangyang Si, Denan Li, Yijie Li, Changsheng Chen, Jingxuan Li, Chao Zhou, Hao Xiong, Tianfu Zhang, Wenjing Liao, Zhongqi Ren, Huaicheng Yuan, Dong Li, Jing-Kai Qin, Cheng-Yan Xu, Ye Zhu, Yunlong Tang, Sujit Das, Jieun Kim, Junling Wang, Hao Pan, Fei Li, Zhen Chen, Shi Liu, Zuhuang Chen
Cryogenic energy storage is crucial for the development of frontier nanoelectronics, including deep-space exploration (down to 90 K) and quantum computing (≤4 K). However, conventional electrochemical energy storage systems (such as secondary batteries and electrochemical capacitors) underperform at temperatures below ∼230 K due to restricted ion mobility. Although relaxor-based dielectric capacitors provide high energy efficiency (>80%) above ∼200 K, the intrinsic freezing/growth of polar nanodomains (that is, nanometric regions with local electric polarization) in the extended cryogenic regime (<120 K) limits their practical applications due to deteriorated polarization hysteresis losses. Here we overcome this detrimental effect by engineering a unit-cell disordered dipole-glass state near the antiferroelectric-paraelectric phase boundary. The antiferroelectric-derived dipole glass introduces enhanced unit-cell-level complexity in dipole interactions, thereby suppressing long-range ferroelectric order. This nanoengineering approach enables very low polarization hysteresis operation (with an efficiency >88%) down to 4 K, delivering an energy density of 211 J cm-3 at 9 MV cm-1, stability over 108 charge/discharge cycles and microsecond-scale charge/discharge capability. This work introduces a dipole-glass paradigm that enables control of polar disorder at the unit-cell level, providing insights into the technology development of highly efficient energy storage systems with broad applications.
Batteries, Energy storage, Ferroelectrics and multiferroics, Materials for energy and catalysis, Supercapacitors
Nature Physics
Real-space imaging of moiré-confined excitons in twisted bilayer MoS2
Original Paper | Electronic properties and materials | 2026-08-23 20:00 EDT
Laurens J. M. Westenberg, Lumen Eek, Jort D. Verbakel, Kevin Vonk, Stijn J. H. Borggreve, Kenji Watanabe, Takashi Taniguchi, Paul de Boeij, Rodrigo Arouca, Cristiane Morais Smith, Pantelis Bampoulis
Twisted two-dimensional semiconductors generate a moiré landscape that confines excitons–bound electron-hole pairs–into programmable lattices, and this offers opportunities for efficient light sources, sensing and information processing. However, the real-space imaging of confined excitonic species within a moiré unit cell remains challenging; existing claims are mainly inferred from spatially averaged far-field signals that are intrinsically insufficient to resolve nanometre-scale variations. Here we resolve the site-selective confinement of moiré excitons in a 2° twisted bilayer MoS2 with nanometre resolution using room-temperature photocurrent atomic force microscopy. We show that direct and indirect excitons localize at different stacking registries of the moiré, with contrast governed by alignment between site-selective generation and confinement minima. A Wannier-based effective moiré-exciton model captures the measured energies and the moiré-induced localization of the exciton wavefunction. These species-specific, unit-cell-resolved measurements constrain the microscopic models of moiré excitons, provide benchmarks for excitonic order and establish a device-compatible route to engineering excitonic lattices in van der Waals heterostructures.
Electronic properties and materials, Two-dimensional materials
Decaying and expanding Erk gradients process memory of skeletal size during zebrafish fin regeneration
Original Paper | Biological physics | 2026-08-23 20:00 EDT
Ashley Rich, Ziqi Lu, Alessandro De Simone, Lucas Garcia, Jacqueline Janssen, Kazunori Ando, Jianhong Ou, Massimo Vergassola, Kenneth D. Poss, Stefano Di Talia
Amputated salamander limbs or fish fins precisely regenerate to their pre-injury size, providing a paradigm for positional memory. Although this phenomenon has been appreciated for centuries, how position-dependent cues control tissue growth remains unresolved. Here we quantify extracellular signal-regulated kinase (Erk) activity in whole populations of osteoblasts during zebrafish fin regeneration. We show that Erk activity scales with the amount of amputated tissue, predicts the likelihood of osteoblast cycling and predicts the size of regenerated skeletal structures. We find that osteoblast Erk activity depends on fibroblast growth factor receptor signalling and organizes into millimetre-long gradients spanning from the distal tip to the amputation site. Mathematical modelling suggests gradients are established by acute, distally restricted deposition of ligand, whose activity is long-lived and transported by tissue growth. This mechanism is supported by the observed scaling of the expression of essential epidermal ligand Fgf20a with extents of amputation. Our work provides evidence that the localized, scaled expression of pro-regenerative ligands instructs long-range signalling and cycling to control size in regenerating appendages.
Biological physics, Biophysics
arXiv
Criticality in Neural Network Function Space through Wilsonian Fixed Points and Finite-Width Corrections
New Submission | Disordered Systems and Neural Networks (cond-mat.dis-nn) | 2026-08-24 20:00 EDT
Eric Howard, Iftekher S. Chowdhury, Hardique Dasore, Hom Nath Dhungana
Neural networks can be studied not only as parameterized computational models but also as probability distributions over functions. In this paper we develop a Wilsonian interpretation of criticality in the neural network-quantum field theory correspondence, treating the infinite width Gaussian-process limit as a free field fixed point and finite width corrections as perturbations that create non-Gaussian interactions. In this way, we do not see the departure from infinite width as a small approximation error but as the process by which interaction, complexity, expressivity and phase-like behaviour enter neural network function space. Width, depth, activation nonlinearity, initialization variance, and training dynamics are considered as control parameters that change the effective action of the network ensemble. The critical regime is when the higher-order connected correlation functions become non-negligible, and when the finite width operators become relevant or marginal scaling factors, and when the function distribution becomes sensitive to scale-dependent structure. There we can view overparameterization as suppressing a relationship of interacting terms and we find that the critical structure of finite neural networks is given by finite-width effects. This framework is a theoretical basis for studying trainability, generalization, and architectural universality of neural network functions through Wilsonian fixed points, perturbations, and critical surfaces.
Disordered Systems and Neural Networks (cond-mat.dis-nn), Quantum Physics (quant-ph)
30 pages, 16 figures, presented at the 3rd International Conference Mathematical Analysis and Applications in Science and Engineering (ICMASC) 2026 Conference, Portugal
Robust Discovery of Coarse-Grained Continuum Equations from Microscopic Dynamics
New Submission | Soft Condensed Matter (cond-mat.soft) | 2026-08-24 20:00 EDT
Partha Sarathi Mondal, Manav Kumar Jalan, Anish Kumar, Shradha Mishra
The discovery of governing partial differential equations (PDEs) directly from spatiotemporal data has emerged as a powerful tool for understanding the dynamics of complex systems. In this work, we apply PDE-SINDy to well-known phase-separating systems and examine how its performance depends on the amount of available data, the size of the function library, and the presence of noise. Our results show that the accuracy of equation discovery depends strongly on the amount of available data. Although the correct equation can be identified with limited data, several spurious terms also acquire finite selection probabilities. As the amount of data increases, these spurious terms are progressively suppressed, leading to a more robust identification of the governing equation. In contrast, increasing the size of the function library adversely affects the efficiency of equation discovery. Further, for the Glauber spin-flip Ising model, we show that the selection probabilities reveal a hierarchy of equations with varying levels of complexity. A sufficiently stringent selection threshold recovers a Model-A-like dynamical equation that accurately reproduces the dynamical and statistical features of phase separation and domain growth.
Soft Condensed Matter (cond-mat.soft), Statistical Mechanics (cond-mat.stat-mech), Machine Learning (cs.LG)
14 pages, 12 figures
Centipede-Like Metastrip Enables On-Demand Programmable Droplet Motion
New Submission | Soft Condensed Matter (cond-mat.soft) | 2026-08-24 20:00 EDT
Sergio Britto, Stefano Gonella
We demonstrate programmable, frequency-tunable and size-selective drop motion on an elastic metastrip substrate with a centipede-like array of cantilever resonators. Under harmonic excitation, the strip experiences simultaneously an in-plane (IP) collective motion and out-of-plane (OOP) deformation, thus establishing a frequency-dependent IP-OOP phase landscape. This prescribes the direction of motion to the drops on the strip based on their position, causing the emergence of clustering and rarefaction regions. By tuning the tip masses of the resonators, we open reconfigurable OOP bandgaps that modify the IP-OOP phase makeup and locally suppress drop motion, contributing an additional layer of spatial selectivity. Using multi-frequency excitations, we selectively actuate drops based on their resonances, effectively filtering them by volume and position.
Soft Condensed Matter (cond-mat.soft), Materials Science (cond-mat.mtrl-sci)
6 pages, 4 figures
Graphon Spin Systems as Exactly Solvable Models
New Submission | Disordered Systems and Neural Networks (cond-mat.dis-nn) | 2026-08-24 20:00 EDT
Artem Alexandrov, Georgi S. Medvedev
Graphons are measurable functions used to describe the asymptotic behavior of convergent graph families. Originally motivated by problems in combinatorics and graph theory, graphons have found numerous applications in the modeling and analysis of dynamical processes on networks.
In this work, we use graphons to formulate the Ising model on convergent graph sequences, which include many network topologies common in applications. We derive the mean-field limit for the resulting model and obtain exact results for phase transitions in such systems. Specifically, we show that the critical temperatures of the Ising model on graphons are determined by the eigenvalues of the Hilbert-Schmidt operator associated with the graph limit. For many important network topologies, these eigenvalues can be computed explicitly.
We illustrate our results with three representative random network models: Erdős-Rényi, small-world, and power-law. In the small-world case, we demonstrate phase transitions to both ferromagnetic and antiferromagnetic phases, as well as coexistence of local minima of the free energy. The latter gives rise to multistability, as confirmed by Monte Carlo simulations.
The results of this work demonstrate that the Ising model on graphons combines the analytical tractability of exactly solvable mean-field models with the ability to accommodate a broad range of network topologies. We expect that the use of graphons in spin models will lead to new insights into the statistical physics of interacting systems on complex networks.
Disordered Systems and Neural Networks (cond-mat.dis-nn), Mathematical Physics (math-ph)
Modelling the onset and evolution of immiscible viscous fingering in porous media
New Submission | Soft Condensed Matter (cond-mat.soft) | 2026-08-24 20:00 EDT
Paulo L. K. Caetano Chang, Kundan Kumar, Arne Skauge, Kenneth S. Sorbie
The simulation of viscous fingering in porous media is of direct relevance to displacement processes in petroleum engineering and hydrogeology. Building on recent work proposing a modelling approach for well-defined fingers at very adverse viscosity ratios, we investigate the physical mechanisms behind viscous fingering and the modelling requirements for capturing the finger scales and saturation patterns observed in experiments. We simulate and match a viscous fingering experiment at a viscosity ratio of $ \mu_{o}/\mu_{w}{=}2000$ , discussing the physical significance of each modelling step. Linear stability analysis is used to characterize the early-stage instability of the displacement. Subsequent numerical simulations show that, for the simulated finger scales to match the experiment, the most unstable wavelength at onset must be several times smaller than the desired finger width—so that, after accounting for shielding and merging in the nonlinear regime, the fingers remain thin. Small-scale channelling effects are also required to disrupt the trailing stable region commonly observed in simulations of viscous fingering in nearly homogeneous media. Finally, we show that including a weakly oil-wet capillary pressure function enables our model to capture the bypassed oil observed in the experiment.
Soft Condensed Matter (cond-mat.soft)
One-dimensional Polar Spinor Droplets
New Submission | Quantum Gases (cond-mat.quant-gas) | 2026-08-24 20:00 EDT
Hao Zhu, Wen-Kai Bai, Yi-Ran Shen, Xiao-Fei Zhang, Wu-Ming Liu, Boris A. Malomed
We derive a channel-resolved Lee-Huang-Yang correction and construct an extended GrossPitaevskii model for one-dimensional polar spin-1 quantum droplets. The fluctuation contribution separates into density and spin channels, which supports self-bound droplets even when the spinindependent mean-field interaction is repulsive. Stationary solutions exhibit a continuous crossover from soliton-like to flat-top droplets, accompanied by saturation of the chemical potential and peak density as the particle number increases. Within the parameter range examined here, linear Bogoliubov analysis together with weak-perturbation dynamics supports the stability of both droplet types. A quadratic-Zeeman quench reveals a finite-size crossover in breathing dynamics and distinct nonequilibrium roles of the density and spin fluctuation channels. Representative head-on collisions further show that the finite-size crossover modulates phase-sensitive nonlinear scattering, with in-phase impact producing coalescence-like central retention and out-of-phase impact favoring quasi-elastic separation. The analysis clarifies how density and spin fluctuations shape equilibrium structure and nonequilibrium response in low-dimensional polar spinor droplets.
Quantum Gases (cond-mat.quant-gas)
to be published on Physical Review A
Revisiting the hydromechanical formulation of a micromechanics-based phase-field model for poro-elastoplastic media
New Submission | Soft Condensed Matter (cond-mat.soft) | 2026-08-24 20:00 EDT
Hanzhang Li, Tao You, Keita Yoshioka, Yuhao Liu, Yi Rui, Fengshou Zhang
Even for tension-dominated fracture propagation, porous materials may deform plastically adjacent to the propagating fracture. As is common for porous materials, existing phase-field models typically employ a non-associative flow rule for plasticity, and a Helmholtz free energy based on strain and fluid pressure. This work revisits the hydromechanically coupled formulation of the phase-field model for fracture in poro-elastoplastic media by analyzing the strength surface and fracture driving force. Our analyses show that these common choices of flow rule and free energy will lead to a discontinuous strength surface across the tension-compression transition. A non-associative flow rule introduces a jump at the strength surface, while treating fluid pressure-rather than fluid content-as the independent variable in the Helmholtz free energy omits a coupling term from the phase-field driving force, also breaking continuity. Incorporating an associative Drucker-Prager flow rule and this omitted coupling term ensures a continuous strength surface and the accurate fracture driving force. The proposed model exhibits improved accuracy in hydromechanical responses when compared against the analytical solution of the Kristianovich-Geertsma-de Klerk hydraulic fracturing benchmark. Numerical simulations of hydraulic fracturing and biaxial compression in poro-elastoplastic media show that the model can reproduce both shear-dominated fractures induced by mechanical disturbance and tension-dominated fractures driven by fluid injection in saturated porous media.
