CMP Journal 2025-08-09
Statistics
Physical Review Letters: 11
Physical Review X: 2
arXiv: 62
Physical Review Letters
AI-Enabled Parallel Assembly of Thousands of Defect-Free Neutral Atom Arrays
Research article | Atom & ion trapping & guiding | 2025-08-08 06:00 EDT
Rui Lin, Han-Sen Zhong, You Li, Zhang-Rui Zhao, Le-Tian Zheng, Tai-Ran Hu, Hong-Ming Wu, Zhan Wu, Wei-Jie Ma, Yan Gao, Yi-Kang Zhu, Zhao-Feng Su, Wan-Li Ouyang, Yu-Chen Zhang, Jun Rui, Ming-Cheng Chen, Chao-Yang Lu, and Jian-Wei Pan
To demonstrate a new system for rapidly rearranging thousands of atoms, researchers produced an animation featuring Schrödinger’s famous feline.
Phys. Rev. Lett. 135, 060602 (2025)
Atom & ion trapping & guiding, Quantum computation, Quantum information with atoms & light, Qubits
Deciphering the Soliton-Halo Relation in Fuzzy Dark Matter
Research article | Dark matter | 2025-08-08 06:00 EDT
Pin-Yu Liao (廖品瑜), Guan-Ming Su (蘇冠銘), Hsi-Yu Schive (薛熙于), Alexander Kunkel, Hsinhao Huang (黃新豪), and Tzihong Chiueh (闕志鴻)
Soliton cores at the center of fuzzy dark matter (FDM) halos provide a promising way to distinguish FDM from other dark matter models. However, the relation between solitons and their host halos remains contentious. Here, we rigorously examine this soliton-halo relation (SHR) using a rich set of cosmological simulations across various FDM particle masses, halo masses, and redshifts. We explicitly demonstrate thermal equilibrium between solitons and surrounding halo granules, energy equipartition within halos, and an FDM concentration-mass-nonisothermality relation. For each FDM halo, we confirm that its density profile outside the central soliton matches a collisionless N-body simulation from the same initial condition, serving as stringent numerical convergence tests. Our refined SHR agrees well with virialized halos in simulations, with a $1\sigma $ deviation of less than 30%. These findings not only reaffirm the SHR proposed by Schive et al. [Understanding the core-halo relation of quantum wave dark matter from 3D simulations, Phys. Rev. Lett. 113, 261302 (2014)] but also offer a more comprehensive understanding that extends its applicability.
Phys. Rev. Lett. 135, 061002 (2025)
Dark matter, Galactic halos, Astrophysical & cosmological simulations
Search for Higher Harmonic Signals from Close White Dwarf Binaries in the mHz Band
Research article | Gravitational waves | 2025-08-08 06:00 EDT
Naoki Seto
Space-based gravitational wave (GW) detectors, such as LISA, are expected to detect thousands of Galactic close white dwarf binaries emitting nearly monochromatic GWs. In this study, we demonstrate that LISA is reasonably likely to detect higher harmonic GW signals, particularly the $(l,|m|)=(3,3)$ mode, from a limited sample of nearby close white dwarf binaries, even with small orbital velocities $v/c$ of order ${10}^{- 3}$. The amplitudes of these post-Newtonian modes provide robust probes of mass asymmetry in such systems, making them valuable observational targets, especially in mass-transferring binaries. Long-term, coordinated detector operations will further improve the prospects for detecting these informative signals.
Phys. Rev. Lett. 135, 061402 (2025)
Gravitational waves, Binary stars
Wheeler-DeWitt Equation and Bondi-Metzner-Sachs (BMS) Symmetry
Quantum aspects of black holes | 2025-08-08 06:00 EDT
Marc Henneaux
The Hamiltonian formulation of the BMS symmetry on spacelike hypersurfaces enables one to define its action on solutions of the Wheeler-DeWitt equation. Using the Becchi-Rouet-Stora-Tyutin (BRST) reformulation of the theory, we provide operator expressions for the matrix elements of the BMS operators between Wheeler-DeWitt states. To that end, we construct the BRST-invariant extensions of the BMS generators, which form a BRST extension of the BMS algebra.
Phys. Rev. Lett. 135, 061501 (2025)
Quantum aspects of black holes, Quantum gravity
Search for a Neutral Gauge Boson with Nonuniversal Fermion Couplings in Vector Boson Fusion Processes in Proton-Proton Collisions at $\sqrt{s}=13\text{ }\text{ }\mathrm{TeV}$
Research article | Hypothetical gauge bosons | 2025-08-08 06:00 EDT
A. Hayrapetyan et al. (CMS Collaboration)
The first search for a heavy neutral spin-1 gauge boson (${Z}^{‘ }$) with nonuniversal fermion couplings produced via vector boson fusion processes and decaying to tau leptons or $W$ bosons is presented. The analysis is performed using LHC data at $\sqrt{s}=13\text{ }\text{ }\mathrm{TeV}$, collected from 2016 to 2018 with the CMS experiment and corresponding to an integrated luminosity of $138\text{ }\text{ }{\mathrm{fb}}^{- 1}$. The data are consistent with the standard model predictions. Upper limits are set on the product of the cross section for production of the ${Z}^{‘ }$ boson and its branching fraction to $\tau \tau $ or $WW$. The presence of a ${Z}^{‘ }$ boson decaying to ${\tau }^{+}{\tau }^{- }$ (${W}^{+}{W}^{- }$) is excluded for masses up to 2.45(1.60) TeV, depending on the ${Z}^{‘ }$ boson coupling to standard model weak bosons, and assuming a ${Z}^{‘ }\rightarrow {\tau }^{+}{\tau }^{- }$ (${W}^{+}{W}^{- }$) branching fraction of 50%.
Phys. Rev. Lett. 135, 061803 (2025)
Hypothetical gauge bosons, Tau leptons, Hadron colliders
Polarization Faticons: Chiral Localized Structures in Self-Defocusing Kerr Resonators
Research article | Dissipative dynamics | 2025-08-08 06:00 EDT
Erwan Lucas, Gang Xu, Pengxiang Wang, Gian-Luca Oppo, Lewis Hill, Pascal Del’Haye, Bertrand Kibler, Yiqing Xu, Stuart G. Murdoch, Miro Erkintalo, Stéphane Coen, and Julien Fatome
We report on numerical predictions and experimental observations of a novel type of temporal localized dissipative structures that manifest themselves in the self-defocusing regime of driven nonlinear optical resonators with two polarization modes. These chiral dissipative solitons, which we term ‘’polarization faticons,’’ break both temporal and polarization symmetry and consist of two bright lobes of opposite polarization handedness, interlocked by a domain wall. Our study reveals that faticons are connected to a vectorial modulational instability, from which they can be excited through a collapsing dynamic. Faticons could offer a novel pathway for frequency comb generation in normal dispersion resonators. More generally, they offer new fundamental insights into vectorial localized dissipative structures and could be relevant to other multicomponent dissipative systems.
Phys. Rev. Lett. 135, 063803 (2025)
Dissipative dynamics, Modulation instability, Nonlinear optics, Nonlinear resonance, Optical solitons, Polarization of light, Spontaneous symmetry breaking, Cavity resonators
Charged Particle Cross-Field Transport due to Geometric Jumps of Adiabatic Invariant
Research article | Chaos | 2025-08-08 06:00 EDT
S. R. Kamaletdinov, A. V. Artemyev, A. I. Neishtadt, and V. Angelopoulos
We examine energetic electron transport in Earth’s outer radiation belt, presenting a mechanism for rapid (nondiffusive) radial transport. This process relies on electron crossings of an asymmetric separatrix in slow-fast Hamiltonian system, occurring in Earth’s dayside magnetosphere due to interactions with the interplanetary magnetic field. The resulting asymmetry quickly destroys adiabatic invariant through geometric jumps, driving exponential phase-space mixing and enhancing radial transport of $\gtrsim 1\text{ }\text{ }\mathrm{MeV}$ electrons during geomagnetically quiet conditions.
Phys. Rev. Lett. 135, 065202 (2025)
Chaos, Nonlinear phenomena in plasmas, Plasma transport, Turbulent mixing, Earth’s magnetosphere, Radiation belts
Emergent Universal Drag Law in a Model of Superflow
Research article | Superfluidity | 2025-08-08 06:00 EDT
M. T. M. Christenhusz, A. Safavi-Naini, H. Rubinsztein-Dunlop, T. W. Neely, and M. T. Reeves
Despite the fundamentally different dissipation mechanisms, many laws and phenomena of classical turbulence equivalently manifest in quantum turbulence. The Reynolds law of dynamical similarity states that two objects of the same geometry across different length scales are hydrodynamically equivalent under the same Reynolds number, leading to a universal drag coefficient law. In this Letter we confirm the existence of a universal drag law in a superfluid wake, facilitated by the nucleation of quantized vortices. We numerically study superfluid flow across a range of Reynolds numbers for the paradigmatic classical hard wall and the Gaussian obstacle, popular in experimental quantum hydrodynamics. In addition, we provide a feasible method for measuring superfluid drag forces in an experimental environment using control volumes.
Phys. Rev. Lett. 135, 066001 (2025)
Superfluidity, Turbulence, Two-dimensional turbulence, Vortex shedding, Bose-Einstein condensates, Classical fluids, Helium-4 superfluids, Superfluids
Persistent Spin Grids with a Spin-Orbit-Coupled 2D Electron Gas
Research article | Non-Abelian gauge theories | 2025-08-08 06:00 EDT
A. V. Poshakinskiy
We consider the diffusive spin dynamics of a 2D electron gas with spin-orbit coupling confined within a grid of narrow channels. We show that the lifetime of certain spin distributions in such grids greatly exceeds that in an unconfined 2D electron gas and diverges as the channel width approaches zero. Such persistent spin grids are akin to spin crystals and occur if the electron spin orientation remains invariant after diffusion around the grid plaquette. We establish a topological ${\mathbb{Z}}_{2}$ classification for persistent spin grids and show how the grids with spatially varying parameters can simulate non-Abelian lattice gauge theories.
