CMP Journal 2025-06-24
Statistics
Nature: 1
Nature Reviews Materials: 1
Physical Review Letters: 6
Physical Review X: 1
arXiv: 115
Nature
Structural and functional characterization of human sweet taste receptor
Original Paper | Electron microscopy | 2025-06-23 20:00 EDT
Zongjun Shi, Weixiu Xu, Lijie Wu, Xiaolei Yue, Shenhui Liu, Wei Ding, Jinyi Zhang, Bing Meng, Lianghao Zhao, Xiaoyan Liu, Junlin Liu, Zhi-Jie Liu, Tian Hua
Sweet taste perception influences dietary choices and metabolic health. The human sweet taste receptor, a class C G protein-coupled receptor (GPCR) heterodimer composed of TAS1R2-TAS1R31,2, senses a wide range of sweet compounds – including natural sugars, artificial sweeteners and sweet proteins – impacting metabolic regulation beyond taste. However, the lack of three-dimensional structures hinders our understanding of its precise working mechanism. Here, we present cryo-EM structures of the full-length human sweet taste receptor in apo- and sucralose-bound states. These structures reveal a distinct asymmetric heterodimer architecture, with sucralose binding exclusively to the Venus flytrap domain of TAS1R2. Combining mutagenesis and molecular dynamics simulations, this work delineates the sweeteners recognition modes in TAS1R2. Structural comparisons further uncover the conformational changes upon ligand binding and unique activation mechanism. These findings illuminate the signal transduction mechanisms of chemosensory receptors in class C GPCRs and provide molecular basis for new-generation sweetener design.
Electron microscopy, Receptor pharmacology, Taste receptors
Nature Reviews Materials
Ionic potential for battery materials
Review Paper | Batteries | 2025-06-23 20:00 EDT
Qidi Wang, Yong-Sheng Hu, Hong Li, Hui-Ming Cheng, Tianshou Zhao, Chenglong Zhao
Developing high-performance rechargeable batteries requires a revolutionary advancement in battery materials, guided by a fundamental understanding of their underlying science and mechanisms. However, this task remains a challenge owing to the complex relationship among composition, structure and property in electrode and electrolyte materials. Ionic potential, a concept derived from geochemistry, has been incorporated into battery materials research since 2020 as a methodology for predicting and optimizing their functional properties. Defined as the ratio of charge number of an ion to its ionic radius, ionic potential serves as a measure of the interaction strength within the structure of a material. In this Perspective, we explore the role of ionic potential in guiding the design of advanced materials for rechargeable batteries. Specifically, we discuss how integrating ionic potential into material design frameworks can capture critical structural interactions, thereby enabling improvements in properties such as ionic conductivity, redox activity and phase transition behaviours. Furthermore, we identify the broader relevance of ionic potential in battery systems, highlighting its potential in advancing fundamental understanding and performance capabilities in battery technology.
Batteries, Energy, Materials for energy and catalysis
Physical Review Letters
Global Becomes Local: Efficient Many-Body Dynamics for Global Master Equations
Research article | Open quantum systems & decoherence | 2025-06-23 06:00 EDT
Alexander Schnell
This Letter makes progress on the issue of global vs local master equations. Global master equations like the Redfield master equation (following from standard Born and Markov approximation) require a full diagonalization of the system Hamiltonian. This is especially challenging for interacting quantum many-body systems. We discuss a short-bath-correlation-time expansion in reciprocal (energy) space, leading to a series expansion of the jump operator, which avoids a diagonalization of the Hamiltonian. For a bath that is coupled locally to one site, this typically leads to an expansion of the global Redfield jump operator in terms of local operators. We additionally map the local Redfield master equation to a novel local Lindblad form, giving an equation which has the same conceptual advantages of traditional local Lindblad approaches while being applicable in a much broader class of systems. Our ideas give rise to a nonheuristic foundation of local master equations, which can be combined with established many-body methods.
Phys. Rev. Lett. 134, 250401 (2025)
Open quantum systems & decoherence, Quantum fluctuations & noise, Quantum optics, Quantum statistical mechanics, Quantum transport, Nonequilibrium systems, Quantum spin models, Quantum wires, Computational complexity, Lindblad equation, Markovian processes, Master equation, Perturbative methods
First Constraints on General Neutrino Interactions Based on KATRIN Data
Research article | Beta decay | 2025-06-23 06:00 EDT
M. Aker et al. (KATRIN Collaboration)
*et al.*The KATRIN experiment places competitive constraints on the general neutrino interaction couplings using a fraction of the dataset from their second measurement campaign.
Phys. Rev. Lett. 134, 251801 (2025)
Beta decay, Neutrino interactions, Heavy neutrinos, Neutrinos
Gaussian-to-Non-Gaussian Transition of a Quantum Spin Bath Revealed by Fourth-Order Correlation
Research article | Quantum correlations in quantum information | 2025-06-23 06:00 EDT
Fan Xia, Shuowei Li, Xin-Yu Pan, Ping Wang, and Gang-Qin Liu
Non-Gaussian fluctuations are one of the essential properties of quantum systems. However, the direct detection of non-Gaussian fluctuations has not yet been achieved in experiments since the specific order of correlation has to be isolated from the complex dynamics of the whole system. In this Letter, we measure the second- and fourth-order correlations of $^{13}\mathrm{C}$ nuclear spins around a nitrogen vacancy center in diamond, using the recently developed quantum nonlinear spectroscopy. By adjusting the detection window and the spectral resolution, we observe the Gaussian to non-Gaussian transition of the multispin system. We find that the fourth-order correlation provides a fingerprint signal that can be used to identify individual spins with the same precession frequency, suggesting that Gaussianity is a potential quantum resource for quantum sensing. Our results shed light on the study of nonequilibrium quantum many-body dynamics and quantum materials at the nanoscale.
Phys. Rev. Lett. 134, 253601 (2025)
Quantum correlations in quantum information, Quantum sensing, Quantum-to-classical transition
Topological Landau Theory
Research article | Landau theory | 2025-06-23 06:00 EDT
Canon Sun and Joseph Maciejko
Contrary to conventional wisdom, so-called order parameters that distinguish symmetry-governed phases of matter can have topological structure.
Phys. Rev. Lett. 134, 256001 (2025)
Landau theory, Superconductivity, Topological phases of matter, BCS theory, Group theory
Intrinsic Thermal Hall Effect in Mott Insulators
Research article | Thermal Hall effect | 2025-06-23 06:00 EDT
Jixun K. Ding, Emily Z. Zhang, Wen O. Wang, Tessa Cookmeyer, Brian Moritz, Yong Baek Kim, and Thomas P. Devereaux
In light of recent experimental data indicating a substantial thermal Hall effect in square lattice antiferromagnetic Mott insulators, we investigate whether a simple Mott insulator can sustain a finite thermal Hall effect. We verify that the answer is ‘’no’’ if one performs calculations within a spin-only low-energy effective spin model with noninteracting magnons. However, by performing determinant quantum Monte Carlo simulations, we show the single-band $t\text{- }{t}^{‘ }\text{- }U$ Hubbard model coupled to an orbital magnetic field does support a finite thermal Hall effect when ${t}^{‘ }\ne 0$ and $B\ne 0$ in the Mott insulating phase. We argue that the (carrier agnostic) necessary conditions for observing a finite thermal Hall effect are time-reversal and particle-hole symmetry breaking. By considering magnon-magnon scattering using a semiclassical Boltzmann analysis, we illustrate a physical mechanism by which finite transverse thermal conductivity may arise, consistent with our symmetry argument and numerical results. Our results indicate that square and triangular lattices with SU(2) symmetry can support a finite thermal Hall effect and call for a critical reexamination of thermal Hall effect data in insulating magnets, as the magnon contribution should not be excluded a priori.
Phys. Rev. Lett. 134, 256501 (2025)
Thermal Hall effect, Mott insulators, Quantum Monte Carlo
Dynamic Scaling Theory for a Field Quench near the Kasteleyn Transition in Spin Ice
Research article | Dynamic critical phenomena | 2025-06-23 06:00 EDT
Stephen Powell and Sukla Pal
We present a dynamic scaling theory to describe relaxation dynamics following a magnetic-field quench near an unconventional phase transition in the magnetic material spin ice. Starting from a microscopic model, we derive an effective description for the critical dynamics in terms of the seeding and growth of string excitations, and use this to find scaling forms in terms of time, reduced temperature, and monopole fugacity. We confirm the predictions of scaling theory using Monte Carlo simulations, which also show good quantitative agreement with analytical expressions valid in the limit of low monopole density. As well as being relevant for experiments in the spin ice materials, our results open the way for the study of dynamic critical properties in a family of unconventional classical phase transitions.
Phys. Rev. Lett. 134, 256701 (2025)
Dynamic critical phenomena, Frustrated magnetism, Magnetic phase transitions, Spin dynamics, Spin ice, Stochastic processes
Physical Review X
Morse Theory and Meron-Mediated Interactions Between Disclination Lines in Nematic Materials
Research article | Line defects | 2025-06-23 06:00 EDT
Joseph Pollard and Richard G. Morris
Ideas from Morse theory reveal that smooth topological features called merons govern the complex linking and rearranging of defect lines in 3D nematic liquid crystals, offering a fuller understanding of their topology.
Phys. Rev. X 15, 021099 (2025)
Line defects, Topological defects, Active defects, Active nematics, Liquid crystals, Topology
arXiv
Electron conductive self-assembled hybrid low-molecular weight glycolipid-nanosilver gels
New Submission | Soft Condensed Matter (cond-mat.soft) | 2025-06-24 20:00 EDT
Korin Gasia Ozkaya (LCMCP-SMiLES), Othmane Darouich (LCMCP), Hynd Remita (ICP), Isabelle Lampre (ICP), Lionel Porcar (ILL), Alain Carvalho (ICS), M. Schmutz (ICS), Sandra Casale (LRS), Christel Laberty-Robert (LCMCP), Niki Baccile (LCMCP-SMiLES)
Low-molecular weight (LMW) hydrogels are gaining interest over macromolecular gels due to their reversible, dynamic and stimuli-responsive nature. They are potentially interesting functional materials for advanced applications such as catalysis, nanoelectronics or regenerative medicine. One common strategy to enhance the functional properties is to incorporate inorganic nanostructures. However, simultaneous control of the gel mechanics, shape and size of the nanostructures and functional properties is challenging. Here, a biobased, double amphiphilic, bolaform, single-glucose lipid (containing glucose and COOH in opposite directions) is able to coordinate silver ions, drive the formation of a self-assembled fibrous hydrogel and, after controlling the reduction time (seconds to hours) of the reduction process (NaBH4, ascorbate, $ \gamma$ -rays), stabilize Ag nanoparticles (NPs) of controlled size (2.8 nm $ \pm$ 13%). The NPs are spontaneously embedded in the fibers’ core following a two-dimensional anisotropic long-range order. Precise control of the reduction parameters (ascorbate) drives the formation of Ag nanowires, possibly due to an anisotropic coalescence process of the nanoparticles. Samples containing Ag nanowires have shown an electronic conductive response, observed with impedance spectroscopy. This works shows the potential of biological amphiphiles to develop under soft conditions (pseudo single step, water, room temperature) advanced hybrid organic/inorganic (O/I) materials with a multiscale structure, order and electron conductivity functionality
Soft Condensed Matter (cond-mat.soft), Materials Science (cond-mat.mtrl-sci)
CLOUD: A Scalable and Physics-Informed Foundation Model for Crystal Representation Learning
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-06-24 20:00 EDT
Changwen Xu, Shang Zhu, Venkatasubramanian Viswanathan
The prediction of crystal properties is essential for understanding structure-property relationships and accelerating the discovery of functional materials. However, conventional approaches relying on experimental measurements or density functional theory (DFT) calculations are often resource-intensive, limiting their scalability. Machine learning (ML) models offer a promising alternative by learning complex structure-property relationships from data, enabling faster predictions. Yet, existing ML models often rely on labeled data, adopt representations that poorly capture essential structural characteristics, and lack integration with physical principles–factors that limit their generalizability and interpretability. Here, we introduce CLOUD (Crystal Language mOdel for Unified and Differentiable materials modeling), a transformer-based framework trained on a novel Symmetry-Consistent Ordered Parameter Encoding (SCOPE) that encodes crystal symmetry, Wyckoff positions, and composition in a compact, coordinate-free string representation. Pre-trained on over six million crystal structures, CLOUD is fine-tuned on multiple downstream tasks and achieves competitive performance in predicting a wide range of material properties, demonstrating strong scaling performance. Furthermore, as proof of concept of differentiable materials modeling, CLOUD is applied to predict the phonon internal energy and heat capacity, which integrates the Debye model to preserve thermodynamic consistency. The CLOUD-DEBYE framework enforces thermodynamic consistency and enables temperature-dependent property prediction without requiring additional data. These results demonstrate the potential of CLOUD as a scalable and physics-informed foundation model for crystalline materials, unifying symmetry-consistent representations with physically grounded learning for property prediction and materials discovery.
Materials Science (cond-mat.mtrl-sci), Machine Learning (cs.LG)
36 pages, 11 pages of Supporting Information
Quantum Geometric Origin of the Intrinsic Nonlinear Hall Effect
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2025-06-24 20:00 EDT
Yannis Ulrich, Johannes Mitscherling, Laura Classen, Andreas P. Schnyder
We analyze the quantum geometric contribution to the intrinsic second-order nonlinear Hall effect (NLHE) for a general multiband Hamiltonian. The nonlinear conductivity, obtained in Green’s function formalism, is decomposed into its quantum geometric constituents using a projector-based approach. In addition to the previously identified Berry curvature and interband quantum metric dipoles, we obtain a third term of quantum geometric origin, given by the momentum derivative of the $ intraband$ quantum metric. This contribution, which we term the intraband quantum metric dipole, provides substantial corrections to the NLHE in topological magnets and becomes the dominant geometric term in topological antiferromagnets with gapped Dirac cones. Considering generalized 2D and 3D Weyl/Dirac Hamiltonians, describing a large class of topological band crossings with sizable quantum geometry, we derive analytical expressions of the NLHE, thereby revealing the individual contributions of the three quantum geometric terms. Combined with an exhaustive symmetry classification of all magnetic space groups, this analysis leads to the identification of several candidate materials expected to exhibit large intrinsic NLHE, including the antiferromagnets $ \text{Yb}_3\text{Pt}_4$ , $ \text{CuMnAs}$ , and $ \text{CoNb}_3\text{S}_6$ , as well as the nodal-plane material $ \text{MnNb}_3\text{S}_6$ . Finally, our projector-based approach yields a compact expression for the NLHE in terms of momentum derivatives of the Bloch Hamiltonian matrix alone, enabling efficient numerical evaluation of each contribution in the aforementioned materials.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Materials Science (cond-mat.mtrl-sci), Strongly Correlated Electrons (cond-mat.str-el)
9+28 pages, 2+2 tables, 1+3 figures. Any comments are welcome!
Specific-heat anomaly in frustrated magnets with vacancy defects
New Submission | Disordered Systems and Neural Networks (cond-mat.dis-nn) | 2025-06-24 20:00 EDT
Muhammad Sedik, Siyu Zhu, Sergey Syzranov
Motivated by frustrated magnets and spin-liquid-candidate materials, we study the thermodynamics of a 2D geometrically frustrating magnet with vacancy defects. The presence of vacancies imposes constraints on the bulk spins, which freezes some of the degrees of freedom in the system at low temperatures. With increasing temperature, these constraints get relaxed, resulting in an increase in the system’s entropy. This leads to the emergence of a peak in the heat capacity $ C(T)$ of the magnet at a temperature determined by the concentration of the vacancy defects. To illustrate the emergence of such an anomaly, we compute analytically the heat capacity of the antiferromagnetic (AFM) Ising model on the triangular lattice with vacancy defects. The presence of the vacancy leads to a peak in $ C(T)$ at the temperature $ T_\text{imp}=-6J/\ln n_\text{imp}$ , where $ J$ is the AFM coupling between the spins and $ n_\text{imp}$ is the fraction of the missing sites.
Disordered Systems and Neural Networks (cond-mat.dis-nn), Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Statistical Mechanics (cond-mat.stat-mech), Strongly Correlated Electrons (cond-mat.str-el)
Tunable anyonic permeability across ${\mathbb{Z}_2}$ spin liquid junctions
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2025-06-24 20:00 EDT
Sayak Bhattacharjee, Soumya Sur, Adhip Agarwala
We introduce two classes of junctions in a toric code, a prototypical model of a $ \mathbb{Z}_2$ quantum spin liquid, and study the nature of anyonic transport across them mediated by Zeeman fields. In the first class of junctions, termed potential barrier junctions, the charges sense effective static potentials and a change in the band mass. In a particular realization, while the junction is completely transparent to the electric charge, magnetic charge transmission is allowed only after a critical field strength. In the second class of junctions we stitch two toric codes with operators which do not commute at the junction. We show that the anyonic transmission gets tuned by effective pseudospin fluctuations at the junction. Using exact analytical mappings and numerical simulations, we compute charge-specific transmission probabilities. Our work, apart from uncovering the rich physical mechanisms at play in such junctions, can motivate experimental work to engineer defect structures in topologically ordered systems for tunable transport of anyonic particles.
Strongly Correlated Electrons (cond-mat.str-el), Quantum Physics (quant-ph)
7 pages, 3 figures, and Supplemental Material
Negative intrinsic viscosity in graphene nanoparticle suspensions induced by hydrodynamic slip
New Submission | Soft Condensed Matter (cond-mat.soft) | 2025-06-24 20:00 EDT
Adyant Agrawal, Catherine Kamal, Simon Gravelle, Lorenzo Botto
The viscosity of nanoparticle suspensions is always expected to increase with particle concentration. However, a growing body of experiments on suspensions of atomically thin nanomaterials such as graphene contradicts this expectation. Some experiments indicate effective suspension viscosity values that fall below that of pure solvent at high shear rates and low solid concentrations, i.e., the intrinsic viscosity is negative. To explain this puzzling phenomenon, we combined molecular dynamics and boundary integral simulations to investigate the shear viscosity of few-nanometer graphene sheets in water at high Péclet numbers (Pe $ > 100$ ). Our results, covering geometric aspect ratios from 4.5 to 12.0, show robustly that the intrinsic viscosity decreases with increasing aspect ratio and becomes negative beyond a threshold aspect ratio $ \approx 5.5$ . We demonstrate that this anomalous behavior originates from hydrodynamic slip at the liquid-solid interface, which suppresses particle rotation and promotes stable alignment with the flow direction, thereby reducing viscous dissipation relative to dissipation in pure solvent. This slip mechanism holds for both fully 3D disc-like and quasi-2D particle geometries explored in the molecular simulations. As the concentration of graphene particles increases in the dilute regime, the viscosity initially decreases, falling below that of pure water. At higher concentrations, however, particle aggregation becomes significant, leading to a rise in viscosity after a minimum is reached. These findings confirm the occurrence of a negative intrinsic viscosity in a graphene suspension due only to hydrodynamic effects. Our work has important implications for the design of lubricants, inks, and nanocomposites with tunable viscosity.
Soft Condensed Matter (cond-mat.soft)
Electron beam irradiation-induced transport and recombination in p-type Gallium Oxide grown on (001) \b{eta}-Ga2O3 substrate
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-06-24 20:00 EDT
Gabriel Marciaga, Jian-Sian Li, Chao-Ching Chiang, Fan Ren, Stephen J. Pearton, Corinne Sartel, Zeyu Chi, Yves Dumont, Ekaterine Chikoidze, Alfons Schulte, Arie Ruzin, Leonid Chernyak
This study investigates minority electron diffusion length and carrier recombination phenomena within p-type, 300 nm-thick Ga2O3 epitaxial films. Utilizing Electron Beam-Induced Current (EBIC) and Cathodoluminescence (CL) spectroscopy, these characteristics were examined as a function of both temperature and the duration of electron beam excitation. While the electron diffusion length in these p-Ga2O3 films diminish with increasing temperature, a continuous electron beam excitation of a particular location on the surface of a p-Ga2O3 epitaxial layer leads to an elongation of the diffusion length. and decay of cathodoluminescence intensity in that location under beam exposure. These latter two effects are attributed to non-equilibrium electrons, generated by an electron beam, being captured at acceptor-related point defect levels in Gallium Oxide. The activation energies characterizing these processes were obtained from the independent EBIC and CL experiments to garner insight into defect landscape and its influence on transport and recombination dynamics.