Soft Condensed Matter (cond-mat.soft), Mathematical Physics (math-ph), Geophysics (physics.geo-ph)
34 pages, 14 figures
Conservation capacity of local learning rules in physical networks
New Submission | Disordered Systems and Neural Networks (cond-mat.dis-nn) | 2026-08-24 20:00 EDT
How many memories can a local learning rule protect, and what fixes the number? Physical learning rules train resistive networks through local measurements, and the standard rules conserve a mass-like function of the conductances, a law whose general form was posed as an open problem with the expectation that no useful solution theory exists. We answer it, in the direction the expectation ran against, and the answer is a capacity theory. The Tellegen identity behind the conserved mass localizes: the feedback state is pinned to zero at the inputs, so every sector of the circuit that the input electrodes separate carries its own private conserved mass, by an argument consuming only Kirchhoff’s law and that boundary condition, hence valid for arbitrary nonlinear branch laws. The number of independent sector masses is a topological property of the circuit, bounded by the number of output electrodes. An untrainable element can destroy the mass of its own sector and of no other, which says where fixed nonlinear components may be placed; per-edge learning rates select which functionals are conserved and never how many; and adjoint coupled learning, which clamps its outputs before measuring, drains every output-carrying sector at a rate set by the squared output multipliers. In linear circuits we then classify the identities: exact rational computation over all 502 circuits on up to five vertices with two inputs and one or two outputs, and hundreds of larger ones, yields a closed-form count, proved on that family and conjectured in general, with the sector statement a theorem at every circuit size. The anticipated series-parallel polynomial laws appear as exactly the series-class cubic differences, and the number the opening question asks for is a budget: one designed mass per sector, the differences the topology donates, and one broadcast scalar for each protected functional beyond.
Disordered Systems and Neural Networks (cond-mat.dis-nn), Soft Condensed Matter (cond-mat.soft)
9 pages, 2 figures
An LLM agent for end-to-end computational materials discovery
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-08-24 20:00 EDT
Chen Yuntong, Huang Ju, Liu Yu, Zhao Dan, Sun Mingqi, Ju Chentian, Liu Yanbing, Huang Lijiang, Zhao Guobin
The coordination of multi-scale tasks is an effective strategy for computational materials discovery, yet the repeated application of diverse algorithms and tools renders it challenging. We report MAESTRO, a large language model (LLM) agent system capable of executing the entire screening pipeline for metal-organic frameworks (MOFs). It processes a large body of MOF literature, links relevant publications to their crystal structures, and curates the results into a computation-ready database, which is then screened through a strategy of progressively increasing computational cost. The promising candidates identified for separation under wet flue gas conditions all originate from unrelated studies. By connecting the heterogeneous stages of computational materials discovery, the LLM-based agents of MAESTRO can operate across application domains and uncover high-performance materials that conventional screening approaches would be unlikely to consider.
Materials Science (cond-mat.mtrl-sci), Artificial Intelligence (cs.AI)
The friction-era VOS amplitude of a $\mathbb{Z}_2$ string network from nematic disclination data
New Submission | Soft Condensed Matter (cond-mat.soft) | 2026-08-24 20:00 EDT
Dimitrios Efstratiou, Evangelos Achilleas Paraskevas, Leandros Perivolaropoulos
A tangle of line defects coarsens as the mean spacing $ L$ between neighbouring lines grows. In a viscous medium the motion is overdamped, and the velocity-dependent one-scale (VOS) model predicts a late-time attractor $ L^{2}=\mathcal{A},\ell_d,t$ , with $ \ell_d=T/\Gamma$ the ratio of line tension to drag and $ \mathcal{A}$ a dimensionless amplitude. The growth law $ L\propto t^{1/2}$ holds for every value of the three model parameters—the momentum parameter $ k\le1$ , the sink coefficient $ \tilde{c}$ , and the curvature ratio $ \lambda\equiv R/L$ —since all three enter only through $ \mathcal{A}=\kappa(\kappa+\tilde{c})$ , $ \kappa\equiv k/\lambda$ . Thus, the exponent constrains none of them, and the amplitude is the only quantity a density history can deliver. We measure it from the disclination data of Chuang, Turok and Yurke on a nematic liquid crystal, whose companion measurement of loop collapse fixes $ \ell_d$ on the same samples, canceling the 5CB material constants. Treating the unmatched per-quench $ \ell_d$ as a nuisance parameter with a Gaussian prior and marginalizing it analytically, we obtain $ \mathcal{A}=10.0^{+1.3}{-1.1}$ from the three quenches in the $ 234\mu$ m cell; the fourth, the only one in the thinner $ 158\mu$ m cell, gives $ \mathcal{A}=3.0^{+0.8}{-0.6}$ and is fitted separately. Converting either into $ \tilde{c}$ requires $ \lambda$ , which these data do not determine, so the result is a curve, $ \tilde{c}(\lambda)=\mathcal{A}\lambda/k-k/\lambda$ , not a number. At $ \lambda=1$ with $ k\le1$ they give $ \tilde{c}\ge9.0$ and $ \tilde{c}\ge2.0$ , against $ \tilde{c}=0.23$ –$ 0.57$ from relativistic $ U(1)$ simulations, values reached only at $ \lambda\simeq0.33$ –$ 0.35$ and $ 0.62$ –$ 0.68$ . We know of no VOS calibration for a cosmological $ \mathbb{Z}_2$ network, so we cannot attribute the excess to topology, and we list what a repeat experiment must measure.
Soft Condensed Matter (cond-mat.soft), High Energy Physics - Phenomenology (hep-ph), High Energy Physics - Theory (hep-th)
16 pages, 6 figures, the numerical analysis files for the production of the figures can be found in the following github repository: this https URL
Self-limiting electrostriction of a single ion in an ultracold polar gas: From mesoscopic ions to crystalline molecular rings
New Submission | Quantum Gases (cond-mat.quant-gas) | 2026-08-24 20:00 EDT
Ruiren Shi, Saajid Chowdhury, Leon Karpa, Jesús Pérez-Ríos
We investigate the self-assembly of polar molecules around a single ion immersed in an ultracold, dilute two-dimensional molecular gas. The ion aligns and attracts the molecules through charge-dipole interactions, producing a strong electrostrictive accumulation around the impurity, while intermolecular repulsion limits further densification and favors spatially extended configurations. By combining global optimization with diffusion Monte Carlo, we calculate the evaporation energy as a function of the number of molecules bound to the ion. In contrast to conventional charged and van der Waals clusters, the evaporation energy exhibits a plateau-like dependence on cluster size, reflecting the sequential formation of concentric molecular rings. These structures are governed by the topology of the ion’s electric field and by the competition between attractive ion-molecule interactions, repulsive intra-ring interactions, and attractive correlations between neighboring rings, rather than by conventional coordination or icosahedral packing. In the weak-interaction regime, the resulting structures form extended mesoscopic molecular ions, whereas stronger interactions produce increasingly rigid, crystal-like molecular rings. We further analyze their stability against thermal perturbations and the time-dependent ion trap and find that a broad range of clusters remain stable under experimentally relevant conditions. The intermolecular repulsion and dipolar geometry also suppress close-range ion-molecule encounters, suggesting an intrinsic shielding mechanism. Our results establish ion-bound polar-molecule clusters as a distinct class of mesoscopic molecular ions and open a route to studying charged impurities in quantum baths with anisotropic interactions.
Quantum Gases (cond-mat.quant-gas), Atomic and Molecular Clusters (physics.atm-clus), Atomic Physics (physics.atom-ph)
18 pages, 13 figures
Carrier Capture at Defects from Finite-Temperature Lattice Dynamics
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-08-24 20:00 EDT
Menglin Huang, Shanshan Wang, Shiyou Chen
Defect-assisted carrier capture is commonly described within nonradiative multiphonon (NMP) theory using normal modes of the equilibrium defect structure. This description becomes inadequate when finite-temperature lattice fluctuations explore configurations that cannot be represented by a fixed normal-mode basis. Here, we present a trajectory-based method for calculating carrier capture rate from first principles, which allows lattice relaxation and electron–lattice coupling matrix element to be reconstructed directly from correlation functions of finite-temperature lattice dynamics. For hole capture at C$ _\mathrm{N}$ in GaN within harmonic regime, the method reproduces static NMP results including mode mixing and agrees with experiment. For oxygen vacancy in SiO$ _2$ , by contrast, the thermally sampled potential energy surface is substantially softer than the zero-temperature normal-mode harmonic expansion, strongly modifying the lattice relaxation and electron–lattice coupling, and producing pronounced changes in both the capture coefficient and its temperature dependence. These results establish the finite-temperature configurational ensemble, rather than phonon occupations alone, as an essential ingredient of defect-assisted carrier capture.
Materials Science (cond-mat.mtrl-sci)
Quantum critical behavior in chains of hindered dipolar planar rotors
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2026-08-24 20:00 EDT
Wenxue Zhang, Muhammad Shaeer Moeed, Estevao De Oliveira, Hui Li, Pierre-Nicholas Roy
We study the ground-state properties of linear chains of dipolar planar rotors hindered by a six-fold on-site potential, a model motivated by water molecules confined in the hexagonal cavities of beryl. Using density matrix renormalization group (DMRG) calculations, we locate the quantum phase transition between the disordered and ferroelectrically ordered phases using the von Neumann entanglement entropy and the Binder ratio of the polarization. A sweep of the six-fold pinning strength shows that increasing hindrance shifts the critical dipolar coupling gc to smaller values. These results suggest that crystal-field hindrance can promote, rather than suppress, dipolar ordering. This work has implications for ferroelectricity and quantum-device tuning in confined molecular rotors
Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Statistical Mechanics (cond-mat.stat-mech), Chemical Physics (physics.chem-ph)
Revealing the Role of Confined Molecular H$_2$ in the Passivation of Defective Silicon Using First-Principles Simulations
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-08-24 20:00 EDT
Hania Azzam (1 and 2), Tobias Binninger (1), Benedikt Fischer (3), Uwe Rau (3), Michael Eikerling (1 and 2) ((1) Theory and Computation of Energy Materials (IET-3), Forschungszentrum Jülich, 52425 Jülich, Germany, (2) Chair of Theory and Computation of Energy Materials, Faculty of Georesources and Materials Engineering, RWTH Aachen University, 52062 Aachen, Germany (3) Energy Materials and Devices - Photovoltaics (IMD-3), Forschungszentrum Jülich, 52425 Jülich, Germany)
The passivation of silicon dangling bonds by hydrogen is a crucial requirement for silicon-based optoelectronic technology, especially for solar cells. Recent experiments on intense light soaking of silicon heterojunction solar cells unveiled interesting dynamical aspects of hydrogen passivation that are linked to Si-H bond breaking and repassivation. These processes take place predominantly in porous regions near the amorphous/crystalline interface, where hydrogen can exist in molecular form. This work addresses the question of whether molecular H$ _2$ directly participates in Si-H depassivation and repassivation. Using density functional theory, we calculate and compare formation energies of point defects, multivacancy cavities and the Si(100) surface to identify relevant passivated and depassivated states. Furthermore, we employ nudged elastic band calculations to determine the activation barriers of the corresponding pathways. We find that sufficient local free volume enables a direct double-H pathway for depassivation through the formation of confined molecular H$ _2$ . Despite involving the breaking of two Si-H bonds, the double-H process can be energetically and kinetically competitive with the single-H process and can exhibit a reverse repassivation barrier as low as $ 0.15,$ eV under p-type conditions. These findings provide a plausible atomistic explanation for passivation recovery during light soaking and illuminated annealing in porous regions near amorphous/crystalline silicon interfaces.
Materials Science (cond-mat.mtrl-sci)
17 pages, 10 figures
$\mathcal{PT}$ and anti-$\mathcal{PT}$ phase transitions in a trimerized Su–Schrieffer–Heeger chain with nonreciprocal Rashba spin-orbit coupling
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2026-08-24 20:00 EDT
Milad Jangjan, Linhu Li, Longwen Zhou, Mir Vahid Hosseini
We theoretically investigate a one-dimensional trimerized Su–Schrieffer–Heeger chain with three sublattices per unit cell subjected to a nonreciprocal Rashba spin-orbit coupling. Invoking a spin-flip symmetry, the non-Hermitian Hamiltonian decomposes into two independent spin sectors, enabling a spin-resolved analysis of non-Hermitian skin effects and system symmetries. We identify a rich phase diagram consisting of four bulk phases and two edge-state phases. The bulk phases include fully $ \mathcal{PT}$ -unbroken (real-spectrum) and fully anti-$ \mathcal{PT}$ -unbroken (imaginary-spectrum) regimes, as well as two mixed phases where one band remains on the real or imaginary axis while the other two form complex-conjugate pairs. The two edge-state phases correspond to topological edge modes with either $ \mathcal{PT}$ -unbroken (real) or anti-$ \mathcal{PT}$ -unbroken (imaginary) energies. Using non-Bloch band theory and Cardano’s method, we derive closed-form expressions for phase boundaries and establish the bulk-edge correspondence for each spin sector. Calculations of Berry phase and directional inverse participation ratios confirm our analytical predictions. Our results provide a minimal platform for realizing spin-resolved non-Hermitian topology and edge-selective symmetry preservation, in which the bulk and edge states belong to distinct symmetry classes.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Quantum Physics (quant-ph)
17 pages, 7 figures
Photon-mediated thermodynamics and density fluctuations in an ensemble of laser-cooled Cesium atoms
New Submission | Quantum Gases (cond-mat.quant-gas) | 2026-08-24 20:00 EDT
Arnab Ghosh, Inderpreet Kaur, Hemant Yadav, Shiva Kant Dwivedi, R Shanmukesh, Mithun Thudiyangal, Matthew J. Davis, Bodhaditya Santra
We present an experimental study of detuning-dependent properties of a laser-cooled cesium cloud in a magneto-optical trap. Fluorescence images are used to extract the cloud size, shot-to-shot width fluctuations, optical depth, density profiles, and spatial density fluctuation spectra as the trapping-laser detuning is varied. Near resonance, the cloud exhibits larger spatial extent, increased width fluctuations, higher optical depth, and enhanced density-fluctuation power, while larger detunings produce a more reproducible and spatially confined cloud. The measured density profiles are analysed phenomenologically using a generalized Lane-Emden model with a polytropic equation of state, yielding detuning-dependent effective fit parameters in a weak-interaction regime. Power-spectrum and autocorrelation analyses reveal reproducible scale-dependent density correlations. The results provide a quantitative characterization of detuning-dependent radiative and collective effects in a cesium MOT and establish a basis for future measurements that can more directly test nonequilibrium transport and photon-mediated interaction models.
Quantum Gases (cond-mat.quant-gas)
Interplay of nonrelativistic and relativistic spin splittings in altermagnets
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-08-24 20:00 EDT
Daegeun Jo, Peter M. Oppeneer, Mohsen Yarmohammadi
Despite their compensated magnetic moments, altermagnets (AMs) exhibit nonrelativistic spin splitting (NRSS) that offers routes to spintronic functionality without relying on relativistic spin-orbit coupling. However, how NRSS influences relativistic phenomena remains largely unexplored. Here we show that NRSS plays a crucial role in reshaping the Rashba effect in AMs with broken inversion symmetry. Using a tight-binding model, we demonstrate that Rashba spin splitting, whose magnitude is typically limited by the strength of spin-orbit coupling, is governed by NRSS energy scales. The resulting Rashba bands combined with NRSS generate anomalously large charge-to-spin conversion with a Néel-vector-tunable spin polarization. First-principles calculations for the noncentrosymmetric AM GdAlSi corroborate the emergence of these effects in a real system. Our results reveal the interplay between nonrelativistic and relativistic effects in AMs and identify them as fertile platforms for spin-orbitronic applications.