Phys. Rev. Lett. 135, 066205 (2025)
Non-Abelian gauge theories, Spin diffusion, Spin relaxation, Spin-orbit coupling, Nanostructures, Quantum wells, Two-dimensional electron gas, Lattice gauge theory
Observation and Control of Chiral Spin Frustration in BiYIG Thin Films
Research article | Dzyaloshinskii-Moriya interaction | 2025-08-08 06:00 EDT
Jinlong Wang, Hanchen Wang, Zhewen Xu, Artim L. Bassant, Junfeng Hu, Wenjie Song, Chaozhong Li, Xiangrui Meng, Mengqi Zhao, Song Liu, Guozhi Chai, Peng Gao, Wanjun Jiang, Desheng Xue, Dapeng Yu, William Legrand, Christian L. Degen, Rembert A. Duine, Pietro Gambardella, and Haiming Yu
Chiral spin frustration can be identified and controlled via scanning nitrogen-vacancy magnetometry and spin pumping.
Phys. Rev. Lett. 135, 066705 (2025)
Dzyaloshinskii-Moriya interaction, Frustrated magnetism, Magnons, NV centers, Spin pumping
Coherent Coulomb Intra- and Intervalley Many-Body Effects in Single-Layer Transition Metal Dichalcogenides
Research article | Carrier dynamics | 2025-08-08 06:00 EDT
Thomas Deckert, Henry Mittenzwey, Oleg Dogadov, Micol Bertolotti, Giulio Cerullo, Daniele Brida, Andreas Knorr, and Stefano Dal Conte
The reduced Coulomb screening in single-layer (1L) transition metal dichalcogenides (TMDs) offers an ideal setting to explore excitonic many-body correlations. The interactions between excitons result in intra- and intervalley biexcitonic multiparticle states, whose contributions to the nonlinear optical response have remained elusive so far. Here, by using helicity-resolved transient absorption spectroscopy with sub-10 fs temporal resolution combined with a microscopic theory based on the excitonic Bloch equations we are able to unambiguously disentangle the contribution of two particle exciton and four particle biexciton correlations to the coherent optical response of $1\mathrm{L}\text{- }{\mathrm{WSe}}_{2}$ semiconductor. Upon resonant excitation of valley-polarized A exciton population we observe competing excitation-induced energy shift of the A exciton transition along with a coherent gain in the pumped valley and an instantaneous formation of an additional absorption peak in the unpumped valley, which we attribute to the effect of bound intervalley biexcitons. An excellent agreement between experimental results and calculations allows us to deepen understanding of many-body effects in 1L-TMDs, which is crucial for the development of excitonic and valleytronics devices.
Phys. Rev. Lett. 135, 066902 (2025)
Carrier dynamics, Charge dynamics, Excitons, Valley degrees of freedom, Valleytronics, Transition metal dichalcogenides, Ultrafast pump-probe spectroscopy
Physical Review X
Systematic Biases in Estimating the Properties of Black Holes Due to Inaccurate Gravitational-Wave Models
Research article | Gravitational waves | 2025-08-08 06:00 EDT
Arnab Dhani, Sebastian H. Völkel, Alessandra Buonanno, Hector Estelles, Jonathan Gair, Harald P. Pfeiffer, Lorenzo Pompili, and Alexandre Toubiana
Even the most advanced models used to interpret gravitational-wave signals can introduce systematic errors in estimating black-hole properties–especially for rapidly spinning black holes or unequal-mass binaries.
Phys. Rev. X 15, 031036 (2025)
Gravitational waves, Astronomical black holes, Binary stars
Geometric Floquet Theory
Research article | Geometric & topological phases | 2025-08-08 06:00 EDT
Paul M. Schindler and Marin Bukov
A new geometric reformulation of Floquet theory introduces a way to uniquely define ground energies for Floquet states, enabling clearer classification of nonequilibrium phases and improved simulation of driven quantum systems.
Phys. Rev. X 15, 031037 (2025)
Geometric & topological phases, Phase transitions, Quantum control, Quantum simulation, Floquet systems
arXiv
Unstable periodic orbits galore and quantum hyperscarring in highly frustrated magnets
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2025-08-08 20:00 EDT
Andrea Pizzi, Claudio Castelnovo, Johannes Knolle
Highly frustrated magnets, with their macroscopically-degenerate classical ground states and massively-entangled quantum spin liquid phases, have been pivotal to the development of modern condensed matter concepts such as emergent symmetries, topological order, and fractionalisation. The effects of frustration and massive degeneracies at high energy, where the many-body dynamics becomes chaotic, have hitherto been far less explored. Here, we identify a high-energy dynamical analog of highly-frustrated magnetism, in the form of an extensive manifold of classical ‘’interaction-suppressing’’ configurations giving rise to unstable periodic orbits. These are in general neither protected by symmetry nor integrability, and emerge from a set of dynamical local constraints that effectively nullify the interactions while allowing extensively many local degrees of freedom. The proliferation of unstable periodic orbits corresponds in the quantum case to ‘’hyperscarring’’, that is, quantum scarring on exponentially many unstable periodic orbits. On the product states associated to the latter, the amplitudes of the mid-spectrum thermal eigenstates exhibit a power-law distribution, in stark contrast to the expected exponential Porter-Thomas distribution that holds for generic product states. Our results reveal a new constrained dynamical regime where many-body quantum chaos coexists with structured manifolds of coherent dynamics, and establishes a mechanism for hitherto elusive extensive scarring.
Strongly Correlated Electrons (cond-mat.str-el), Chaotic Dynamics (nlin.CD), Quantum Physics (quant-ph)
5 + 2 pages, 3 + 2 figures
Spin-resolved quasiparticle interference patterns on altermagnets via non-spin-resolved scanning tunneling microscopy
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2025-08-08 20:00 EDT
Eric Petermann, Kristian Mæland, Björn Trauzettel
We investigate quasiparticle interference on an altermagnetic Lieb-like lattice and show how a non-spin-polarized scanning tunneling microscopy measurement can yield effectively spin-resolved information. Within a four-site tight-binding model, which can be tuned between an antiferromagnetic and a Lieb-type altermagnetic state, we introduce on-site impurities at distinct sublattice sites and compute the real space local density of states (LDOS) via a Green’s function approach. A Fourier transformation of the impurity-induced LDOS yields the characteristic $ d$ -wave spin-split Fermi surface contours of the altermagnetic phase. Notably, by choosing which sublattice the impurity is placed upon, we show that the scattering amplitudes effectively encode spin-dependent contrasts: Impurities on one of the magnetic sublattices highlights predominantly spin-up contributions along one crystallographic direction, while impurities on the other one favor the complementary spin-down channel and orientation.
Strongly Correlated Electrons (cond-mat.str-el)
9 pages, 4 figures
Quantum-impurity sensing of altermagnetic order
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2025-08-08 20:00 EDT
V.A.S.V. Bittencourt, H. Hosseinabadi, J. Sinova, L. Šmejkal, J. Marino
Quantum sensing with individual spin defects has emerged as a versatile platform to probe microscopic properties of condensed matter systems. Here we demonstrate that quantum relaxometry with nitrogen-vacancy (NV) centers in diamond can reveal the anisotropic spin dynamics of altermagnetic insulators together with their characteristic spin polarised bands. We show that the distance and orientation dependent relaxation rate of a nearby quantum impurity encodes signatures of momentum space anisotropy in the spin diffusion response, a hallmark of altermagnetic order. This directional sensitivity is unprecedented in the landscape of quantum materials sensing, and it enables the distinction of altermagnets from conventional antiferromagnets via local, noninvasive measurements. Our results could spark new NV-sensing experiments on spin transport and symmetry breaking in altermagnets, and highlight the role of NV orientation to probe anisotropic phenomena in condensed matter systems.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Quantum Physics (quant-ph)
5 pages, 3 figures plus Supplementary material
peaks: a Python package for analysis of angle-resolved photoemission and related spectroscopies
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-08-08 20:00 EDT
Phil D. C. King, Brendan Edwards, Shu Mo, Tommaso Antonelli, Edgar Abarca Morales, Lewis Hart, Liam Trzaska
The electronic band structure, describing the motion and interactions of electrons in materials, dictates the electrical, optical, and thermodynamic properties of solids. Angle-resolved photoemission spectroscopy (ARPES) provides a direct experimental probe of such electronic band structures, and so is widely employed in the study of functional, quantum, and 2D materials. \texttt{peaks} (\textbf{P}ython \textbf{E}lectron spectroscopy \textbf{A}nalysis by \textbf{K}ing group @ \textbf{S}t Andrews) provides a Python package for advanced data analysis of ARPES and related spectroscopic data. It facilitates the fast visualisation and analysis of multi-dimensional datasets, allows for the complex data hierarchy typical to ARPES experiments, and supports lazy data loading and parallel processing, reflecting the ever-increasing data volumes used in ARPES. It is designed to be run in an interactive notebook environment, with extensive inline and pop-out GUI support for data visualisation.