Materials Science (cond-mat.mtrl-sci), Applied Physics (physics.app-ph)
21 pages, 8 figures
Finite time path field theory and a new type of universal quantum spin chain quench behaviour
New Submission | Statistical Mechanics (cond-mat.stat-mech) | 2025-06-24 20:00 EDT
Domagoj Kuić, Alemka Knapp, Diana Šaponja-Milutinović
We discuss different quench protocols for Ising and XY spin chains in a transverse magnetic field. With a sudden local magnetic field quench as a starting point, we generalize our approach to a large class of local non-sudden quenches. Using finite time path field theory perturbative methods, we show that the difference between the sudden quench and a class of quenches with non-sudden switching on the perturbation vanishes exponentially with time, apart from non-substantial modifications that are systematically accounted for. As the consequence of causality and analytic properties of functions describing the discussed class of quenches, this is true at any order of perturbation expansion and thus for the resummed perturbation series. The only requirements on functions describing the perturbation strength switched on at a finite time t=0 are: (1) their Fourier transform f(p) is a function that is analytic everywhere in the lower complex semiplane, except at the simple pole at p=0 and possibly others with Im (p) < 0, and (2) that f(p)/p converges to zero at infinity in the lower complex semiplane. Prototypical function of this class is tanh(eta t), to which the perturbation strength is proportional after the switching on time t=0. In the limit of large eta, such a perturbation approaches the case of a sudden quench. It is shown that, because of this new type of universal behaviour of Loschmidt echo that emerges in exponentially short time scale, our previous results (Kuić, D. et al. Universe 2024, 10, 384) for the sudden local magnetic field quench of Ising and XY chains, obtained by resummation of the perturbative expansion, extend in the long time limit to all non-sudden quench protocols in this class, with non-substantial modifications systematically taken into account. We also show that analogous universal behaviour exists in disorder quenches, and ultimately global ones.
Statistical Mechanics (cond-mat.stat-mech), High Energy Physics - Theory (hep-th), Mathematical Physics (math-ph), Quantum Physics (quant-ph)
25 pages, 1 figure, revtex4-1
Normal modes and shockwaves in cold atoms
New Submission | Quantum Gases (cond-mat.quant-gas) | 2025-06-24 20:00 EDT
Numerical methods are developed to simulate the dynamics of atoms in a Magneto-Optic Trap (MOT), based on the fluid description of ultracold gases under laser cooling and magnetic trapping forces. With this model, equilibrium hydrostatic profiles and normal modes are calculated, and numerical results are validated against theoretical predictions. As a test case, shock wave formation due to rapid gas expansion and contraction of the ultracold gas is simulated. The latter is caused by a sudden change of the value of its effective collective charge. Limitations of the current methods and future improvements are discussed. This work provides a foundation for studying numerically complex MOT behaviors and their use as analog simulators for astrophysical phenomena.
Quantum Gases (cond-mat.quant-gas), Atomic Physics (physics.atom-ph)
Tunable symmetry breaking in a hexagonal-stacked moiré magnet
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-06-24 20:00 EDT
Zeliang Sun, Gaihua Ye, Xiaohan Wan, Ning Mao, Cynthia Nnokwe, Senlei Li, Nishkarsh Agarwal, Siddhartha Sarkar, Zixin Zhai, Bing Lv, Robert Hovden, Chunhui Rita Du, Yang Zhang, Kai Sun, Rui He, Liuyan Zhao
Symmetry plays a central role in defining magnetic phases, making tunable symmetry breaking across magnetic transitions highly desirable for discovering non-trivial magnetism. Magnetic moiré superlattices, formed by twisting two-dimensional (2D) magnetic crystals, have been theoretically proposed and experimentally explored as platforms for unconventional magnetic states. However, despite recent advances, tuning symmetry breaking in moiré magnetism remains limited, as twisted 2D magnets, such as rhombohedral (R)-stacked twisted CrI_3, largely inherit the magnetic properties and symmetries of their constituent layers. Here, in hexagonal-stacked twisted double bilayer (H-tDB) CrI_3, we demonstrate clear symmetry evolution as the twist angle increases from 180^{\circ} to 190^{\circ}. While the net magnetization remains zero across this twist angle range, the magnetic phase breaks only the three-fold rotational symmetry at 180^{\circ}, but it breaks all of the rotational, mirror, and time-reversal symmetries at intermediate twist angles between 181^{\circ} and 185^{\circ}, and all broken symmetries are recovered at 190^{\circ}. These pronounced symmetry breakings at intermediate twist angles are accompanied by metamagnetic behaviors, evidenced by symmetric double hysteresis loops around zero magnetic field. Together, these results reveal that H-tDB CrI_3 at intermediate twist angles host a distinct moiré magnetic phase, featuring periodic in-plane spin textures with broken rotational, mirror, and time-reversal symmetries, which is markedly different from the out-of-plane layered antiferromagnetism in bilayer CrI_3 and the predominantly out-of-plane moiré magnetism in R-tDB CrI_3. Our work establishes H-stacked CrI_3 moiré magnets as a versatile platform for engineering magnetic properties, including and likely beyond complex spin textures.
Materials Science (cond-mat.mtrl-sci)
Raman scattering from moiré phonons
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2025-06-24 20:00 EDT
Vitor Dantas, Héctor Ochoa, Rafael M. Fernandes, Natalia B. Perkins
We develop a theoretical framework for probing moiré phonon modes using Raman spectroscopy, and illustrate it with the example of twisted bilayer graphene (TBG). These moiré phonons arise from interlayer sliding motion in twisted 2D materials and correspond to fluctuations of the stacking order in reconstructed moiré superlattices. These include both acoustic-like phason modes and a new set of low-energy optical modes originating from the zone-folding of monolayer graphene’s acoustic modes, which are accessible via Raman spectroscopy. We show that the Raman response of TBG exhibits a series of low-frequency peaks that clearly distinguish it from that of decoupled layers. We further examine the role of anharmonic interactions in shaping the phonon linewidths and demonstrate the strong dependence of the Raman spectra on both the twist angle and the polarization of the incident light. Our findings establish Raman spectroscopy as a powerful tool for exploring moiré phonons in a broad class of twisted van der Waals systems.
Strongly Correlated Electrons (cond-mat.str-el)
5 pages, 2 figures, supplemental materials included
Robustness of Majorana modes to potential disorder in Fe chains on a superconducting Rashba alloy
New Submission | Superconductivity (cond-mat.supr-con) | 2025-06-24 20:00 EDT
Harim Jang, Daniel Crawford, Khai Ton That, Lucas Schneider, Jens Wiebe, Makoto Shimizu, Harald O. Jeschke, Stephan Rachel, Roland Wiesendanger
Majorana modes offer great potential for fault-tolerant quantum computation due to their topological protection. However, for superconductor-semiconductor nanowire hybrids, intrinsic disorder makes the unambiguous detection of Majorana modes difficult. Here, we construct 1D spin chains from individual Fe atoms on the Rashba surface alloy BiAg2/Ag(111) with proximity-induced superconductivity from a Nb(110) substrate. While the Fe chains exhibit perfect crystalline order, we observe nano-scale potential disorder of the BiAg2/Ag(111)/Nb(110) heterostructure by scanning tunneling microscopy. However, this does not prevent the emergence of zero-energy modes at both ends of the Fe chains, in agreement with tight-binding calculations showing that they are only found in the topologically non-trivial regime of the phase diagram. These Majorana modes are indeed robust against potential disorder.
Superconductivity (cond-mat.supr-con), Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
25 pages, 4 figures
A Morphologically Self-Consistent Phase Field Model for the Computational Study of Memristive Thin Film Current-Voltage Hysteresis
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-06-24 20:00 EDT
John F. Sevic, Ambroise Juston, Nobuhiko P. Kobayashi
A multiphysics phase field model is used for the computational study of memristive thin film morphology and current-voltage hysteresis. In contrast to previous computational methods, no requirements are made on conducting filament geometry. Our method correctly predicts conducting filaments evolve on thermodynamic paths that are energetically favored due to stochastic structural and chemical variations naturally occurring at the atomic-level, due to both latent and intentional fabrication effects. These results have significant implications for the computational design of a broad class of memristive thin films, enabling practical wafer-scale mapping, uniformity, and endurance analysis and optimization.
Materials Science (cond-mat.mtrl-sci), Applied Physics (physics.app-ph)
There six pages of text and figures and one additional page for references. There are four figures. We have also a movie if the reviewer is interested
Sedimentation equilibrium as a probe of the pressure equation of state of active colloids
New Submission | Soft Condensed Matter (cond-mat.soft) | 2025-06-24 20:00 EDT
Yunhee Choi, Elijah Schiltz-Rouse, Parvin Bayati, Stewart A. Mallory
We introduce a theoretical and computational framework for extracting the pressure equation of state (EoS) of an active suspension from its steady-state sedimentation profile. As EoSs are prerequisites for many theories in active matter, determining how pressure depends on key parameters such as density, activity, and interparticle interactions is essential to make quantitative predictions relevant to materials design and engineering applications. Focusing on the one-dimensional active Brownian particle (1D-ABP) model, we show that the pressure measured in a homogeneous periodic system can be recovered from the spatial profiles established in sedimentation equilibrium. Our approach is based on exact mechanical considerations and provides a direct route for determining pressure from experimentally measurable quantities. This work compares sedimentation-derived equations of state with those obtained from periodic simulations, establishing a foundation for using sedimentation as a generic tool to characterize the behavior of active suspensions.
Soft Condensed Matter (cond-mat.soft), Statistical Mechanics (cond-mat.stat-mech)
(11 pages, 5 figures) Comments Welcome!
The influence of nitrogen doping and annealing on the silicon vacancy in 4H-SiC
New Submission | Other Condensed Matter (cond-mat.other) | 2025-06-24 20:00 EDT
Samuel G. Carter, Infiter Tathfif, Charity Burgess, Brenda VanMil, Suryakanti Debata, Pratibha Dev
The silicon vacancy ($ V_{Si}$ ) in 4H-SiC at its cubic site (V2-center) has shown significant promise for quantum technologies, due to coherent spin states, the mature material system, and stable optical emission. In these SiC-based applications, doping plays a crucial role. It can be used to control the charge state of $ V_{Si}$ and formation of different types of defects. Despite its importance, there has been little research on the effects of doping. In this work, we perform a study of the effects of nitrogen doping and annealing on the photoluminescence (PL), optically-detected magnetic resonance (ODMR) contrast, and dephasing times of ensembles of V2 in epilayers of 4H-SiC. The results show an enhancement of PL that depends on the electron irradiation dose for a given electron concentration, supported by theoretical modeling of the charge state of $ V_{Si}$ in the presence of nitrogen. Nitrogen substituted for carbon is shown to very efficiently donate one electron to $ V_{Si}$ . We also observe that the ODMR contrast can be increased from 0.5% in low doped SiC to 1.5% by nitrogen doping of $ 10^{17}$ to $ 10^{18}$ cm$ ^{-3}$ and annealing at 500-600 $ ^{\circ}$ C for 1 hour, with only a 20% decrease in PL compared to unannealed. Some of the improvement in contrast is offset by a reduction in $ T_2^\ast$ at these doping levels, but the estimated cw ODMR shot-noise limited sensitivity is still 1.6 times higher than that of undoped, unannealed SiC.
Other Condensed Matter (cond-mat.other), Quantum Physics (quant-ph)
Single crystalline orthorhombic GdAlGe as a rare earth magnetic Dirac nodal-line metal
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-06-24 20:00 EDT
Antu Laha, Juntao Yao, Asish K. Kundu, Niraj Aryal, Anil Rajapitamahuni, Elio Vescovo, Fernando Camino, Kim Kisslinger, Lihua Zhang, Dmytro Nykypanchuk, J. Sears, J. M. Tranquada, Weiguo Yin, Qiang Li
Crystal engineering is a method for discovering new quantum materials and phases, which may be achieved by external pressure or strain. Chemical pressure is unique in that it generates internal pressure perpetually to the lattice. As an example, GdAlSi from the rare-earth ($ R$ ) $ R$ Al$ X$ ($ X =$ Si or Ge) family of Weyl semimetals is considered. Replacing Si with the larger isovalent element Ge creates sufficiently large chemical pressure to induce a structural transition from the tetragonal structure of GdAlSi, compatible with a Weyl semimetallic state, to an orthorhombic phase in GdAlGe, resulting in an inversion-symmetry-protected nodal-line metal. We find that GdAlGe hosts an antiferromagnetic ground state with two successive orderings, at $ T_\mathrm{N1}$ = 35 K and $ T_\mathrm{N2}$ = 30 K. In-plane isothermal magnetization shows a magnetic field induced metamagnetic transition at 6.2 T for 2 K. Furthermore, electron-hole compensation gives rise to a large magnetoresistance of $ \sim 100%$ at 2 K and 14 T. Angle-resolved photoemission spectroscopy measurements and density functional theory calculations reveal a Dirac-like linear band dispersion over an exceptionally large energy range of $ \sim$ 1.5 eV with a high Fermi velocity of $ \sim 10^6$ m/s, a rare feature not observed in any magnetic topological materials.
Materials Science (cond-mat.mtrl-sci)
11 pages, 9 figures
Hydrodynamic Equations for Active Brownian Particles in the High Persistence Regime
New Submission | Soft Condensed Matter (cond-mat.soft) | 2025-06-24 20:00 EDT
Martín Pinto-Goldberg, Rodrigo Soto
Based on a recently proposed kinetic description of non-inertial active Brownian particles, Navier–Stokes-like equations are derived in the high persistence regime, where polarization is a slow field together with density. Using the Chapman–Enskog method, all transport coefficients in the equations are obtained in terms of microscopic quantities. A linear stability analysis of the homogeneous and isotropic state shows the appearance of a density instability, allowing us to determine the regions of phase space where the motility induced phase separation occurs. Numerical solutions of the equations in one spatial dimension show the need of an additional regularizing pressure term. With the inclusion of this term, the solutions illustrate in detail the clustering dynamics in homogeneous conditions, as well as the behavior that emerges when a gravitational field is applied in presence of a wall.
Soft Condensed Matter (cond-mat.soft)
On the Photoluminescence Theory in Nanocrystalline Silicon: A New Improvement
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-06-24 20:00 EDT
Silicon has long been the foundational semiconductor material for a broad range of electronic devices, owing to its numerous advantages: wide natural availability, ease of synthesis in both crystalline and amorphous forms, and relatively low production cost. However, despite these benefits, silicon is inherently limited in the field of optoelectronics due to its indirect bandgap, which results in low quantum efficiency for light emission, typically in the infrared region. One promising strategy to address this limitation is the development of nanocrystalline silicon, which consists of low-dimensional nanostructures such as quantum wires (QWs) and quantum dots (QDs). These structures exhibit enhanced photoluminescence and electroluminescence, primarily due to quantum confinement of excitons within the conduction and valence bands, leading to significantly improved quantum efficiency. Although research into these processes has spanned several decades, a definitive consensus on the mechanisms underlying photoluminescent emission in nanocrystalline silicon remains elusive. This work reviews two leading theoretical models proposed to explain this phenomenon and introduces a new, more comprehensive model that may provide a deeper and more accurate understanding of photoluminescence in nanocrystalline silicon. The new theory is applied in a case study.
Materials Science (cond-mat.mtrl-sci), Applied Physics (physics.app-ph)
9 pages, 4 figures, letter style
A review of heat transport in solvated gold nanoparticles: Molecular dynamics modeling and experimental perspectives
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2025-06-24 20:00 EDT
Md Adnan Mahathir Munshi, Emdadul Haque Chowdhury, Luis E. Paniagua-Guerra, Jaymes Dionne, Ashutosh Giri, Bladimir Ramos-Alvarado
Turning gold nanoparticles (AuNPs) into nanoscale heat sources via light irradiation has prompted significant research interest, particularly for biomedical applications over the past few decades. The AuNP’s tunable photothermal effect, notable biocompatibility, and ability to serve as vehicles for temperature-sensitive chemical linkers enable thermo-therapeutics, such as localized drug/gene delivery and thermal ablation of cancerous tissue. Thermal transport in aqueous AuNP solutions stands as the fundamental challenge to developing targeted thermal therapies; thus, this review article surveys recent advancements in our understanding of heat transfer and surface chemistry in AuNPs, with a particular focus on thermal boundary conductance across gold- and functionalized-gold-water interfaces. This review article highlights computational advances based on molecular dynamics simulations that offer valuable insights into nanoscopic interfacial heat transfer in solvated interfaces, particularly for chemically functionalized AuNPs. Additionally, it outlines current experimental techniques for measuring interfacial thermal transport, their limitations, and potential pathways to improve sensitivity. This review further examines computational methodologies to guide the accurate modeling of solvated gold interfaces. Finally, it concludes with a discussion of future research directions aimed at deepening our understanding of interfacial heat transfer in solvated AuNPs, crucial to optimize thermoplasmonic applications.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Materials Science (cond-mat.mtrl-sci)
67 pages, 12 figures
Interfacial instability of confined 3D active droplets
New Submission | Soft Condensed Matter (cond-mat.soft) | 2025-06-24 20:00 EDT
Bennett C. Sessa, Federico Cao, Robert A. Pelcovits, Thomas R. Powers, Guillaume Duclos
Instabilities of fluid-fluid interfaces are ubiquitous in passive soft matter. Adding activity to the interface or either fluid can dramatically change the stability of the interface. Using experiment and theory, we investigate the interfacial instability of a deformable 3D active nematic liquid crystal droplet in the isotropic phase surrounded by a passive fluid and confined between two parallel plates. Spontaneous active flows drive the growth of undulations along the active/passive interface, with the mode number of the fastest-growing mode increasing with droplet radius and decreasing with gap height. We apply the lubrication approximation to a minimal nematohydrodynamic model to determine the growth rates of all interfacial modes. The magnitude of the growth rate is determined by the active timescale and the relaxation timescales associated with liquid crystalline order, as well as capillary and viscous stresses. We find multiple points of agreement between experiment and theory, including the shape evolution of individual droplets, the growth rates of unstable modes averaged across many droplets, and the extensional shear flows observed within droplets.
Soft Condensed Matter (cond-mat.soft)
Large volume ‘chunk’ lift out for 3D tomographic analysis using analytical plasma focussed ion beam – scanning electron microscopy
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-06-24 20:00 EDT
Ruth Birch, Shuheng Li, Sharang Sharang, Warren J. Poole, Ben Britton
Characterization of the structure and properties of materials in three dimensions, including grains and the residual pattern of deformation, provides necessary information required to guide materials design as well as support materials modelling efforts. In this work, we present an overview of site-specific large volume ‘chunk’ lift out and 3D serial sectioning of substantive volumes (e.g. 200 x 200 x 400 um3), where sectioning is optimized for 3D electron backscatter diffraction (EBSD) based crystallographic analysis, using a plasma (Xe) focussed ion beam scanning electron microscope (plasma FIB-SEM) equipped to perform EBSD using a ‘static’ configuration (i.e. slicing and EBSD-mapping are performed without moving the sample). This workflow is demonstrated through the 3D plasma FIB-SEM based EBSD analysis of an indent made within a polycrystal of pure magnesium. The lift out approach is suitable for a wide range of materials, and we offer a step-by-step guide within the present work to provide opportunity for others to more easily enter this field and collect valuable data.
Materials Science (cond-mat.mtrl-sci), Instrumentation and Detectors (physics.ins-det)
Toward a Circular Nanotechnology for Biofuels: Integrating Sustainable Synthesis, Recovery, and Performance Optimization
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-06-24 20:00 EDT
Lydia Lonardi, Caitlyn Lew-Tong, Brian Dunsten Miranda, Chandraleka V.S., Evelyn (Wenxuan)Li, Bhaavyaa Sahukari, Harshit Poddar, Keerthana Satheesh, Utkarsh Chadha
This review exhaustively evaluates the role of nanomaterials across synthesis, characterization and application stages of biofuel systems. The common types of nanomaterials that are used for biofuel applications include metal oxides, carbon-based structures, and hybrids are evaluated for their effectiveness in efficient biofuel production. The properties of such nanomaterials are being utilized as an aid to produce biofuels through improved catalysis, enzyme immobilization and thermal stability. Common synthesis methods such as sol-gel, co-precipitation, and green synthesis are compared, alongside characterization tools like TEM, SEM, FTIR, and BET. This study focuses on transesterification, biomass pretreatment, and fermentation processes, where nanomaterials significantly improve yield and reusability. There are several challenges despite the merit of using nanomaterials, the tradeoffs include costs, scalability, and environmental impact, which further expands into evaluating the life cycle of such materials being used. This review outlines the practical potential of the nanomaterials in enabling more efficient and sustainable biofuel production.