Materials Science (cond-mat.mtrl-sci), Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
Perspectives on Magnetic/Superconductor Hybrid Systems: Long-range Electromagnetic Phenomena Induced by Proximity Effect and Interfacial Spin-orbit Coupling
New Submission | Superconductivity (cond-mat.supr-con) | 2026-08-24 20:00 EDT
S. V. Mironov, A. S. Mel’nikov, A. I. Buzdin
In this Perspective we review recent achievements in physics and applications of hybrid superconductor-ferromagnet structures. In particular, we focus on the manifestations of the electromagnetic phenomena in these systems originating from the response of the induced superconducting correlations modified by the exchange field and additional effects coming from the interface Rashba-type spin-orbit coupling. The review includes the long-range electromagnetic proximity effect and related modification of magnetic textures, spontaneous currents, properties of vortex matter and its interaction with magnetic ordering, spin-galvanic, photogalvanic and nonreciprocal transport phenomena in exemplary hybrid systems. We also present our views on the future development of this field including both the theoretical challenges and promising opportunities for fundamental experiments.
Superconductivity (cond-mat.supr-con)
Published in Journal of Applied Physics, original version of the paper before copyediting, 21 pages, 16 figures
J. Appl. Phys. 140, 070901 (2026)
Reversing strain deformations probe mechanisms for enhanced segmental mobility of polymer glasses
New Submission | Soft Condensed Matter (cond-mat.soft) | 2026-08-24 20:00 EDT
Optical probe reorientation measurements were performed to monitor changes in segmental dynamics resulting from the nonlinear deformation of a polymer glass. Segmental dynamics were monitored in a poly(methyl methacrylate) glass near Tg before and after a series of reversing deformations in which the sample was extended at constant strain rate and then allowed to retract back to zero stress at constant strain rate. Evidence of a rejuvenation mechanism, as quantified by a departure of the segmental dynamics from the quiescent aging dynamics after the reversing deformation, is observed for deformations which reach 60% of the yield strain or greater. By this measure, a saturation of the rejuvenation mechanism is not observed until at least five times the yield strain. For comparison, purely mechanical measurements of rejuvenation, based upon the reduction of the yield stress in a subsequent deformation, were also performed. These purely mechanical experiments show broad qualitative agreement with the probe reorientation experiments, but quantitatively differ in the pre-yield regime. The results are discussed in the context of recent theoretical approaches and simulations which provide a molecular-level description of polymer glass deformation.
Soft Condensed Matter (cond-mat.soft), Materials Science (cond-mat.mtrl-sci)
41 pages, 6 figures, 57 references
Macromolecules 2017, 50, 1016-1026
A non-local power-law baseline for transient flux penetration in YBCO films: parameter degeneracy and constitutive limitations
New Submission | Superconductivity (cond-mat.supr-con) | 2026-08-24 20:00 EDT
O. A. Hernández-Flores, C. Romero-Salazar, F. Pérez-Rodr'ıguez
We assess whether a non-local thin-film model with a bounded, constant-exponent power law can reproduce high-speed magneto-optical measurements of transient flux penetration in a $ 3\times3$ mm$ ^2$ YBa$ _2$ Cu$ _3$ O$ _{7-\delta}$ film. The model is solved forward in physical units and used as a controlled constitutive baseline. The critical sheet current is constrained by the final penetration geometry, while the criterion field and creep exponent are constrained by the turnover and relaxation times. The calibration reveals an intrinsic degeneracy: the turnover time depends primarily on the product of the criterion field and saturation parameter, equivalently on the saturated sheet resistivity, so these quantities cannot be identified independently. After parameterizing this degeneracy, the model captures a guarded-current turnover near 22ms, a relaxation constant of 41.2ms compared with the measured 37.5 and 43.7ms, and a late maximum approximately 0.92~mm from the film edge. The amplitude remains discrepant: the calculated transient maximum is $ 1.90J_{c0}$ and the peak-to-225-ms ratio is 2.13, compared with the reported 1.20. This excess persists under changes in the creep exponent, the degenerate parameter direction, the Kim field dependence, and mesh resolution. Matching the measured ratio through the criterion field would require a value about three orders of magnitude below the conventional scale, while spatial exclusion sufficient to match it would remove the edge peak itself. We also decompose the electric field into irrotational and solenoidal parts and quantify the boundary layer where spectral and finite-difference forms of Faraday’s law disagree. The results establish a reproducible non-local power-law baseline and identify limitations of the bounded, constant-exponent constitutive family rather than of non-local thin-film electrodynamics.
Superconductivity (cond-mat.supr-con)
12 pages, 5 figures
Highly organized smectic-like packing in vapor-deposited glasses of a liquid crystal
New Submission | Soft Condensed Matter (cond-mat.soft) | 2026-08-24 20:00 EDT
Ankit Gujral, Jaritza Gomez, Jing Jiang, Chengbin Huang, Kathryn A. OHara, Michael F. Toney, Michael L. Chabinyc, Lian Yu, M.D. Ediger
Glasses of a model smectic liquid crystal-forming molecule, itraconazole, were prepared by vapor deposition onto substrates with temperatures ranging from Tsubstrate = 0.78 Tg to 1.02 Tg, where Tg = 330 K is the glass transition temperature. The films were characterized using x-ray scattering techniques. For Tsubstrate near and below Tg, glasses with layered smectic-like structures can be prepared and the layer spacing can be tuned by 16% through choice of Tsubstrate. Remarkably, glasses prepared with Tsubstrate above Tg exhibit much higher structural organization than a thermally annealed film. These results are explained by a mechanism based upon preferred molecular orientation and enhanced molecular motion at the free surface, indicating that molecular organization in the glass is independent of the anchoring preferred at the substrate. These results suggest new strategies of optimizing molecular packing within active layers of organic electronic and optoelectronic devices.
Soft Condensed Matter (cond-mat.soft), Materials Science (cond-mat.mtrl-sci)
7 figures, 50 references, 35 pages; Supplemental information (3 figures)
Chem. Mater. 2017, 29, 849-858
A molecular perspective on the yield and flow of polymer glasses: The role of enhanced segmental dynamics during active deformation
New Submission | Soft Condensed Matter (cond-mat.soft) | 2026-08-24 20:00 EDT
The mechanical properties of polymer glasses are often critical in determining the best material for a particular application. Extremely stiff materials (high modulus) may be important for some applications while avoiding catastrophic failure due to fracture (high toughness) may be more important for others. The mechanical properties of a polymer glass will depend upon both molecular structure and many experimental variables, including temperature and the mode of deformation (tension, compression, or shear). In this chapter we discuss the mechanical response of polymer glasses from a molecular perspective. In particular, we consider how deformation changes the rate at which polymer segments rearrange and how this in turn influences the mechanical response of the material. It will be shown that this focus on the changes in dynamics provides an understanding of many important features of polymer glass deformation. Of course, it is also true that the structure of a polymer glass must be altered by nonlinear deformation. Although not a major focus, we will make some comments about these structural changes at the end of this chapter.
Soft Condensed Matter (cond-mat.soft), Materials Science (cond-mat.mtrl-sci)
12 figures, 65 references, 43 pages
Chapter 10 in Polymer Glasses, edited by Connie Roth (Taylor and Francis) (2016) CRC Press. ISBN 9781498711876
Interband plasmons due to Mexican hat dispersion in two-dimensional materials with inverted bands
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2026-08-24 20:00 EDT
Two-dimensional topological materials with Mexican-hat dispersion exhibit numerous nontrivial features, such as double-valued isoenergetic contours in k-space, strong mixing of electron and hole states, a van Hove singularity in the density of states, and specific quantum geometric properties. We find that, due to these features, Mexican-hat dispersion significantly strengthens interband plasmons, reduces their damping, and gives rise to an additional branch of the plasmon spectrum when electron-hole symmetry is broken. The plasmon spectra are limited to a finite range of the wave vector, the boundaries of which depend on the strength of the electron-electron interaction. We also reveal a relationship between the features of the plasmon spectrum and singularities of the joint density of states with a finite plasmon wave vector q, as well as features of the interband quantum metric, which also depend on q.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
12 pages, 12 figures
Physica E: Low-dimensional Systems and Nanostructures, 2026, 116638
AutoMOOSE: Use Case and Logical Views of Agentic Phase-Field Simulation Software
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-08-24 20:00 EDT
Sukriti Manna, Henry Chan, Subramanian Sankaranarayanan
AutoMOOSE is an agentic software framework that converts a natural-language request into an executed, screened, and interpreted MOOSE phase-field simulation. Here, we deploy AutoMOOSE as a agentic software, complementing our prior work which focused on development of the agentic tool. We describe our software framework and architecture through Use Case and logical views of the 1+5 architectural-views model, covering its user roles, component structure, six-agent pipeline, physics plugin layer, Model Context Protocol interface, and screening/falsification/recovery loop. Our architecture separates physical falsification from automatic repair, so corrected simulations remain inspectable and must be re-admitted before acceptance. We focus on software design, extensibility, interoperability, and reuse of the AutoMoose framework for broad utilization in multiphysics materials design problems.
Materials Science (cond-mat.mtrl-sci), Software Engineering (cs.SE)
Machine Learning Guided Discovery of Corundum High Entropy Oxides
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-08-24 20:00 EDT
Abraham A. Mancilla, Oliver A. Dicks, Solveig S. Aamlid, Mario Ulises González-Rivas, Karl Tsang, Dongjoon Song, Jörg Rottler, Alannah M. Hallas
Early thinking in the field of high entropy oxides (HEOs) emphasized their likely abundance, with combinatorial arguments hinting at a myriad of new materials. The experimental reality has proven more challenging: the stability of HEOs cannot be straightforwardly predicted based on ionic radii, lattice geometry, and charge-balancing considerations alone. In this work, we employ machine learning interatomic potentials (MLIPs) to predict the synthesizability of HEOs of the form $ A_2$ O$ _3$ derived from a selection of trivalent cations. From nearly 500 possible compositions, we identify 16 promising candidates for experimental validation with solid-state and combustion synthesis. We discover three new HEOs in the corundum structure, including (Al,Cr,Fe,Rh,Sc)$ _2$ O$ _3$ , and one novel cation-ordered phase, (Al,Fe,Ga,Sc)$ _2$ O$ _3$ . By far the most common synthesis outcome was a mixture of competing phases, sometimes involving redox reactions. Our results also reveal profound synthesis method dependence for the final product, where qualitatively equivalent outcomes between the two synthesis methods were only observed for 3 of the 16 tested compositions. We conclude that the occurrence rate of HEOs is far rarer than initially believed and that machine learning approaches can effectively guide us to the “needle in the haystack”.
Materials Science (cond-mat.mtrl-sci)
Note on proliferation transitions of non-Abelian anyons
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2026-08-24 20:00 EDT
We study phase transitions out of a (2+1)d topological phase driven by the proliferation of anyons in a braided fusion subcategory. We describe a general theoretical framework for such transitions, in which the topological quantum field theory (TQFT) is coupled to dynamical matter associated with anyons in the subcategory. We interpret this construction using symmetry topological field theory (SymTFT), where the dynamics is localized on the symmetry boundary of the (3+1)d slab. We analyze several examples, and present explicit Chern-Simons-Higgs (CSH) field theories realizing the proliferation transitions. We also examine proliferation transitions that implement gauging of non-invertible one-form symmetry in the parent TQFT. This includes a general construction for $ {\rm Rep}(G)$ one-form symmetry for a finite group $ G$ , and a CSH realization of the non-invertible one-form gauging $ {\rm SU}(2)_{10}\rightarrow {\rm Spin}(5)_1$ . We discuss which anyons proliferate at these transitions.
Strongly Correlated Electrons (cond-mat.str-el), High Energy Physics - Theory (hep-th)
Aging Phase Diagram and Exact Asymptotic Energies of Mixed Spherical Spin Glasses
New Submission | Disordered Systems and Neural Networks (cond-mat.dis-nn) | 2026-08-24 20:00 EDT
Johannes Lang, Vincenzo Citro, Luca Leuzzi, Federico Ricci-Tersenghi
We determine the aging phase diagram of mixed spherical $ (p+s)$ -spin glasses quenched from random configurations to zero temperature. Solving the asymptotic dynamical equations of Cugliandolo and Kurchan, we find transitions between aging states with one, two, and continuously many effective temperatures, including phases in which discrete and continuous hierarchies coexist. We obtain analytic expressions for the energies reached asymptotically by the dynamics. In models combining pairwise and higher-order interactions, and sufficiently separated interaction orders ($ s>3$ ), a fully continuous phase exists, where the gradient descent relaxation converges to the algorithmic energy lower bound. Instead, in mixed models with only high-order interactions ($ p\ge3$ ) the energy relaxation remains strictly above it. Numerical integration of the dynamical equations is consistent with the predicted two-step and mixed discrete–continuous aging states.
Disordered Systems and Neural Networks (cond-mat.dis-nn), Statistical Mechanics (cond-mat.stat-mech)
5 + 2 pages, 4 figures
Distinguishing Mott and strain-induced anisotropic semimetals in magic-angle twisted bilayer graphene using Landau level spectroscopy
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2026-08-24 20:00 EDT
Keshav Singh, Juan Felipe Mendez-Valderrama, Erez Berg, B. Andrei Bernevig, Oskar Vafek
Recent quantum twisting microscopy experiments [1] have provided unprecedented momentum- and energy-resolved imaging of magic-angle twisted bilayer graphene, revealing a stark dichotomy between the heavy and light electronic characters of its narrow bands. In this work, we provide a sharp distinguishing criterion between the two most likely candidate states that exhibit spectroscopic features consistent with the experimental results. Focusing on charge neutrality, these states are 1) the ‘Mott semimetal’, governed by strong dynamical correlations, and 2) the ‘strain-induced anisotropic semimetal’, characterized by weak Hartree-Fock effects. We demonstrate that an out-of- plane magnetic field serves as a sharp discriminating probe based on the expected Landau level gap size hierarchy. We find that the strain-induced anisotropic semimetal has a robust gap hierarchy where the Chern C gaps, \Delta_C , decrease in order \Delta_{\pm 4} > \Delta_{\pm 8} > \Delta_{\pm 12}. In contrast, for the Mott semimetal, \Delta_{\pm 4} remains the largest gap, while the relative magnitude of the C = \pm 8, \pm 12 gaps depends sensitively on the applied magnetic field. We test the robustness of these results against strain orientation and lattice relaxation finding consistency between the gap hierarchy of the strained semimetal and previous incompressibility measurements at finite magnetic field [2].
Strongly Correlated Electrons (cond-mat.str-el)
6+107 pages, 3+53 figures
Orbital-Selective Spin Splitting in the Altermagnetic Ti$_2$XX’ Monolayers
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-08-24 20:00 EDT
Altermagnets have attracted intensive attention recently, owing to their unique combination of zero net magnetic moment of antiferromagnets and momentum space spin-splitting of ferromagnets. Herein, we systematically explore monolayer altermagnetic Ti$ 2$ XX’ (X/X’ = F, Cl, Br, I) materials for novel electronic properties. Especifically, spin-splitting exists in the valence bands of all studied materials, whereas several compositions exhibit nearly spin-degenerate conduction bands near the Fermi level, which is markedly different from conventional altermagnets. This phenomenon can be attributed to the bond-angle-sensitive super-exchange occurring in the $ d{xz}$ or $ d_{yz}$ orbitals, while the super-exchange of the $ d_{x^2-y^2}$ orbital is not sensitive to the Ti-X-Ti bond angle. Motivated by this intriguing phenomenon, Fermi level modulation via doping or heterostructure construction enables the transition between two electronic states, endowing these materials great application potential in information storage devices.