Materials Science (cond-mat.mtrl-sci), Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Strongly Correlated Electrons (cond-mat.str-el), Superconductivity (cond-mat.supr-con)
Engineering Phonons in Compositionally Complex Carbide Ceramics
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-08-08 20:00 EDT
Linu Malakkal, Jarin C French, Lanh Trinh, Kaustubh K Bawane, Shuxiang Zhou, Zilong Hua, Lingfeng He, Yongfeng Lu, Bai Cui
In the pursuit of advanced ceramic materials with exceptional irradiation-resistance and high-temperature tolerance for nuclear applications, compositionally complex carbides (CCCs) have emerged as a highly promising class of candidate materials for extreme environments. In such conditions, critical material properties such as thermal stability, elasticity, thermal conductivity and thermodynamics behavior are predominantly influenced by phonons. In CCCs, pronounced cation disorder can lead to significant phonon scattering due to inherent mass and force constant variations, impacting these critical properties. In this study, we used ab initio calculations to predict the phonon band structures and systematically explore the influence of mass and force constant variance on the phonon spectral function of CCCs with a rock salt structure, ranging from binary to five-metal component carbides. Our findings reveal that the selection and concentration of constituent elements can be strategically utilized to tune the phonon band structure, phonon bandgap and phonon scattering in CCCs, thereby enabling control over phonon-related properties. Additionally, we measured the thermal conductivity of some of these CCCs using the spatial-domain thermoreflectance technique. Interestingly, the measured thermal conductivity of some of these CCCs indicates that five-component ceramics exhibit higher thermal conductivity than certain ternary and binary alloys. This observation contrasts with the expectation that greater cation disorder would result in more scattering and lower thermal conductivity. This intriguing result opens up the possibility of discovering CCCs with better thermal conductivity, presenting new opportunities for their application in extreme environments.
Materials Science (cond-mat.mtrl-sci)
A Comprehensive Study on A$_2$PdH$_2$: From Ambient to High Pressure
New Submission | Superconductivity (cond-mat.supr-con) | 2025-08-08 20:00 EDT
Zahra Alizadeh, Yue-Wen Fang, Ion Errea, M.R. Mohammadizadeh
We present a comprehensive first–principles study of the structural stability and superconducting behavior of Li$ _2$ PdH$ _2$ under high pressure. Using random structure searching and phonon calculations, we identify a pressure–induced phase transition from a tetragonal I4/mmm structure, stable up to 5 GPa, to a monoclinic C2/m phase that remains thermodynamically stable up to 50 GPa. Superconductivity is absent in the tetragonal phase, even when anharmonic effects are considered, due to weak electron–phonon coupling and limited hydrogen involvement near the Fermi level. In contrast, the monoclinic phase exhibits a weak but pressure-enhanced superconducting transition, with Tc increasing from 0.6 K at 10 GPa to 4.7 K at 50 GPa, mainly driven by low–frequency Li and Pd-derived phonon modes. We further explore the isostructural A$ _2$ PdH$ _2$ (A = Na, K, Rb, Cs) series to evaluate the impact of alkali-metal substitution on stability and superconductivity. Na, K, and Rb analogs retain dynamic stability at ambient pressure, with weak superconducting critical temperatures of 3.2 K, 2.1 K, and negligible Tc, respectively. Cs$ _2$ PdH$ _2$ , however, exhibits phonon instabilities, suggesting a need for external stabilization. These findings highlight the delicate balance between lattice dynamics, electronic structure, and atomic mass in tuning superconductivity in palladium-based hydrides.
Superconductivity (cond-mat.supr-con)
Inverse Lieb Materials: Altermagnetism and More
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-08-08 20:00 EDT
Po-Hao Chang, Igor I. Mazin, Kirill D. Belashchenko
The Lieb lattice, originally proposed for cuprate superconductors, has gained new attention in the emerging field of altermagnetism as a minimal analytical model for the latter. While initially the so-called inverse Lieb lattice (ILL) was deemed only a theoretical model, recently several real materials with this crystallographic motif have been found. The unique geometry of ILL can accommodate complex magnetic orderings arising from competing exchange interactions and geometric frustration, offering great tunability for magnetic properties. In this work, we provide comprehensive insights into magnetic phases in ILL materials and establish guidelines for efficient identification of altermagnetic materials within this family. We begin by constructing phase diagrams using a simple Heisenberg model to elucidate the fundamental mechanisms underlying altermagnetism and other complex magnetic phases observed experimentally. To bridge theory with experiment, we systematically investigate a series of existing ILL compounds using density functional theory (DFT) calculations to determine their magnetic ground states. Our computational results are in good agreement with experimental observations. Importantly, we identify a trend linking magnetic ordering to the $ d$ -shell filling of transition metal ions, with $ d^{2-3}$ and $ d^{5}$ configurations showing propensity for altermagnetic behavior. Additionally, we identify a promising metallic compound Sr$ _{2}$ CrO$ _{2}$ Cr$ _{2}$ OAs$ {2}$ as an altermagnet that is highly anisotropic in its $ J_2$ exchange couplings with large Néel temperature ($ \sim 600$ K). Using exchange coupling parameters extracted from DFT calculations, we compute the magnon spectra for altermagnetic systems. As expected, chiral splittings in the magnon dispersion are directly correlated with anisotropy between crystallographically inequivalent $ J{2}$ exchange interactions.
Materials Science (cond-mat.mtrl-sci)
11 pages, 8 figures
Data Driven Insights into Composition Property Relationships in FCC High Entropy Alloys
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-08-08 20:00 EDT
Nicolas Flores, Daniel Salas Mula, Wenle Xu, Sahu Bibhu, Daniel Lewis, Alexandra Eve Salinas, Samantha Mitra, Raj Mahat, Surya R. Kalidindi, Justin Wilkerson, James Paramore, Ankit Srivastiva, George Pharr, Douglas Allaire, Ibrahim Karaman, Brady Butler, Vahid Attari, Raymundo Arroyave
Structural High Entropy Alloys (HEAs) are crucial in advancing technology across various sectors, including aerospace, automotive, and defense industries. However, the scarcity of integrated chemistry, process, structure, and property data presents significant challenges for predictive property modeling. Given the vast design space of these alloys, uncovering the underlying patterns is essential yet difficult, requiring advanced methods capable of learning from limited and heterogeneous datasets. This work presents several sensitivity analyses, highlighting key elemental contributions to mechanical behavior, including insights into the compositional factors associated with brittle and fractured responses observed during nanoindentation testing in the BIRDSHOT center NiCoFeCrVMnCuAl system dataset. Several encoder decoder based chemistry property models, carefully tuned through Bayesian multi objective hyperparameter optimization, are evaluated for mapping alloy composition to six mechanical properties. The models achieve competitive or superior performance to conventional regressors across all properties, particularly for yield strength and the UTS/YS ratio, demonstrating their effectiveness in capturing complex composition property relationships.
Materials Science (cond-mat.mtrl-sci), Machine Learning (cs.LG)
Push and Pull: Elastic Interaction Between Pressurized Spherical Cavities in Nonlinear Elastic Media
New Submission | Soft Condensed Matter (cond-mat.soft) | 2025-08-08 20:00 EDT
Ali Saeedi, Mrityunjay Kothari
Elastic interaction of pressurized spherical cavities embedded in a three-dimensional hyperelastic medium is computationally analyzed. Using finite element analysis across several positive and negative pressure scenarios, we calculate the system’s potential energy and configurational driving force for neo-Hookean, Mooney-Rivlin, and Arruda-Boyce material models. Our results show that while the interaction is always attractive for negative pressures, a non-monotonic energy landscape emerges for positive pressures above a critical value. In this regime, cavities attract at close range and repel when further apart. The critical separation distance for this transition is shown to be dependent on the material’s strain-stiffening parameters. These findings are consolidated into phase diagrams, providing a clear map of interaction behaviors.
Soft Condensed Matter (cond-mat.soft)
15 figures, 16 pages (including appendix)
Optimization of Ab-Initio Based Tight-Binding Models
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-08-08 20:00 EDT
The electronic structure of solids can routinely be calculated by standard methods like density functional theory. However, in complicated situations like interfaces, grain boundaries or contact geometries one needs to resort to more simplified models of the electronic structure. Tight-binding models are using a reduced set of orbitals and aim to approximate the electronic structure by short range hopping processes. For example, maximally localized Wannier functions are often used for that purpose. However, their accuracy is limited by the need to disentangle the electronic bands. Here, we develop and investigate a different procedure to obtain tight-binding models inspired by machine-learning techniques. The model parameters are optimized in such a way as to reproduce ab-initio band structure data as accurately as possible using an as small as possible number of model parameters. The procedure is shown to result in models with smaller ranges and fewer orbitals than maximally localized Wannier functions but same or even better accuracy. We argue that such a procedure is more useful for automated construction of tight-binding models particularly for large-scale materials calculations.
Materials Science (cond-mat.mtrl-sci), Computational Physics (physics.comp-ph)
16 pages, 6 figures
Casimir Interaction between Polydisperse Colloids Trapped at a Fluid Interface
New Submission | Soft Condensed Matter (cond-mat.soft) | 2025-08-08 20:00 EDT
Seyed Emad Mousavi, Ehsan Noruzifar
We investigate the effect of polydispersity on fluctuation-induced interactions between Janus colloidal particles trapped at a fluid interface. Using the scattering-matrix formalism, we calculate the thermal Casimir energy in both two- and three-body systems, considering three distinct fluctuation scenarios for the colloids: (a) fixed, (b) bobbing, and (c) bobbing and tilting. Our results reveal a pronounced sensitivity to polydispersity that strongly depends on the fluctuating boundary conditions: while fixed colloids show modest deviations, bobbing and especially bobbing+tilting configurations exhibit orders-of-magnitude amplification in the energy deviation due to polydispersity. These effects are further enhanced at large separations. Our findings highlights the interplay between geometry, colloids fluctuations, and fluctuation-induced forces, with implications for colloidal self-assembly and interface engineering.