Materials Science (cond-mat.mtrl-sci)
Currently Submitted to “Advanced Sustainable Systems”
Physisorption on Nanomechanical Resonators: The Overlooked Influence of Trace Moisture
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2025-06-24 20:00 EDT
Hemant Kumar Verma, Suman Kumar Mandal, Darkasha Khan, Faizan Tariq Beigh, Manoj Kandpal, Jaspreet Singh, Sushobhan Avasthi, Srinivasan Raghavan, Akshay Naik
Short gas pulses introduced in a vacuum chamber have long been utilized to showcase the ultra-low mass resolutions achievable with nanomechanical resonators. The resonance frequency shifts are used as evidence of gas adsorption. However, there is very little clarity as to what exactly is adsorbing on to the resonators. We demonstrate that the physisorption of gases on cantilevers is predominantly the effect of moisture content that is present even in ultra-high purity gases. The experimental work is performed at low temperatures and in a high vacuum and is supported by theoretical calculations and simulation.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Applied Physics (physics.app-ph)
The free propagator of strongly anisotropic systems with free surfaces
New Submission | Statistical Mechanics (cond-mat.stat-mech) | 2025-06-24 20:00 EDT
A brief overview of fluctuation-induced forces in statistical systems with film geometry at the critical point and the calculation of Casimir amplitudes, which characterize these forces quantitatively, is presented. Particular attention is paid to the special features of strongly anisotropic $ m$ -axis systems at the Lifshitz point, specifically, in the case of a “$ perpendicular$ “ orientation of surfaces with free boundary conditions. Beyond the simplest one-loop approximation, calculations of Casimir amplitudes are impossible without knowledge of the Gaussian propagator, which corresponds to the lines of Feynman diagrams in the perturbation theory. We present an explicit expression for such a propagator in the case of an anisotropic system confined by parallel surfaces $ perpendicular$ to one of the anisotropy axes. Using this propagator, we reproduce the one-loop result derived earlier in an essentially different way. The knowledge of the propagator provides the possibility of higher-order calculations in perturbation theory.
Statistical Mechanics (cond-mat.stat-mech)
Morphoelastic ribbons: Differential growth-induced curvature and torsion
New Submission | Soft Condensed Matter (cond-mat.soft) | 2025-06-24 20:00 EDT
Hao Liu, Mingwu Li, Dabiao Liu
Natural slender structures, such as plant leaves, petals, and tendrils, often exhibit complex three-dimensional (3D) morphologies-including twisting, helical coiling, and saddle-bending-driven by differential growth. The resulting internal stresses are partially relieved through the development of intrinsic curvature and torsion. The fundamental challenge lies in effectively correlating microscopic growth fields to the macroscopic shapes and mechanical responses of the ribbon structures. However, existing ribbon or shell models struggle to directly link growth gradients to macroscopic curvature and torsion, necessitating a reduced-dimensional framework. This work establishes a unified one-dimensional (1D) morphoelastic ribbon model derived rigorously from 3D finite elasticity theory via a two-step asymptotic dimension reduction. The reduced-order model captures key geometric nonlinearities and finite rotations while retaining explicit dependence on the growth tensor. We obtain analytical solutions for saddle-bending and twisting configurations induced by specific growth gradients. Furthermore, numerical continuation, based on the reduced model, reveals post-buckling transitions into helical morphologies, identifying bifurcation thresholds and constructing phase diagrams. This framework explicitly links growth fields to ribbon curvature and torsion, providing fundamental mechanics insights into the morphogenesis of slender plant organs and offering the potential for bioinspired soft robotics design.
Soft Condensed Matter (cond-mat.soft)
41 pages, 12 figures
Field-Free Superconducting Diode Enabled by Geometric Asymmetry and Perpendicular Magnetization
New Submission | Superconductivity (cond-mat.supr-con) | 2025-06-24 20:00 EDT
Jiaxu Li, Zijian Zhang, Shiqi Wang, Yu He, Haochang Lyu, Qiusha Wang, Bowen Dong, Daoqian Zhu, Hisakazu Matsuki, Dapeng Zhu, Guang Yang, Weisheng Zhao
The superconducting diode effect (SDE)- manifested as directional, dissipationless supercurrents - is pivotal for realizing energy-efficient superconducting logic and memory technologies. Achieving high-efficiency SDE without external magnetic fields, however, remains a fundamental challenge. Here, we report a strongly enhanced, field-free SDE in Pt/Co/Nb heterostructures, enabled by the interplay of engineered geometric asymmetry and stray fields from a perpendicularly magnetized Co layer. This configuration promotes directional vortex entry and spatially selective pinning, yielding diode efficiencies that exceed all previously reported field-free values. Temperature- and field-dependent transport measurements, supported by micromagnetic simulations, reveal that the enhanced nonreciprocity stems from three cooperative mechanisms: asymmetric vortex entry, localized magnetic pinning, and Lorentz-force imbalance. These findings establish a scalable, CMOS-compatible platform for high-performance superconducting rectifiers, offering new opportunities for cryogenic spintronics and quantum electronics.
Superconductivity (cond-mat.supr-con)
Diffusion of Tracer Particles in Early Growing Biofilms. A Computer Simulation Study
New Submission | Soft Condensed Matter (cond-mat.soft) | 2025-06-24 20:00 EDT
Fabian A. Garcia Daza, Alvaro Rodriguez-Rivas, Fernando Govantes, Alejandro Cuetos
The diffusion of particles in complex media has gained significant interest due to its dual relevance: probing the viscoelastic properties of materials via microrheology and assessing the extent of particle displacement over time. In this work, we explore the early-stage diffusion of a tracer particle within a developing bacterial biofilm using implicit-solvent Brownian dynamics simulations. At these initial stages, bacterial colonies form two-dimensional structures that expand through cell growth and division. Employing an agent-based computational model (IbM), we analyse the passive diffusion of a spherical tracer within colonies of varying compaction levels. Our findings reveal that, at very short timescales, tracer diffusion follows a standard diffusive regime, modulated by colony ageing. However, at longer times, the dominant factor governing tracer motion is colony growth, which effectively confines the tracer within the expanding structure, except in cases where the microcolony is highly unstructured or the tracer is sufficiently small. Additionally, through MR techniques, we quantify the elastic and viscous moduli of the growing microcolony, offering insight into its evolving viscoelastic behavior.
Soft Condensed Matter (cond-mat.soft), Biological Physics (physics.bio-ph)
Brightening dark trions in WS2 monolayers via introducing atomic sulfur vacancies
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-06-24 20:00 EDT
Xuguang Cao, Wanggui Ye, Debao Zhang, Ji Zhou, Lei Peng, Changcheng Zheng, Kenji Watanabe, Takashi Taniguchi, Jiqiang Ning, Shijie Xu
Understanding the effects of atomic defects on the optical functionality of two-dimensional (2D) layered materials is critical to develop novel optical and optoelectronic applications of these ultimate materials. Herein, we correlate sulfur vacancies (VS) and luminescence properties of dark trions in monolayer WS2 through introducing VS defects and conducting a systematic optical spectroscopic characterization at cryogenic and room temperatures. It is unraveled that the VS defects can brighten the dark trions via introducing a stronger spin-orbit coupling due to the space inversion symmetry broken by the defects. Furthermore, the wavefunction localization of the dark trions bound at VS defects results in significant enhancement of the phonon scattering from the K2 valley phonons and hence makes the K2 phonon replica dominant in the emission spectrum. Theoretical calculations of the temperature-dependent photoluminescence spectra with quantum mechanics-based multimode Brownian oscillator model show strong support for the above arguments. Brightening the dark excitons not only sheds light on the understanding of the intriguing excitonic properties of 2D semiconductors, but also may open a way for regulating the optoelectronic performance of two-dimensional semiconductors.
Materials Science (cond-mat.mtrl-sci)
Vertex corrections to nonlinear photoinduced currents in 2D superconductors
New Submission | Superconductivity (cond-mat.supr-con) | 2025-06-24 20:00 EDT
A. V. Parafilo, V. M. Kovalev, I. G. Savenko
The emergence of a rectified steady-state supercurrent as a response to the photoexcited current of the quasiparticles constitutes the concept of a superconducting photodiode. This phenomenon occurs in a two-dimensional thin superconducting film with a built-in DC supercurrent that is exposed to a circularly polarized external electromagnetic field. The flow of a Cooper-pair condensate, resulting as a second-order photo-response in a direction transverse to the initially built-in supercurrent, represents a superconducting counterpart to the photogalvanic effect. In this paper, we examine the photodiode supercurrent by restoring gauge invariance within the mean-field BCS framework. To achieve this, we derive an impurity-sensitive BCS-interaction-induced correction to the vertex function by performing self-consistent calculations within the Keldysh Green’s function technique. The resulting photodiode current can be utilized for spectroscopic analysis of typical relaxation times in superconducting films.
Superconductivity (cond-mat.supr-con), Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Optics (physics.optics)
Resolving the Ti-V Phase Diagram Discrepancy with First-Principles Calculations and Bayesian Learning
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-06-24 20:00 EDT
Timofei Miryashkin, Olga Klimanova, Alexander Shapeev
Conflicting experiments disagree on whether the titanium-vanadium (Ti-V) binary alloy exhibits a body-centred cubic (BCC) miscibility gap or remains completely soluble. A leading hypothesis attributes the miscibility gap to oxygen contamination during alloy preparation. To resolve this controversy, we use an ab initio + machine-learning workflow that couples an actively-trained Moment Tensor Potential to Bayesian thermodynamic inference. Using this workflow, we obtain Ti-V binary system across the entire composition range, together with confidence intervals in the thermodynamic limit. The resulting diagram reproduces all experimental features, demonstrating the robustness of our approach, and clearly favors the variant with a BCC miscibility gap terminating at T = 980 K and c = 0.67. Because oxygen was excluded from simulations, the gap cannot be attributed to impurity effects, contradicting recent CALPHAD reassessments.
Materials Science (cond-mat.mtrl-sci), Artificial Intelligence (cs.AI), Computational Physics (physics.comp-ph)
Wealth Thermalization Hypothesis
New Submission | Statistical Mechanics (cond-mat.stat-mech) | 2025-06-24 20:00 EDT
Klaus M. Frahm, Dima L. Shepelyansky
We introduce the wealth thermalization hypothesis according to which the wealth shared in a country or the whole world is described by the Rayleigh-Jeans thermal distribution with two conserved quantities of system wealth and norm or number of agents. This distribution depends on a dimensional parameter being the ratio of system total wealth and its dispersion range determined by highest revenues. At relatively small values of this ratio there is a formation of the Rayleigh-Jeans condensate, well studied in such physical systems as multimode optical fibers. This leads to a huge fraction of poor households and a small oligarchic fraction which monopolizes a dominant fraction of total wealth thus generating a strong inequality in human society. We show that this thermalization gives a good description of real data of Lorenz curves of US, UK, the whole world and capitalization of S&P500 companies at New York Stock Exchange. Possible actions for inequality reduction are briefly discussed.
Statistical Mechanics (cond-mat.stat-mech)
14 pages (5 main and 9 SupMat), 6+12 figures
Atomic layer deposition on particulate materials from 1988 through 2023: A quantitative review of technologies, materials and applications
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-06-24 20:00 EDT
Peter M. Piechulla, Mingliang Chen, Aristeidis Goulas, Riikka L. Puurunen, J. Ruud van Ommen
Atomic layer deposition (ALD) is widely studied for numerous applications and is commercially employed in the semiconductor industry, where planar substrates are the norm. However, the inherent ALD feature of coating virtually any surface geometry with atomistic thickness control is equally attractive for coating particulate materials (supports). In this review, we provide a comprehensive overview of the developments in this decades-old field of ALD on particulate materials, drawing on a bottom-up and quantitative analysis of 799 articles from this field. The obtained dataset is the basis for abstractions regarding reactor types (specifically for particles), coating materials, reactants, supports and processing conditions. Furthermore, the dataset enables direct access to specific processing conditions (for a given material, surface functionality, application etc.) and increases accessibility of the respective literature. We also review fundamental concepts of ALD on particles, and discuss the most common applications, i.e., catalysis (thermo-, electro-, photo-), batteries, luminescent phosphors and healthcare. Finally, we identify historical trends, and provide an outlook on prospective developments.
Materials Science (cond-mat.mtrl-sci)
Supporting Information at the end of the manuscript; to be published in ACS Chemistry of Materials
Room-temperature intrinsic nonlinear planar Hall effect in TaIrTe4
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-06-24 20:00 EDT
Chang Jiang, Fan Yang, Jinshan Yang, Peng Yu, Huiying Liu, Yuda Zhang, Zehao Jia, Xiangyu Cao, Jingyi Yan, Zheng Liu, Xian-Lei Sheng, Cong Xiao, Shengyuan A. Yang, Shaoming Dong, Faxian Xiu
Intrinsic responses are of paramount importance in physics research, as they represent the inherent properties of materials, independent of extrinsic factors that vary from sample to sample, and often reveal the intriguing quantum geometry of the band structure. Here, we report the experimental discovery of a new intrinsic response in charge transport, specifically the intrinsic nonlinear planar Hall effect (NPHE), in the topological semimetal TaIrTe4. This effect is characterized by an induced Hall current that is quadratic in the driving electric field and linear in the in-plane magnetic field. The response coefficient is determined by the susceptibility tensor of Berry-connection polarizability dipole, which is an intrinsic band geometric quantity. Remarkably, the signal persists up to room temperature. Our theoretical calculations show excellent agreement with the experimental results and further elucidate the significance of a previously unknown orbital mechanism in intrinsic NPHE. This finding not only establishes a novel intrinsic material property but also opens a new route toward innovative nonlinear devices capable of operating at room temperature.
Materials Science (cond-mat.mtrl-sci)
Spin-1/2 operators exactly mapped to spinful canonical Fermi operators present in two bands
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2025-06-24 20:00 EDT
Recently it has been shown that the quantum spin-1/2 spin operators can be exactly transformed not only in spinless, but also in spinful canonical Fermi operators in 1D [\cite{JW1}], and 2D [\cite{JW2}] as well. In this paper, using the same technique based on an extended Jordan-Wigner transformation, we show in 1D, that the quantum spin-1/2 operators can be exactly transformed also in spinful canonical Fermi operators of spin-1/2 fermions that are belong to two bands.
Strongly Correlated Electrons (cond-mat.str-el)
22 pages, no figures, EPJB 2025 accepted for publication
Residual Connection-Enhanced ConvLSTM for Lithium Dendrite Growth Prediction
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-06-24 20:00 EDT
Hosung Lee, Byeongoh Hwang, Dasan Kim, Myungjoo Kang
The growth of lithium dendrites significantly impacts the performance and safety of rechargeable batteries, leading to short circuits and capacity degradation. This study proposes a Residual Connection-Enhanced ConvLSTM model to predict dendrite growth patterns with improved accuracy and computational efficiency. By integrating residual connections into ConvLSTM, the model mitigates the vanishing gradient problem, enhances feature retention across layers, and effectively captures both localized dendrite growth dynamics and macroscopic battery behavior. The dataset was generated using a phase-field model, simulating dendrite evolution under varying conditions. Experimental results show that the proposed model achieves up to 7% higher accuracy and significantly reduces mean squared error (MSE) compared to conventional ConvLSTM across different voltage conditions (0.1V, 0.3V, 0.5V). This highlights the effectiveness of residual connections in deep spatiotemporal networks for electrochemical system modeling. The proposed approach offers a robust tool for battery diagnostics, potentially aiding in real-time monitoring and optimization of lithium battery performance. Future research can extend this framework to other battery chemistries and integrate it with real-world experimental data for further validation
Materials Science (cond-mat.mtrl-sci), Artificial Intelligence (cs.AI)
14pages, 6figures, accepted to Journal of The Electrochemical Society
2D Su-Schrieffer-Heeger Model with static domain walls and quasiperiodic disorder
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2025-06-24 20:00 EDT
We revisit the problem of a two dimensional Su-Schrieffer-Heeger (SSH) model on a square lattice to first minutely analyze its spectra including zero energy states (ZES) and in-gap states both under periodic and open boundaries. Thereafter, a series of antiphase domain walls (DW), distributed along two orthogonal lines, are introduced in the lattice with SSH like hoppings and this causes the ZES to localize not only at the corners but also at the intersection of the lines of domain walls. In-gap states not only populate at the edges but also show finite amplitudes along the DW lines. A different scenario appears for a radially symmetric distribution of domain walls along a circle around a poit within the lattice. It produces in-gap states localized at the center of the DW circle while the ZES show localizations around it in a symmetric fashion in the square lattice. We also probe the effect of a diagonal quasiperiodic disorder on the spectra and eigen-states of the 2D SSH model. This gives localization of the states more with a stronger disorder. We calculate participation ratios of the states and their averages to demonstrate how such localization develops with disorder. Lastly we also elaborate further on the eigenvalue and eigenstates of a few periodically hopping modulated cases, previously outlined briefly in the article: Jour. Phys. Cond.-Mat.{\bf 36}, 065301 (2024) and also give an account of the changed features of the spectra as a result of the application of DWs there. Our findings on these various fronts can increase many-fold the visibility of this popular model and the outcomes can be utilized in many emerging fields like topological quantum information processing, for example, by designing topological shielding of various kinds.
Strongly Correlated Electrons (cond-mat.str-el), Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
Initial Draft
Ab initio calculation of electronic band structure of Cd$_{1-x}$Fe$_x$Se
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-06-24 20:00 EDT
Matanat A. Mehrabova, Elshad Allahyarov, Niyazi H. Hasanov, Nurana R. Gasimova
The purpose of this work was to calculate the electronic band structure of Cd$ _{1-x}$ Fe$ x$ Se. Ab-initio, calculations are performed in the Atomistix Toolkit program within the Density Functional Theory and Local Spin Density Approximation on Tight Tiger basis. We have used Hubbard U potential $ U{Fe} = 2.42$ eV for 3d states for Fe ions. Super-cells of 8 and 64 atoms were constructed. After the construction of Cd$ _{1-x}$ Fe$ _x$ Se ($ x=$ 6.25%; 25%) super-cells, atom relaxation and optimization of the crystal structure were carried out. Electronic band structure,and density of states were calculated, and total energy have been defined in antiferromagnetic and ferromagnetic phases. The band gap for the Cd$ _{1-x}$ Fe$ _x$ Se, $ x=0.06$ in ferromagnetic phase is equal to $ E_g=1.77$ eV, in antiferromagnetic phase $ E_g=1.78$ eV. For $ x=0.25$ , $ E_g=1.92$ eV. Antiferromagnetic phase considered more stable. Our calculations show that the band gap increases with the increases in Fe ion concentration.
Materials Science (cond-mat.mtrl-sci), Soft Condensed Matter (cond-mat.soft), Chemical Physics (physics.chem-ph)
6 pages and 5 figures
Baku State University: Journal of Physics & Space Sciences, 2024, v 1 (2), p. 57-62
CLAMM: a spin CLuster expansion–Monte Carlo toolkit for Alloys and Magnetic Materials
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-06-24 20:00 EDT
Brian Blankenau, Tianyu Su, Namhoon Kim, Elif Ertekin
Finite-temperature magnetism gives rise to many phenomena in alloy materials, such as magnetic phase transformations, short or medium range order in magnetic alloys, spin waves, critical phenomena, and the magnetocaloric effect. Lattice models, such as the Ising, Potts, cluster expansion, and magnetic cluster expansion models, are powerful tools for studying complex magnetic alloys and compounds. In this paper we introduce CLAMM, which is a new open source toolkit for developing custom lattice models from density functional theory (DFT) data sets. The toolkit is comprised of three main components. The first component is CLAMM_Prep, a python tool that converts data sets consisting of the Vienna Ab-initio Simulation Package (VASP) DFT simulations into a compact format. The second component, CLAMM_Fit, is also python-based and uses the compact data set to parameterize a lattice model, chosen from a set of available options (cluster expansion, Ising, and others). The third component is CLAMM_MC, which is a C++ Monte Carlo solver for generating ensembles of configurations, accounting for both magnetic and alloy configurational entropies, at different temperatures. These ensembles and their analysis can be used for simulating phase transformations and constructing phase diagrams. The code can also be used for generating special quasi-random structures and structures with user-defined short-range order. This document provides a comprehensive overview of each CLAMM tool in order to demonstrate CLAMM’s potential for the computational materials community.