Materials Science (cond-mat.mtrl-sci), Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
18 pages, 3 figures
Magnetic-Field Selection of Magnetic Order in Altermagnets and Noncollinear Antiferromagnets
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-08-24 20:00 EDT
Qiu-Shi Huang, Chaoxi Cui, Yilin Han, Junxi Duan, Zhi-Ming Yu, Yugui Yao
Conventional field selection of magnetic order relies on the Zeeman coupling, which, however, vanishes in magnets without net magnetization, a rapidly growing class including altermagnets (AMs), noncollinear antiferromagnets (nc-AFMs), and PT-symmetric antiferromagnets (PT-AFMs). Here we show that the quantity that fundamentally couples a magnet to a uniform magnetic field is not the magnetization, but the binary order parameter eta that labels the two time-reversal-related minima of the Landau free energy. We develop a Landau theory of order selection based on eta under the constraints of magnetic point-group (MPG) symmetry, in which eta couples to odd-degree polynomials in the magnetic field. Within this framework, the linear term is the ferromagnetic Zeeman coupling, while higher-order couplings with leading degree n = 3, 5, 7, and 9 naturally appear in AMs and nc-AFMs. In contrast, combined PT symmetry forbids any such coupling. Consequently, it is the order-(n-1) magnetic susceptibility, rather than the net magnetization, that serves as the primary experimental observable for identifying the magnetic order of AMs and nc-AFMs. For all 122 MPGs, we classify the leading coupling degree and the corresponding polynomial forms. We demonstrate our framework in two representative materials: the AM MnF2 and the nc-AFM MnTe2. We further construct a symmetry-allowed spin model for an AM system to reveal the microscopic origin of the higher-order coupling and establish the coupling coefficient explicitly in terms of the spin-model parameters. Our work unifies the description of magnetic-order selection across magnets with and without net magnetization, offers a microscopic origin for this counterintuitive physics, and provides fingerprints for distinguishing intrinsic field selection from extrinsic switching.
Materials Science (cond-mat.mtrl-sci)
Prediction of a layer nonlinear Hall effect in bilayer nonmagnetic or antiferromagnetic systems
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-08-24 20:00 EDT
Zehou Li, Shenda He, Pan Zhou, Baoru Pan, Rui Tan, Lizhong Sun
Nonlinear Hall effects provide a powerful probe of quantum geometry in solids and enable rectification phenomena beyond the constraints of linear response. In this Letter, we predict a \emph{layer nonlinear Hall effect} (LNHE) in stacked bilayer systems composed of nonmagnetic or antiferromagnetic materials with a vanishing linear Hall conductivity. In such systems, the second- or third-order nonlinear Hall responses are intrinsically layer odd: the contributions from the two constituent layers have equal magnitude but opposite sign, resulting in exact cancellation under layer-exchange symmetry. An out-of-plane electric field $ E_z$ can break this symmetry, thereby unveiling the hidden response and converting it into a switchable macroscopic nonlinear Hall signal. Using a minimal $ k!\cdot!p$ model, we demonstrate that the LNHE can originate from the Berry curvature dipole mechanism. A systematic symmetry analysis of all 80 layer groups further yields a complete classification of the symmetry constraints and stacking configurations that allow for this type of LNHE. Beyond this mechanism, additional symmetry analysis reveals that LNHE may also arise from quantum metric dipole or inversed mass dipole. Remarkably, even in cases where second-order nonlinear Hall responses are symmetry forbidden, a third-order LNHE can still survive in certain stacked bilayer configurations. First-principles calculations on representative bilayers—nonmagnetic 1T$ ‘$ -WTe$ _2$ and 1T$ ‘$ -ReS$ _2$ —explicitly demonstrate electrically reversible second-order LNHE, in full agreement with our symmetry-based predictions. Overall, our results establish LNHE as a universal phenomenon in a wide range of layered quantum materials and provide a robust route toward electrically tunable nonlinear transport.
Materials Science (cond-mat.mtrl-sci), Quantum Physics (quant-ph)
Two-dimensional percolation with algebraically decaying interactions II: Critical exponents in the long-range regime
New Submission | Statistical Mechanics (cond-mat.stat-mech) | 2026-08-24 20:00 EDT
Ziyu Liu, Tianning Xiao, Zhijie Fan, Youjin Deng
We present a comprehensive Monte Carlo study of two-dimensional bond percolation with algebraically decaying connection probabilities $ p(r)\propto 1/r^{2+\sigma}$ , establishing the universality diagram in the long-range (LR) regime for $ \sigma\le2$ . Using the event-based ensemble method, we simulate systems with linear sizes up to $ L=16384$ and investigate three universality regimes: LR Wilson–Fisher (WF) A ($ 1<\sigma\le2$ ), LR Wilson–Fisher B ($ 2/3<\sigma\le1$ ), and LR mean-field (MF) ($ 0<\sigma\le2/3$ ). In the LR-WF-B regime, the anomalous dimension is consistent with $ \eta=2-\sigma$ , in agreement with mathematical results for $ 2/3<\sigma<1$ , while the correlation-length exponent $ \nu(\sigma)$ exhibits nontrivial, non-Gaussian variation. In the LR-WF-A regime, although $ \eta$ remains close to $ 2-\sigma$ for smaller $ \sigma$ , statistically resolvable deviations $ \delta\eta(\sigma)=\eta-(2-\sigma)>0$ start to appear near $ \sigma\simeq3/2$ and grow toward the short-range crossover at $ \sigma=2$ . Finally, by complementing the event-based simulations with conventional ensemble simulations, we reveal the coexistence of complete-graph asymptotics and LR Gaussian-fixed-point scaling in the LR-MF regime. These results further clarify the critical properties in long-range percolation and provide crucial benchmarks for long-range statistical systems.
Statistical Mechanics (cond-mat.stat-mech)
14 pages, 7 figures
Quantum Wake Dynamics from Distinct Spectroscopic Perturbations
New Submission | Statistical Mechanics (cond-mat.stat-mech) | 2026-08-24 20:00 EDT
Umesh Kumar, Gonzalo Alvarez, David Alan Tennant, Satoshi Okamoto
Quantum wake dynamics in quantum magnets have recently been inferred from the dynamical spin structure factor, which probes only a restricted class of local perturbations. Here, we show that resonant inelastic x-ray scattering (RIXS) selection rules act as an operator filter on fractionalized excitations, producing distinct quantum wakes in the spin-$ \frac{1}{2}$ Heisenberg antiferromagnetic chain. Using explicit real-time evolution of single-spin and spin-conserving bond correlators, we find that the conventional spin response propagates up to the maximum spinon velocity, $ v_s=\frac{\pi}{2} J$ , whereas the bond channels concentrate their spectral weight into a slower dominant wake with $ v\simeq 0.92 J$ , while weaker components remain bounded by the full spinon light cone. The corresponding momentum- and frequency-resolved responses map onto experimentally accessible RIXS channels, demonstrating that different spectroscopic perturbations resolve complementary pathways of many-body propagation beyond the neutron-scattering spin structure factor. Their inelastic spectral weights further provide access to quantum Fisher information, while equal-time bond sum rules connect the same spectroscopic channels to the ground-state energy. Because the same correlators can be prepared and measured on quantum hardware, they also define direct, experimentally anchored benchmarks for quantum simulations, particularly in frustrated and higher-dimensional magnets where controlled classical real-time calculations become challenging.
Statistical Mechanics (cond-mat.stat-mech), Strongly Correlated Electrons (cond-mat.str-el)
7+6 pages, 4 figure
Planar Nanofluidic Memristors Enabled by Surface Charge Gradient
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2026-08-24 20:00 EDT
Zhongyuan Zhao, Ziyi Yin, Chudi Qi, Yuheng Li, Shoushan Fan, Qunqing Li, Yang Wei
Nanofluidic memristors, exploiting ion transport in nanochannels, hold promise for neuromorphic applications. A planar architecture is particularly desired for scalable integration with established micro- and nanofabrication technologies. Here, using the Poisson-Nernst-Planck framework, we theoretically propose planar nanofluidic memristors enabled by surface charge gradient, providing an alternative to the commonly used geometrically asymmetric architectures. The resulting memristive behavior is governed by a diffusion-mediated secondary enrichment effect. By systematically solving the PNP equations, we obtain the scaling of the characteristic memory time across the parameter space. We also reveal that the memory effect is related to the first-order moment of surface charge, for arbitrary charge profiles. These results provide a theoretical basis for rationally designing and optimizing planar nanofluidic memristors through spatially patterned surface charge.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
Main text: 7 pages, 4 figures. Supplementary material: 17 pages, 13 figures
An Informational Route to Negative Mobility
New Submission | Soft Condensed Matter (cond-mat.soft) | 2026-08-24 20:00 EDT
Ziluo Zhang, Shigeyuki Komura, Zhihong You
Mobility links an applied force to the resulting motion and is generally positive near equilibrium. Far from equilibrium, however, internal energy input can reverse this response. Here we show that information feedback provides a distinct route to negative mobility. We consider an overdamped dimer consisting of a run-and-tumble particle coupled by a spring to a passive Brownian particle. Information enters through periodic measurements of the relative displacement, which are processed to reset the active polarity. Although the unloaded dimer has no net drift, an applied force biases its internal configuration, and an information-mechanical feedback amplifies and converts this bias into active propulsion against the force, producing negative mobility. We develop an analytical theory that captures this mechanism and yields a feedback-gain criterion for response reversal. Including the information-processing cost reveals a tradeoff: rapid feedback enhances reverse transport but incurs a growing informational cost, yielding an optimal finite feedback rate for information-inclusive efficiency. These results show that information can reshape nonequilibrium response by controlling how internally supplied energy is converted into macroscopic transport.
Soft Condensed Matter (cond-mat.soft), Statistical Mechanics (cond-mat.stat-mech)
6 pages, 3 figures
Phase control of magnon-phonon coupling via magnetic field
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2026-08-24 20:00 EDT
Yasuhiro Todaka, Motoki Asano, Isamu Yasuda, Masashi Kawaguchi, Daiki Hatanaka, Masamitsu Hayashi
We study the phase of the coupling between magnons and surface acoustic wave (SAW) phonons in magnetic thin films. The coupling constant changes from a real to a complex number as the external magnetic field is reduced. Below a transition field, the imaginary coupling constant allows SAW phonons to couple to overdamped magnons whose resonance frequency is close to zero and far from the SAW resonance. The strength of the imaginary coupling constant and the magnitude of the transition field both scale with magnetic damping. We find the coupling produces a broad, pronounced minimum in the SAW transmittance spectrum near zero magnetic field in a Ni/Ru/Ni synthetic antiferromagnet with large magnetic damping. These results demonstrate that the phase of the complex magnon-phonon coupling constant can be tuned via magnetic field in strongly damped magnets, offering a platform to explore novel regimes of magnon-phonon interactions.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Materials Science (cond-mat.mtrl-sci)
First-principles design of main-group dimer defects in ZnO as candidate quantum defects
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-08-24 20:00 EDT
Taejoon Park, Erik Alfredo Perez, Shimin Zhang, Yuan Ping, Hosung Seo
Zinc oxide (ZnO), a wide-band-gap semiconductor with mature growth techniques, is a promising host for optically active quantum spins. Yet, optically active quantum defects in ZnO remain largely unexplored. Here, we identify and characterize a family of double substitutional impurities in ZnO, formed by main-group donor-acceptor (DA) pairs, as candidates for optically active quantum defects. Using hybrid density functional theory (DFT), we systematically investigate double substitutional DA complexes and their defect physics, including electronic structure, thermodynamic stability, and optical properties. The proposed defects exhibit isolated defect states, strong spin localization on the acceptor site, and $ C_{3v}$ symmetry. Importantly, the electronic structure of the DA pairs is largely determined by the atomic properties of their constituent atoms. We further examine their optical characteristics, including zero-phonon lines (ZPLs), radiative lifetimes, and nonradiative decay to assess their viability as color centers. Notably, among the dimers, (Si$ _{Zn}$ -B$ _O$ )$ ^+$ and (Ge$ _{Zn}$ -B$ _O$ )$ ^+$ exhibit visible optical transitions with sub-microsecond radiative lifetimes and robust charge states against optical ionization, while (Si$ _{Zn}$ -C$ _O$ )$ ^{2+}$ shows the smallest Huang-Rhys factor, approximately 5.6. Our results propose a new family of main-group donor-acceptor defects in ZnO as promising candidates for optically active spin defects.
Materials Science (cond-mat.mtrl-sci), Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Quantum Physics (quant-ph)
13 pages, 5 figures
Electronic Toroidal Metals: Landau Theory and Magnetoelectric Fingerprints
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2026-08-24 20:00 EDT
Toroidal order is a higher-rank multipolar order whose intrinsic realization in itinerant-electron systems remains unexplored. Here, we develop a generic theory of the electronic toroidal metal (ETM), in which toroidal order emerges spontaneously from electronic degrees of freedom near the Fermi surfaces. Because candidate toroidal bilinears can overlap by symmetry with the uniform charge current, we formulate a projected instability criterion that removes the noncondensable current component. Within this current-orthogonal sector, we identify a soft collective mode in the $ \mathcal{P}$ -odd and $ \mathcal{T}$ -odd particle-hole channel and demonstrate that ETM arises as a Fermi-liquid instability. We then define the toroidal moment in an itinerant system through the antisymmetric magnetoelectric response tensor. We further establish an intimate connection between this response and the topology of pseudospin texture: the rearrangement of pseudospin vortices changes the winding structure of the Fermi surfaces and markedly enhances the magnetoelectric response. ETM also exhibits characteristic nonlinear charge transport, including a pronounced enhancement of its interband quantum-geometric contribution. Our results establish ETM as a distinct metallic Landau phase and provide a general framework for understanding toroidal order generated by itinerant electrons.