Soft Condensed Matter (cond-mat.soft), Statistical Mechanics (cond-mat.stat-mech)
Robust surface superconductivity and vortex lattice in the Weyl semimetal $γ$-PtBi$_2$
New Submission | Superconductivity (cond-mat.supr-con) | 2025-08-08 20:00 EDT
Jose Antonio Moreno, Pablo García Talavera, Edwin Herrera, Sara López Valle, Zhuoqi Li, Lin-Lin Wang, Sergey Bud’ko, Alexander I. Buzdin, Isabel Guillamón, Paul C. Canfield, Hermann Suderow
The layered compound $ \gamma$ -PtBi$ 2$ is a topological semimetal with Fermi arcs at the surface joining bulk Weyl points. Recent work has found a peculiar surface superconducting state with a critical temperature two orders of magnitude larger than the bulk value. However, no superconducting vortices have been identified, raising questions about the robustness of the phase coherence in this new surface superconducting state. Here we measure the superconducting gap and visualize the vortex lattice through very low temperature Scanning Tunneling Microscopy (STM). We find vortices that are anomalously mobile and show that the extremely weak electrostatic interaction between the vortex charge and the STM tip is sufficient to drag the vortices of the surface superconductor. Our results show that surface superconductivity with $ T_c=2.9$ K and $ H{c2}\approx 1.8$ T is extraordinarily robust in $ \gamma$ -PtBi$ _2$ . Furthermore, quasiparticle scattering is enhanced at the position in the reciprocal space of the Fermi arcs, suggesting a connection between Weyl points and surface superconductivity.
Superconductivity (cond-mat.supr-con), Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Strongly Correlated Electrons (cond-mat.str-el)
SERS Raman detection of the CO$_2$ Moisture Swing
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-08-08 20:00 EDT
Javier Mendez-Lozoya, Estrella Solis Mata, J. Jesus Velazquez Salazar, Alondra Hernandez Cedillo, Miguel Jose Yacaman, Jennifer L. Wade
The development of scalable, energy-efficient carbon dioxide capture technologies is critical for achieving net-zero emissions. Moisture swing sorbents offer a promising alternative to traditional thermal regeneration methods by enabling reversible CO$ _2$ binding through humidity-driven ion hydrolysis. In this study, we investigate the anion speciation dynamics in two classes of MS materials, an anion-exchange resin with bicarbonate anion and activated carbon impregnated with potassium bicarbonate salt using both sorption measurements and in situ surface-enhanced Raman spectroscopy. Ni coated Ag nanowires were employed as SERS substrates to enhance signal intensity and enable the real-time detection of carbonate , bicarbonate , and hydroxide species under controlled humidity conditions in both air and nitrogen atmospheres. The results reveal humidity-dependent interconversion between anionic species, with significant spectral shifts confirming the reversible hydrolysis reactions that drive the MS mechanism. Under humid conditions, we observed the depletion of bicarbonate signals and a concurrent increase in carbonate species, consistent with moisture-induced desorption of CO$ _2$ . These findings not only validate the mechanistic models of humidity-driven anion exchange in moisture swing sorbents but also demonstrate the practical potential of SERS as an operando diagnostic tool for monitoring CO$ _2$ capture media. The ability to resolve and quantify the reversible transformation of carbonate, bicarbonate, and hydroxide ions under realistic environmental conditions provides valuable insight for the rational design, performance optimization, and quality control of next-generation sorbent materials for direct air capture applications.
Materials Science (cond-mat.mtrl-sci), Soft Condensed Matter (cond-mat.soft)
37 pages including SI, 9 main body figures, 5 SI figures, submitting to ACS Applied Materials and Interfaces
Intrinsic Layer-Dependent Surface Energy and Exfoliation Energy of van der Waals Materials
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-08-08 20:00 EDT
Lin-Lin Wang, Jiaqiang Yan, Yong Han, Claire C. Wang, Jian-Xiang Qiu, Su-Yang Xu, Adam Kaminski, Michael C. Tringides, Paul C. Canfield
Stacking and twisting 2D van der Waals (vdW) layers have become versatile platforms to tune electron correlation. These platforms rely on exfoliating vdW materials down to a single and few vdW layers. We calculate the intrinsic layer-dependent surface and exfoliation energies of typical vdW materials such as, graphite, h-BN, black P, MX$ _2$ (M=Mo and W, X=S, Se and Te), MX (M=Ga and In, X=S, Se and Te), Bi$ _2$ Te$ _3$ and MnBi$ _2$ Te$ _4$ using density functional theory. For exchange-correlation functionals with explicit vdW interaction, a single vdW layer always has the smallest surface energy, giving a surface energy reduction when compared to thicker vdW layers. However, the magnitude of this surface energy reduction quickly decreases with increasing number of atomic layers inside the single vdW layer for different vdW materials. Such atomic-layer-dependence in surface energy reduction helps explain the different effectiveness of exfoliation for different vdW materials down to a single vdW layer.
Materials Science (cond-mat.mtrl-sci)
26 pages, 6 figures
Observation of σ-πcoupling and mode selection in optically trapped artificial polariton molecules
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2025-08-08 20:00 EDT
Krzysztof Sawicki, Valtýr Kári Daníelsson, Dmitriy Dovzhenko, Pavlos G. Lagoudakis, Simone De Liberato, Helgi Sigurðsson
Microcavity exciton-polariton condensates under additional transverse confinement constitute a flexible optical platform to study the coupling mechanism between confined nonequilibrium and nonlinear states of matter. Driven far from equilibrium, polariton condensates can display spontaneous synchronization and instabilities depending on excitation and material parameters, showcasing emergent and intricate interference patterns based on mode competition over mutual gain landscapes. Here, we explore this coupling mechanism between polariton condensates populating the first excited $ {\it p}$ -state manifold of coupled optically trapped condensates and show a rich structure of patterns based on excitation parameters. The optical reconfigurability of the laser excitation patterns enables the creation of an annular-shaped beam to confine polaritons in a tailored trapping potential, whilst the dissipative nature of the optical traps enables effective interaction with neighboring condensates. Our results underpin the potential role of polariton condensates in exploring and simulating $ \sigma$ and $ \pi$ molecular bonding mechanisms between artificial two-dimensional diatomic orbitals and beyond.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Quantum Gases (cond-mat.quant-gas), Optics (physics.optics)
Micromagnetic Design of Bias-Free Reconfigurable Microwave Properties in Hexagonal Shaped Multilayer Nanomagnets
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2025-08-08 20:00 EDT
Magnetic miniaturized nanostructures hold great promise for current and future microwave technologies due to their magnetization dynamics in the GHz frequency range. This work presents a method for investigating reconfigurable microwave properties using a novel hexagonal nanomagnet structure. Micromagnetic simulations are employed to investigate the magnetic static and dynamic properties of the nanomagnets. A simple field initialization method is used to examine two distinct magnetic remanent states in each sample. A nanosecond-width magnetic pulse field can be applied to tune the unique magnetization dynamics parameters corresponding to the different remanent states. Find that for both single-layer and multilayer nanomagnets, there is a notable frequency shift in the sub-GHz and GHz regions between the two distinct magnetic remanent states.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
Total pages 21 and included supplemetary material in same pdf
Engineering Topological Materials
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2025-08-08 20:00 EDT
The tenfold classification provides a powerful framework for organizing topological phases of matter based on symmetry and spatial dimension. However, it does not offer a systematic method for transitioning between classes or engineering materials to realize desired topological properties. In this work, we introduce a general method for designing topological materials by embedding defects or spatial textures, which alter symmetry or dimension. This enables controlled navigation across the tenfold table, allowing one to induce topological phase transitions on demand. We illustrate this approach through several nontrivial examples, demonstrating how local defects can generate phases with different symmetries and topological invariants.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
6 pages and supplementary material
Chern junctions in Moiré-Patterned Graphene/PbI2
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2025-08-08 20:00 EDT
Sun Yan, M. Monteverde, V. Derkach, K. Watanabe, T. Taniguchi, F. Chiodi, H. Bouchiat, A.D. Chepelianskii
Expanding the moiré material library continues to unlock novel quantum phases and emergent electronic behaviors. In this work, we introduce PbI2 into the moiré family and investigate the magnetotransport properties of moiré superlattice in a hexagonal boron nitride/graphene/PbI2 heterostructures. In high-field quantum Hall regime, we observe a robust dissipationless transport at charge neutrality point, indicative of incompressible states stabilized at the filling factor vh = 0. Additionally, a fractional conductance plateau at 2/3 e2/h emerges, which we attribute to a Chern junction between domains with distinct Chern numbers originating from moiré-modulated and conventional integer quantum Hall states. The moiré Hofstadter spectrum displays an unconventional flavor sequence, likely influenced by proximity-induced spin-orbit coupling from the PbI2 layer. We also see coherent electronic interference along lines with Chern number vm = -2. These findings position PbI2-based heterostructures as a versatile platform for realizing spin-orbit-enhanced moiré phenomena and engineering coherent edge transport in two-dimensional quantum materials.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Materials Science (cond-mat.mtrl-sci), Quantum Physics (quant-ph)
9 pages, 4 figures
Magnetic Anisotropy in Two-dimensional van der Waals Magnetic Materials and Their Heterostructures: Importance, Mechanisms, and Opportunities
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-08-08 20:00 EDT
Two-dimensional (2D) magnetism in atomically thin van der Waals (vdW) monolayers and heterostructures has attracted significant attention due to its promising potential for next-generation spintronic and quantum technologies. A key factor in stabilizing long-range magnetic order in these systems is magnetic anisotropy, which plays a crucial role in overcoming the limitations imposed by the Mermin-Wagner theorem. This review provides a comprehensive theoretical and experimental overview of the importance of magnetic anisotropy in enabling intrinsic 2D magnetism and shaping the electronic, magnetic, and topological properties of 2D vdW materials. We begin by summarizing the fundamental mechanisms that determine magnetic anisotropy, emphasizing the contributions from strong ligand spin-orbit coupling of ligand atoms and unquenched orbital magnetic moments. We then examine a range of material engineering approaches, including alloying, doping, electrostatic gating, strain, and pressure, that have been employed to effectively tune magnetic anisotropy in these materials. Finally, we discuss open challenges and promising future directions in this rapidly advancing field. By presenting a broad perspective on the role of magnetic anisotropy in 2D magnetism, this review aims to stimulate ongoing efforts and new ideas toward the realization of robust, room-temperature applications based on 2D vdW magnetic materials and their heterostructures.