Materials Science (cond-mat.mtrl-sci)
States decoupled from the surface in short Si atomic chains
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2025-06-24 20:00 EDT
Tomasz Kwapiński, Marek Dachniewicz, Marcin Kurzyna, Mieczysław Jałochowski
We analyze both the stationary and time-dependent properties of molecular states in atomic chains on a surface, some of which are composed of atomic states decoupled from the substrate - a phenomenon analogous to dark states in quantum dot systems. To illustrate this effect at the atomic scale, we performed scanning tunneling microscopy (STM) experiments on short silicon chains fabricated on a Si(553)-Au surface. In contrast to quantum dots, which typically involve characteristic energies in the meV range or lower, the atomic chains studied here operate in a high-energy regime, with energies in the eV range. Furthermore, we demonstrate that the local density of states of the chains carries clear signatures of these decoupled states, which significantly affect STM imaging. The topography becomes highly sensitive to the bias polarity, to the extent that some atomic sites may appear nearly invisible to the STM tip. Our time-resolved theoretical analysis reveals that these decoupled states emerge over a finite time interval. This oscillatory dynamical evolution, primarily driven by nearest-neighbor interactions, suggests a universal relaxation mechanism that is largely insensitive to the length of the atomic chain.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
11 pages, 7 figures, Phys. Rev. B 2025: accepted
Non-algebraic first return probability of a stretched random walk near a convex boundary and its effect on adsorption
New Submission | Statistical Mechanics (cond-mat.stat-mech) | 2025-06-24 20:00 EDT
Daniil Fedotov, Sergei Nechaev
The $ N$ -step random walk, stretched in the vicinity of a disc (in 2D) or a sphere (in 3D) of radius $ R$ , demonstrates a non-algebraic stretched exponential decay $ P_N\sim \exp\left(-{\rm const}, N^{1/3}\right)$ for the first return probability $ P_N$ in the double-scaling limit $ N=\frac{L}{a}\gg 1, \frac{R}{a}\gg 1$ conditioned that $ \frac{L}{R}=c={\rm const}$ . Stretching means that the length of the walk, $ L=Na$ (where $ a$ is the unit step length) satisfies the condition $ L = cR$ , where $ c > \pi$ . Both analytic and numerical evidences of the non-algebraic behavior of $ P_N$ are provided. Considering the model of a polymer loop stretched (“inflated”) by external force, we show that non-algebraic behavior of $ P_N$ affects the adsorption of a polymer at the boundary of a sticky disc in 2D, manifesting in a first order localization transition.
Statistical Mechanics (cond-mat.stat-mech), Soft Condensed Matter (cond-mat.soft)
16 pages, 3 figures
Boosting biocompatibility and mechanical property evolution in a high-entropy alloy via nanostructure engineering and phase transformations
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-06-24 20:00 EDT
Thanh Tam Nguyen, Payam Edalati, Shivam Dangwal, Karina Danielle Pereira, Alessandra Cremasco, Ricardo Floriano, Augusto Ducati Luchessi, Kaveh Edalati
High-entropy alloys (HEAs), as multi-component materials with high configurational entropy, have garnered significant attention as new biomaterials; still, their low yield stress and high elastic modulus need to be overcome for future biomedical applications. In this study, nanograin generation is used to enhance the strength and phase transformation is employed to reduce the elastic modulus of a biocompatible Ti-Zr-Hf-Nb-Ta-based HEA. The alloy is treated via the high-pressure torsion (HPT) process, leading to (i) a BCC (body-centered cubic) to omega phase transformation with [101]{\omega}//[011]BCC and [211]omega//[121]BCC through a twining mechanism, (ii) nanograin formation with a mean grain size of 20 nm, and (iii) dislocation generation particularly close to BCC-omega interphase boundaries. These structural and microstructural features enhance hardness, increase tensile strength up to 2130 MPa, achieve tensile elongation exceeding 13%, reduce elastic modulus down to 69 GPa and improve biocompatibility. Additionally, the HEA exhibits improved anodization, resulting in a homogenous distribution of oxide nanotubes on the surface with a smaller tube diameter and a higher tube length compared to pure titanium. These remarkable properties, which are engineered by the generation of defective nanograins and the co-existence of BCC and metastable omega phases, highlight the potential of HEAs treated using severe plastic deformation for future biomedical usage, particularly in the orthopedic sector.
Materials Science (cond-mat.mtrl-sci), Medical Physics (physics.med-ph)
Influence of nanostructuring through high-pressure torsion (HPT) on superconductivity of a high-entropy alloy
New Submission | Superconductivity (cond-mat.supr-con) | 2025-06-24 20:00 EDT
Kaveh Edalati, Alexy Bertrand, Payam Edalati, Thanh Tam Nguyen, Nariman Enikeev, Masaki Mito
High-entropy alloys (HEAs) have emerged as favorable choices for different applications, including superconductors. The present work examines the impact of nanostructuring via high-pressure torsion (HPT) on the superconducting properties of the equiatomic TiZrHfNbTa HEA. Structural characterization reveals a progressive refinement of grain size and increased dislocation density, together with partial phase transformation to an {\omega} phase with HPT processing. Magnetic susceptibility and magnetization measurements indicate a systematic enhancement in the superconducting transition temperature (from $ T_c =$ 6.2 K to 7.2 K) and critical magnetic field, as well as the stabilization of the superconductivity state by HPT processing. The improvement of superconducting properties is attributed to microstructural modifications such as grain boundary density, defect generation and phase transformations, and their impact on vortex pinning, quantum confinement and electron scattering. The results suggest that nanostructuring through severe plastic deformation provides an appropriate route to optimize superconducting properties in high-entropy superconductors.
Superconductivity (cond-mat.supr-con), Materials Science (cond-mat.mtrl-sci)
A continuous damage accumulation scenario for elastomeric frictional wear
New Submission | Soft Condensed Matter (cond-mat.soft) | 2025-06-24 20:00 EDT
Ombeline Taisne, Julien Caillard, Côme Thillaye du Boullay, Marc Couty, Costantino Creton, Jean Comtet
Understanding how materials wear off following frictional sliding is a long-standing question in tribology. In this respect, the particular case of the wear of soft rubbery elastomeric materials stands apart: tire wear produces several million tonnes of abraded materials per year, bearing immense industrial and environmental impact, while the soft nature of elastomers and their inability to accommodate plastic deformation before failure renders their wear mechanisms almost intractable. Here, we harness mechanochemical approaches on model elastomeric materials, to reveal that mild elastomeric wear does not proceed from crack propagation processes, but rather from the continuous accumulation of diffuse damage by chain scission, extending well below the surface of the material. Damage accumulates in a discontinuous manner through micro-slippage events at the rough contacting asperities, with in-depth damage extension set by the characteristic asperity size. Surprisingly, damage grows through a slow logarithmic-like process over successive cycles, which we interpret as the occurrence of stress-activated scission events in a broad strand elastic energy landscape. These observations point to the probabilistic nature of this fatigue-like damage accumulation mechanism and allow us to formulate the wear rate as an integral of the damage cumulated over successive asperity sliding. Finally, by tuning the molecular architecture of our materials, we evidence an antagonistic relation between fracture resistance and wear resilience, set by the sensitivity of the material to stress fluctuations. Revealing the role of previously invisible subsurface damage in elastomeric wear, our approach should stimulate further physical-based approaches allowing for the development of sustainable and wear-resilient materials.
Soft Condensed Matter (cond-mat.soft), Materials Science (cond-mat.mtrl-sci)
Computational Discovery of Metastable NaMnO$_2$ Polymorphs as High-Performance Cathodes with Ultralow Na$^+$ Migration Barriers
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-06-24 20:00 EDT
Fukuan Wang, Chen Zhou, Busheng Wang, Yong Liu
Using an ab initio evolutionary algorithm combined with first-principles calculations, two metastable NaMnO$ _2$ polymorphs, $ I4_1/amd$ and Cmcm, are identified as promising cathode materials for sodium-ion batteries. Both phases exhibit excellent thermodynamic stability, lying within 35meV/atom of the ground-state \textit{Pmmn} phase across 0–50GPa, and are dynamically and thermally stable under ambient conditions following high-pressure synthesis, as confirmed by phonon and ab initio molecular dynamics simulations. During desodiation, a Jahn–Teller-induced magnetic transition enhances Mn–O hybridization, reduces the bandgap, and promotes robust charge compensation and oxygen retention. Remarkably, the Cmcm phase achieves record-low Na$ ^+$ migration barriers (0.39eV at high Na concentration; 0.27eV at low concentration), representing 47% and 36% reductions respectively compared to conventional $ C2/m$ , while delivering a higher average voltage (3.19V vs 2.88V). The $ I4_1/amd$ phase exhibits concentration-dependent diffusion with a low-energy pathway (0.38eV) and maintains competitive voltage (2.94V). These findings suggest that metastable NaMnO$ _2$ polymorphs may offer viable alternatives to conventional cathode materials, particularly where fast ionic conduction is required.
Materials Science (cond-mat.mtrl-sci)
23 pages, 7 figures
Polarons with arbitrary nonlinear electron-phonon interaction
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2025-06-24 20:00 EDT
Stefano Ragni, Tomislav Miškić, Thomas Hahn, Nikolay Prokof’ev, Osor S. Barišić, Naoto Nagaosa, Cesare Franchini, Andrey S. Mishchenko
We develop an exact computational method based on numerical X-propagators for solving polaron models with arbitrary nonlinear couplings of local vibration modes to the electron density and magnitude of the hopping amplitude. Our approach covers various polaron models, some of which were impossible to treat by any existing approximation-free techniques. Moreover, it remains efficient in the most relevant but computationally challenging regime of phonon frequencies much smaller than the electron bandwidth. As a case study, we consider the double-well type nonlinear model with quadratic ($ g_2<0$ ) and quartic ($ g_4>0$ ) interactions describing a broad class of technologically important materials, such as quantum paraelectric compounds and halide perovskites. We observe, depending on the model parameters, three qualitatively different regimes: (i) quantum interplay of quartic and quadratic interactions which suppresses effects of the quadratic coupling, (ii) intermediate-coupling regime with exponential $ \propto \exp(\alpha g_2 \Omega^{-1/4})$ scaling of the quasiparticle weight and mass renormalization, and (iii) strong-coupling asymptotic behavior.
Strongly Correlated Electrons (cond-mat.str-el), Materials Science (cond-mat.mtrl-sci)
15 pages, 12 figures
Stacking-Dependent Electronic Properties in GaSe/GaTe Heterobilayers: A First-Principles Study
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-06-24 20:00 EDT
In this study, we use first-principles calculations to investigate the stacking-dependent electronic properties of GaSe/GaTe van der Waals heterobilayers. By analyzing five representative stacking configurations–AA, AA$ ‘$ , A$ ‘$ C, A$ ‘$ B, and AB–we show that interlayer atomic registry affects orbital hybridization and interfacial interactions, leading to distinct electronic structures and stabilities. Projected density of states analyses reveal valence and conduction band edges arise from orbitals localized in different layers, confirming a type-II band alignment that facilitates spatial charge separation. Orbital contributions and spectral features vary with stacking, reflecting how interlayer coupling modulates hybridization and electronic behavior. This study provides atomic-level insights for designing and optimizing layered heterostructures in nanoelectronic devices.
Materials Science (cond-mat.mtrl-sci)
21 pages, 6 figures
Spin Polarization Control via Magnetic Field in Dissipative Bosonic Systems
New Submission | Quantum Gases (cond-mat.quant-gas) | 2025-06-24 20:00 EDT
Yaoyuan Fan, Shuoyu Shi, Lang Cao, Qiuxin Zhang, Dong Hu, Yu Wang, Xiaoji Zhou
Engineering spin polarization in dissipative bosonic systems is crucial for advancing quantum technologies, especially for applications in quantum metrology and space-based quantum simulations. This work demonstrates precise magnetic moment control in multicomponent Bose gases during evaporative cooling via tailored magnetic fields. By adjusting the magnetic field gradients, null point position, and duration, we selectively tune evaporation rates of magnetic sublevels, achieving targeted spin polarization. Theoretical models, validated by numerical simulations and Stern-Gerlach experiments, reveal how magnetic fields reshape trapping potentials and spin-dependent dissipation. The results establish a dissipative spin-selection mechanism governing polarization evolution in evaporatively cooled Bose gases and provide a framework for engineering spin-polarized quantum states.
Quantum Gases (cond-mat.quant-gas), Atomic Physics (physics.atom-ph)
9 pages, 5 figures
Threshold Displacement Energies of Oxygen in YBa$_2$Cu$_3$O$_7$: A Multi-Physics Analysis
New Submission | Superconductivity (cond-mat.supr-con) | 2025-06-24 20:00 EDT
Ashley Dickson, Mark R. Gilbert, Duc Nguyen-Manh, Samuel T. Murphy
Neutron bombardment of high temperature superconducting (HTS) magnets may compromise the integrity of the magnetic confinement in future fusion reactors. The amount of damage produced by a single neutron can be predicted from the threshold displacement energies (TDE) of the constituent ions in the HTS materials, such as the Rare Earth Cuperates. Therefore, in this work a Multiphysics simulation approach is adopted to determine the threshold displacement energies for oxygen in YBa2Cu3O7. Classical molecular dynamics (MD) simulations are employed to determine statistically representative TDEs for all four oxygen sites and these results are validated using Born-Oppenheimer MD employing forces derived from Density Functional Theory (DFT). The simulations were performed at the operational temperature (25 K) and the temperature of existing neutron irradiation studies (360 K) enabling a discussion about the relevance of this data. Overall, these findings enhance our understanding of radiation-induced damage in HTS materials and provide data that can be incorporated into higher order models offering critical insights into shielding design and magnet longevity.
Superconductivity (cond-mat.supr-con), Materials Science (cond-mat.mtrl-sci)
(15 pages, 12 figures)
Kitaev model in regular hyperbolic tilings
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2025-06-24 20:00 EDT
We study the Kitaev model on regular hyperbolic trivalent tilings. Depending on the length $ p$ of the elementary polygons, we examine two distinct tri-colorings of the tiling. Using a recent conjecture on the ground-state flux sector, we compute the phase diagram via exact diagonalizations and derive analytical expressions for the effective Hamiltonians in the isolated-dimer limit which are valid for all values of $ p$ . Our results interpolates between the Euclidean honeycomb lattice and the trivalent Bethe lattice ($ p=\infty$ ) for which we derive the exact solution of the phase boundaries.
Strongly Correlated Electrons (cond-mat.str-el), Quantum Physics (quant-ph)
9 pages, 10 figures
Exploring the impact of Ti/Al on L12 nanoprecipitation and deformation behavior in CoNiFeAlTi multi-principal element alloys through atomistic simulations
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-06-24 20:00 EDT
Amin Esfandiarpour, Anshul D. S. Parmar, Silvia Bonfanti, Pawel Sobkowicz, Byeong-Joo Lee, Mikko Alava
Recent studies on CoNi-based multi-principal element alloys (MPEAs) have demonstrated high strength and ductility, attributed to the formation of stable L12 nanoscale precipitates. However, the fundamental mechanisms behind such impressive properties in these complex alloys are not well understood. In this work, we investigate the effects of Ti and Al concentrations on the formation of L12 precipitates in (CoNiFe)84(Al8Ti8), (CoNiFe)86(Al7Ti7), (CoNiFe)88(Al6Ti6), and (CoNiFe)94(Al4Ti2) MPEAs using hybrid molecular dynamics/Monte Carlo (MD/MC) simulations and a MEAM interatomic potential for the CoNiFeTiAl system. Additionally, we study the effect of L12 precipitation on the mechanical properties and stacking fault energy (SFE) of these MPEAs using MD. Our hybrid MD/MC simulations show that the (CoNiFe)86(Al7Ti7) alloy exhibits the highest amount of L12 nanoprecipitates. We find that L12 precipitation increases the SFE, with higher Al and Ti contents leading to greater increases. Tensile simulations reveal that L12 precipitates enhance yield strength, with alloys exhibiting higher precipitation showing increased flow stress. We also investigate dislocation-nanoprecipitate interactions with different precipitate sizes in the (CoNiFe)86(Al7Ti7) alloy. Larger nanoprecipitate sizes result in stronger dislocation pinning. Dislocations predominantly shear through 4-8 nm precipitates instead of looping around them (Orowan mechanism), enhancing strength while maintaining good ductility. Although the lattice mismatch between the L12 nanoprecipitate and the matrix is low (0.139%), the significant difference in SFE between the L12 nanoprecipitate and the matrix results in stronger dislocation pinning. This understanding can guide the design of MPEAs with tailored properties by controlling nanoscale precipitation.
Materials Science (cond-mat.mtrl-sci)
20 pages, 8 figures
J. Alloys Compd. 1035 (2025) 181580 J. Alloys Compd. 1035 (2025) 181580 J. Alloys Compd. 1035 (2025) 181580
Mechanical inhibition of dissipation in a thermodynamically consistent active solid
New Submission | Soft Condensed Matter (cond-mat.soft) | 2025-06-24 20:00 EDT
Luca Cocconi, Michalis Chatzittofi, Ramin Golestanian
The study of active solids offers a window into the mechanics and thermodynamics of dense living matter. A key aspect of the non-equilibrium dynamics of such active systems is a mechanistic description of how the underlying mechano-chemical couplings arise, which cannot be resolved in models that are phenomenologically constructed. Here, we follow a bottom-up theoretical approach to develop a thermodynamically consistent active solid (TCAS) model, and uncover a non-trivial cross-talk that naturally ensues between mechanical response and dissipation. In particular, we show that dissipation reaches a maximum at finite stresses, while it is inhibited under large stresses, effectively reverting the system to a passive state. Our findings establish a mechanism potentially responsible for the non-monotonic behaviour observed in recent experimental measurements of entropy production rate in an actomyosin material.
Soft Condensed Matter (cond-mat.soft), Statistical Mechanics (cond-mat.stat-mech)
8 pages (main) + 8 pages (SM)
Pairing-induced Momentum-space Magnetism and Its Implication In Optical Anomalous Hall Effect In Chiral Superconductors
New Submission | Superconductivity (cond-mat.supr-con) | 2025-06-24 20:00 EDT
The intrinsic mechanisms of the magneto-optical Kerr signal in chiral superconductors often involve multi-orbital degree of freedom. Here by considering a generic single-orbital and spinful Hamiltonian, we generalize the Onsager’s relation to obtain the necessary conditions for the optical anomalous Hall effect. Using the down-folding method, we identify two types of effective momentum-space magnetism responsible for the optical anomalous Hall conductivity from non-unitary and unitary pairing potentials respectively. The former is due to the angular momentum of Cooper pair, while the latter requires the participation of the spin-orbit coupling in the normal state and has been largely overlooked previously. Using concrete examples, we show that the unitary pairing can lead to both ferromagnetism and complicated antiferromagnetic spin texture in the momentum space, resulting in an in-plane optical anomalous Hall effect with the magnetism parallel to the Hall-deflection plane. Our work reveals the essential role of spin degree of freedom in the optical anomalous Hall effect.
Superconductivity (cond-mat.supr-con), Materials Science (cond-mat.mtrl-sci)
6 pages, 2 figures
Nanoscale imaging of reduced forward bias at V-pits in green-emitting nitride LEDs
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-06-24 20:00 EDT
C. Fornos, N. ALyabyeva, Y. W. Ho, J. Peretti, A. C. H. Rowe, J. S. Speck, C. Weisbuch
Record wall-plug efficiencies in long-wavelength, nitride light-emitting diodes (LEDs) have recently been achieved in devices containing high V-pit densities. Numerical modeling suggests this may be due to improved electrical efficiencies (EE). In order to test this proposition, a novel scanning tunneling luminescence microscope (STLM) is used to map the local optoelectronic properties of commercial, green-emitting LED heterostructures around V-pits with nanoscale spatial resolution. Using the STLM tip as the hole injector, injection at the lips of V-pits is found to be drastically different from injection on the heterostructure’s c-plane. A $ \approx$ 3-fold improvement in internal quantum efficiency near V-pits is observed at low injection, and at higher injection a $ \approx$ 1.75 V reduction in the forward bias unambiguously confirms the EE hypothesis for hole injection.
Materials Science (cond-mat.mtrl-sci)
6 pages, 5 figures
Enhanced UV Photodetector Efficiency with a ZnO/Ga$_2$O$_3$ Heterojunction
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-06-24 20:00 EDT
Shashi Pandey, Swaroop Ganguly, Alok Shukla, Anurag Tripathi
Heterostructures comprising uncoated ZnO and coated with thin layers of Ga$ 2$ O$ 3$ were produced using spin-coating and subsequent hydrothermal processing. X-ray diffraction examination verifies the structural integrity of the synthesized heterostructures (HTs). Optical and photoluminescence spectra were recorded to assess the variation in absorption and emission of the Ga$ 2$ O$ 3$ -coated HTs in comparison to the pristine ZnO. We conducted comparative density-functional theory (DFT) computations to corroborate the measured band gaps of both categories of HTs. To assess the stability of our devices, the transient response to on/off light switching under zero bias has been studied. The rise time $ \tau{r1}$ ($ \tau{r2}$ ) is 2300 (500) ms and the decay time $ \tau{d1}$ ($ \tau{d2}$ ) is 2700 (5000) ms have been observed for bare ZnO and ZnO/Ga$ _2$ O$ _3$ HTs, respectively. A significant amount of change was also observed in the electrical transport properties from bare ZnO to ZnO/Ga$ _2$ O$ _3$ . To see the performance of device, responsivity (R) and detectivity (D = 1/NEP$ _B$ ) have been measured. It is evident from observation that responsivity of a device shows maximum value in UV region while it is reducing with visible region for HTs. In case of detectivity, the maximum value reached was $ 145 \times 10^{14}$ Hz$ ^{1/2}$ /W (at ~ 200 nm) and $ 38 \times 10^{14}$ Hz$ ^{1/2}$ /W (at 300 nm) for Ga$ _2$ O$ _3$ coated ZnO, and bare ZnO HTs, respectively. The maximum responsivity measured for the bare ZnO HTs is 7 (A/W) while that of Ga$ _2$ O$ _3$ coated ZnO HTs is 38 (A/W). It suggests a simple way of designing materials for fabricating broad-range cost-effective photodetectors.