Strongly Correlated Electrons (cond-mat.str-el)
14 pages, 6 figures
Towards Ultra Scalability of Non-Volatile Magnetic Tunnel Junctions with a 3D Storage Layer
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2026-08-24 20:00 EDT
Nuno Caçoilo, Shunsuke Fukami, Olivier Fruchart, Ioan-Lucian Prejbeanu
The perpendicular Spin Transfer Torque Magnetic Random Access Memory is one of the most promising emerging non-volatile memory technologies, based on ultra-thin magnetic tunnel junctions. However, as these devices are limited by their thermal stability factor at technological nodes smaller than 20 nm, their scalability is compromised. A possible solution to this limitation relies on taking advantage of the shape anisotropy, by increasing substantially the thickness of the storage layer. Thanks to the combination of a vertical aspect-ratio and enhanced volume, high thermal stability can be maintained at sub-10 nm nodes. Here, we present the technological advancements and understanding of the magnetisation reversal that led to faster switching speeds at reduced switching voltage, providing a viable approach for dense arrays of ultra-small magnetic tunnel junctions.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Materials Science (cond-mat.mtrl-sci), Applied Physics (physics.app-ph)
30 pages, 18 figures, Review paper
Time-Resolved Thermal Susceptibility Mapping via Low-Temperature Scanning Laser Microscopy
New Submission | Superconductivity (cond-mat.supr-con) | 2026-08-24 20:00 EDT
Nicolas Lejeune, Simon Van der Heyde, Alejandro V. Silhanek
We present a multiharmonic lock-in detection approach that utilizes the inverse Fast Fourier Transform to reconstruct the time evolution of thermal susceptibility with high spatial resolution. The method is implemented on a custom-built, modular scanning laser microscope designed for operation in low working-distance optical cryostats and thoroughly calibrated for spatial accuracy. A demonstrative case study using a superconducting resonator highlights the capability of this technique to generate thermal images on time scales significantly shorter than the intrinsic scanning speed, thus enabling dynamic thermal characterization with high spatial fidelity. The proposed technique of low-temperature time-resolved scanning laser microscopy offers unique opportunities to explore superconducting devices, 2D materials, hybrid planar structures, and other low-dimensional systems.
Superconductivity (cond-mat.supr-con)
Long-lived Laughlin pairs in a depleted quantum Hall edge channel
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2026-08-24 20:00 EDT
Girts Barinovs, Agris Buzs, Vyacheslavs Kashcheyevs
On-demand sources and mesoscopic beam splitters allow individual ballistic electrons to collide in depleted quantum Hall edge channels, where their unscreened Coulomb interaction acts as a strong, controllable nonlinearity. Theory suggests a more striking possibility: in a strong magnetic field, the repulsion can drive quantized relative circulation, allowing two electrons to propagate together as a positive-energy Laughlin pair. The relevance of such pairs to experiment depends on quantitative lifetimes in realistic guiding potentials and on whether the proposed collision pathway to pair formation survives full two-dimensional dynamics. We develop a microscopic theory of quasibound Laughlin pairs using the physical two-electron Hamiltonian. For a general local electric-field gradient, we determine the dissociation threshold, number of quasibound states, and decay rates. Complex scaling and analytic tunneling theory show that lifetimes grow exponentially with pair energy above threshold. Applied to reported GaAs parameters, the theory indicates that existing devices may already support the lowest spin-polarized pair, with a leading lifetime estimate about three orders of magnitude longer than typical propagation times. We simulate a collision with the full finite-field Hamiltonian, demonstrating both a framework for nonlinear two-electron quantum dynamics and the creation of a Laughlin pair in a representative two-electron collision. We use Husimi distributions and their zeros to visualize both quasibound resonances and transient collision states in phase space. These results place the preparation, propagation, and detection of repulsively paired electrons within reach of existing single-electron circuit technology. They identify kinematic stabilization under constrained one-dimensional propagation as a pairing mechanism that may extend to anyonic quantum Hall edge excitations.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
16 pages, 5 figures
Dissipation driven boundary localization in higher order topological insulators
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2026-08-24 20:00 EDT
Xue Ping Ren, Xiao Ran Wang, Xin Ran Ma, Xi Hu, Su Peng Kou
We study dissipation driven boundary localization in a Bernevig Hughes Zhang type second order topological insulator by introducing inhomogeneous, spin dependent boundary dissipation. After projection onto the edge subspace, the dominant component of the boundary dissipation lies in the same Pauli channel as the kinetic term. This channel gives both counter-propagating edge modes the same real transfer exponent. The two modes therefore accumulate at the same dissipative domain wall. For the corner states, the dissipative envelope competes with Jackiw Rebbi localization. Increasing dissipation moves their weight from the geometric corners to the dissipative domain wall. Propagating edge states also localize at this wall. Numerical calculations confirm the qualitative predictions of the edge theory. A fixed energy Feshbach reduction captures finite size effects. Inhomogeneous boundary dissipation thus controls boundary state localization without changing the bulk topology.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Quantum Physics (quant-ph)
12 pages, 5 figures
Velocity of an interface driven by an entropic force under shear flow
New Submission | Soft Condensed Matter (cond-mat.soft) | 2026-08-24 20:00 EDT
Thermal fluctuations can drive an interface when bulk fluctuation amplitudes differ between two phases. We study how shear flow modifies this mechanism using a stochastic non-conserved order- parameter model. For a planar interface parallel to the imposed shear, we derive its propagation velocity in the weak-noise and small-bias regime. The driving force comprises a shear-modified entropic contribution determined by bulk fluctuation spectra and a non-equilibrium contribution arising from the breaking of time-reversal symmetry. At low shear rates, the entropic term provides the dominant contribution to the velocity of an interface near the zero-velocity plane of the shear flow, and the shear-induced change in the velocity scales as the 4/3 power of the shear rate. At high shear rates, two-dimensional simulations show that the measured velocity is largely accounted for by the modified bulk entropic contribution.
Soft Condensed Matter (cond-mat.soft), Statistical Mechanics (cond-mat.stat-mech)
13 pages, 6 figures,
Systematic and accurate anharmonic formation free energies of metastable defects via a constrained Bayesian Adaptive Biasing Force framework
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-08-24 20:00 EDT
Clovis Lapointe, Anruo Zhong, Manuel Athènes, Mihai-Cosmin Marinica
Computing the formation free energies of metastable defects at finite temperature remains challenging due to anharmonicity, the multiplicity of basins and the frequent occurrence of migration events. Using the previously introduced constrained Bayesian Adaptive Biasing Force method (BABFc), we establish a practical thermodynamic integration framework for computing restricted anharmonic formation free energies associated with individual metastable defect basins. We demonstrate that BABFc can be exploited as a robust, systematic and numerically efficient tool for addressing a long standing bottleneck in atomistic materials science: the finite temperature thermodynamic characterization of metastable defects in complex, highly anharmonic energy landscapes. The proposed workflow requires only a reference local minimum and a confinement strategy and does not rely on defect specific collective variables. It therefore provides a general route to assign well-defined free energies to individual metastable basins, even when these basins are separated by low barriers and embedded in a dense landscape of competing configurations. In this setting, BABFc enables stable, bias corrected free energy estimates with statistical accuracies at the meV/atom level and a very low failure rate, including for systems containing approximately one thousand atoms. We demonstrate this capability through thousands of independent free energy calculations covering hundreds of four-interstitial and four-vacancy configurations in bcc $ \alpha$ -Fe over a broad temperature range, using both a traditional empirical potential and a data driven force field.
Materials Science (cond-mat.mtrl-sci)
21 pages, 9 figures
The Trachenko-Zaccone equation: nonlinear relaxation from glasses to complex systems
New Submission | Disordered Systems and Neural Networks (cond-mat.dis-nn) | 2026-08-24 20:00 EDT
Alessio Zaccone, Valeriy V. Ginzburg, Oleg V. Gendelman, Sofia F. Mauro, John C. Mauro
The Trachenko-Zaccone equation provides a compact nonlinear dynamical framework for describing non-Debye relaxation in disordered condensed matter. Originally developed to rationalize stretched- and compressed-exponential relaxation in liquids and glasses from the dynamics of interacting local relaxation events, the same equation has subsequently appeared in broader contexts, including polymer relaxation and nonlinear models of global population dynamics. This review retraces the conceptual development of the equation, with particular emphasis on its physical origin in Kostya Trachenko’s feed-forward interaction mechanism, its mathematical structure, and its possible generalizations. We also include personal recollections of the work with Kostya Trachenko at Queen Mary University of London in August 2019, during which the equation emerged in essentially its present form. After reviewing applications to stress relaxation, glassy materials, polymer relaxation and population dynamics, we discuss future directions including time-dependent feedback parameters, coupled order parameters, heterogeneous and spatially resolved formulations, flux terms, network versions and stochastic extensions. The central theme of the review is that the Trachenko-Zaccone equation should be viewed not only as a model of glassy relaxation, but as a general nonlinear feedback equation with potential applications across complex systems.
Disordered Systems and Neural Networks (cond-mat.dis-nn), Materials Science (cond-mat.mtrl-sci), Soft Condensed Matter (cond-mat.soft), Dynamical Systems (math.DS), Chaotic Dynamics (nlin.CD)
In memoriam Prof. Kostya Trachenko
Artificial spin ice systems on single edge length tilings
New Submission | Other Condensed Matter (cond-mat.other) | 2026-08-24 20:00 EDT
Artificial spin ices (ASIs) are decorations of single domain nanomagnets on geometric lattices allowing for study of magnetic interactions on easily varied lattice geometries. We extend the study of ASIs on single rhomb tilings by simulating an ASI with the aperiodic hexagonal $ H_{\frac{1}{2}\frac{1}{2}}$ tiling as the base structure, and the periodic dice lattice for additional comparison. Using a point dipole metropolis Monte Carlo approach, we cool our arrays of nanoislands to form a low energy configuration, assessing individual vertex excitations as identified through complementary micromagnetic simulations. Using the energy and charge landscape of final spin states, we propose a potential ground state spin configuration for the aperiodic system.
Other Condensed Matter (cond-mat.other)
14 Pages, 9 figures, submitted to Acta Crystallographica A as part of a collection of articles from ICQ16. Uploaded for community feedback
Interedge backscattering in quantum spin Hall-based NS and SNS junctions
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2026-08-24 20:00 EDT
Cajetab Heinz, Patrik Recher, Fernando Dominguez
We investigate the microscopic conditions that allow for the coupling between opposite quantum spin Hall (QSH) edges in hybrid junctions with superconductors. Using a microscopic Bernevig–Hughes–Zhang model and the Bogoliubov–de Gennes formalism, we model a potential barrier along the NS interface and identify the parameter regimes in which the QSH edges are coupled. In normal–superconductor junctions, such coupling manifests as deviations from the quantized zero-bias Andreev conductance $ G=4e^2/h$ . These deviations are controlled by the induced gap in the barrier, the barrier geometry, the interface transparency, orbital and Fermi-velocity mismatch, and disorder strength as well as the bias voltage leading to a zero-bias peak. We then analyze the impact of this interedge-coupling mechanism in Josephson junctions at equilibrium and show that it hybridizes the edge-resolved Andreev branches, opens gaps at the time-reversal-invariant phase differences $ \varphi=0$ and $ \varphi=\pi$ , and modifies the superconducting quantum interference pattern. In a reflection-symmetric geometry, the relative sizes of the two gap openings provide complementary information about the interedge dynamical phase, which also determines the parity of the suppressed lobes in the magnetic interference pattern. This investigation sheds light on the microscopic details that control the coupling of helical edge states in actual devices and the resulting consequences for superconducting hybrid systems.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
9+6 pages and 5+7 figures, comments are welcome
Broken Inversion Symmetry via a Magic Methyl Effect
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-08-24 20:00 EDT
Calum J Gibb, Jordan Hobbs, Caitlin O Brien, Kate Hille, Benji Maher, Christopher M Pask, Richard J Mandle
Polar liquid crystals - fluid phases in which molecular dipoles organise into ferro- or antiferroelectric states - present a highly constrained molecular design space, where small changes can entirely suppress polar organisation. Here we demonstrate, contrary to expectations, that installation of a methyl group in the 5-position of a 1,3-dioxane ring substantially increases the onset temperature of polar order. Remarkably, this effect proves transferable across several liquid-crystal families, including examples where the methylated derivative exhibits a polar phase whereas its parent compound does not. Across 8 matched pairs, we find that a 5-methyl group can enhance the onset temperature of polar order in 1,3-dioxane materials by up to 120 °C. These findings establish a simple and general molecular design strategy for enhancing and enabling spontaneous dipolar ordering in liquid crystals.
Materials Science (cond-mat.mtrl-sci), Soft Condensed Matter (cond-mat.soft)
Scalable Cyclic Olefin Copolymer Encapsulation for High Optical Quality of TMD Monolayers
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-08-24 20:00 EDT
Suprova Das, Md Tarik Hossain, Zlata Fedorova, Zifei Zhang, Axel Printschler, Begimai Adilbekova, Honey Jayeshkumer Shah, Stefan Velja, Caterina Cocchi, Andrey Turchanin, Isabelle Staude
Monolayer transition metal dichalcogenides (TMDs) combine a direct bandgap, strongly bound excitons, and pronounced second-order optical nonlinearity, which makes them promising materials for ultrathin optoelectronic and nanophotonic devices. However, their optical performance is often degraded by environmental exposure and substrate-induced charge trapping, motivating the development of scalable encapsulation strategies. Here, we investigate spin-coated cyclic olefin copolymer (COC) as a scalable encapsulant for TMDs. Room-temperature and cryogenic optical spectroscopy reveal enhanced photoluminescence and second-harmonic generation, accompanied by excitonic linewidth narrowing and an increased exciton-to-trion ratio. In addition, COC encapsulation induces an excitonic peak splitting and an overall spectral blueshift. First-principles calculations attribute these spectral modifications to local symmetry breaking at the chalcogen interface and macroscopic compressive strain, respectively. These findings establish spin-coated COC as an effective, scalable encapsulation strategy and a potential platform for post-growth excitonic and band-structure engineering.
Materials Science (cond-mat.mtrl-sci)
Quasi-one-dimensional topological band structure and van Hove singularities in monolayer TaIrTe$_4$ from laser $μ$-ARPES
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-08-24 20:00 EDT
Honey Boban, Tanguy Prongué, Amarjyoti Choudhury, Dario Marchiani, Andrés Bareño, Felix Eder, Enrico Giannini, Fabian O. von Rohr, Alberto F. Morpurgo, Marco Gibertini, Anna Tamai, Felix Baumberger
Recent transport experiments reported a quantum spin Hall insulator phase in monolayer 1T-TaIrTe$ _4$ gated away from charge neutrality. This phase is not predicted by band structure calculations and has been attributed to an electronic instability induced by strong correlations at a putative van Hove singularity. Here, we investigate the electronic structure of exfoliated monolayer 1T-TaIrTe$ _4$ using micro-focus laser angle resolved photoemission. We find a strongly anisotropic band structure susceptible to density wave instabilities. Our data further reveal a saddle point singularity in the density of states. However, we find that the saddle point lies at a density for which transport experiments found no anomalies. Moreover, the quasiparticle line widths suggest weak electron correlations only. This points to a secondary role of van Hove singularities and electron correlations in the transport phase diagram of monolayer 1T-TaIrTe$ _4$ .
Materials Science (cond-mat.mtrl-sci), Strongly Correlated Electrons (cond-mat.str-el)
Polymer Genome in the Age of Artificial Intelligence
New Submission | Soft Condensed Matter (cond-mat.soft) | 2026-08-24 20:00 EDT
Artificial intelligence (AI) is redefining the landscape of polymer science. Although numerous AI applications have been introduced in this field, the roles of polymer encoding strategies and different applications of AI models in polymer design remain insufficiently understood. Here, we build upon the foundation of polymer databases to critically examine the performance and applicability of current encoding strategies across different use cases. We then focus on two major AI application domains, property prediction and inverse design, to evaluate the strengths, weaknesses and suitable scenarios for various model architectures. Finally, we emphasize the significance of the online platforms for promoting data accessibility and accelerating the migration from experience-based discovery toward AI-driven innovation in polymer science and engineering. Through these discussions, we aim to provide practical guidance for future research and development in AI-assisted polymer design.