Materials Science (cond-mat.mtrl-sci)
A topic review of magnetic anisotropy of 2D magnetic materials
Advanced Functional Materials (2025)
Extraordinary surface critical behavior induced by a topological dimer phase in a two-dimensional Heisenberg quantum magnet
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2025-08-08 20:00 EDT
Zhe Wang, Longye Lu, Shang-Qiang Ning, Zenan Liu, Yan-Cheng Wang, Zheng Yan, Wenan Guo
Using quantum Monte Carlo simulations, we study the dimerized spin-1/2 Heisenberg model on a square lattice, focusing on the paramagnetic dimer phase and its edge states, and associated surface criticality behavior. The model can also be viewed as two-dimensional antiferromagnetically (AF) coupled usual ladders with AF rungs. We demonstrate that the dimer phase of the model, previously considered topologically trivial, is actually a quasi-one-dimensional (Q1D) Haldane phase belonging to a symmetry-protected topological (SPT) state. This is established by measuring generalized strange correlators introduced in this work and further confirmed by showing that the nontrivial edge state on a zigzag cut in the dimer phase is ferromagnetically ordered, resulting from effective ferromagnetic interactions between degenerate spinons generated on each side of the zigzag cut. Furthermore, we show that the ordered edge state gives rise to an extraordinary surface critical behavior at the (2+1)-dimensional O(3) bulk critical points of the model, which contradicts theoretical predictions based on classical-quantum mapping.
Strongly Correlated Electrons (cond-mat.str-el)
9 pages, 7 figures
Kinetic energy in random recurrent neural networks
New Submission | Statistical Mechanics (cond-mat.stat-mech) | 2025-08-08 20:00 EDT
The relationship between unstable fixed points and chaotic dynamics in high-dimensional neural dynamics remains elusive. In this work, we investigate the kinetic energy distribution of random recurrent neural networks by combining dynamical mean-field theory with extensive numerical simulations. We find that the average kinetic energy shifts continuously from zero to a positive value at a critical value of coupling variance (synaptic gain), with a power-law behavior close to the critical point. The steady-state activity distribution is further calculated by the theory and compared with simulations on finite-size systems. This study provides a first step toward understanding the landscape of kinetic energy, which may reflect the structure of phase space for the non-equilibrium dynamics.
Statistical Mechanics (cond-mat.stat-mech), Chaotic Dynamics (nlin.CD), Neurons and Cognition (q-bio.NC)
8 pages, 6 figures
Strongly correlated electronic superconductivity in the noncentrosymmetric Re-Os-based high/medium-entropy alloys
New Submission | Superconductivity (cond-mat.supr-con) | 2025-08-08 20:00 EDT
Rui Chen, Longfu Li, Lingyong Zeng, Kuan Li, Peifeng Yu, Kangwang Wang, Zaichen Xiang, Shuangyue Wang, Jingjun Qin, Wanyi Zhang, Yucheng Li, Tian Shang, Huixia Luo
The class of unconventional superconductors, particularly noncentrosymmetric superconductors, has been highly considered as potential materials for understanding the complex properties of quantum materials. Here, five previously unreported Re3.5Os3.5Ta0.5Hf0.5Nb3, Re3Os3Ta0.5Hf0.5Nb3, Re3.5Os3.5Mo0.5Hf0.5Nb3, Re3.5Os3.5Mo0.5W0.5Nb3, and Re3Os3Mo0.5Hf0.5Nb3 Re-Os-based high/medium-entropy alloys (MEAs-HEAs) with valence electron count ranging from 6.45 to 6.81 were synthesized and investigated using x-ray diffraction, transport, magnetization, and specific heat measurements. Our analyses confirm that all five compounds crystallize in a noncentrosymmetric {\alpha}-Mn-type structure and exhibit type-II superconductivity with Tc values from 4.20 K to 5.11 K, respectively. Unexpectedly, despite being immersed in an acidic environment for one month, the structures and superconducting properties of HEAs remain stable. Our findings indicate that the Tc increases with an increasing valence electron count in MEAs-HEAs. Furthermore, these noncentrosymmetric {\alpha}-Mn-type HEA superconductors have large Kadowaki-Woods ratios (KWR), implying the presence of strong electronic correlations.
Superconductivity (cond-mat.supr-con)
27 pages, 7 figures, 1 table; The manuscript with the same title will be published by Acta Materialia
Acta Materialia 2025
Alpha-, Beta-, and Gamma-TODD-G: Novel 2D Planar Carbon Allotropes
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-08-08 20:00 EDT
Kleuton A. L. Lima, Jose A. S. Laranjeira, Alysson M. A. Silva, Bill. D. Aparicio-Huacarpuma, Fabrício M. Vasconcelos, Julio R. Sambrano, Douglas S. Galvão, Luiz A. Ribeiro Junior
We present a comprehensive first-principles investigation of three novel two-dimensional carbon allotropes: alpha-, beta-, and gamma-TODD-Graphene (TODD-G), composed of 3-8-12-16, 3-8-12-16, and 3-4-8-12 interconnected carbon rings with sp/sp2 hybridization, respectively. Structural optimization, phonon spectra, and ab initio molecular dynamics simulations confirm their thermal and dynamical stability. All phases exhibit metallic electronic behavior, with distinct Dirac-like features and tilted Dirac cones that suggest anisotropic charge transport. Mechanical analysis reveals tunable anisotropy: alpha-TODD-G is strongly anisotropic, beta-TODD-G shows moderate anisotropy, and gamma-TODD-G displays an almost isotropic mechanical response. Optical spectra further differentiate the phases, with gamma-TODD-G showing strong absorption in the infrared region, while alpha- and beta-TODD-G mainly absorb in the visible and ultraviolet ranges.
Materials Science (cond-mat.mtrl-sci), Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
12 pages, 7 figures
Rotational-Mode-Enhanced Piezoelectricity in a Ferroelectric Double Helix
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-08-08 20:00 EDT
Recent theoretical work has predicted the existence of a dipole spiral" structure in strained freestanding membranes, promising a route to giant electromechanical responses[\href{this https URL}{PRL \textbf{133}, 046802 (2024)}]. However, its microscopic nature, energetic landscape, and electronic consequences remain largely unexplored. Here, using first-principles calculations on PbTiO$ _3$ under biaxial tensile strain, we unveil a novel form of polar order: a chiral, non-collinear ferroelectric double helix. We find that the Pb- and Ti-cation sublattices form two distinct, intertwined helices, reminiscent of DNA. This intricate topology is stabilized by a collective helical twisting of the oxygen octahedral framework, which mediates an emergent electric Dzyaloshinskii-Moriya this http URL unique structure, conceptualized as a self-Moiré” crystal, manifests two coupled functionalities. First, it possesses a rotational pseudo-zero-energy mode that underpins a giant piezoelectric response ($ e_{33}\approx$ 16 C/m$ ^2$ ). Second, the spiral’s long-period potential fundamentally reconstructs the electronic band structure, leading to an emergent multi-valley electronic topology at the valence band edge. Our work establishes a powerful, purely physical route to designing complex chiral order and provides a unified platform where structural topology, giant electromechanical coupling, and multi-valley electronics are intrinsically linked.
Materials Science (cond-mat.mtrl-sci)
Aharonov-Bohm interference from coherent spin-polarized edge transport in Fe(Te,Se) superconducting rings
New Submission | Superconductivity (cond-mat.supr-con) | 2025-08-08 20:00 EDT
Mohammad Javadi Balakan, Shiva Heidari, Genda Gu, Qiang Li, Kenji Watanabe, Takashi Taniguchi, Ji Ung Lee
We report the coexistence of Aharonov-Bohm and Little-Parks oscillations in mesoscopic Fe(Te,Se) rings. The magnetoresistance shows two distinct periodicities: an $ h/e$ component from ballistic edge interference and an $ h/2e$ component from fluxoid quantization of Cooper pairs. Aharonov-Bohm oscillations persist deep into the superconducting phase, exhibit current-field symmetry, and follow a temperature dependence captured by a helical Luttinger liquid model, consistent with edge states in a topological superconductor.
Superconductivity (cond-mat.supr-con), Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Strongly Correlated Electrons (cond-mat.str-el)
Observation of Super-ballistic Brownian Motion in Liquid
New Submission | Statistical Mechanics (cond-mat.stat-mech) | 2025-08-08 20:00 EDT
Jason Boynewicz, Michael C. Thumann, Mark G. Raizen
Brownian motion is a foundational problem in physics and is characterized by a mean squared displacement that scales linearly in time in thermal equilibrium, known as diffusion. At short times, the mean squared displacement becomes ballistic, scaling as t^2. This effect was predicted by Einstein in 1907 and recently observed experimentally. We report that this picture is only true on average; by conditioning specific initial velocities, we predict theoretically and confirm by experiment that the mean squared displacement becomes super-ballistic, with a power scaling law of t^(5/2). This new result is due to the colored noise of incompressible fluids, resulting in a non-zero first moment for the thermal force when conditioned on non-zero initial velocities. These results are a first step towards the unraveling of nonequilibrium dynamics of fluids.