Materials Science (cond-mat.mtrl-sci)
23 pages, 10 figures
ACS Appl. Electron. Mater. 7, 1173 (2025)
Four-body physics in low-dimensional bosons with three-body interaction
New Submission | Quantum Gases (cond-mat.quant-gas) | 2025-06-24 20:00 EDT
V. Polkanov, O. Hryhorchak, V. Pastukhov
The two-channel model for bosons with the three-body interaction is proposed. Similar to the Hamiltonian describing narrow Feshbach resonance in the two-body sector, our model includes the finite-range effects of the three-body potential and is well-defined in the ultraviolet (UV). A detailed exploration of the Efimov-like effect in the fractal-dimension system of four bosons is carried out. Peculiarities of the four-body bound states and the low-energy atom-trimer scattering in one dimension are revealed.
Quantum Gases (cond-mat.quant-gas), Quantum Physics (quant-ph)
5 + epsilon pages, 3 figures; comments and relevant references are welcome
Superfluid stiffness bounds in time-reversal symmetric superconductors
New Submission | Superconductivity (cond-mat.supr-con) | 2025-06-24 20:00 EDT
Yongxin Zeng, Andrew J. Millis
Quantum geometry has been shown to make an important contribution to the superfluid stiffness of superconductors, especially for flat-band systems such as moiré materials. In this work we use mean-field theory to derive an expression for the superfluid stiffness of time-reversal symmetric superconductors at zero temperature by computing the energy of the mean-field ground state as a function of pairing momentum. We show that the quantum geometric contribution to superfluid stiffness is a consequence of broken Galilean invariance in the interaction Hamiltonian, arising from momentum-dependent form factors related to the momentum dependence of Bloch states. The effects of broken Galilean invariance are not fully parametrized by the quantum metric considered in previous work. We obtain general lower and upper bounds that apply to both continuum and lattice models and present numerical calculations of the precise value in several important cases. The superfluid stiffness of superconductivity in a Landau level saturates the lower bound and the superfluid stiffness of the other cases we consider is close to the general lower bound we derive. In multilayer rhombohedral graphene the geometric contribution is shown not to be the dominant contribution to the superfluid stiffness, despite the flat band behavior in the vicinity of the Fermi level. Finally, assuming contact interaction and uniform pairing, we show that the superfluid stiffness is proportional to the ``minimal quantum metric” introduced in previous work. We provide a continuum version of the minimal quantum metric and explain its physical origin.
Superconductivity (cond-mat.supr-con), Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
Nitrogen Vacancies Induce Fatigue in Ferroelectric $\mathrm{Al_{0.93}B_{0.07}N}$
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-06-24 20:00 EDT
Walter J. Smith, Betul Akkopru-Akgun, Erdem Ozdemir, Bogdan Dryzhakov, John Hayden, Jon-Paul Maria, Kyle P. Kelley, Clive A. Randall, Susan Trolier-McKinstry, Thomas E. Beechem
Wurtzite ferroelectrics (e.g., $ \mathrm{Al_{0.93}B_{0.07}N}$ ) are being explored for high-temperature and emerging near-, or in-compute, memory architectures due to the material advantages offered by their large remanent polarization and robust chemical stability. Despite these advantages, current $ \mathrm{Al_{0.93}B_{0.07}N}$ devices do not have sufficient endurance lifetime to meet roadmap targets. To identify the defects responsible for this limited endurance, a combination of electronic measurements and optical spectroscopies characterized the evolution of defect states within $ \mathrm{Al_{0.93}B_{0.07}N}$ with cycling. Ultrathin ($ \sim$ 10 nm) metal contacts were used to optically probe regions subject to ferroelectric switching; photoluminescence spectroscopy identified the emergence of a transition near 2.1 eV whose intensity scaled with the non-switching polarization quantified via positive-up negative-down (PUND) measurements. Accompanying thermally stimulated depolarization current (TSDC) and modulus spectroscopy measurements also observed the strengthening of a state near 2.1 eV. The origin of this feature is ascribed to transitions between a nitrogen vacancy and another defect deeper in the bandgap. Recognizing that the impurity concentration is largely fixed, strengthening of this transition indicates an increase in the number of nitrogen vacancies. Switching, therefore, creates vacancies in $ \mathrm{Al_{0.93}B_{0.07}N}$ likely due to hot-atom damage induced by the aggressive fields necessary to switch wurtzite materials that ultimately limits endurance.
Materials Science (cond-mat.mtrl-sci)
An Extended Model of Fractional-Dimensional Space for Anisotropic Solids with Deformed Derivatives
New Submission | Statistical Mechanics (cond-mat.stat-mech) | 2025-06-24 20:00 EDT
In this work, we extend a fractional-dimensional space model for anisotropic solids by incorporating a q-deformed derivative operator, inspired by Tsallis’ nonadditive entropy framework. This generalization provides an analytical framework for exploring anisotropic thermal properties, within a unified and flexible mathematical formalism. We derive modified expressions for the phonon density of states and specific heat capacity, highlighting the impact of the deformation parameters on thermodynamic behavior. We apply the model to various solid-state materials, achieving excellent agreement with experimental data, across a wide temperature range and demonstrating its effectiveness in capturing anisotropic and subextensive effects in real systems.
Statistical Mechanics (cond-mat.stat-mech), Materials Science (cond-mat.mtrl-sci), Soft Condensed Matter (cond-mat.soft), Mathematical Physics (math-ph), Classical Physics (physics.class-ph)
28 pages. 10 Figures
Thermal phase slips in superconducting films
New Submission | Superconductivity (cond-mat.supr-con) | 2025-06-24 20:00 EDT
Mikhail A. Skvortsov, Artem V. Polkin
A dissipationless supercurrent state in superconductors can be destroyed by thermal fluctuations. Thermally activated phase slips provide a finite resistance of the sample and are responsible for dark counts in superconducting single photon detectors. The activation barrier for a phase slip is determined by a space-dependent saddle-point (instanton) configuration of the order parameter. In the one-dimensional wire geometry, such a saddle point has been analytically obtained by Langer and Ambegaokar in the vicinity of the critical temperature, $ T_c$ , and for arbitrary bias currents below the critical current $ I_c$ . In the two-dimensional geometry of a superconducting strip, which is relevant for photon detection, the situation is much more complicated. Depending on the ratio $ I/I_c$ , several types of saddle-point configurations have been proposed, with their energies being obtained numerically. We demonstrate that the saddle-point configuration for an infinite superconducting film at $ I\to I_c$ is described by the exactly integrable Boussinesq equation solved by Hirota’s method. The instanton size is $ L_x\sim\xi(1-I/I_c)^{-1/4}$ along the current and $ L_y\sim\xi(1-I/I_c)^{-1/2}$ perpendicular to the current, where $ \xi$ is the Ginzburg-Landau coherence length. The activation energy for thermal phase slips scales as $ \Delta F^\text{2D}\propto (1-I/I_c)^{3/4}$ . For sufficiently wide strips of width $ w\gg L_y$ , a half-instanton is formed near the boundary, with the activation energy being 1/2 of $ \Delta F^\text{2D}$ .
Superconductivity (cond-mat.supr-con), Exactly Solvable and Integrable Systems (nlin.SI)
5 pages, 2 figures
Beyond-quasiparticles transport with vertex correction: self-consistent ladder formalism for electron-phonon interactions
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-06-24 20:00 EDT
We present a self-consistent many-body framework for computing phonon-limited electronic transport from first principles, incorporating both beyond-quasiparticle effects and vertex corrections. Using the recently developed first-principles scGD0 method, we calculate spectral functions with nonperturbative effects such as broadening, satellites, and energy-dependent renormalization. We show that the scGD0 spectral functions outperform one-shot G0D0 and cumulant approximations in model Hamiltonians and real materials, eliminating unphysical spectral kinks and correctly predicting the phonon emission continuum. Building on this, we introduce the self-consistent ladder formalism for transport, which captures vertex corrections due to electron-phonon interactions. This approach unifies and improves upon the two state-of-the-art approaches for first-principles phonon-limited transport: the bubble approximation and the Boltzmann transport equation. Moreover, as a charge-conserving approximation, it enables consistent calculations of the optical conductivity and dielectric function. We validate the developed method against numerically exact results for model Hamiltonians and apply it to real materials. Our results show quantitative agreement with the experimental dc conductivities in intrinsic semiconductors Si and ZnO and the SrVO3 metal, as well as excellent agreement with the experimental THz optical and dielectric properties of Si and ZnO. This work unifies first-principles and many-body approaches for studying transport, opening new directions for applying many-body theory to materials with strong electron-phonon interactions.
Materials Science (cond-mat.mtrl-sci)
Hydroflux Crystal Growth of Alkali Tellurate Oxide-Hydroxides
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-06-24 20:00 EDT
Madalyn R. Gragg, Allana G. Iwanicki, Maxime A. Siegler, Tyrel M. McQueen
This study investigates the synthesis of novel magnetic materials via hydroflux synthesis, a method that combines flux-based and hydrothermal techniques. Single crystals of three novel alkali tellurate oxide-hydroxides were synthesized. One, CsTeO$ _3$ (OH), is nonmagnetic and a new member of the series ATeO$ _3$ (OH) (A = alkali). The other two phases contain magnetic Cu-Te sublattices, one of which, KCu$ _2$ Te$ _3$ O$ _{8}$ (OH), is structurally three-dimensional and undergoes several magnetic ordering transitions; the other, Cs$ _2$ Cu$ _3$ Te$ _2$ O$ _{10}$ , is structurally two-dimensional and remains paramagnetic above T = 2K. These exploratory investigations of novel phase spaces reveal key factors including hydroxide concentration, precursor solubility, and oxidizing power of the solution which govern the formation and composition of alkali tellurate oxide-hydroxides.
Materials Science (cond-mat.mtrl-sci)
17 pages, 13 figures, 6 tables
Anomalies in G and 2D Raman Modes of Twisted Bilayer Graphene Near the Magic Angle
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2025-06-24 20:00 EDT
Darshit Solanki, Kenji Watanabe, Takashi Taniguchi, A. K. Sood, Anindya Das
The role of twist angle ($ \theta_t$ ) in tailoring the physical properties of heterostructures is emerging as a new paradigm in two-dimensional materials. The influence of flat electronic bands near the magic angle ($ \sim$ 1.1$ ^{\circ}$ ) on the phononic properties of twisted bilayer graphene (t-BLG) is not well understood. In this work, we systematically investigate the G and 2D Raman modes of t-BLG samples with twist angles ranging from $ \sim$ 0.3$ ^{\circ}$ to $ \sim$ 3$ ^{\circ}$ using micro-Raman spectroscopy. A key finding of our work is the splitting of the G mode near the magic angle due to moiré potential induced phonon hybridization. The linewidth of the low-frequency component of the G mode (G$ ^-$ ), as well as the main component of the 2D mode, exhibits enhanced broadening near the magic angle due to increased electron-phonon coupling, driven by the emergence of flat electronic bands. Additionally, temperature-dependent Raman measurements (6-300 K) of magic-angle twisted bilayer graphene sample ($ \theta_t \sim$ 1$ ^{\circ}$ ) reveal an almost tenfold increase in phonon anharmonicity-induced temperature variation in both components of the split G mode, as compared to Bernal-stacked bilayer graphene sample, further emphasizing the role of phonon hybridization in this system. These studies could be important for understanding the thermal properties of the twisted bilayer graphene systems.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Materials Science (cond-mat.mtrl-sci)
Phys. Rev. B - Accepted on 16th June, 2025 [this https URL]; 13 pages, 12 figures
Hyperfine electro-nuclear coupling at the quantum criticality of YbCu4Zn
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2025-06-24 20:00 EDT
S. Gabani, I. Curlik, F. Akbar, M. Giovannini, J.G. Sereni
An increasing number of Yb-based compounds fulfill the conditions for the investigation of hyperfine electro-nuclear coupling effects related to 171-Yb and 173-Yb isotopes. Among them, the lack of magnetic order down to the milikelvin range in compounds with robust localized electronic moments and their nuclear magnetism. Although reminiscences of short range magnetic interactions may be observed below 1K, such perturbation can be dodged investigating compounds located close to a quantum critical point (QCP), where quantum fluctuations prevent the development of magnetic correlations to develop. Within the family of cubic YbCu4M compounds (M = Ni, Au and Zn), we have investigated YbCu4Zn that shows a logarithmic temperature dependence: C_P /T ~ ln(T/TQ) in its electronic specific heat, as predicted for a QCP. Simultaneously, no signs of RKKY interactions are detected down to 0.03K. Due to the low Kondo temperature of its doublet ground state, the localized 4f electrons weakly couple with conduction electrons, allowing the coupling between nuclear and 4f electron moments to become relevant. However, the reminder Kondo interaction acts on the electronic hyperfine field producing a small deviation from the standard nuclear C_N ~ 1/T^2 dependence into a n < 2 power law. The expected n = 2 dependence is progressively recovered under applied magnetic field.
Strongly Correlated Electrons (cond-mat.str-el)
9 pages, 8 figures
Corner Topology Makes Woven Baskets into Stiff, yet Resilient Metamaterials
New Submission | Soft Condensed Matter (cond-mat.soft) | 2025-06-24 20:00 EDT
Guowei Wayne Tu, Evgueni T. Filipov
Basket weaving is a traditional craft used to create practical three-dimensional (3D) structures. While the geometry and aesthetics of baskets have received considerable attention, the underlying mechanics and modern engineering potential remain underexplored. This work shows that 3D woven structures offer similar stiffness yet substantially higher resilience than their non-woven continuous counterparts. We explore corner topologies that serve as building blocks to convert 2D woven sheets into 3D metamaterials that can carry compressive loads. Under small deformations, the woven corners exhibit axial stiffness similar to continuous structures because the woven ribbons are engaged with in-plane loads. Under large deformations, the woven corners can be compressed repeatedly without plastic damage because ribbons can undergo elastic local buckling. We present a modular platform to assemble woven corners into complex spatial metamaterials and demonstrate applications including damage-resilient robotic systems and metasurfaces with tailorable deformation modes. Our results explain the historic appeal of basket weaving, where readily available ribbons are crafted into 3D structures with comparable stiffness yet far superior resilience to continuous systems. The modular assembly of woven metamaterials can further revolutionize design of next-generation automotive components, consumer devices, soft robots, and more where both resilience and stiffness are essential.
Soft Condensed Matter (cond-mat.soft), Applied Physics (physics.app-ph), Computational Physics (physics.comp-ph)
Presented at APS March Meeting 2025
Ultrafast scintillating metal-organic frameworks films
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-06-24 20:00 EDT
Lorena Dhamo, Jacopo Perego, Irene Villa, Charl X. Bezuidenhout, Ilaria Mattei, Alessia Landella, Silvia Bracco, Angiolina Comotti, Angelo Monguzzi
Compositionally engineered metal-organic frameworks (MOFs) have been designed and used to fabricate ultrafast scintillating films with emission in both the UV and visible regions. The inclusion of hafnium (Hf) ions in the nodes of the MOF increases the interaction cross-section with ionizing radiation, partially compensating for the low density of the porous material and dramatically increasing the system scintillation yield. The high diffusivity of bimolecular excitons within the framed conjugated ligands allows bimolecular annihilation processes between excited states that partially quench the MOF luminescence, resulting in ultrafast scintillation pulses under X-ray excitation with kinetics in the hundreds of picoseconds time scale. Despite the quenching, the gain in scintillation yield achieved by incorporating Hf ions is large enough to maintain the light yield of the films above 104 ph/MeV under soft X-rays. These unprecedented high efficiencies and simultaneous ultrafast emission kinetics obtained at room temperature in a technologically attractive solid-state configuration, together with the versatility of its composition allowing for further application-specific modifications, place the MOF platform in a prominent position for the realization of the next generation of ultrafast scintillation counters for high-energy physics studies and medical imaging applications.
Materials Science (cond-mat.mtrl-sci), Applied Physics (physics.app-ph)
Towards a hybrid 3D transmon qubit with topological insulator-based Josephson junctions
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2025-06-24 20:00 EDT
Sheng-Wen Huang, Ramya Suresh, Jian Liao, Botao Du, Zachary Miles, Leonid P. Rokhinson, Yong P. Chen, Ruichao Ma
Superconducting quantum circuits provide a versatile platform for studying quantum materials by leveraging precise microwave control and utilizing the tools of circuit quantum electrodynamics (QED). Hybrid circuit devices incorporating novel quantum materials could also lead to new qubit functionalities, such as gate tunability and noise resilience. Here, we report experimental progress towards a transmon-like qubit made with a superconductor-topological insulator-superconductor (S-TI-S) Josephson junction using exfoliated BiSbTeSe2. We present a design that enables us to systematically characterize the hybrid device, from DC transport of the S-TI-S junction, to RF spectroscopy, to full circuit QED control and measurement of the hybrid qubit. In addition, we utilize a high-quality-factor superconducting cavity to characterize material and fabrication-induced losses, thereby guiding our efforts to improve device quality.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Quantum Physics (quant-ph)
Transport properties of the pseudospin-3/2 Dirac-Weyl fermions in the double-barrier-modulated two-dimensional system
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2025-06-24 20:00 EDT
In this work, we analytically solved the pseudospin-3/2 Dirac equation and investigated the electronic transport properties in the double-barrier modulated two-dimensional system. The probability current density operator is explicitly derived from the time-dependent pseudospin-3/2 Dirac equation, which paves way for investigation of the electronic transport properties of general pseudospin-$ s$ Dirac-Weyl systems with $ s$ an integer or half integer larger than 1. As a result of the double-cone band structure, the pseudospin-3/2 system has two incident channels for a single incident energy and incident angle pair. Similar to its counterparts of pseudospin-1/2 and pseudospin-1 Dirac-Weyl systems, the Klein tunneling and resonant tunneling effects in the transmission probability are numerically observed for incidence coming from both Dirac cones in the double-barrier-modulated pseudospin-3/2 system. In contrast to its pseudospin-1/2 and -1 counterparts, the Klein tunneling and resonant tunneling effects are differentiated into double-channel and single-channel incidences, corresponding to different regimes in the $ E$ -$ k_y$ dispersion plane. Without a flat band, the super Klein tunneling effect of the pseudospin-1 Dirac-Weyl system does not occur in the pseudospin-3/2 system. Using the numerically obtained probability current density, the zero-temperature conductivity, shot noise, and Fano factor are calculated. As a combined result of double-channel incidence, Klein tunneling, and resonant tunneling, in comparison with its pseudospin-1/2 (graphene) and pseudospin-1 counterparts, the conductivity and shot noise in the pseudospin-3/2 double-barrier structure is enhanced. A Fano factor between 0.4 and 0.5 close to the Dirac point $ {E_F}={V_0}$ is observed.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
Boltzmann-Ginzburg-Landau theory for autochemotaxis of active rod-like particles
New Submission | Soft Condensed Matter (cond-mat.soft) | 2025-06-24 20:00 EDT
We investigate the interplay between chemotaxis and alignment interactions in active rod-like particles, such as E. coli and Janus rods. Starting from a discrete model of self-propelled rods with chemotactic responses, we employ a Boltzmann-Ginzburg-Landau (BGL) approach to derive coarse-grained dynamical equations for the density, polar and nematic orientational order parameters, and the concentration field of the chemoattractant. We perform a linear stability analysis for fluctuations around uniform steady states corresponding to isotropic and nematic phases. In both phases, we find that translational chemotactic response promotes instability, while rotational chemotactic response suppresses it, elucidating their contrasting effects on the onset of collective dynamics.