Soft Condensed Matter (cond-mat.soft), Other Condensed Matter (cond-mat.other)
26 pages, 6 figures, 2 tables. review
Optical conductivity signature of Van Hove singularity in altermagnetic topological systems
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2026-08-24 20:00 EDT
Fang Qin, Rui Chen, Xiao-Bin Qiang
We investigate the topological phases, joint density of states (JDOS), optical conductivities, and magneto-optical responses of a two-dimensional $ d$ -wave altermagnet with spin-orbit coupling and Zeeman splitting. The system hosts Dirac gaps at the high-symmetry points $ \Gamma$ , $ \textrm{M}$ , $ \textrm{X}$ , and $ \textrm{Y}$ . We show that the JDOS exhibits kinks at the corresponding Dirac gap frequencies and pronounced peaks at Van Hove singularities, whose positions can be tuned by the altermagnetic order. These features are reflected in the optical conductivities, with complementary signatures in their real and imaginary parts. Particularly, the Van Hove signatures in the transverse optical conductivity disappear in the absence of $ d$ -wave altermagnetism, revealing an altermagnet-induced optical signature of the Van Hove singularity. Finally, the Faraday and Kerr rotations inherit characteristic features of the optical conductivity. Our results establish optical and magneto-optical spectroscopy as sensitive probes of Dirac gaps and Van Hove singularities in altermagnetic topological systems.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
10 pages, 5 figures
Scalable photoexcitation-induced molecular dynamics with machine-learned Hamiltonians
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-08-24 20:00 EDT
Leyu Cai, Yunzhe Jia, Daqiang Chen, Sheng Meng
Ultrafast photoexcitation offers a controllable route to steer structural dynamics in solids, yet predicting how nonequilibrium electronic excitation drives lattice motion across extended spatial and temporal scales remains a major computational challenge. Here we introduce time-dependent ab-initio propagation with electronic machine learning (TDAP-eML), a framework that explicitly incorporates electronic evolution into scalable simulations of photoexcitation-induced lattice dynamics. By integrating machine-learned electronic structure with atomistic propagation, TDAP-eML describes how photoexcitation reshapes the evolving energy landscapes and forces governing structural motion. Across representative examples including silicon and FeSe, the framework reproduces key photoexcited lattice responses obtained from first-principles time-dependent density functional theory calculations and captures coherent phonon dynamics together with their dependence on excitation conditions. Its computational advantage increases with system size, reaching nearly three orders of magnitude reduction in computational cost for the large systems examined. TDAP-eML thus establishes a scalable framework for coupled electronic and lattice evolution, linking nonequilibrium excitation to photoinduced forces, predictive structural dynamics, and experimentally accessible observables.
Materials Science (cond-mat.mtrl-sci), Computational Physics (physics.comp-ph)
13 pages, 5 figures
On Transmission Function Amplitude and Phase Recovery in Multislice Electron Ptychography
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-08-24 20:00 EDT
Bridget R. Denzer, Colin Gilgenbach, James M. LeBeau
{Multislice electron ptychography commonly accounts for inelastic scattering by including an absorptive object potential in the reconstruction forward model that attenuates the elastic signal. However, it remains unclear how the reconstruction is quantitatively impacted by thermal scattering. Here, we use the quantum excitation of phonons (QEP) formalism, which explicitly separates elastic and inelastic (thermal diffuse) scattering within a single multislice propagation, to simulate four-dimensional scanning transmission electron microscopy (4D STEM) datasets of PbTiO$ _3$ and SrTiO$ _3$ and reconstruct their phase and amplitude. We find that reconstructions of the QEP total and elastic-only datasets are nearly indistinguishable across sample thicknesses from 11 to 40 nm and across atomic species, demonstrating that the reconstruction is largely insensitive to incoherent thermal diffuse scattering within the collected angular range. Reconstructions from multislice phase-only simulations further confirm that appreciable amplitude does not arise from multiple elastic scattering, but instead reflects attenuation of the coherent elastic signal due to thermal scattering. Further comparison of the QEP elastic-only reconstruction with absorptive multislice simulations reveals substantial amplitude contrast deviations for heavy Pb columns (up to 17%), arising from the approximations used to evaluate the absorptive potential for the 4D STEM simulation. These results thus indicate that reconstruction phase and amplitude accuracy are not significantly limited by the absorptive potential forward model, even in the presence of thermal diffuse scattering.
Materials Science (cond-mat.mtrl-sci), Computational Physics (physics.comp-ph)
Identification of the length scale parameter of simplified strain gradient elasticity from standard Mode I fracture tests
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-08-24 20:00 EDT
Yury Solyaev, Kirill Shelkov, Pavel Polyakov
Recently, it was shown that additional material constants of strain gradient elasticity (SGE) can be identified for brittle and quasi-brittle materials based on the analysis of experimental data on the crack size effect. In the present paper, we perform precise numerical simulations within SGE and derive regression relations for processing experimental data from standard fracture mechanics tests under pure Mode I loading conditions (CCT, SENT, SENB). We consider the simplified SGE, whose constitutive relations contain a single length scale parameter $ \ell$ in addition to the classical elastic constants. We show that, for brittle materials, this parameter can be explicitly identified as $ \ell \approx 0.362 (K_{Ic}/\sigma_{ult})^2$ . This identification ensures that the fracture loads predicted by classical linear elastic fracture mechanics (LEFM) and by the simplified SGE coincide for relatively long Mode I cracks. However, within the simplified SGE, these fracture loads are evaluated from the nonsingular stress field using the maximum principal stress criterion. For quasi-brittle materials, we derive regression relations that describe the non-classical size effect on strength. This effect is usually treated within nonlinear fracture mechanics but can be naturally captured by SGE. Examples of identification of the length scale parameter $ \ell$ based on the established relations and the experimental data for chopped fiber composites and for porous and dense quasi-brittle ceramics are presented.
Materials Science (cond-mat.mtrl-sci), Other Condensed Matter (cond-mat.other)
Soft and chiral phonons in chiral phase of K3NiO2
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-08-24 20:00 EDT
Hong Dang Nguyen, Fedir Borodavka, Miroslav Lebeda, Nazar Zaremba, Peter Hoehn, Eteri Svanidze, Jan Drahokoupil, Ales Vlk, Stanislav Kamba
Raman scattering measurements confirmed the theoretical prediction that the structural phase transition from the achiral tetragonal to the chiral tetragonal phase, which occurs near 400 K, is induced by a doubly degenerate soft phonon at the Z point of the Brillouin zone. In the low-temperature chiral phase, the soft mode activates in Raman spectra, splits into two components with A1 and B1 symmetries and harden with cooling according to Cochran law. Circularly polarized Raman scattering did not reveal the angular momentum of these singly degenerate phonons at the Gamma point, which is consistent with theory. We also calculated the phonon branches in the whole Brillouin zone for both crystalline phases and compared the results with the phonons observable in the Raman spectra. The calculations revealed that some phonons with nonzero k have angular momentum in the chiral phase. A pronounced circular motion of atoms can be observed, for example, in a Dirac-type topological phonon at the M-point of the Brillouin zone with a frequency of 168 cm-1.
Materials Science (cond-mat.mtrl-sci)
17 pages, 8 figures
Doping-driven Mott transition from steady-state density functional theory
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2026-08-24 20:00 EDT
The doping-driven Mott transition in the Hubbard model is described within the frame- work of steady-state density functional theory, or i-DFT. In order to access the many-body spectral function in i-DFT, an approximation for the exchange-correlation (xc) bias at arbitrary density and current is required. By using Fermi-liquid theory, a connection between the xc bias of i-DFT and the quasiparticle weight of many-body theory is derived and the results are employed to guide the construction of the approximation. Numerical results obtained with this functional demonstrate that the doping-driven Mott transition can indeed be captured with i-DFT.
Strongly Correlated Electrons (cond-mat.str-el)
22 pages, 5 figures
Sulfur-rich Spirofluorene-Bridged N Heterotriangulene Redox-Active Polymers
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-08-24 20:00 EDT
Angelina Jocic, Tom Wickenhäuser, Sebastian Lindenthal, Alexander Welle, Vanessa Trouillet, Ronald Curticean, Irene Wacker, Jana Zaumseil, Rasmus R. Schröder, Rüdiger Klingeler, Milan Kivala
Sulfur-rich spirofluorene-bridged N-heterotriangulene (FTN) polymers featuring covalently linked oligosulfide units and a terthiophene-based analogue were synthesized via nucleophilic aromatic substitution and Stille cross-coupling polymerization. The resulting materials are amorphous, insoluble solids with high thermal stability and sulfur contents up to 25 wt%. Structural and compositional analyses by combustion analysis, ToF-SIMS, FT-IR, XPS, and solid-state NMR confirm the efficient incorporation of short oligosulfide to disulfide linkages and well-defined terthiophene units in the respective polymers. Electrochemical characterization in lithium half-cells reveals a reversible, high-voltage oxidation of the FTN unit at 3.8-4.0 V (vs. Li/Li+), accompanied by low-voltage sulfur- or terthiophene-based redox processes between 1.5-2.5 V (vs. Li/Li+). Sulfur incorporation markedly increases the theoretical and initial discharge capacities (up to 129 mA h g-1), while the sulfide conversion processes exhibit rapid fading and poor reversibility due to sulfide dissolution. In contrast, the terthiophene-linked polymer shows only transient low-voltage activity while maintaining high Coulombic efficiencies (ca. 99.7%) governed by the persistent FTN backbone redox event. Our results highlight how different redox-active linkers influence the electrochemical behavior of FTN-based polymers and provide insights into the design of functional organic cathode materials featuring multi-redox processes.
Materials Science (cond-mat.mtrl-sci)
Synthetic Metals 320, 118233 (2026)
Electric-Field-Induced Second Harmonic Generation at a Reconfigurable LaAlO$_3$/SrTiO$_3$ Nanojunction
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2026-08-24 20:00 EDT
Pubudu Wijesinghe, Melanie Dieterlen, Kyoungjun Lee, Ahmed Omran, Aswini Ramankutty, Chang-Beom Eom, Patrick Irvin, Jeremy Levy
Electrically tunable nonlinear optical responses at the nanoscale remain challenging to achieve because conventional nonlinear materials lack the combination of large susceptibility, nanoscale confinement, and in situ reconfigurability. Here we report electric-field-induced second harmonic (EFISH) generation from a nanoscale tunnel junction defined by conductive atomic force microscope lithography at the LaAlO$ 3$ /SrTiO$ 3$ interface. A conducting channel written at the interface is interrupted by a nanoscale insulating gap, across which applied DC bias produces local electric fields exceeding $ 10^7$ V/m. The SHG signal is spatially localized at the junction, exhibits a quadratic bias dependence described by $ I(2\omega) \propto |\chi^{(2)}\mathrm{0} + \chi^{(3)} E\mathrm{DC}|^2$ with no hysteresis, a modulation depth exceeding 380% at $ |V_\mathrm{DC}| = 1$ V, and shows a two-lobed input-polarization pattern aligned with the junction axis, consistent with EFISH from a centrosymmetric host. Calibration against a BBO reference crystal gives $ |\chi^{(3)}| \approx 1\times10^{-19}$ m$ ^2$ /V$ ^2$ at 6 K. These results establish cAFM-written oxide nanojunctions as a reconfigurable platform for nanoscale nonlinear optics in which the junction geometry sets the symmetry of the response and the large field-induced $ \chi^{(2)}$ of SrTiO$ _3$ provides the optical nonlinearity. Because the nonlinearity is both generated and read out within the same nanoscale gap, the junction operates simultaneously as a subwavelength source and a near-field detector of optical nonlinearity.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Materials Science (cond-mat.mtrl-sci), Optics (physics.optics)
12 pages, 7 figures
Active Reinforcement of Jammed Emulsions by Living Microswimmers
New Submission | Soft Condensed Matter (cond-mat.soft) | 2026-08-24 20:00 EDT
Marie Corpart, Hugo Le Roux, Daniel Bonn, Antoine Deblais
We show that living microswimmers mechanically reinforce dense emulsions. Castor-oil-in-water emulsions laden with the microalga Chlamydomonas reinhardtii are compared in three states: without algae, with immobilized algae, and with motile algae, over a broad range of oil fractions spanning the jamming transition. Oscillatory rheology reveals that motile algae systematically increase the yield stress, by up to a factor of two, whereas immobilized cells at the same concentration leave it essentially unchanged. The reinforcement thus originates from activity rather than from the mere presence of inclusions. Single-cell tracking shows that the droplet network confines the swimmers in pores that shrink as the oil fraction increases, and confinement is known to amplify the propulsion force of C. reinhardtii. A simple estimate based on this confinement-enhanced force accounts for the measured excess yield stress and indicates an effective, activity-induced depletion-like attraction between the passive droplets. These results identify a feedback loop: the microstructure confines the swimmers, confinement amplifies the forces they exert, and these forces stiffen the microstructure. Active emulsions thus emerge as a model platform for programming the mechanics of disordered soft solids through activity.
Soft Condensed Matter (cond-mat.soft), Fluid Dynamics (physics.flu-dyn)
12 pages, 8 figures
Pair size versus coherence length and quantum geometry in the spin-orbit coupled BCS-BEC crossover
New Submission | Quantum Gases (cond-mat.quant-gas) | 2026-08-24 20:00 EDT
We investigate the interplay between pairing correlations and quantum geometry in the spin-orbit-coupled BCS-BEC crossover. Working in the helicity basis, we derive the exact pair-size tensor for the two-body bound states and show that it separates into intraband and quantum-geometric interband contributions, with the latter determined by the quantum metric. We extend this decomposition to two distinct many-body length scales at zero temperature: the Cooper-pair size, obtained from mean-field BCS theory, and the coherence length, obtained from the Gaussian fluctuation theory. Although these quantities almost coincide in the BCS regime, they describe distinct physical properties away from it, with the pair size characterizing the internal extent of a pair and the coherence length characterizing the long-wavelength response of the order parameter. We evaluate both quantities for three-dimensional Rashba, three-dimensional Weyl, and two-dimensional Rashba spin-orbit coupling models. We find that the pair size decreases monotonically with increasing spin-orbit coupling as the pair localizes, whereas the coherence length develops a pronounced minimum in the crossover regime before growing again in the BEC regime as the composite bosons become weakly interacting. This minimum is tied to the collapse of the noninteracting Fermi surface onto the ring or sphere of helicity-band minima. The quantum-geometric contributions reach up to nearly one third of the pair size and about 40% of the coherence length, tracking these same changes in the underlying helicity Fermi-surface topology.