Statistical Mechanics (cond-mat.stat-mech)
20 pages, 8 figures
Constitutive modeling of viscoelastic solids at large strains based on the theory of evolving natural configurations
New Submission | Soft Condensed Matter (cond-mat.soft) | 2025-08-08 20:00 EDT
The theory of evolving natural configurations is an effective technique to model dissipative processes. In this paper, we use this theory to revisit nonlinear constitutive models of viscoelastic solids. Particularly, a Maxwell and a Kelvin-Voigt model and their associated standard solids, viz., a Zener and a Poynting-Thompson solids respectively, have been modeled within a Lagrangian framework. We show that while a strain-space formulation of the evolving natural configurations is useful in modeling Maxwell-type materials, a stress-space formulation that incorporates a rate of dissipation function in terms of the relevant configurational forces is required for modeling the Kelvin-Voigt type materials. Furthermore, we also show that the basic Maxwell and Kelvin-Voigt models can be obtained as limiting cases from the derived standard solid models. Integration algorithms for the proposed models have been developed and numerical solutions for a relevant boundary value problem are obtained. The response of the developed models have been compared and benchmarked with experimental data. Specifically, the response of the novel Poynting-Thompson model is studied in details. This model shows a very good match with the existing experimental data obtained from a uniaxial stretching of polymers over a large extent of strain. The relaxation behavior and rate effects for the developed models have been studied.
Soft Condensed Matter (cond-mat.soft), Computational Physics (physics.comp-ph)
This article is prepared for a proposed special issue in a journal which is currently under editorial review
Theory of magnon hydrodynamics in collinear antiferromagnets
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2025-08-08 20:00 EDT
Vivianne Olguín-Arias, Alireza Qaiumzadeh, Roberto E. Troncoso
We investigate the transport of spin angular momentum and linear momentum carried by magnons in electrically insulating collinear antiferromagnets (AFs). Focusing on both transverse and longitudinal geometries, we model magnons as a viscous fluid and explore the hydrodynamic transport regime that emerges when the magnon-magnon scattering length is shorter than the momentum-relaxation length, such that momentum-conserving processes dominate over momentum-relaxing ones. We develop a theoretical framework to investigate viscous effects in the magnon hydrodynamic regime, which give rise to measurable transport signatures such as nonlocal resistance and spin and thermal conductance. Accounting for both momentum and spin relaxations, we derive hydrodynamic equations governing magnon momentum and spin transport. Notably, interspecies scattering between antiferromagnetic magnons with opposite spin angular momentum induces drag-like effects that strongly modify spin current propagation. We derive expressions for magnon conductivity and introduce an accessibility parameter quantifying intra-band momentum transfer. Our results establish antiferromagnetic insulators as a promising platform for observing magnon-fluid dynamics and exploring collective spin transport phenomena.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Materials Science (cond-mat.mtrl-sci)
10 pages, 5 figures
Superconducting gap symmetry of 2DEG at (111)-oriented LaAlO$_3$/SrTiO$_3$ interface
New Submission | Superconductivity (cond-mat.supr-con) | 2025-08-08 20:00 EDT
J. Czarnecki, M. Zegrodnik, P. Wójcik
We investigate the superconducting properties of the two-dimensional electron gas at the (111) LaAlO$ _3$ /SrTiO$ 3$ interface. Using a multiorbital tight-binding model defined on a hexagonal lattice, we analyze the emergence of superconductivity driven by both interlayer (nearest-neighbor) and intralayer (next-nearest-neighbor) pairing interactions, with a particular focus on the symmetry of the superconducting gap. We demonstrate that, in both pairing scenarios, the superconducting gap transforms according to the $ A_1$ irreducible representation of the $ C{6v}$ point group. Within the interlayer pairing scenario, the superconducting phase is characterized by a fully gapped quasiparticle excitation spectrum exhibiting extended $ s$ -wave symmetry, accompanied by an enhancement of the superconducting gap magnitude in the vicinity of the van Hove singularity. Conversely, the intralayer pairing channel produces a distinctive double-dome structure in the superconducting phase diagram, with the gap symmetry evolving from a fully gapped, extended $ s$ -wave at low carrier densities to a nodal extended $ s$ -wave state at higher electron concentrations. The qualitative agreement with experimentally observed nonmonotonic behavior of the critical temperature $ T_c(V_g)$ suggests that intralayer next-nearest-neighbor pairing may play a dominant role in the superconductivity of the (111) LAO/STO interface.
Superconductivity (cond-mat.supr-con), Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
15 pages, 12 figures
Order-Disorder Transition in Delay Vicsek Model
New Submission | Soft Condensed Matter (cond-mat.soft) | 2025-08-08 20:00 EDT
Interactions in active matter systems inherently involve delays due to information processing and actuation lags. We numerically investigate the impact of such delays on the phase behavior of the Vicsek model for motile active matter at a large but fixed system size. While the delayed Vicsek model retains the same three phases as the standard version – an ordered state, a liquid-gas coexistence state, and a disordered state – the presence of delay qualitatively alters the system’s dynamics. At the relatively high velocity considered in this study, the critical noise for the transition between the ordered and coexistence states exhibits a non-monotonic dependence on delay, whereas the critical noise required for the transition to the disordered state increases with delay. Consequently, the width of the noise interval in which phase separation occurs broadens with increasing delay. Short delays stabilize the ordered phase, while long delays destabilize it in favor of the coexistence phase, which is consistently stabilized compared to the disordered state. Furthermore, the number of bands observed in the coexistence state at a given noise increases, and the time required for their formation decreases with delay. This acceleration is attributed to the emergence of swirling structures whose typical radius grows with increasing delay. Our results demonstrate that time delay in the Vicsek model acts as an effective control parameter for tuning the system’s dynamic phase behavior.
Soft Condensed Matter (cond-mat.soft)
20 pages, 9 figures
Multiple quantum spin Hall states and topological current divider in Twisted Bilayer WSe$_2$
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2025-08-08 20:00 EDT
Hao He, Zhao Gong, Shuai Li, Jian-Jun Liu, Hui-Ying Mu, Xing-Tao An
It has been demonstrated that topological quantum spin Hall (QSH) state exist in twisted bilayers of transition metal dichalcogenides. However, a comprehensive theoretical characterization of the topological edge states remains a topic of interest and an unresolved issue. Here, the topological transport properties of the twisted WSe$ _2$ bilayers are investigated. Beyond the conventional single QSH, we identify emergent double and quartuple quantum spin Hall states, hosting two and four pairs of counter-propagating helical edge channels respectively. Furthermore, the charge carriers in these edge states are not localized at edge but rather the high potential point of the moire superlattice boundary, undergoing interlayer transitions and propagating forward continuously. We term these edge states as moire edge states. These edge states can survive in non-magnetic disorder, with the robustness of double QSH states surpassing that of single QSH states. At a twisting angle of 2.45$ ^\circ$ , the transition between the single and double QSH states can be achieved by adjusting the gate on the surface. Based on this, we propose a five-terminal device to as a topological current devider. Our findings provide support for the development of dissipationless spintronics.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
Non-Hermitian superconducting diode effect
New Submission | Superconductivity (cond-mat.supr-con) | 2025-08-08 20:00 EDT
Junjie Qi, Ming Lu, Jie Liu, Chui-Zhen Chen, X. C. Xie
The study of non-reciprocal phenomena has long captivated interest in both Hermitian and non-Hermitian systems. The superconducting diode effect (SDE) is a non-reciprocal phenomenon characterized by unequal critical charge supercurrents flowing in opposite directions in Hermitian superconducting systems. In this study, we introduce an SDE driven by non-Hermiticity in a superconducting quantum interference device (SQUID) under an external magnetic flux, which we refer to as the non-Hermitian SDE. Non-Hermiticity is introduced by coupling one of the two Josephson junctions to a gapless electron reservoir, introducing phase decoherence. Remarkably, we find that an emergent non-Hermitian Fermi-Dirac distribution can give rise to SDE in the non-Hermitian SQUID. We analyze the behavior of the SDE under both direct current (dc) and alternating current (ac) biases, highlighting the appearance of direction-dependent critical currents and asymmetric Shapiro steps as hallmarks of the SDE. Our findings not only reveal an experimentally accessible mechanism for non-Hermitian SDE but also open new avenues for investigating non-reciprocal phenomena in non-Hermitian systems.
Superconductivity (cond-mat.supr-con), Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
Symmetry breaking and competing valence bond states in the star lattice Heisenberg antiferromagnet
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2025-08-08 20:00 EDT
Pratyay Ghosh, Jan Koziol, Samuel Nyckees, Kai Phillip Schmidt, Frédéric Mila
We investigate the ground state phase diagram of the spin-$ 1/2$ antiferromagnetic Heisenberg model on the star lattice using infinite projected entangled pair states (iPEPS) and high-order series expansions. The model includes two distinct couplings: $ J_d$ on the dimer bonds and $ J_t$ on the trimer bonds. While it is established that the system hosts a valence bond solid (VBS) phase for $ J_d \ge J_t$ , the ground state phase diagram for $ J_d < J_t$ has remained unsettled. Our iPEPS simulations uncover a first-order phase transition at $ J_d/J_t \approx 0.18$ , significantly lower than previously reported estimates. Beyond this transition, we identify a close competition between two valence bond crystal (VBC) states: a columnar VBC and a $ \sqrt{3} \times \sqrt{3}$ VBC, with the latter consistently exhibiting lower energy across all finite bond dimensions. The high-order series expansion supports this by finding that the $ \sqrt{3} \times \sqrt{3}$ VBC state indeed becomes energetically favorable, but only at sixth order in perturbation theory, revealing the subtle nature of the competition between candidate states.