Soft Condensed Matter (cond-mat.soft)
10 pages, 4 figures
Residual gauge theory for quanta of surface plasmons
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2025-06-24 20:00 EDT
We develop a gauge-theoretical framework to investigate the quanta of surface plasmons. Our formulation, based on quantum electrodynamics, highlights the importance of residual gauge symmetry. We emphasize that residual gauge symmetry, which imposes constraint equations on physical states, is fundamentally linked to Joule heating. This framework is applied to metals, semiconductors, and quantum Hall states, suggesting the presence of a latent transverse electric mode and that the quanta have the ability to maintain light-matter entanglement.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Quantum Physics (quant-ph)
13 pages, 2 figures
Doping-induced Polyamorphic Transitions in Fluorite Oxides
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-06-24 20:00 EDT
Hao Yang, Qiaotong Luan, Qing Zhang, Yuhao Yue, Yawen Xu, Xiaohui Liu, Zheng Wen, Zhaoru Sun
Fluorite oxides such as HfO$ _2$ exhibit rich and tunable phase behavior, making them promising candidates for next generation electronic devices. A key challenge is to design amorphous HfO$ _2$ -based high-$ k$ materials with both structural and performance stability. Here, using molecular dynamics simulations supported by experimental measurements, we reveal that Ba doping stimulates a polyamorphic transition in HfO$ _2$ , yielding a semi-ordered amorphous (SA) phase characterized by disordered oxygens embedded within an ordered metal sublattice. We find that this phase arises from degenerate short-range symmetry breaking modes, consistent with Pauling’s parsimony rule. Notably, the SA structure is thermodynamically stable and displays a wider bandgap and higher dielectric constant than conventional random-packing amorphous structure, owing to suppressed subgap states and increased Born effective charges. We further demonstrate that this structural motif generalizes to Ba-, Sr-, and Ca-doped HfO$ _2$ and ZrO$ _2$ , establishing a broadly applicable strategy for designing high-performance amorphous dielectrics.
Materials Science (cond-mat.mtrl-sci), Statistical Mechanics (cond-mat.stat-mech)
4 figures
Wide-field Hyperspectral Optical Microscopy for Rapid Characterization of Two-Dimensional Semiconductors and Heterostructures
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-06-24 20:00 EDT
Zhenghan Peng, Adeyemi Uthman, Zhepeng Zhang, Anh Tuan Hoang, Xiang Zhu, Eric Pop, Andrew J. Mannix
Electronic and optoelectronic applications of two-dimensional (2D) semiconductors demand precise control over material quality, including thickness, composition, doping, and defect density. Conventional benchmarking methods (e.g., charge transport, confocal mapping, electron or scanning probe microscopy) are slow, perturb sample quality, or involve trade-offs between speed, resolution, and scan area. To accelerate assessment of 2D semiconductors, we demonstrate a broadband, wide-field hyperspectral optical microscope for 2D materials (2D-HOM) that rapidly captures a spatial-spectral data cube within seconds. The data cube includes x-y spatial coordinate (a 300 \ast 300 $ \mu\mathrm{m}^2$ field, with ~ 1 $ \mu\mathrm{m}$ resolution) and a selectable wavelength range between 1100 to 200 nm at each pixel. Using synthesized films and heterostructures of transition metal dichalcogenides ($ \mathrm{MoS}{2}$ , $ \mathrm{WS}{2}$ , $ \mathrm{V}{x}\mathrm{W}{1-x}\mathrm{S}{2}$ , and $ \mathrm{WSe}{2}$ ), we show that this cost-effective technique detects spectral fingerprints of material identity, doping, grain boundaries, and alloy composition, and enables advanced analysis, including unsupervised machine learning for spatial segmentation.
Materials Science (cond-mat.mtrl-sci)
Optical Excitations of Flat Bands Induced by Exciton Condensation in Ta$_2$Pd$3$Te${5}$
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-06-24 20:00 EDT
Shaohui Yi, Zhiyu Liao, Chenhao Liang, Sheng Zhang, Xiutong Deng, Yongjie Xie, Lincong Zheng, Yujie Wang, Yubiao Wu, Zhijun Wang, Youguo Shi, Xianggang Qiu, Bing Xu
We report on the charge dynamics of Ta$ _2$ Pd$ _3$ Te$ _5$ using temperature-dependent optical spectroscopy with polarized light. We observe a metal-insulator transition characterized by the collapse of Drude response and the emergence of sharp and narrow absorption peaks at low temperatures. Unlike previous excitonic insulator candidates such as TiSe$ _2$ and Ta$ _2$ NiSe$ _5$ , where the excitonic order is intertwined with charge density wave or structural instabilities, the sharp features in Ta$ _2$ Pd$ _3$ Te$ _5$ point to intrinsic excitonic excitations associated with ultra-flat bands driven by many-body renormalization of the band structure via spontaneous exciton condensation. Our findings thus provide clear-cut optical evidence for exciton condensation in a bulk crystal and establish Ta$ _2$ Pd$ _3$ Te$ _5$ as a promising platform for exploring correlated quantum phases and novel excitonic phenomena.
Materials Science (cond-mat.mtrl-sci), Strongly Correlated Electrons (cond-mat.str-el)
7 pages, 3 figures
First-principles prediction of altermagnetism in transition metal graphite intercalation compounds
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-06-24 20:00 EDT
Weida Fu, Guo-Dong Zhao, Tao Hu, Wencai Yi, Hui Zhang, Alessandro Stroppa, Wei Ren, Zhongming Ren
We report the emergence of altermagnetism, a magnetic phase characterized by the coexistence of compensated spin ordering and momentum-dependent spin splitting, in graphite intercalation compounds (GICs), a prototypical material system long investigated for its tunable electronic and structural properties. Through first-principles calculations, we demonstrate that vanadium-intercalated stage-1 graphite compounds, exhibit inherent altermagnetic properties. The hexagonal crystal system and antiferromagnetic ordering of V atoms generate a magnetic space group that enforces alternating spin polarization in momentum space while maintaining zero net magnetization. The calculated band structure reveals robust altermagnetic signatures: along the high-symmetry direction, we observe a pronounced spin splitting of ~270 meV with alternating spin polarization. Crucially, the spin splitting exhibits minimal sensitivity to spin-orbit coupling (SOC) effect, highlighting the dominance of exchange interactions over relativistic effects. From Monte Carlo simulations, we predict a magnetic transition temperature ($ T_m$ ) of ~228 K, indicating stable magnetic ordering above liquid nitrogen temperatures. The combination of symmetry-protected spin textures, SOC-independent splitting, and elevated $ T_m$ temperature makes V-GICs as a promising candidate for spintronic applications, particularly for zero-field spin-polarized current generation and topologically robust spin transport. As the first demonstration of carbon-based alternating magnetic systems, this work offers a design paradigm for engineering spin-polarized quantum states governed by crystalline symmetry constraints.
Materials Science (cond-mat.mtrl-sci), Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
In situ 2D visualization of hydrogen entry into Zn-coated steels in NaCl solutions: Roles of Zn dissolution and potential distribution
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-06-24 20:00 EDT
Hiroshi Kakinuma, Saya Ajito, Koki Okumura, Makoto Akahoshi, Yu Takabatake, Tomohiko Omura, Motomichi Koyama, Eiji Akiyama
The hydrogen entry behavior of a partially Zn-coated steel sheet in NaCl solutions was investigated employing a polyaniline-based hydrogenochromic sensor, electrochemical hydrogen permeation tests, and potential measurements using a scanning Kelvin probe. While the Zn coating mitigated corrosion of the steel substrate, it simultaneously accelerated the hydrogen entry. The hydrogen entry occurred at the bare steel surface regions exposed to the NaCl solution, with the hydrogen flux exhibiting non-uniform distribution: higher near the dissolving Zn coating. While no significant differences in Zn dissolution behavior or galvanic current were observed between 0.1 and 0.01 M NaCl solutions, the total hydrogen flux decreased with decreasing Cl ion concentration. This reduction was attributed to a potential gradient induced by differences in electrolyte conductivity. The results demonstrate that potential distribution, rather than galvanic current, is a dominant factor influencing hydrogen entry under the investigated conditions.
Materials Science (cond-mat.mtrl-sci)
74 pages, 24 figures
Probing d-wave superconducting gap of high-$T_\mathrm{c}$ cuprate $\mathrm{Bi}_2\mathrm{Sr}_2\mathrm{Ca}_2\mathrm{Cu}3\mathrm{O}{10+δ}$ by resonant inelastic X-ray scattering
New Submission | Superconductivity (cond-mat.supr-con) | 2025-06-24 20:00 EDT
Kunhao Li, Qizhi Li, Changwei Zou, Jaewon Choi, Chaohui Yin, Mirian Garcia-Fernandez, Stefano Agrestini, Shilong Zhang, Chengtian Lin, Xingjiang Zhou, Ke-Jin Zhou, Yi Lu, Yingying Peng
The superconducting gap is a characteristic feature of high-T$ _c$ superconductors and provides crucial information on the pairing mechanism underlying high-temperature superconductivity. Here, we employ high-resolution resonant inelastic X-ray scattering (RIXS) at the Cu $ L_3$ -edge to investigate the superconducting gap in the overdoped cuprate $ \mathrm{Bi}_2\mathrm{Sr}_2\mathrm{Ca}2\mathrm{Cu}3\mathrm{O}{10+\delta}$ ($ T\mathrm{c}$ = 107 K). By analyzing antisymmetrized, temperature-dependent RIXS spectra over a range of in-plane momentum transfers, we observe a clear suppression of low-energy spectral weight below T$ c$ , indicative of superconducting gap formation. This suppression is most pronounced at small momentum transfers ($ |\boldsymbol{q}\parallel| \leq 0.18$ r.l.u.) and corresponds to a gap size of approximately 2$ \Delta_0 \sim$ 130 meV. Comparison with theoretical calculations of the momentum-dependent charge susceptibility supports a d-wave symmetry of the superconducting gap, while an isotropic s-wave gap fails to reproduce key experimental features. These findings establish RIXS as a powerful, bulk-sensitive probe of superconducting gap symmetry and highlight its utility for studying materials beyond the reach of surface-sensitive techniques such as ARPES and STM.
Superconductivity (cond-mat.supr-con), Strongly Correlated Electrons (cond-mat.str-el)
11 pages, 10 figures
High-throughput development of flexible amorphous materials showing large anomalous Nernst effect via automatic annealing and thermoelectric imaging
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-06-24 20:00 EDT
Sang J. Park, Ravi Gautam, Abdulkareem Alasli, Takamasa Hirai, Fuyuki Ando, Hosei Nagano, Hossein Sepehri-Amin, Ken-ichi Uchida
This work demonstrates high-throughput screening of flexible magnetic materials for efficient transverse thermoelectric conversion based on the anomalous Nernst effect (ANE). The approach integrates automated annealing and contactless measurement of transport properties using lock-in thermography. We screen 151 Fe-based alloy ribbons with varying compositions and annealing conditions. Seven high-performance candidates with mechanical flexibility are identified, exhibiting anomalous Nernst coefficients of up to 4.8 uV/K, the highest value reported for flexible materials. Structural analysis reveals that ANE enhancement occurs universally near the first crystallization temperature of the Fe-based ribbons, without strong correlation with composition. Notably, the enhancement is also observed in samples without Cu or Fe nanoclusters, indicating that short-range atomic order in the amorphous matrix may play a role in ANE. These findings demonstrate the effectiveness of high-throughput methodologies for discovering advanced ANE materials and provide new insights into thermoelectric conversion in disordered systems where conventional design principles fall short.
Materials Science (cond-mat.mtrl-sci), Disordered Systems and Neural Networks (cond-mat.dis-nn)
SeWS/bilayer-SiC heterojunction: An S-scheme photocatalyst with high visible-light absorption, excellent carrier mobility and adjustable band gap
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-06-24 20:00 EDT
Liuzhu Yang, Wenhui Wan, Yanfeng Ge, Qiuyue Ma, Zhicui Wang, Yong Liu
Vertically stacked heterojunctions have garnered significant attention for their tunable electronic structures and photocatalytic performance, making them promising candidates for next-generation nanodevices. Using first-principles calculations, we systematically investigate the electronic structure, optical characteristics, and charge transfer of WSSe/SiC heterojunctions. Our results reveal that SeWS/monolayer-SiC, SeWS/bilayer-SiC, and SWSe/monolayer-SiC exhibit type-II band alignment, whereas SWSe/bilayer-SiC displays type-I alignment. Notably, SeWS/bilayer-SiC possesses a direct bandgap, in contrast to the indirect bandgaps of the other three configurations. Remarkably, the SeWS/bilayer-SiC heterojunction demonstrates a high absorption coefficient ($ 10^{5}\mathrm{cm}^{-1}$ ) in the visible range and exhibits exceptional anisotropy in carrier transport, with an outstanding hole mobility of $ 9.58 \times 10^{3}\mathrm{cm}^{2},\mathrm{V}^{-1},\mathrm{s}^{-1}$ along the Y-direction. Furthermore, combining thermodynamic stability with an S-scheme charge transfer mechanism, this system exhibits superior redox capability for photocatalytic water splitting, achieving a high hydrogen evolution efficiency of 22.15%, which surpasses the commercial viability threshold (10%). Furthermore, we demonstrate effective band gap modulation via external electric fields and biaxial strains, with optical absorption coefficients exhibiting strong strain dependence. This work provides fundamental insights into the design of WSSe/SiC heterojunctions for high-efficiency photocatalytic and tunable photodetector applications.
Materials Science (cond-mat.mtrl-sci)
24 pages, 9 figures
Interaction-Driven Topological Transitions in Monolayer TaIrTe4
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2025-06-24 20:00 EDT
Jiangxu Li, Jian Tang, Louis Primeau, Thomas Siyuan Ding, Rahul Soni, Tiema Qian, Kenji Watanabe, Takashi Taniguchi, Ni Ni, Adrian Del Maestro, Qiong Ma, Yang Zhang
Discovering materials that combine topological phenomena with correlated electron behavior is a central pursuit in quantum materials research. Monolayer TaIrTe$ _4$ has recently emerged as a promising platform in this context, hosting robust quantum spin Hall insulator (QSHI) phases both within a single-particle gap and within a correlation-induced gap arising from van Hove singularities (vHSs), accessed via electrostatic doping. Its intrinsic monolayer nature offers exceptional tunability and the potential to realize a versatile array of interaction-driven topological phases. In this work, we combine theory and experiment to map the phase landscape of monolayer TaIrTe$ _4$ . Using Hartree-Fock calculations, we investigate the interaction-driven phase diagram near the vHSs under commensurate filling conditions. By systematically tuning the dielectric screening and strain, we uncover a rich set of ground states–including QSHI, trivial insulator, higher-order topological insulator, and metallic phase–among which are interaction-driven topological phase transitions. Experimentally, we perform both local and nonlocal transport measurements across a broad set of devices, which–due to unavoidable strain variations during fabrication-realize several phases consistent with theoretical predictions. Together, our results lay the groundwork for understanding correlation-driven topological phenomena in TaIrTe$ _4$ and open new directions for engineering exotic quantum phases in low-dimensional materials beyond the limitations of moiré superlattices.
Strongly Correlated Electrons (cond-mat.str-el)
12+18 pages, 8+14 figures
Determining the grain orientations of battery materials from electron diffraction patterns using convolutional neural networks
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-06-24 20:00 EDT
Jonas Scheunert, Shamail Ahmed, Thomas Demuth, Andreas Beyer, Sebastian Wissel, Bai-Xiang Xu, Kerstin Volz
Polycrystalline materials have numerous applications due to their unique properties, which are often determined by the grain boundaries. Hence, quantitative characterization of grain as well as interface orientation is essential to optimize these materials, particularly energy materials. Using scanning transmission electron microscopy, matter can be analysed in an extremely fine grid of scan points via electron diffraction patterns at each scan point. By matching the diffraction patterns to a simulated database, the crystal orientation of the material as well as the orientation of the grain boundaries at each scan point can be determined. This pattern matching approach is highly time intensive. Artificial intelligence promises to be a very powerful tool for pattern recognition. In this work, we train convolutional neural networks (CNNs) on dynamically simulated diffraction patterns of LiNiO2, an important cathode-active material for Lithium-ion batteries, to predict the orientation of grains in terms of three Euler angles for the complete fundamental orientation region. Results demonstrate that these networks outperform the conventional pattern matching algorithm with increased accuracy and efficiency. The increased accuracy of the CNN models can be attributed to the fact that these models are trained by data incorporating dynamical effects. This work is the first attempt to apply deep learning for analysis of electron diffraction data and enlightens the great potential of ML to accelerate the analysis of electron microscopy data, toward high-throughput characterization technique.
Materials Science (cond-mat.mtrl-sci)
Comment on “Storage properties of a quantum perceptron”
New Submission | Disordered Systems and Neural Networks (cond-mat.dis-nn) | 2025-06-24 20:00 EDT
The recent paper “Storage properties of a quantum perceptron” [Phys. Rev. E 110, 024127] considers a quadratic constraint satisfaction problem, motivated by a quantum version of the perceptron. In particular, it derives its critical capacity, the density of constraints at which there is a satisfiability transition. The same problem was considered before in another context (classification of geometrically structured inputs, see [Phys. Rev. Lett. 125, 120601; Phys. Rev. E 102, 032119; J. Stat. Mech. (2021) 113301]), but the results on the critical capacity drastically differ. In this note, I substantiate the claim that the derivation performed in the quantum scenario has issues when inspected closely, I report a more principled way to perform it and I evaluate the critical capacity of an alternative constraint satisfaction problem that I consider more relevant for the quantum perceptron rule proposed by the article in question.
Disordered Systems and Neural Networks (cond-mat.dis-nn), Quantum Physics (quant-ph)
6 pages, 2 figures. Comment on arXiv:2111.08414, published in Phys. Rev. E 110, 024127
Probing universal phase diagram of dimensional crossover with an atomic quantum simulator
New Submission | Quantum Gases (cond-mat.quant-gas) | 2025-06-24 20:00 EDT
Jinyuan Tian, Zhongcheng Yu, Jing Liu, Chi-Kin Lai, Lorenzo Pizzino, Chengyang Wu, Hongmian Shui, Thierry Giamarchi, Hepeng Yao, Xiaoji Zhou
Dimensionality is a fundamental concept in physics, which plays a hidden but crucial role in various domains, including condensed matter physics, relativity and string theory, statistical physics, etc. In quantum physics, reducing dimensionality usually enhances fluctuations and leads to novel properties. Owing to these effects, quantum simulators in which dimensionality can be controlled have emerged as a new area of interest. However, such a platform has only been studied in specific regimes and a universal phase diagram is lacking. Here, we produce an interacting atomic quantum simulator with continuous tunability of anisotropy and temperature, and probe the universal phase diagram of dimensional crossover. At low temperatures, we identify the regimes from quantum three to zero dimensions. By increasing temperature, we observe the non-trivial emergence of a thermal regime situated between the quantum zero and integer dimensions. We show that the quantum-to thermal transition falls into four different universality classes depending on the dimensionality. Surprisingly, we also detect a fifth type where the high-dimensional quantum system can reach the thermal phase by crossing a low-dimensional quantum regime. Our results provide a crucial foundation for understanding the projective condensed matter structures in unconventional dimensions.
Quantum Gases (cond-mat.quant-gas)
Atomistic simulations of irradiation damage on the engineering timescale: Examining the dose rate effect in tungsten
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-06-24 20:00 EDT
Max Boleininger, Daniel R. Mason, Thomas Schwarz-Selinger, Pui-Wai Ma
The change in materials properties subjected to irradiation by highly energetic particles strongly depends on the irradiation dose rate. Atomistic simulations can in principle be used to predict microstructural evolution where experimental data is sparse or unavailable, however, fundamental limitations of the method make it infeasible to replicate the experimental timescale spanning from seconds to hours. Here, we present an atomistic simulation method where the motion of vacancies is accelerated, while the fast degrees of freedom are propagated with standard molecular dynamics. The resulting method is free of adjustable parameters and can predict microstructural evolution under irradiation at elevated temperatures. Simulating the microstructural evolution of tungsten under irradiation at dose rates of $ 10^{-5}$ , $ 10^{-4}$ , and $ 10^{-3}$ dpa/second, we find that increasing the temperature or reducing the dose rate primarily results in a reduction of the steady-state defect concentration, in qualitative agreement with deuterium retention and post-irradiation resistivity recovery experiments. The formation of a nanoscale void is observed if a system initially containing a large dislocation loop is irradiated. We present a minimally simple rate theory model which reproduces the time-dependent defect concentration and volume swelling behaviour obtained from the simulations.
Materials Science (cond-mat.mtrl-sci)
16 pages, 8 figures
Leveraging neural network interatomic potentials for a foundation model of chemistry
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-06-24 20:00 EDT
So Yeon Kim, Yang Jeong Park, Ju Li
Large-scale foundation models, including neural network interatomic potentials (NIPs) in computational materials science, have demonstrated significant potential. However, despite their success in accelerating atomistic simulations, NIPs face challenges in directly predicting electronic properties and often require coupling to higher-scale models or extensive simulations for macroscopic properties. Machine learning (ML) offers alternatives for structure-to-property mapping but faces trade-offs: feature-based methods often lack generalizability, while deep neural networks require significant data and computational power. To address these trade-offs, we introduce HackNIP, a two-stage pipeline that leverages pretrained NIPs. This method first extracts fixed-length feature vectors (embeddings) from NIP foundation models and then uses these embeddings to train shallow ML models for downstream structure-to-property predictions. This study investigates whether such a hybridization approach, by ``hacking” the NIP, can outperform end-to-end deep neural networks, determines the dataset size at which this transfer learning approach surpasses direct fine-tuning of the NIP, and identifies which NIP embedding depths yield the most informative features. HackNIP is benchmarked on Matbench, evaluated for data efficiency, and tested on diverse tasks including \textit{ab initio}, experimental, and molecular properties. We also analyze how embedding depth impacts performance. This work demonstrates a hybridization strategy to overcome ML trade-offs in materials science, aiming to democratize high-performance predictive modeling.