Quantum Gases (cond-mat.quant-gas), Strongly Correlated Electrons (cond-mat.str-el), Superconductivity (cond-mat.supr-con)
14 pages with 3 figures
An autonomous feedback protocol: responding to temperature and potential changes in energy converters
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2026-08-24 20:00 EDT
Krishna Lyn Delima, Elsa Danielsson, Bruno Bertin-Johannet, Janine Splettstoesser
Nanoscale thermoelectric devices convert tiny amounts of heat into power. But what happens if the external conditions and resulting temperature differences are not a priori known? We propose a feedback mechanism that optimizes the performance of a quantum-point-contact-based heat engine (QPC). A quantum-dot detector measures the external conditions and gives autonomous feedback on the QPC’s properties. We expect this feedback mechanism to be experimentally relevant for steady-state engines with unknown external conditions and for adapting dynamic charging processes to the potential buildup.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Quantum Physics (quant-ph)
9 pages, 4 figures; Supplemental Material 11 pages, 4 figures
Symmetry-engineering ferroelectricity in silicon dioxides
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-08-24 20:00 EDT
It is a long-established rule for classical ferroelectricity that any ferroelectric crystal must adopt one of the 10 specific polar point groups. Here we predict a unique type of ferroelectricity that can be generated in some crystals belonging to nonpolar noncentrosymmetric groups. This principle can be applicable to many systems including silicon dioxides, the most widely used dielectric materials. Most of their crystalline phases do not belong the polar groups, while the nonlinear Si-O-Si configurations lead to multiple identical states. We show first-principles evidence that the crystal symmetry forbidding the formation of polarizations, can be broken by either parallel surfaces in thin-films or applying a uniaxial strain. As a result, the multiple identical states are endowed with polarizations of different directions, and low-barrier ferroelectric switching can be realized via transition between them, which can be room-temperature robust down to the thickness of 1 nm. Our findings may not only enable low-cost and large-scale manufacture of ferroelectrics directly integrated in silicon chips, but also open a new avenue for exploring ferroelectricity in prevalent nonpolar materials.
Materials Science (cond-mat.mtrl-sci)
Berry-Curvature Effect in Anomalous Transport
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2026-08-24 20:00 EDT
A theory of the Berry-phase effect in anomalous transport in ferromagnets driven by statistical forces such as the gradient of temperature or chemical potential has been developed by Di Xiao et al in Phys. Rev. Lett. 97, 026603 (2006) based on a field-dependent density of states generating an additional contribution to the current density. We present an alternative derivation of the Berry- phase effect in anomalous transport in altermagnets and noncentrosymmertric metals based on quasiclassic matrix kinetic equation. Along with anomalous Hall effect an anomalous heat flow and anomalous thermalelectric currents are also derived.
Strongly Correlated Electrons (cond-mat.str-el)
5 pages
Continuously control of polarization via electrically driven long-distance superlubric sliding
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2026-08-24 20:00 EDT
Sliding ferroelectricity widely exists in various van der Waals bilayers or multilayers, which is induced by asymmetric stacking of commensurate interface. The greatly reduced switching barriers via interlayer sliding lead to high speed with low energy cost, while they are still much higher compared with superlubric sliding of incommensurate interfaces. The polarizations of such incommensurate interfaces are not switchable, which is the major obstacle of combing superlubricity and sliding ferroelectricity for ultralow barriers. Here we propose a design of such combination based on previous synthesis of lateral heterojunctions of 2D materials, which can be extensively applicable to various systems including PN junctions. In such long-distance superlubric ferroelectricity, the vertical polarization can be continuously controlled by superlubric sliding of incommensurate interfaces between lateral heterojunction bilayers, where the series of multiple stable states are long-sought for artificial synaptic devices. The unconventionality of our findings does not only include unprecedented barriers down to the magnitude of mu-eV, but also unprecedented long ion displacements distinct from the small deviations in classical paradigm of ferroelectricity. Our predicted superlubric sliding electrically driven by low vertical voltage is also hitherto reported, much more efficient compared with previously reported sliding mechanically driven by tips, resolving a major issue for practical applications.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
Quantum Fisher information in a quenched $p + ip$ superfluid
New Submission | Quantum Gases (cond-mat.quant-gas) | 2026-08-24 20:00 EDT
The quantum Fisher information (QFI) is widely used to characterize quantum phases and transitions, but its diagnostic power sometimes relies on selecting special generators based on prior knowledge of the underlying physics. We ask whether this requirement can be relaxed in nonequilibrium systems by studying the QFI of the long-time asymptotic state of a two-dimensional p+ip superfluid following an instantaneous quench of the coupling strength, using the particle number within a large subextensive subsystem as the generator. In equilibrium, the ground-state QFI is continuous across the topological transition between the weak-pairing BCS and the strong-pairing BEC phases, showing no direct signature of the transition. After the quench, however, the QFI associated with the same generator distinguishes the three dynamical phases and can encode the topology of the pre-quench state. In phase I, with a vanishing order parameter, the QFI Fourier spectrum consists of a single zero-frequency spike determined by the nonequilibrium distribution function. In phase II, with a constant nonzero order parameter, the QFI spectrum contains a zero-frequency spike and two continua separated by a gap set by the minimum asymptotic quasiparticle energy. The continuum edge behavior reveals whether this minimum occurs at zero or finite momentum. In the former case, the spectral weight vanishes at the edge, with the sign just inside the continuum encoding the pre-quench topology for large subsystem. In phase III, with a time-periodic order parameter, the QFI spectrum exhibits discrete peaks at integer multiples of the oscillation frequency, together with continua associated with the Floquet quasienergy spectrum. Our results show that driving the system out of equilibrium can enhance the diagnostic power of the QFI for a standard physical observable, revealing information inaccessible in equilibrium.
Quantum Gases (cond-mat.quant-gas), Superconductivity (cond-mat.supr-con), Quantum Physics (quant-ph)
16 pages, 6 figures
Symmetry-Induced Weyl Nodes in Interacting Multi-Terminal Josephson Junctions
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2026-08-24 20:00 EDT
Peter Zalom, Gustavo Diniz, David Christian Ohnmacht, Wolfgang Belzig
We show that an emergent geometric symmetry generates non-trivial topology in quantum-dot-based multi-terminal Josephson junctions. It confines same-spin Andreev bound state crossings to an analytic one-dimensional manifold of the synthetic Brillouin zone, where interdot coupling selects Weyl nodes of charge $ \pm1$ in the singlet sector and doubly degenerate cones of charge $ \pm2$ in the doublet sector, at gate-tunable locations. The mechanism yields a spectroscopic detection protocol and a design principle for fabricating devices with non-trivial topological signatures.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
8 pages, 5 figures
Non-Monotonic Dynamical Correlations Across The Glass Crossover
New Submission | Soft Condensed Matter (cond-mat.soft) | 2026-08-24 20:00 EDT
Corentin C. L. Laudicina, Ilian Pihlajamaa, Liesbeth M. C. Janssen, Thomas Voigtmann, Tommaso Rizzo
The dramatic slowing down of structural relaxation in supercooled liquids is accompanied by the emergence of dynamic heterogeneity. A monotonically increasing dynamical correlation length, measured at the $ \alpha$ -timescale, is one of the remarkable features of this phenomenon. Here we show that this picture is incomplete: the dynamical correlation length measured in the $ \beta$ -relaxation regime exhibits a striking non-monotonic temperature dependence, reaching a maximum near the mode-coupling crossover temperature $ T_c$ and decreasing upon further cooling, even as local dynamical fluctuations continue to intensify. This behavior suggests a crossover from spatially extended, maximally cooperative motion near $ T_c$ to increasingly compact and localized relaxation events below it. We demonstrate that this evolution is quantitatively captured by stochastic beta-relaxation theory, an extension of mode-coupling theory beyond mean-field that explicitly predicts an avoided dynamical transition in finite dimensions. Our results provide the first direct spatial evidence in favor of the avoided-transition picture of the mode-coupling crossover, and establish the peak of the $ \beta$ -regime correlation length as a robust indicator of the mode-coupling crossover.
Soft Condensed Matter (cond-mat.soft), Disordered Systems and Neural Networks (cond-mat.dis-nn), Materials Science (cond-mat.mtrl-sci)
10 pages, 6 figures
The Continuum Model for Uniaxially Strained Bilayer Graphene Moiré Systems
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2026-08-24 20:00 EDT
Tong Liu (1 and 3), X. R. Wang (2), Jiansheng Wu (3) ((1) Department of Physics, Hong Kong University of Science and Technology, Hong Kong, (2) School of Science and Engineering, Chinese University of Hong Kong (Shenzhen), Shenzhen, China, (3) Shenzhen Institute for Quantum Science and Engineering, Southern University of Science and Technology, Shenzhen, China)
We construct a continuum model for a one-dimensional moiré superlattice formed by stretching one layer of AB-stacked bilayer graphene along the x direction by a factor s. Following the spirit of the Bistritzer-MacDonald model for twisted bilayer graphene, we treat the interlayer coupling as hopping between several Dirac points. At a critical stretch factor s ~ 1.018 the two bands near the Fermi level touch, forming two degeneracy points along the k_y direction. This gap closing is accompanied by a topological phase transition, in which the Chern number changes from 1 to -1, and by a sign change of the Berry-curvature dipole, which we propose can be detected through the nonlinear Hall effect. We find that uniaxial strain modulates inter-Dirac-valley coupling, which drives band gap collapse and subsequent topological number inversion. This opens a route to engineer topological transport and quantum anomalous Hall effects via strain engineering of moiré heterostructures.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
17 pages, 13 figures
Emergent Vibronic Spectral Hierarchy in a Kagome Flat-Band Insulator
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2026-08-24 20:00 EDT
Jun Shu, Jun Shen, Yanmin Zhang, Hong Du, Qingsong Wang, Zeyuan Wang, Bin Wang, Zeliang Xu, Dengjing Wang, Hengfu Lin, Zunming Lu, Lei Qin, Jie Yuan, Jinbo Peng, Zhida Song, Fedor V Kusmartsev, Anna Kusmartseva, Kui Jin, Ruidan Zhong, Ge He
Electron-phonon coupling is usually understood in terms of electronic quasiparticles interacting with dispersive lattice vibrations. Much less is known about the complementary limit in which the relevant phonon mode is itself localized or weakly dispersive. Here we investigate this regime in the kagome compound Rb$ _{2}$ Ni$ _{3}$ S$ _{4}$ , which undergoes an unconventional insulating transition near $ T^{\ast} \approx$ 260-280K. Combining polarization-resolved Raman spectroscopy with temperature-dependent x-ray diffraction, scanning tunneling microscopy, and electrical, thermal, and magnetic measurements, we show that the transition involves electronic localization without a conventional structural or magnetic order parameter. Raman spectra reveal a giant Franck-Condon progression associated with a nearly dispersionless 333.7cm$ ^{-1}$ phonon, decorated by an equally spaced comb-like fine structure with a characteristic spacing of 40.6~cm$ ^{-1}$ . The comb spacing is insensitive to magnetic field, whereas its spectral weight is strongly field tunable. Rather than treating either hierarchy alone as pure phonon effect, we interpret their nested coexistence as evidence for a strongly coupled electron-vibrational manifold involving a localized lattice coordinate. These results identify dispersionless phonons as an active route to vibronic correlations in solids and suggest that such electron-vibrational self-trapping is closely associated with the insulating phase of Rb$ _{2}$ Ni$ _{3}$ S$ _{4}$ .
Strongly Correlated Electrons (cond-mat.str-el)
10 pages, 4 figures
Meandering stripes in the frustrated $J_1$-$J_2$ Ising model on the honeycomb lattice
New Submission | Statistical Mechanics (cond-mat.stat-mech) | 2026-08-24 20:00 EDT
Denis Gessert, Martin Weigel, Wolfhard Janke
We study the frustrated $ J_1$ -$ J_2$ Ising model on the honeycomb lattice with ferromagnetic nearest-neighbor couplings fixed at $ J_1=1$ and strong antiferromagnetic next-nearest-neighbor interactions, i.e., $ J_2 \leq -1/4$ . Little is known for this range of $ J_2$ , whereas for less negative values of $ J_2$ the system orders ferromagnetically at low temperatures and appears to remain in the Ising universality class. In previous work it was shown that the model has a largely degenerate ground state, and it was conjectured that there is some kind of phase transition. We introduce a complex-valued nematic order parameter, which can differentiate between the high-temperature paramagnetic phase and the observed partially-disordered stripe phase at lower temperatures. Configurations in this phase consist of stripes of spins parallel with respect to one lattice direction, which collectively meander along the remaining two, producing partially disordered ground states. The sharp peaks in the specific heat observed in earlier work only appear when using periodic boundary conditions and are absent for free boundaries. Additionally, we reveal a striking dependence of the behavior on the aspect ratio of the considered samples. Ultimately, even a careful finite-size scaling analysis for $ J_2 = -0.5$ and $ J_2 = -1$ is unable to clearly discern between a crossover without any singularities and some form of continuous transition, including the possibility of an infinite-order transition of the Berezinskii-Kosterlitz-Thouless (BKT) type. For $ J_2=-1/4$ we find that the system remains disordered at all temperatures and that it exhibits a finite ground-state entropy per site, for which our simulations provide the accurate asymptotic estimate $ S(T=0)/N = 0.230,960,93(14)$ in the thermodynamic limit $ N\rightarrow\infty$ .
Statistical Mechanics (cond-mat.stat-mech), Computational Physics (physics.comp-ph)
25 pages, 21 figures, 3 tables
LCST and Closed-Loop Phase Behavior in Non-Associating Fully Symmetric Multicomponent Polymer Systems
New Submission | Soft Condensed Matter (cond-mat.soft) | 2026-08-24 20:00 EDT
Artem Petrov, Alfredo Alexander-Katz
Multicomponent liquids can phase separate upon heating, exhibiting a lower critical solution temperature (LCST). Moreover, a narrow class of materials can undergo disordering transition upon further heating, yielding closed-loop phase diagrams. Previously, it was shown that LCST or closed-loop phase behavior can appear in the models of liquids in which components are asymmetric or interaction potentials have a specifically designed attraction. Here, we show theoretically that LCST and closed-loop phase behavior can occur in a significantly wider set of models. In particular, we found that these phenomena can be exhibited by the simplest and widely used coarse-grained (CG) models of any multicomponent liquid in which species are fully symmetric and where all particles interact via an arbitrary repulsive potential. In addition, we discovered that LCST and closed-loop phase behavior in these models emerges merely due to the basic property of CG liquid models, namely, the appearance of strong monomer-monomer positional correlations at low monomer number density $ \rho$ . We simulated the models of fully symmetric binary blends and diblock copolymer melts where nonbonded monomers interacted via a generic T-independent purely repulsive harmonic potential. As predicted, LCST and closed-loop phase behavior emerged at $ \rho$ sufficiently low to cause strong monomer-monomer correlations leading to a strong T-dependence of the effective coordination number, which, in turn, induced a nonmonotonic T-dependence of the Flory-Huggins parameter. To summarize, we discovered that the simplest fully symmetric non-associating CG models of multicomponent liquids can exhibit complex temperature response due to a mechanism stemming from the basic nature of any CG liquid model. This mechanism might contribute to the emergence of LCST and closed-loop phase behavior in many existing polymer materials.