Strongly Correlated Electrons (cond-mat.str-el)
12 pages, 9 Figures
A case for resonant x-ray Bragg diffraction by a collinear antiferromagnet Li2Ni3P4O14
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2025-08-08 20:00 EDT
Magnetic axial and polar (Dirac) nickel multipoles contribute to resonant x-ray Bragg amplitudes in a symmetry informed analysis of monoclinic Li2Ni3P4O14 presented for future diffraction experiments. Magnetic long-range order below a temperature 14.5 K can be viewed as a two-dimensional trimerized antiferromagnet with Ni ions in two Wyckoff positions in the centrosymmetric magnetic space group P21/c. It permits the coupling to circular polarization in the primary x-ray beam, unlike the corresponding diffraction by an antiferromagnet characterized by anti-inversion and a linear magnetoelectric effect, e.g., historically significant chromium sesquioxide (Cr2O3) and Cu2(MoO4)(SeO3) (Lovesey & van der Laan, 2024). The space group is inferred from neutron Bragg diffraction patterns, without an allowance for permitted Dirac dipoles (anapoles) and quadrupoles (Chikara et al., 2025).
Strongly Correlated Electrons (cond-mat.str-el)
Electronic mean free path of the cuprate superconductor Bi$_2$Sr$_2$CaCu$2$O${8+δ}$ from thermal Hall conductivity
New Submission | Superconductivity (cond-mat.supr-con) | 2025-08-08 20:00 EDT
Emma Campillo, Manel Mezidi, Lu Chen, Ashvini Vallipuram, Jordan Baglo, Munkhtuguldur Altangerel, Gaël Grissonnanche, Genda Gu, Louis Taillefer
We use thermal transport to access the electronic mean free path of $ d$ -wave quasiparticles in one of the most widely studied cuprate superconductors, Bi$ 2$ Sr$ 2$ CaCu$ 2$ O$ {8+\delta}$ (Bi2212). We have measured the thermal conductivity $ \kappa{\rm xx}$ and the thermal Hall conductivity $ \kappa{\rm xy}$ of three single crystals across a range of dopings. In the overdoped and optimally-doped samples, a clear enhancement is observed in both $ \kappa{\rm xx}$ and $ \kappa{\rm xy}$ upon cooling below the critical temperature $ T_{\rm c}$ , due to a suppression of the inelastic electron-electron scattering as electrons condense into pairs. The underdoped sample shows no enhancement in either, pointing to a high degree of disorder in that sample. For the two highest dopings, the magnitude of the enhancement in $ \kappa_{\rm xy}$ is controlled by the strength of the elastic impurity scattering. Using a prior model to estimate the mean free path from $ \kappa_{\rm xy}$ data, we find that the mean free path in Bi2212 is approximately 7 times shorter than in YBa$ _2$ Cu$ _3$ O$ _7$ , considered to be one of the least disordered cuprates. We conclude that the thermal Hall technique is a good way to compare the mean free path of $ d$ -wave quasiparticles in various cuprate materials.
Superconductivity (cond-mat.supr-con), Strongly Correlated Electrons (cond-mat.str-el)
Unraveling Size Dependent Bi- and Tri-exciton Characteristics in CdSe/CdS Core/Shell Quantum Dots via Ensemble Time Gated Heralded Spectroscopy
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2025-08-08 20:00 EDT
Einav Scharf, Rotem Liran, Adar Levi, Omer Alon, Nadav Chefetz, Dan Oron, Uri Banin
Multiexcitons (MXs) in quantum dots (QDs) manifest many body interactions under quantum confinement. Beyond this fundamental interest, MXs are of importance in numerous optoelectronic applications including QD lasing, light emitting diodes and photocatalysis. Yet, the strong interactions between MXs leading to rapid non-radiative decay introduce challenges for their characterization. While so far, the measurement techniques rely either on indirect methods or on single particle studies, herein we introduce a new method to study MXs in QD ensembles utilizing spectrally resolved time-gated heralded spectroscopy. With this approach we extract the biexciton binding energies in a series of CdSe/CdS QD ensembles of several core/shell sizes, manifesting a transition between attractive and repulsive exciton-exciton interactions. Additionally, for triexcitons, which involve occupation of two excitons in the 1s energy levels, as well as one exciton in the 1p energy levels, we address the open issues of isolating the spectra of the two triexciton pathways from one another and from high-order MXs, and extract the MX lifetimes. The measurements on ensembles provide high photon counts and low noise levels, and alongside the time-gated heralded approach thus enable the observation of MX characteristics that are difficult to resolve in single particle studies. The approach can be further implemented in the characterization of the energies and lifetimes of MXs in other QD systems to enable rapid characterization and understanding of the MX properties. Such insight bears relevance to optoelectronic applications ranging from lasing to electroluminescent devices to quantum light sources.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
29 pages manuscript, 5 figures; 16 pages SI, 18 figures, 1 table
Entropy production in non-reciprocal polar active mixtures
New Submission | Statistical Mechanics (cond-mat.stat-mech) | 2025-08-08 20:00 EDT
Kim L. Kreienkamp, Sabine H. L. Klapp
The out-of-equilibrium character of active systems is often twofold, arising from both the activity itself and from non-reciprocal couplings between constituents. A well-established measure to quantify the system’s distance from equilibrium is the informatic entropy production rate. Here, we ask the question whether and how the informatic entropy production rate reflects collective behaviors and transitions in an active mixture with non-reciprocal polar couplings. In such systems, non-reciprocal orientational couplings can induce chiral motion of particles. At the field-theoretical level, transitions to these time-dependent chiral states are marked by so-called exceptional points. Here, we show that at a particle level, the entropy production rate within the chiral states increases with the degree of non-reciprocity, provided it is sufficiently strong. Moreover, even at small degrees of non-reciprocity, the transitions via exceptional points leave clear signatures in the entropy production rate, which exhibits pronounced peaks at coupling strengths corresponding to the field-theoretical exceptional points. Overall, the increase and peaks of the entropy production rate mirror the susceptibility of the polarization order parameter at the particle level. This correspondence is supported by a field-theoretical analysis, which reveals that, in the long-wavelength limit, the entropy production rate scales with the susceptibilities of the polarization fields.
Statistical Mechanics (cond-mat.stat-mech), Soft Condensed Matter (cond-mat.soft)
Quantum criticality and emergent orders in the spin-1 bilinear-biquadratic-Kitaev chain
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2025-08-08 20:00 EDT
Zhiling Wei, Zhengzhong Du, Xiaodong Cao, Wen-Long You, Yi Lu
Higher-spin quantum magnets with competing interactions offer a rich platform for exploring quantum phases that transcend the paradigms of spin-1/2 systems, owing to their enlarged local Hilbert spaces and the emergence of multipolar correlations. We investigate a one-dimensional spin-1 chain where quadrupolar order is promoted by two distinct mechanisms: conventional bilinear-biquadratic exchange and bond-directional antiferromagnetic Kitaev frustration. Using density matrix renormalization group calculations, we determine the complete ground-state phase diagram and uncover two emergent phases induced by the Kitaev interaction: a Kitaev nematic phase and a Kitaev-dimer phase. The Kitaev nematic phase emerges from a fragile biquadratic dimer state via a continuous quantum phase transition in the Ising universality class. The Kitaev dimer phase spontaneously breaks a screw symmetry to favor either $ x$ - or $ y$ -spin bonding, forming a gapped state that coexists with a crystalline order of alternating $ \mathbb{Z}_2$ fluxes.
Strongly Correlated Electrons (cond-mat.str-el)
12 pages, 12 figures
Many-body perturbation theory vs. density functional theory: A systematic benchmark for band gaps of solids
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-08-08 20:00 EDT
Max Großmann, Marc Thieme, Malte Grunert, Erich Runge
We benchmark many-body perturbation theory against density functional theory (DFT) for the band gaps of solids. We systematically compare four $ GW$ variants $ -$ $ G_{0}W_{0}$ using the Godby-Needs plasmon-pole approximation ($ G_{0}W_{0}$ -PPA), full-frequency quasiparticle $ G_{0}W_{0}$ (QP$ G_{0}W_{0}$ ), full-frequency quasiparticle self-consistent $ GW$ (QS$ GW$ ), and QS$ GW$ augmented with vertex corrections in $ W$ (QS$ G\hat{W}$ ) $ -$ against the currently best performing and popular density functionals mBJ and HSE06. Our results show that $ G_{0}W_{0}$ -PPA calculations offer only a marginal accuracy gain over the best DFT methods, however at a higher cost. Replacing the PPA with a full-frequency integration of the dielectric screening improves the predictions dramatically, almost matching the accuracy of the QS$ G\hat{W}$ . The QS$ GW$ removes starting-point bias, but systematically overestimates experimental gaps by about $ 15%$ . Adding vertex corrections to the screened Coulomb interaction, i.e., performing a QS$ G\hat{W}$ calculation, eliminates the overestimation, producing band gaps that are so accurate that they even reliably flag questionable experimental measurements.
Materials Science (cond-mat.mtrl-sci), Computational Physics (physics.comp-ph)
Observe novel tricritical phenomena in self-organized Fermi gas induced by higher order Fermi surface nesting
New Submission | Quantum Gases (cond-mat.quant-gas) | 2025-08-08 20:00 EDT
Yilun Xu, Feng-Xiao Sun, Qiongyi He
Cold atom systems in optical lattices have long been recognized as an ideal platform for bridging condense matter physics and quantum optics. Here, we investigate the 1D fermionic superradiance in an optical lattice, and observe novel tricritical phenomena and multistability in finite-temperature cases. As a starting point, which can be analytically calculated, we compare the 1D and 2D Fermi gases in zero-temperature limit. It turns out that the tricritical point originates from the higher-order Fermi surface nesting (FSN), and the infrared divergence in 1D systems is absent in 2D cases. When extending to finite-temperature cases, our numerical results reveal that both quantum- and classical-type trcritical phenomena can be observed simultaneously. Moreover, there exists an optimal temperature for observing superradiance. This work provides a new approach to understanding the relation between quantum and classical phase transitions.