Materials Science (cond-mat.mtrl-sci), Machine Learning (cs.LG)
29pages, 10 figures
Electromagnetic Proximity Effect: Superconducting Magnonics and Beyond
New Submission | Superconductivity (cond-mat.supr-con) | 2025-06-24 20:00 EDT
Tao Yu, Xi-Han Zhou, Gerrit E. W. Bauer, Irina Bobkova
The exchange interaction at interfaces between superconductors (SCs) and ferromagnets (FMs) has been a central topic in condensed matter physics for many decades, starting with the prediction of exotic phases such as the Fulde-Ferrell-Larkin-Ovchinnikov states and leading to the discovery of triplet superconductivity. This review focuses on new phenomena in SC$ |$ FM heterostructures caused by the \textit{non-contact dipolar interaction} between magnons, i.e., the quanta of spin wave excitations in the ferromagnet, and the superconducting order. A universal non-relativistic spin-orbit coupling locks the polarization and momentum of their evanescent stray magnetic fields and leads to chiral screening by proximate superconductors. The interaction-induced hybrid quasiparticles are magnon-Meissner collective modes, magnon-cooparon, Josephson plasmonic modes, and nodal magnon-photon polaritons. Superconducting and normal metallic gates modulate and control the magnetodipolar interaction and thereby magnetization and energy transport at interfaces and in thin films.
Superconductivity (cond-mat.supr-con)
108 pages, 45 figures
Angular-momentum-selective nanofocusing with Weyl semimetals
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2025-06-24 20:00 EDT
Marco Peluso, Alessandro De Martino, Reinhold Egger, Francesco Buccheri
We investigate the theory of surface plasmon polaritons on a magnetic Weyl semimetal conical tip. We show that the axion term in the effective electrodynamics modifies the surface plasmon polariton dispersion relation and allows all modes with a given sign of the orbital angular momentum to be focused at the end of the tip. This is in contrast with normal metals, in which only one mode can reach the end. We discuss how this orbital angular momentum nanofocusing expands the potential of technologies that use this degree of freedom.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
10 pages, 5 figures
Bimodal distribution of delay times and splitting of the zero-bias conductance peak in a double-barrier normal-superconductor junction
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2025-06-24 20:00 EDT
C.W.J. Beenakker, V.A. Zakharov
We formulate a scattering theory of the proximity effect in a weakly disordered SININ junction (S = superconductor, I = insulating barrier, N = normal metal). This allows to relate the conductance and density of states of the junction to the scattering times $ \tau$ (eigenvalues of the Wigner-Smith time-delay matrix). The probability density $ P(\tau)$ has two peaks, at a short time $ \tau_{\rm min}$ and a late time $ \tau_{\rm max}$ . The density of states at the Fermi level is the geometric mean of the two times. The splitting of the zero-bias conductance peak is given by $ \hbar/\tau_{\rm max}$ .
Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Superconductivity (cond-mat.supr-con)
7 pages, 5 figures
Intercalation-Altermagnet-Driven Ferrimagnetic-Ferroelastic Multiferroics and Anomalous and Spin Transport
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-06-24 20:00 EDT
Long Zhang, Yuxin Liu, Junfeng Ren, Guangqian Ding, Xiaotian Wang, Guangxin Ni, Guoying Gao, Zhenxiang Cheng
Spin splitting in emerging altermagnets is non-relativistic and momentum-dependent, yet energy-independent and localized, posing challenges for practical applications. Here, we propose a paradigm of intercalation-driven altermagnets to attain ameliorative electronic structures, multiferroic characteristics, and anomalous and spin transport functionalities. As a representative system, we investigate electrochemistry- and self-intercalated V2Se2O bilayers, building on the recently reported room-temperature K- and Rb-intercalated V2Se2O family, utilizing density functional theory, Wannier function analyses, Monte Carlo simulations, and non-equilibrium Green function methods. Intercalation induces room-temperature intralayer ferrimagnetic and interlayer ferromagnetic couplings (358 K for Li-intercalation and 773 K for V-intercalation), ferroelasticity (1 % signal intensity), in-plane uniaxial magnetic anisotropy and metallization, while modifying the anomalous Hall effect. Notably, Li- and V-intercalated V2Se2O bilayers exhibit enhanced spin splitting and half-metallic behavior, respectively, yielding near-perfect spin filtering efficiencies. Intercalation substantially boosts spin transport in V2Se2O-based devices, enabling giant magnetoresistance (877 %), ultra-high thermal tunneling magnetoresistance (12000 %), and observable spin Seebeck and temperature negative differential resistance effects. Such intercalation-altermagnet-driven paradigm pioneers the expansion of altermagnetic functionalities through multifunctional integration, offering promising avenues for advanced, miniaturized, room-temperature utilization of anomalous, electron, and spin transport.
Materials Science (cond-mat.mtrl-sci), Applied Physics (physics.app-ph), Computational Physics (physics.comp-ph)
30pages, 5 figures
Data-Driven Design-Test-Make-Analyze Paradigm for Inorganic Crystals: Ultrafast Synthesis of Ternary Oxides
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-06-24 20:00 EDT
Haiwen Dai, Matthew J. McDermott, Andy Paul Chen, Jose Recatala-Gomez, Wei Nong, Ruiming Zhu, Maung Thway, Samuel Morris, Christian Schürmann, Shreyas Dinesh Pethe, Chenguang Zhang, Wuan Geok Saw, Bich Ngoc Tran, Pritish Mishra, Fengxia Wei, Albertus Denny Handoko, Sabrine Hachmioune, Haipei Shao, Ming Lin, Chong Wai Liew, Kristin A. Persson, Kedar Hippalgaonkar
Data-driven methodologies hold the promise of revolutionizing inorganic materials discovery, but they often face challenges due to discrepancies between theoretical predictions and experimental validation. In this work, we present an end-to-end discovery framework that leverages synthesizability, oxidation state probability, and reaction pathway calculations to guide the exploration of transition metal oxide spaces. Two previously unsynthesized target compositions, ZnVO3 and YMoO3, passed preliminary computational evaluation and were considered for ultrafast synthesis. Comprehensive structural and compositional analysis confirmed the successful synthesis ZnVO3 in a partially disordered spinel structure, validated via Density Functional Theory (DFT). Exploration of YMoO3 led to YMoO3-x with elemental composition close to 1:1:3; the structure was subsequently identified to be Y4Mo4O11 through micro-electron diffraction (microED) analysis. Our framework effectively integrates multi-aspect physics-based filtration with in-depth characterization, demonstrating the feasibility of designing, testing, synthesizing, and analyzing (DTMA) novel material candidates, marking a significant advancement towards inorganic materials by design.
Materials Science (cond-mat.mtrl-sci)
related repo at this https URL
Spin waves involved in three-magnon splitting in synthetic antiferromagnets
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-06-24 20:00 EDT
Asma Mouhoub, Nathalie Bardou, Jean-Paul Adam, Aurélie Solignac, Thibaut Devolder
An important nonlinear effect in magnonics is the 3-magnon splitting where a high frequency magnon splits into two magnons of lower frequencies. Here, we study the 3-magnon splitting in spin wave conduits made from synthetic antiferromagnets. By combining inductive excitation, inductive detection, Brillouin Light Scattering imaging of the spin waves and analytical modeling based on conservation laws, we elucidate the nature of the spin waves involved in this process. We show in particular that low order optical spin waves propagating along the conduit can split in doublets of non-degenerate acoustic spin waves that have a standing wave character in the confined direction and unsymmetrical wavevectors in the direction of the spin wave conduit. Generally, several splitting channels run in parallel. The rules governing the three-magnon splitting and its interplay with the mode confinement have consequences for the applications in non-linear microwave signal processing based on spin waves.
Materials Science (cond-mat.mtrl-sci), Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
Two dimensional Coulomb gas in a non-conservative trap
New Submission | Statistical Mechanics (cond-mat.stat-mech) | 2025-06-24 20:00 EDT
David S. Dean, Rashed Aljasmi, Satya N. Majumdar
We study the nonequilibrium steady state of a two dimensional Coulomb gas under the action of an anisotropic harmonic trapping potential along with a non-conservative rotational force. In the case without rotation, the equilibrium (zero temperature) steady state has a uniform density supported over a a static elliptical droplet. The addition of a rotational force drives the system into a nonequilibrium steady state where the density is still uniform inside an ellipse, but the ellipse gets tilted by a a fixed angle compared to the non-rotational case. In addition, a nonzero current is generated inside the droplet which run concentrically to the droplet boundary. For large rotational force, the droplet develops a purely circular form. Our results are predicted by a simple hydrodynamic calculation and are confirmed by numerical simulations and provide a full understanding of a novel driven non-equilibrium state in a strongly interacting system.
Statistical Mechanics (cond-mat.stat-mech)
12 pages 5 figures
Stability of universal properties against perturbations of the Markov Chain Monte Carlo algorithm
New Submission | Statistical Mechanics (cond-mat.stat-mech) | 2025-06-24 20:00 EDT
We numerically investigate the stability of universal properties at continuous phase transitions against perturbations of the Markov Chain Monte Carlo algorithm used to simulate the system. We consider the three dimensional XY model as test bed, and both local (single site Metropolis) and global (single cluster) updates, introducing deterministic truncation-like perturbations and stochastic perturbations in the acceptance probabilities. In (almost) all the cases we find a remarkable stability of the universal properties, even against large perturbations of the Markov Chain Monte Carlo algorithm, with critical exponents and scaling curves consistent with those of the standard XY model within statistical uncertainties.
Statistical Mechanics (cond-mat.stat-mech), High Energy Physics - Phenomenology (hep-ph)
11 pages, 16 pdf figures
Giant orbital magnetization in two-dimensional materials
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-06-24 20:00 EDT
Orbital magnetization typically plays a minor role in compounds where the magnetic properties are governed by transition metal elements. However, in some cases, the orbital magnetization may be fully unquenched, which can have dramatic consequences for magnetic anisotropy and various magnetic response properties. In the present work, we start by summarizing how unquenched orbital moments arise from particular combinations of crystal field splitting and orbital filling. We exemplify this for the cases of two-dimensional (2D) VI$ _3$ and FePS$ 3$ , and show that Hubbard corrections as well as self-consistent spin-orbit coupling are crucial ingredients for predicting correct orbital moments from first principles calculations. We then search the Computational 2D Materials Database (C2DB) for monolayers having tetrahedral or octahedral crystal field splitting of transition metal $ d$ -states and orbital occupancy that is expected to lead to large orbital moments. We identify 112 monolayers with octahedral crystal field splitting and 62 monolayers with tetrahedral crystal field splitting and for materials with partially filled $ t{2g}$ bands, we verify that inclusion of Hubbard corrections as well as self-consistent spin-orbit coupling typically increases the magnitude of predicted orbital moments by an order of magnitude.
Materials Science (cond-mat.mtrl-sci)
9 pages, 6 figures
Detecting Collective Excitations in Self-Gravitating Bose-Einstein Condensates via Faraday Waves
New Submission | Quantum Gases (cond-mat.quant-gas) | 2025-06-24 20:00 EDT
We propose Faraday waves as a probe for collective excitations in self-gravitating Bose-Einstein condensates (SGBECs), driven by periodic modulation of the $ s$ -wave scattering length. Linear stability analysis of the driven Gross-Pitaevskii-Newton equations reveals that parametric instability follows a Mathieu-like equation, with Faraday waves emerging resonantly when half the driving frequency matches the collective excitation frequency of the SGBEC. This framework yields a stability phase diagram demonstrating the coexistence and interplay between the intrinsic Jeans instability of self-gravitating systems and the unstable tongues of parametric resonance. The phase diagram shows that reducing the driving frequency fragments and narrows parametric resonance structures while expanding the Jeans-dominated regime. We further identify a thermal-gravity competition in the Faraday wavevector, manifested as a sharp transition when thermal energy balances mean-field interaction at low driving frequencies. We numerically simulate Faraday wave formation and dynamics within the SGBEC, including the effects of dissipation; simulations reveal that Faraday wave patterns exhibit high sensitivity to Jeans frequency, transitioning from parametric resonance to Jeans collapse as gravitational strength increases.
Quantum Gases (cond-mat.quant-gas), General Relativity and Quantum Cosmology (gr-qc), Pattern Formation and Solitons (nlin.PS), Quantum Physics (quant-ph)
21pages, 8 figures
Influence of Interlayer Stacking on Optical Behavior in WSe${2}$/MoS${2}$ van der Waals Heterostructures
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2025-06-24 20:00 EDT
Widad Louafi, Karim Rezouali, Daniele Varsano, Maurizia Palummo, Maurits W. Haverkort, Samir Lounis
We investigate the impact of crystal alignment on excitonic behavior in WSe$ _{2}$ /MoS$ _{2}$ van der Waals heterostructures by comparing eclipsed (AA) and staggered (AB) stacking configurations. Our first-principles and symmetry-based analysis reveal that interlayer stacking symmetry plays a central role in determining the nature of electron-hole pairs. We uncover a rich variety of excitonic states, including spatially confined two-dimensional (2D) excitons, delocalized three-dimensional (3D) excitons, and charge-transfer (CT) excitons with interlayer character. The dimensionality and optical activity of these excitons are governed by the interplay among orbital character, interlayer hybridization, and symmetry-imposed selection rules. Our findings establish general principles for engineering excitonic properties in van der Waals heterostructures through controlled layer orientation and stacking order.
Strongly Correlated Electrons (cond-mat.str-el)
11 pages, 5 figures
Nonequilibrium orders in parametrically driven field theories
New Submission | Statistical Mechanics (cond-mat.stat-mech) | 2025-06-24 20:00 EDT
Carl Philipp Zelle, Romain Daviet, Andrew J. Millis, Sebastian Diehl
Driving quantum materials with coherent light has proven a powerful platform to realize a plethora of interesting phases and transitions, ranging from ferroelectricity to superconductivity and limit cycles in pumped magnonics. In this paper we develop the field theoretical framework to describe nonequilibrium phases that emerge in systems pumped by rapid parametric drives. We consider paradigmatic O(N) models that describe the long-wavelength fluctuations of ordering fields in many condensed matter set ups. We show that rapid parametric driving of these models can induce an effective pump mechanism in the long wavelength regime through nonlinear scattering. This induces a nonequilibrium transition into a time-crystalline phase.
Statistical Mechanics (cond-mat.stat-mech)
Shaping Boundaries to Control and Transport Topological Defects in Colloidal Nematic Liquid Crystals
New Submission | Soft Condensed Matter (cond-mat.soft) | 2025-06-24 20:00 EDT
Gerardo Campos-Villalobos, André F. V. Matias, Ethan I. L. Jull, Lisa Tran, Marjolein Dijkstra
Anisotropic rod-like particles form liquid crystalline phases with varying degrees of orientational and translational order. When confined geometrically, these phases can give rise to topological defects, which can be selected and controlled by tuning how the rods align near boundaries, known as anchoring. While anchoring in molecular liquid crystals can be controlled through surface functionalization, this approach is not easily applicable to microscale colloidal systems, which have so far been limited to planar anchoring. Here, using particle-based simulations, Landau-de Gennes theory, and experiments on colloidal rods, we demonstrate that topographical patterning of the boundary can effectively control the anchoring type and, in turn, the defect state in two-dimensional confined nematics. Building on this, we show that dynamically shape-shifting the boundaries can transform and transport topological defects, enabling the design of liquid crystal analogs for binary information storage.
Soft Condensed Matter (cond-mat.soft)
6 pages, 4 figures
Spin-polarized triplet excitonic insulators in Ta3X8 (X=I, Br) monolayers
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-06-24 20:00 EDT
Haohao Sheng, Jingyu Yao, Sheng Zhang, Quansheng Wu, Zhong Fang, Xi Dai, Hongming Weng, Zhijun Wang
Bose-Einstein condensation of spin-polarized triplet excitons can give rise to an intriguing spin supercurrent, enabling experimental detection of exciton condensation. In this work, we predict that Ta3X8 (X=I, Br) ferromagnetic monolayers are spin-polarized triplet excitonic insulators (EIs), based on the systematic first-principles GW calculations coupled with the Bethe-Salpeter equation (GW+BSE). The single-particle calculations of spin-polarized band structures reveal that these monolayers are bipolar magnetic semiconductors, where the highest valence band and the lowest conduction band possess opposite spin polarization. The two low-energy bands, primarily originating from Ta $ d_{z^2}$ orbitals, are almost flat. The same-orbital parity and opposite-spin natures of the band-edge states effectively suppress dielectric screening, promoting the emergence of the EI state. The GW+BSE calculations reveal that the binding energy of the lowest-energy exciton is 1.499 eV for Ta3I8 monolayer and 1.986 eV for Ta3Br8 monolayer. Since both values exceed the respective GW band gaps, these results indicate a strong excitonic instability in these monolayers. A wavefunction analysis confirms that the lowest-energy exciton is a tightly bound Frenkel-like state, exhibiting a spin-polarized triplet nature with $ S_z=1$ . Our findings establish a valuable material platform for investigating spin-polarized triplet EIs, offering promising potential for spintronic applications.
Materials Science (cond-mat.mtrl-sci)
Disordered harmonic chain with random masses and springs: a combinatorial approach
New Submission | Disordered Systems and Neural Networks (cond-mat.dis-nn) | 2025-06-24 20:00 EDT
Maximilien Bernard, Christophe Texier
We study harmonic chains with i.i.d. random spring constants $ K_n$ and i.i.d. random masses $ m_n$ . We introduce a new combinatorial approach which allows to derive a compact approximate expression for the complex Lyapunov exponent, in terms of the solutions of two transcendental equations involving the distributions of the spring constants and the masses. Our result makes easy the asymptotic analysis of the low frequency properties of the eigenmodes (spectral density and localization) for arbitrary disorder distribution, as well as their high frequency properties. We apply the method to the case of power-law distributions $ p(K)=\mu,K^{-1+\mu}$ with $ 0<K<1$ and $ q(m)=\nu,m^{-1-\nu}$ with $ m>1$ (with $ \mu,:\nu>0$ ). At low frequency, the spectral density presents the power law $ \varrho(\omega\to0)\sim\omega^{2\eta-1}$ , where the exponent $ \eta$ exhibits first order phase transitions on the line $ \mu=1$ and on the line $ \nu=1$ . The exponent of the non disordered chain ($ \eta=1/2$ ) is recovered when $ \langle K_n^{-1}\rangle$ and $ \langle m_n\rangle$ are both finite, i.e. $ \mu>1$ and $ \nu>1$ . The Lyapunov exponent (inverse localization length) shows also a power-law behaviour $ \gamma(\omega^2\to0)\sim\omega^{2\zeta}$ , where the exponent $ \zeta$ exhibits several phase transitions~: the exponent is $ \zeta=\eta$ for $ \mu<1$ or $ \nu<1$ ($ \langle K_n^{-1}\rangle$ or $ \langle m_n\rangle$ infinite) and $ \zeta=1$ when $ \mu>2$ and $ \nu>2$ ($ \langle K_n^{-2}\rangle$ and $ \langle m_n^2\rangle$ both finite). In the intermediate region it is given by $ \zeta=\mathrm{min}(\mu,\nu)/2$ . On the transition lines, $ \varrho(\omega)$ and $ \gamma(\omega^2)$ receive logarithmic corrections. Finally, we also consider the Anderson model with random couplings (random spring chain for ``Dyson type I’’ disorder).
Disordered Systems and Neural Networks (cond-mat.dis-nn), Mathematical Physics (math-ph)
25 pages, 7 figures, revtex
Cluster Expansion Toward Nonlinear Modeling and Classification
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-06-24 20:00 EDT
Adrian Stroth, Claudia Draxl, Santiago Rigamonti
A quantitative first-principles description of complex substitutional materials like alloys is challenging due to the vast number of configurations and the high computational cost of solving the quantum-mechanical problem. Therefore, materials properties must be modeled. The Cluster Expansion (CE) method is widely used for this purpose, but it struggles with properties that exhibit non-linear dependencies on composition, often failing even in a qualitative description. By looking at CE through the lens of machine learning, we resolve this severe problem and introduce a non-linear CE approach, yielding extremely accurate and computationally efficient results as demonstrated by distinct examples.