Soft Condensed Matter (cond-mat.soft)
Superconducting ground state study of Cr-based equiatomic high-entropy alloy through $μ\text{SR}$
New Submission | Superconductivity (cond-mat.supr-con) | 2026-08-24 20:00 EDT
Sonika Jangid, Rhea Stewart, Adrian D. Hillier, R. P. Singh
High-entropy alloy superconductors, characterized by extreme chemical disorder and complex electronic environments, have attracted significant attention as model systems for exploring superconductivity in disordered materials. Here, we investigate a Cr-based equiatomic HEA, Cr-V-Ti-Nb-Ta, which contains a magnetic 3d element, providing an opportunity to examine the influence of magnetic elements on superconductivity in highly disordered systems. Despite expected magnetic pair-breaking, this alloy exhibits bulk type-II superconductivity with a transition temperature of $ T_c = 2.33(3)$ K and a high upper critical field. Transverse-field $ \mu$ SR measurements reveal an s-wave superconducting gap close to the BCS value, while zero-field $ \mu$ SR suggests preserved time-reversal symmetry. These results establish Cr-V-Ti-Nb-Ta as a promising platform for exploring the interplay between disorder, magnetism and superconductivity in high entropy alloys.
Superconductivity (cond-mat.supr-con)
10 pages, 6 figures
Two distinct gap structures in the mid-infrared optical conductivity of the Hubbard model
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2026-08-24 20:00 EDT
Mid-infrared (MIR) optical conductivities in cuprate superconductors show universal features. In this study, we demonstrate that these originate from two distinct gaps: the pseudogap mediated by antiferromagnetic spin fluctuations and the Mott-Hubbard gap. The MIR spectra from these two gaps show a characteristic and distinct shape and doping dependence, and can thus be distinguished. Specifically, the Mott-Hubbard correlations, while rendering a peak in the visible spectrum for small dopings, yield a broad optical response starting in the MIR when a ``waterfall’’ develops in the one-particle spectrum at larger dopings. The numerically and analytically determined doping-dependence of both gaps consistently reproduce experiments, and provide a unified microscopic understanding of the cuprate MIR optical conductivity.
Strongly Correlated Electrons (cond-mat.str-el)
Neural quantum states in condensed matter: advances, best practices, and prospects
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2026-08-24 20:00 EDT
Jonas B. Rigo, Björn J. Wurst, Rajah Nutakki, Markus Schmitt, Dante Kennes
Neural quantum states provide flexible variational representations of quantum many-body wave functions by combining neural-network parametrizations with Monte Carlo sampling. In this perspective, we review recent advances in their application to condensed-matter systems, focusing on frustrated quantum magnets, interacting lattice fermions, and non-equilibrium dynamics. We discuss the architectures, symmetry constraints, optimization methods, and sampling strategies underlying state-of-the-art calculations, and summarize practical guidelines for reliable simulations. We also examine the principal remaining challenges, including learning non-trivial sign and phase structures, controlling variational bias, enforcing physical symmetries, scaling optimization to large networks, and achieving stable real-time evolution. Finally, we outline promising directions in which neural quantum states may extend the reach of classical simulations of strongly correlated quantum matter.
Strongly Correlated Electrons (cond-mat.str-el), Computational Physics (physics.comp-ph), Quantum Physics (quant-ph)
42 pages, 9 figures; perspective article
Chemical Control of Electronic Structure and Topology in Tellurium-Encapsulated Silicene
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-08-24 20:00 EDT
Gabriel Elyas Gama Araujo, Andre Luis de Oliveira Batista, Willian Oliveira Santos, Alexandre Amaral Leitao, Alexandre Cavalheiro Dias, Andreia Luisa da Rosa
We investigate chemical control of the electronic, optical, and topological properties of two-dimensional \ce{Si2X2Te2} (\ce{X} = \ce{B}, \ce{Al}, \ce{Ga}, and \ce{In}) monolayers using first-principles calculations. All compounds are dynamically stable semiconductors, with their vibrational and electronic properties evolving systematically upon group-III substitution. Hybrid-functional calculations including spin–orbit coupling reveal predominantly $ p$ -orbital band edges and increasingly pronounced relativistic effects from B to In. Most notably, the calculated $ \mathbb{Z}_2$ invariant identifies \ce{Si2In2Te2} as a candidate quantum spin Hall insulator, while the B-, Al-, and Ga-based monolayers remain topologically trivial. Bethe–Salpeter calculations further show that electron–hole interactions redistribute oscillator strength near the absorption onset while preserving a weak in-plane optical anisotropy. Our results establish group-III substitution as a simple chemical route to tune the electronic structure and drive a transition from trivial to nontrivial topology in \ce{Si2X2Te2} monolayers.
Materials Science (cond-mat.mtrl-sci)
Ultralow-Field Triplon Condensation in a Spin-Ladder Magnet
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2026-08-24 20:00 EDT
Ankit Labh, Ross H. Colman, Jakub Šebesta, Noah Oefele, Elsa Lhotel, Adam Berlie, Paul Steffens, Oksana Zaharko, Pascal Manuel, Iurii Kibalin, Philipp Gegenwart, Dominik Legut, Johanna K. Jochum, Alexander A. Tsirlin, Petr Čermák
We realise the first ultralow-field Bose-Einstein condensation of triplons in a spin-ladder magnet, uncovering a quantum critical point at only $ \mu_0 H_{c1}=0.17$ T in Henmilite ($ \mathrm{Ca_2Cu(OH)_4[B(OH)_4]2}$ ). Unlike dimer magnets, a ladder retains extended one-dimensional correlations in its gapped parent state, making this limit strongly fluctuation dominated. Thermodynamic, magnetoelastic, $ \mu$ SR, and neutron-diffraction measurements overturn the previous assignment of zero-field antiferromagnetic order, establishing a quantum-disordered coupled-ladder parent state with persistent low-energy dynamics. The weak low-temperature anomaly instead marks a gap-controlled crossover from the correlated ladder regime into the activated quantum-disordered state. These measurements further reveal an exceptionally asymmetric ordered dome extending to $ \mu_0 H{c2}\simeq 8.2$ T. Quantum Monte Carlo simulations for the relevant spin Hamiltonian place Henmilite just on the gapped side of the zero-field ladder-ordering instability, naturally accounting for the strong separation between the exchange and residual-gap scales and the tiny critical field. Our findings extend ultralow-field triplon condensation beyond the dimer paradigm and establish Henmilite as a platform for controlled tuning across quantum criticality in a fluctuation-dominated spin ladder.
Strongly Correlated Electrons (cond-mat.str-el)
8 pages, 4 figures; Supplemental Material: 13 pages, 7 figures, 1 table
Dirac Surface States and Nonlocal Quantum Tunneling in Topological Semiconductor Mo$_2$SeTe$_3$ for High-Performance Tunnel FETs
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-08-24 20:00 EDT
Zafar Sadik Mehrub, Suvodip Kundu Arnob, Md. Tareq Mahmud, Nazmul Hasan, Alamgir Kabir
A first-principles and device-level study of the quasi-two-dimensional transition-metal chalcogenide Mo$ _2$ SeTe$ _3$ is performed. The material is found to be a weak topological semiconductor with a finite bulk band gap and symmetry-protected Dirac surface states, indicating strong potential for next-generation low-power quantum electronic devices. An SOC-driven band inversion accompanied by an indirect semiconducting gap of approximately 0.75 eV is observed. Topological nontriviality is rigorously confirmed through Wannier charge-center evolution and $ \mathbb{Z}_2$ invariant analysis, yielding weak topological indices of $ (0;001)$ , while iterative Green’s-function surface-state calculations corroborate Dirac-cone conducting states traversing the bulk gap on symmetry-preserving surfaces. Mo$ _2$ SeTe$ _3$ additionally exhibits exceptional dynamical and mechanical stability, pronounced optical anisotropy, high dielectric polarizability, broad infrared-to-visible optical absorption, a large static dielectric constant, and substantial birefringence, making it favorable for photonic and optoelectronic applications. Thermoelectric transport analyses further reveal enhanced carrier mobility and a competitive figure of merit under $ n$ -type doping near room temperature. A dual-source tunnel field-effect transistor (TFET) is implemented via TCAD simulations with nonlocal band-to-band tunneling, yielding subthreshold switching below the thermionic limit, a high ON/OFF current ratio, and enhanced tunneling efficiency driven by SOC-induced orbital hybridization and topologically enhanced interband coupling. The concurrent realization of nontrivial bulk-boundary correspondence, robust transport properties, and steep-slope switching characteristics establishes Mo$ _2$ SeTe$ _3$ as a multifunctional quantum material platform for topological and next-generation energy-efficient nanoelectronic devices.
Materials Science (cond-mat.mtrl-sci)
Maxwell’s Demon in Markov Chain Monte Carlo: Cooling Information Flow and Entropy Balance
New Submission | Disordered Systems and Neural Networks (cond-mat.dis-nn) | 2026-08-24 20:00 EDT
Markov chain Monte Carlo algorithms can be viewed as feedback devices that compare a proposed move with the target distribution and then accept or reject it. In this paper the Maxwell demon is identified with the acceptance module: it measures a proposed edge, stores the outcome in the accept/reject bit, and uses that bit to shape the probability current. The decision bit carries a genuine Shannon mutual information about the proposal, whereas only its directional part is converted into a cooling information flow. The relative-entropy relaxation rate obeys $ v(t)=\dot{\mathcal I}_{\rm cool}(t)+\dot S(t)$ , which separates useful cooling from housekeeping circulation in nonreversible chains.
Disordered Systems and Neural Networks (cond-mat.dis-nn)
10 pages, 1 figure
Research Square
Crystallization of pristine cubic ice from liquid at ambient pressure
Physical Sciences - Article | Structure of solids and liquids | 2026-08-23 20:00 EDT
Neal Skipper, Chenwei Zheng, Paul Henry, Aasim Shaffi, Sanghamitra Mukhopadhyay, Miroslava Novoveska, Milz Beaumont, Yidan Wang, Camilla Di Mino, Thomas Headen, Marta Falkowska, Christopher A Howard, Adam Clancy, Christoph Salzmann
The phase diagram of frozen water is famously rich: to date, over twenty distinct crystalline polymorphs have been identified [1,2]. Of the low-pressure “ice I” family, hexagonal (Ih) is the principal form on Earth, while cubic (Ic) is much more elusive. Fundamental questions remain open as to whether cubic ice Ic can form directly from the liquid state [3,4], its thermodynamic stability [5,6] and natural occurrence [7,8]. For example, the possibility that it might occur in the Earth’s atmosphere [7-12] or interstellar space [13-15]. To date, pure cubic ice has only been synthesized via complex preparation routes under specialized laboratory conditions [16-18], but a naturally accessible pathway to this important material has yet to be identified. Here we show that pristine cubic ice can be formed at atmospheric pressure simply by cooling a hydrate-forming aqueous solution confined within mesoporous silica. Using primarily neutron scattering, we show unambiguously that under these conditions, cubic ice Ic forms reproducibly and is the only thermodynamically stable crystalline phase of water. Control experiments show that the combination of nanoconfinement and the presence of a clathrate (water-cage) promoter is key. The discovery that cubic ice Ic is directly accessible from the liquid state, and stable at atmospheric pressure, strongly suggests that this polymorph plays a much more significant role in nature than previously thought, across a broad range of terrestrial and extraterrestrial environments.
Research Square:rs-10243371 (2026)
Posted on Research Square and Under Review at Nature Portfolio
Physical sciences/Materials science/Condensed-matter physics/Structure of solids and liquids, Earth and environmental sciences/Climate sciences/Atmospheric science/Atmospheric chemistry, Physical sciences/Physics/Condensed-matter physics/Surfaces, interfaces and thin films
Sequential template-mediated synthesis of interstitially boron-incorporated intermetallic Pt-M nanosheets
Article | Electrocatalysis | 2026-08-23 20:00 EDT
Jong Wook Hong, Hafidatul Wahidah, Hwang Hyun Wook, Bae Jin-Gyu, Ghufran Azizar, Kyeong Hoon Moon, Whang Youngjoo, Ji Hoon Lee, Seok Ki K im
Integrating interstitial light elements into ordered intermetallic frameworks within ultrathin two-dimensional (2D) nanostructures presents a fundamental synthetic conflict. Intermetallic ordering requires high-temperature annealing that sinters ultrathin nanosheets (NSs), whereas premature metal-nonmetal bonding suppresses the disorder-to-order transition. Here we overcome this incompatibility through a sequential template-mediated strategy. A thickness-controlled SiO2 layer affords L10-ordered PtNi NSs without morphological degradation, and the high atomic-diffusion barrier of the ordered superlattice then permits interstitial boron incorporation while preserving both the ordering and the ultrathin geometry. The resulting Int-PtNi-B NSs deliver mass activity of 4.99 A mg-1Pt and specific activity of 12.25 mA cm- 2 for oxygen reduction reaction (ORR), with only 22.8% activity loss after 100,000 cycles. Extension to Int-PtCo-B, Int-PtFe-B, and Int-PtMn-B NSs establishes compositional generality. In-situ X-ray absorption spectroscopy and density functional theory show that ordering suppresses surface oxidation and restructuring, while a boron-induced ligand effect optimizes oxygen-intermediate binding.
Research Square:rs-10673128 (2026)
Posted on Research Square and Under Review at Nature Portfolio
Physical sciences/Materials science/Materials for energy and catalysis/Electrocatalysis, Physical sciences/Chemistry/Electrochemistry/Electrocatalysis, Physical sciences/Nanoscience and technology/Nanoscale materials/Synthesis and processing, Physical sciences/Nanoscience and technology/Nanoscale materials/Two-dimensional materials, Physical sciences/Nanoscience and technology/Nanoscale materials/Structural properties
Exponential Advantage of Multipartite Entanglement over Quantum Communication with Applications to Bounded-Storage Cryptography
Article | Quantum information | 2026-08-23 20:00 EDT
Ananya Chakraborty, Manik Banik, Ronald de Wolf
We establish an exponential communication advantage enabled by multipartite quantum entanglement. Building on the bipartite Hidden Matching problem, we introduce a communication task involving multiple spatially separated senders and a single receiver. We show that a multipartite Greenberger-Horne-Zeilinger state shared among the senders and the receiver enables the task to be done using only logarithmically many bits of classical communication from each sender. In contrast, without preshared entanglement, any protocol achieving high success probability requires polynomial communication from at least one sender, even when \emph{quantum} communication is allowed. Thus, classical communication assisted by multipartite entanglement can be exponentially more powerful than quantum communication without preshared entanglement. As a cryptographic application, we construct a seeded two-source randomness extractor and establish an exponential separation between entangled and unentangled quantum side-information. Specifically, compromising the extractor with two unentangled quantum states storing information about the two sources, respectively, requires polynomial-size memory, whereas exponentially smaller quantum memory suffices in the presence of a small amount of shared entanglement. Together, these findings illuminate the transformative, exponential advantages that multipartite entanglement imparts to both communication and cryptographic regimes.
Research Square:rs-10587821 (2026)
Posted on Research Square and Under Review at Nature Portfolio
Physical sciences/Physics/Quantum physics/Quantum information, Physical sciences/Physics/Information theory and computation