Materials Science (cond-mat.mtrl-sci)
9 pages, 7 figures
Wetting and Pattern Formation in Non-Reciprocal Ternary Phase Separation
New Submission | Soft Condensed Matter (cond-mat.soft) | 2025-06-24 20:00 EDT
Non-reciprocal interactions are among the simplest mechanisms that drive a physical system out of thermal equilibrium, leading to novel phenomena such as oscillatory pattern formation. In this paper, we introduce a ternary phase separation model, with non-reciprocal interactions between two of the three phases and a spectator phase that mimics a boundary. Through numerical simulations, we uncover three distinct phase behaviours: a quasi-static regime, characterized by well-defined non-equilibrium contact angles at the three phase contact line; a limit cycle regime, with the three bulk phases rotating around the three phase contact line; and a travelling wave regime, featuring persistent directional motion. We complement our numerical findings with analytical examination of linear stability and the wave propagation speed near equilibrium. Our model provides a minimal framework for extending classical equilibrium wetting theory to active and non-equilibrium systems.
Soft Condensed Matter (cond-mat.soft), Statistical Mechanics (cond-mat.stat-mech)
Importance of Non-Adiabatic Effects on Kohn Anomalies in 1D metals
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-06-24 20:00 EDT
Enrico Marazzi (1), Samuel Poncé (2 and 3), Jean-Christophe Charlier (1), Gian-Marco Rignanese (2 and 3 and 4) ((1) IMCN Université catholique de Louvain Belgium, (2) ETSF Université catholique de Louvain Belgium, (3) WEL Research Institute Belgium, (4) School of Materials Science and Engineering Northwestern Polytechnical University China)
Kohn anomalies are kinks or dips in phonon dispersions which are pronounced in low-dimensional materials. We investigate the effects of non-adiabatic phonon self-energy on Kohn anomalies in one-dimensional metals by developing a model that analyzes how the adiabatic phonon frequency, electron effective mass, and electron-phonon coupling strength influence phonon mode renormalization. We introduce an electron-phonon coupling strength threshold for low-temperature system instability, providing experimentalists with a tool to predict them. Finally, we validate the predictions of our model against first-principles calculations on a 4 Å-diameter carbon nanotube.
Materials Science (cond-mat.mtrl-sci)
4 pages article, 12 pages Supplemetary Materials, 12 figures total
Local classical correlations between physical electrons in the Hubbard model
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2025-06-24 20:00 EDT
Gabriele Bellomia, Adriano Amaricci, Massimo Capone
We demonstrate that the local nonfreeness, an unbiased measure of correlation between electrons at a single lattice site, can be computed as the mutual information between local natural spin orbitals. Using this concept, we prove that local electron correlations in the Hubbard model are fully classical: in the natural basis the local reduced density matrix is separable and no quantum correlations beyond entanglement are present. Finally, we compare different theoretical descriptions of magnetic and nonmagnetic states, showing that local classical correlations are drastically influenced by nonlocal processes. Our results confirm the relation between local classical correlations within an open system and the nonlocal correlations with its quantum environment.
Strongly Correlated Electrons (cond-mat.str-el), Quantum Physics (quant-ph)
5 pages + references | 3 figures | Comments welcome!
Challenges and opportunities in piezoelectric polymers: Effect of oriented amorphous fraction in ferroelectric semicrystalline polymers
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-06-24 20:00 EDT
Guanchun Rui, Elshad Allahyarov, Zhiwen Zhu, Yanfei Huang, Thumawadee Wongwirat, Qin Zou, Philip L. Taylor, Lei Zhu
Despite extensive research on piezoelectric polymers since the discovery of piezoelectric poly(vinylidene fluoride) (PVDF) in 1969, the fundamental physics of polymer piezoelectricity has remained elusive. Based on the classic principle of piezoelectricity, polymer piezoelectricity should originate from the polar crystalline phase. Surprisingly, the crystal contribution to the piezoelectric strain coefficient d31 is determined to be less than 10%, primarily owing to the difficulty in changing the molecular bond lengths and bond angles. Instead, >85% contribution is from Poisson’s ratio, which is closely related to the oriented amorphous fraction (OAF) in uniaxially stretched films of semicrystalline ferroelectric (FE) polymers. In this perspective, the semicrystalline structure-piezoelectric property relationship is revealed using PVDF-based FE polymers as a model system. In melt-processed FE polymers, the OAF is often present and links the crystalline lamellae to the isotropic amorphous fraction. Molecular dynamics simulations demonstrate that the electrostrictive conformation transformation of the OAF chains induces a polarization change upon the application of either a stress (the direct piezoelectric effect) or an electric field (the converse piezoelectric effect). Meanwhile, relaxor-like secondary crystals in OAF (SCOAF), which are favored to grow in the extended-chain crystal (ECC) structure, can further enhance the piezoelectricity. However, the ECC structure is difficult to achieve in PVDF homopolymers without high-pressure crystallization. We have discovered that high-power ultrasonication can effectively induce SCOAF in PVDF homopolymers to improve its piezoelectric performance. Finally, we envision that the electrostrictive OAF mechanism should also be applicable for other FE polymers such as odd-numbered nylons and piezoelectric biopolymers.
Materials Science (cond-mat.mtrl-sci), Soft Condensed Matter (cond-mat.soft), Chemical Physics (physics.chem-ph)
22 pages, 15 figures
Responsive Materials (Wiley) 2, e20240002 1-22 (2024)
Laser-induced ultrafast structural transformations in thin Fe layer revealed by time-resolved X-ray diffraction
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-06-24 20:00 EDT
O. Liubchenko, J. Antonowicz, K. Sokolowski-Tinten, P. Zalden, R. Minikayev, I. Milov, T. J. Albert, C. Bressler, M. Chojnacki, P. Dłużewski, P. Dzięgielewski, A. Rodriguez-Fernandez, K. Fronc, W. Gawełda, K. Georgarakis, A.L. Greer, I. Jacyna, R.W.E. van de Kruijs, R. Kamiński, D. Khakhulin, D. Klinger, K. Kosyl, K. Kubicek, A. Olczak, N.T. Panagiotopoulos, M. Sikora, P. Sun, H. Yousef, W. Zajkowska-Pietrzak, R. Sobierajski
The ultrafast response of iron lattice to sub-ps pulsed laser-induced heating has been investigated using time-resolved XRD in the partial melting regime. Strong electron-phonon coupling in Fe leads to rapid heating within 1-2 ps post laser-irradiation, followed by lattice expansion and melting on the 2-5 ps timescale. A tetragonal distortion of the remaining bcc-phase emerges at 6 ps and the unit-cell volume increases up to a value characteristic for the bcc-Fe phase. Under the experimental conditions, the bct-Fe remains metastable up to at least 60 ps, gradually relaxing toward the bcc phase without fully reverting. These findings provide new insight into the ultrafast dynamics, structural pathways, and stability of transient phases during the early stages of solid-solid phase transitions in bcc metals.
Materials Science (cond-mat.mtrl-sci), Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
Surface states and finite size effects in triple-fold semimetals
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2025-06-24 20:00 EDT
A.Yu. Prykhodko, E.V. Gorbar, P.O. Sukhachov
Triple-fold or pseudospin-1 semimetals belong to a class of multi-fold materials in which linearly dispersive bands and flat bands intersect at the same point, forming triple-fold crossing points. We conduct an analytical investigation of topologically protected Fermi arc surface states and finite-size effects in three-dimensional (3D) triple-fold and doubly degenerate triple-fold semimetals in continuum low-energy models. Higher topological charge of the triple-fold crossing points leads to two Fermi arcs connecting the nodes. For a single triple-fold crossing point, we found that no term in the Hamiltonian with momentum-independent elements can open a gap, prompting us to consider a doubly-degenerate triple-fold fermion, where the gap can be opened by mixing the degenerate copies. Thin films of triple-fold semimetals allow for mixing between the surface and bulk states in addition to the discretization of energy levels of the latter.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
12 pages, 5 figures
Quantum critical dynamical response of the twisted Kitaev spin chain
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2025-06-24 20:00 EDT
Uliana E. Khodaeva, Dmitry L. Kovrizhin, Johannes Knolle
The dynamical structure factor of the transverse field Ising model (TFIM) shows universal power-law divergence at its quantum critical point, signatures of which have been arguably observed in inelastic neutron scattering studies of quantum spin chain materials, for example CoNb2O6. However, it has been recently suggested that its microscopic description is better captured in terms of a twisted Kitaev spin chain (TKSC) with bond-anisotropic couplings. Here, we present exact results for the dynamical structure factor of the TKSC across its quantum critical point, analyzing both the universal low-frequency response and the non-universal high-energy features. In addition, we explore extensions of the model including broken glide symmetry as well as the case of random, and incommensurate magnetic fields. Notably, in the latter case the fermionic excitations exhibit a localization-delocalization transition, which is manifest in the dynamical response as a distinct signature at finite frequency. We discuss the relevance of these features for the observation of quantum critical response in experiments.
Strongly Correlated Electrons (cond-mat.str-el)
13 pages, 11 figures
To Flow or Not To Flow? The granular Bond number to predict clogging in low gravity
New Submission | Soft Condensed Matter (cond-mat.soft) | 2025-06-24 20:00 EDT
Oliver Gaida, Olfa D’Angelo, Jonathan E. Kollmer
In granular hopper flow, is the clogging probability influenced by gravity? Clogging, the spontaneous arrest of granular flow through a constriction, is a fundamental and widespread phenomenon in granular processing. Accurately predicting clogging risk is essential for space-related activities. Yet, conflicting results leave us without a reliable way to extrapolate terrestrial data to low gravity. We introduce an in-bulk definition of the dimensionless granular Bond number, B, to scale clogging probability from Earth gravity to low gravity. By testing multiple lunar regolith simulants in Earth and Moon gravitational accelerations, using an active drop tower, we reveal that low gravity significantly increases clogging risk, challenging previous findings. We observe a gravity-induced shift in the critical orifice below which clogging occurs by up to one order of magnitude. Scaling data with the Bond number unifies scattered results into a state diagram predicting clogging across materials and gravitational accelerations. Our findings provide a practical tool for anticipating granular clogging in reduced gravity, informing future space missions.
Soft Condensed Matter (cond-mat.soft), Applied Physics (physics.app-ph), Space Physics (physics.space-ph)
Leveraging Transfer Learning to Overcome Data Limitations in Czochralski Crystal Growth
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-06-24 20:00 EDT
Milena Petkovic, Natasha Dropka, Xia Tang, Janina Zittel
The Czochralski (Cz) method is a widely used process for growing high-quality single crystals, critical for applications in semiconductors, optics, and advanced materials. Achieving optimal growth conditions requires precise control of process and furnace design parameters. Still, data scarcity – especially for new materials – limits the application of machine learning (ML) in predictive modeling and optimization. This study proposes a transfer learning approach to overcome this limitation by adapting ML models trained on a higher data volume of one source material (Si) to a lower data volume of another target material (Ge and GaAs). The materials were deliberately selected to assess the robustness of the transfer learning approach in handling varying data similarity, with Cz-Ge being similar to Cz-Si, and GaAs grown via the liquid encapsulated Czochralski method (LEC), which differs from Cz-Si. We explore various transfer learning strategies, including Warm Start, Merged Training, and Hyperparameters Transfer, and evaluate multiple ML architectures across two different materials. Our results demonstrate that transfer learning significantly enhances predictive accuracy with minimal data, providing a practical framework for optimizing Cz growth parameters across diverse materials.
Materials Science (cond-mat.mtrl-sci), Optimization and Control (math.OC)
Submitted to Advanced Theory and Simulations. 21 pages, 8 figures
Role of bubble positioning in force induced melting of DNA
New Submission | Soft Condensed Matter (cond-mat.soft) | 2025-06-24 20:00 EDT
Bidisha Mukherjee, Amit Raj Singh, Garima Mishra
We investigate the role of bubble positioning in the force-induced melting of double-stranded DNA using two distinct approaches: Brownian Dynamics simulations and the Gaussian Network Model. We isolate the effect of bubble positioning by using DNA molecules with 50% AT - 50% GC base-pair composition which ensures constant enthalpy. Our results reveal that it is not just the sequence itself, but its specific arrangement that influences DNA stability. We examine two types of DNA sequences containing a block of either AT or GC base-pairs, resulting in the formation of a large bubble or a smaller bubble within the DNA, respectively. By systematically shifting these blocks along the strand, we investigate how their positioning influences the force-temperature phase diagram of DNA. Our Brownian dynamics simulations reveal that, at high forces, melting of the entire DNA strand is initiated after stretching $ \approx 9$ GC base-pairs, independent of the specific base-pair sequence. In contrast, no such characteristic length scale is observed in the Gaussian network model. Our study suggests that free strand entropy plays a significant role in determining the force-temperature phase diagram of the DNA.
Soft Condensed Matter (cond-mat.soft), Statistical Mechanics (cond-mat.stat-mech)
12, 11
Hierarchical friction memory leads to subdiffusive configurational dynamics of fast-folding proteins
New Submission | Soft Condensed Matter (cond-mat.soft) | 2025-06-24 20:00 EDT
Anton Klimek, Benjamin A. Dalton, Lucas Tepper, Roland R. Netz
Proteins often exhibit subdiffusive configurational dynamics. The origins of this subdiffusion are still unresolved. We investigate the impact of non-Markovian friction and the free energy landscape on the dynamics of fast-folding proteins in terms of the mean squared displacement (MSD) and the mean first-passage-time (MFPT) of the folding reaction coordinate. We find the friction memory kernel from published molecular dynamics (MD) simulations to be well-described by a hierarchical multi-exponential function, which gives rise to subdiffusion in the MSD over a finite range of time. We show that friction memory effects in fast-folding proteins dominate the scaling behavior of the MSD compared to effects due to the folding free energy landscape. As a consequence, Markovian models are insufficient for capturing the folding dynamics, as quantified by the MSD and the MFPT, even when including coordinate-dependent friction. Our results demonstrate the importance of memory effects in protein folding and conformational dynamics and explicitly show that subdiffusion in fast-folding protein dynamics originates from memory effects, not from the free energy landscape and not from coordinate-dependent friction.
Soft Condensed Matter (cond-mat.soft), Biological Physics (physics.bio-ph)
13 pages main text including 5 figures and 8 pages supporting information including additional 7 figures
Chelation of the mercury ions by polyethyleneimine: Atomistic molecular dynamics study
New Submission | Soft Condensed Matter (cond-mat.soft) | 2025-06-24 20:00 EDT
Halyna Butovych, Jaroslav Ilnytskyi, Erkki Lahderanta, Taras Patsahan
Contamination of water by heavy metal ions represents a significant environmental concern. Among various remediation methods, chelation has proven to be an effective technique in water treatment processes. This study investigates the chelating properties of linear polyethyleneimine (PEI) and its complexation with divalent mercury ions (Hg2+) in aqueous solution. Atomistic molecular dynamics (MD) simulations were carried out using the OPLS/AA force field to examine the microscopic structure of PEI-Hg2+ complexes. PEI chains of varying lengths were considered, and it was found that a single linear PEI molecule containing ten amino groups is capable of coordinating up to four Hg2+ ions. The stability of the resulting complexes was further supported by density functional theory (DFT) calculations.
Soft Condensed Matter (cond-mat.soft), Chemical Physics (physics.chem-ph)
Neel Skyrmion interactions derived by their arrangement in regular lattices
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2025-06-24 20:00 EDT
Ioanna Karagianni, Ioannis Panagiotopoulos
The coarse-grained interactions between Néel skyrmions, stabilized by interfacial Dzyaloshinskii-Moriya coupling (iDMI), are studied through the properties of their hexagonal lattices by micromagnetic simulations. The interactions with the film edges are excluded by imposing periodic boundary conditions. The dependence of skyrmion size and interaction energy on the distance is derived. Two types of behavior are observed depending on the value of iDMI compared to the critical value Dc above which the skyrmion size diverges: For iDMI < Dc the skyrmions acquire a finite size that saturates at maximum value independent of the skyrmion distance that corresponds to the one of the isolated skyrmion. This energy is above that of the homogeneous ferromagnetic state. For iDMI > Dc the skyrmions tend to increase in size to the extent that their neighboring skyrmions permit and finite size skyrmions can be stabilized only in arrays due to their mutual repulsion. These configurations have energy below that of the homogeneous ferromagnetic state.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Materials Science (cond-mat.mtrl-sci)
10 pages, 5 figures, oral presentation in International Symposium on Hysteresis Modeling and Micromagnetics (HMM 2025), Tornio 25-28/5/2025
Generalized energy band alignment model for van der Waals heterostructures with a charge spillage dipole
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-06-24 20:00 EDT
Seungjun Lee, Eng Hock Lee, Young-Kyun Kwon, Steven J. Koester, Phaedon Avouris, Vladimir Cherkassky, Jerry Tersoff, Tony Low
The energy band alignment at the interface of van der Waals heterostructures (vdWHs) is a key design parameter for next-generation electronic and optoelectronic devices. Although the Anderson and midgap models have been widely adopted for bulk semiconductor heterostructures, they exhibit severe limitations when applied to vdWHs, particularly for type-III systems. Based on first-principles calculations for approximately $ 10^3$ vdWHs, we demonstrate these traditional models miss a critical dipole arising from interlayer charge spillage. We introduce a generalized linear response (gLR) model that includes this dipole through a quantum capacitance term while remaining analytically compact. With only two readily computed inputs, the charge neutrality level offset and the sum of the isolated-layer bandgaps, the gLR reproduces DFT band line-ups with $ r^2\sim$ 0.9 across type-I, II, and III stacks. Machine-learning feature analysis confirms that these two descriptors dominate the underlying physics, indicating the model is near-minimal and broadly transferable. The gLR framework therefore provides both mechanistic insight and a fast, accurate surrogate for high-throughput screening of the vast vdW heterostructure design space.
Materials Science (cond-mat.mtrl-sci)
19 pages, 4 figures
Finite-momentum superconductivity from chiral bands in twisted MoTe$_2$
New Submission | Superconductivity (cond-mat.supr-con) | 2025-06-24 20:00 EDT
Yinqi Chen, Cheng Xu, Yang Zhang, Constantin Schrade
A recent experiment has reported unconventional superconductivity in twisted bilayer MoTe$ _2$ , emerging from a normal state that exhibits a finite anomalous Hall effect – a signature of intrinsic chirality. Motivated by this discovery, we construct a continuum model for twisted MoTe$ _2$ constrained by lattice symmetries from first-principles calculations that captures the moiré-induced inversion symmetry breaking even in the absence of a displacement field. Building on this model, we show that repulsive interactions give rise to finite-momentum superconductivity via the Kohn-Luttinger mechanism in this chiral moiré system. Remarkably, the finite-momentum superconducting state can arise solely from internal symmetry breaking of the moiré superlattice, differentiating it from previously studied cases that require external fields. It further features a nonreciprocal quasiparticle dispersion and an intrinsic superconducting diode effect. Our results highlight a novel route to unconventional superconducting states in twisted transition metal dichalcogenides moiré systems, driven entirely by intrinsic symmetry-breaking effects.
Superconductivity (cond-mat.supr-con)
Electrostatic control of quantum phases in KTaO3-based planar constrictions
New Submission | Superconductivity (cond-mat.supr-con) | 2025-06-24 20:00 EDT
Jordan T. McCourt, Ethan G. Arnault, Merve Baksi, Samuel J. Poage, Salva Salmani-Rezaie, Divine P. Kumah, Kaveh Ahadi, Gleb Finkelstein
Two-dimensional electron gases (2DEGs) formed at complex oxide interfaces offer a unique platform to engineer quantum nanostructures. However, scalable fabrication of locally addressable devices in these materials remains challenging. Here, we demonstrate an efficient fabrication approach by patterning narrow constrictions in a superconducting KTaO3-based heterostructure. The constrictions are individually tunable via the coplanar side gates formed within the same 2DEG plane. Our technique leverages the high dielectric permittivity of KTaO3 (epsilon_r ~ 5000) to achieve strong electrostatic modulation of the superconducting 2DEG. Transport measurements through the constriction reveal a range of transport regimes: Within the superconducting state, we demonstrate efficient modulation of the critical current and Berezinskii Kosterlitz Thouless (BKT) transition temperature at the weak link. Further tuning of the gate voltage reveals an unexpectedly regular Coulomb blockade pattern. All of these states are achievable with a side gate voltage |V_SG| < 1 V. The fabrication process is scalable and versatile, enabling a platform both to make superconducting field-effect transistors and to study a wide array of physical phenomena present at complex oxide interfaces.
Superconductivity (cond-mat.supr-con), Mesoscale and Nanoscale Physics (cond-mat.mes-hall)