Quantum Gases (cond-mat.quant-gas), Quantum Physics (quant-ph)
Third harmonic-mediated amplification in TWPA
New Submission | Superconductivity (cond-mat.supr-con) | 2025-08-08 20:00 EDT
E. Rizvanov, S. Kern, P. Neilinger, M. Grajcar
In Josephson Traveling-Wave Parametric Amplifiers, higher-order harmonics of the pump tone and its sidebands are commonly present and typically regarded as parasitic. Consequently, most design efforts have focused on suppressing these harmonics. In spite of that, motivated by transient simulations, we extend the coupled-mode theory and demonstrate that, contrary to conventional belief, the third harmonic can enhance amplifier performance, improving both gain and bandwidth. We show that the recently developed plasma oscillation-based amplifier is particularly well-suited for exploiting this effect. Their dispersion relation enables us to observe the phenomenon in transient numerical simulations using JoSIM and WRspice. These simulations reveal improvement of the amplifier’s performance, specifically the doubling of the bandwidth and an increase in the gain.
Superconductivity (cond-mat.supr-con), Quantum Physics (quant-ph)
Enhanced spin-to-charge conversion in La${0.67}$Sr${0.33}$MnO$_3$/NdNiO$_3$ bilayers at the nickelate metal-insulator phase transition
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-08-08 20:00 EDT
Biswajit Sahoo, Sarmistha Das, Akilan K, Alexandre Pofelski, Sebastien Petit-Watelot, Juan-Carlos Rojas-Sánchez, Yimei Zhu, Alex Frano, Eric E Fullerton
Phase transition materials such as NdNiO3 (NNO) when coupled with low damping ferromagnets such as La$ _{0.67}$ Sr$ _{0.33}$ MnO$ _3$ (LSMO) can lead to new multi-functional material systems harnessing the interplay of charge, spin and orbital degrees of freedom. In this study, we probe the evolution of the spin-to-charge conversion in epitaxial all-oxide LSMO (12 nm)/NNO (4, 8, and 16 nm) bilayers. Using spin pumping ferromagnetic resonance we track the spin-charge conversion in the NNO layer through the paramagnetic metal to antiferromagnetic insulator transition and observe a pronounced enhancement of the inverse spin Hall effect signal at the onset of this transition. We attribute this enhancement to the electronic and magnetic disorder in NNO at the first-order phase transition, thereby providing insights into the mechanism of spin transport through the phase transition. The tunability of spin charge conversion in this low damping bilayer system offers a pathway for developing multifunctional, energy-efficient spintronic devices.
Materials Science (cond-mat.mtrl-sci), Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Strongly Correlated Electrons (cond-mat.str-el)
9 Pages, 3 figures in main text and supplementary information combined
Mean first-encounter times of simultaneous random walkers with resetting on networks
New Submission | Statistical Mechanics (cond-mat.stat-mech) | 2025-08-08 20:00 EDT
Daniel Rubio-Gómez, Alejandro P. Riascos, José L. Mateos
We investigate the dynamics of simultaneous random walkers with resetting on networks and derive exact analytical expressions for the mean first-encounter times of Markovian random walkers. Specifically, we consider two cases for the simultaneous dynamics of two random walkers on networks: when only one walker resets to the initial node, and when both walkers return to their initial positions. In both cases, the encounter times are expressed in terms of the eigenvalues and eigenvectors of the transition matrix of the normal random walk, providing a spectral interpretation of the impact of resetting. We validate our approach through examples on rings, Cayley trees, and random networks generated using the Erdős-Rényi, Watts-Strogatz, and Barabási-Albert algorithms, where resetting significantly reduces encounter times. The proposed framework can be extended to other types of random walk dynamics, transport processes, or multiple-walker scenarios, with potential applications in human mobility, epidemic spreading, and search strategies in complex systems.
Statistical Mechanics (cond-mat.stat-mech)
24 pages, 5 figures
J. Phys. A: Math. Theor. 58 325003 (2025)
A Thermodynamic Model for Thermomigration in Metals
New Submission | Statistical Mechanics (cond-mat.stat-mech) | 2025-08-08 20:00 EDT
Daniel J. Long, Edmund Tarleton, Alan C.F. Cocks, Felix Hofmann
We investigate the mechanisms involved in the thermomigration of interstitial hydrogen in metals. Using statistical thermodynamics, we develop a comprehensive mechanistic model to capture the controlling effects. Crucially, through validation against published experimental data, our results demonstrate that an electron-wind effect plays a significant role, particularly for materials in which the thermomigration direction matches the heat flux. These findings provide new insights into the factors that affect the localisation of solutes in metals. Moreover, our results indicate that atomistic models may be inadequate for detailed thermomigration studies due to the omission of electronic effects.
Statistical Mechanics (cond-mat.stat-mech), Materials Science (cond-mat.mtrl-sci)
Stranski-Krastanov Growth of Disordered ScNx Thin Films on MgO(100): Influence of Defect Densities on Electronic Structure and Transport Properties
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-08-08 20:00 EDT
Susmita Chowdhury, Rachana Gupta, Najnin Bano, Yogesh Kumar, Shashi Prakash, Dinesh Kumar Shukla, Vasant G. Sathe, Mukul Gupta
We report a nascent real time Stranski-Krastanov growth of reactively sputtered ScNx thin films on MgO(100). The epitaxial growth was limited to 5 nm at a substrate temperature (Ts) of 25 C while the self-sustaining epitaxial nature along the [100] azimuth was retained up to 25 nm in Ts = 250 and 500 C samples due to enhanced adatom mobility. At Ts = 700 C, the film showed half order in-situ RHEED pattern, with forbidden (hkl) planes indicating N deficient hcp Sc-N phase. Presence of defect densities i.e., N vacancies and O interstitials leads to a disorder in ScNx system with weak localization effect and appearance of Raman relaxed first order transverse and longitudinal optical phonon modes and further leads to metal like Seebeck coefficient. Higher grain boundaries at Ts = 25 C and higher N out-diffusion at Ts = 700 C paves way for incorporation of higher oxygen interstitial in these samples.
Materials Science (cond-mat.mtrl-sci)
Hole-doping reduces the coercive field in ferroelectric hafnia
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-08-08 20:00 EDT
Pravan Omprakash, Gwan Yeong Jung, Guodong Ren, Rohan Mishra
Ferroelectric hafnia holds promise for next-generation memory and logic applications because of its CMOS compatibility. However, the high coercive field required for polarization switching in hafnia remains a critical challenge for efficient device operations. Using first-principles calculations and phenomenological modeling, we predict that hole doping can reduce the coercive field from 8 MV/cm in undoped hafnia to 6 MV/cm in hafnia doped with 0.2 holes per formula unit (f.u.). In the absence of doping, the reversal of polarization of the Pca21 phase is preferred through the non-polar, tetragonal P42/nmc phase. This switching pathway involves the coupling of three hard distortion modes that render undoped hafnia as an improper ferroelectric. The overall energy barrier through this pathway remains unchanged (80 meV/f.u.) upon hole doping. However, the introduction of holes hardens the polar distortion mode that connects the polar Pca21 phase to the non-polar, orthorhombic Pbcm phase, and reduces the energy barrier from 180 meV/f.u. in undoped hafnia to 80 meV/f.u. at 0.2 holes/f.u.. Overall, hole doping makes the latter switching pathway through the Pbcm phase competitive, and renders hafnia as a proper ferroelectric with a lower coercive field.
Materials Science (cond-mat.mtrl-sci), Computational Physics (physics.comp-ph)
Direct Measurement of the Effective Electronic Temperature in Organic Semiconductors
New Submission | Disordered Systems and Neural Networks (cond-mat.dis-nn) | 2025-08-08 20:00 EDT
Anton Kompatscher, Martijn Kemerink
Organic semiconductors show complex phenomena due to their high energetic disorder. A striking example is the possibility of an increased effective temperature T_eff of the charge carrier distribution relative to the lattice temperature, which results from the slow charge carrier relaxation after excitation, either by high electric field or photon absorption. The increased effective temperature has been linked to conductivity enhancements and performance increases in actual devices, but a direct observation has been lacking. Here, we utilize nanoscopic tree-terminal devices to measure the Seebeck voltage arising in a doped organic polymer semiconductor due to a field-driven enhancement of the effective electronic temperature, providing direct proof of the existence of T_eff. The results agree quantitatively with numerical predictions by a kinetic Monte Carlo model. The findings not only provide fundamental understanding but also indicate an avenue towards low-loss thermoelectric devices.
Disordered Systems and Neural Networks (cond-mat.dis-nn)
Stacking-induced type-II quantum spin Hall insulators with high spin Chern number in unconventional magnetism
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2025-08-08 20:00 EDT
Chao-Yang Tan, Panjun Feng, Ze-Feng Gao, Fengjie Ma, Peng-Jie Guo, Zhong-Yi Lu
Generally, stacking two monolayer type-I quantum spin Hall insulators gives rise to a trivial insulator. However, whether or not stacking two type-II quantum spin Hall insulators results in a trivial insulator has not yet been explored. In this letter, based on the calculations of lattice model, we demonstrate that stacking two type-II quantum spin Hall insulators does not yield a trivial insulator, but instead forms a quantum spin Hall insulator with high spin Chern number. In this phase, there are two pairs of topological edge states with opposite chirality and polarization coexisting in the boundary. Our calculations further reveal that the quantized spin Hall conductance of the bilayer is twice that of the monolayer. When U(1) symmetry is present, the high spin Chern number phase remains stable; when U(1) symmetry is broken, it persists over a broad parameter range. Furthermore, based on the first-principles electronic structure calculations, we propose that bilayer Nb$ _2$ SeTeO is a type-II quantum spin Hall insulator with high spin Chern number. Finally, extending this strategy to multilayer stacks naturally leads to quantum spin Hall insulator with larger spin Chern number. Our work not only deepens the distinction between type-I and type-II quantum spin Hall insulators, but also offers a route toward realizing highly quantized spin Hall conductance.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Materials Science (cond-mat.mtrl-sci)
5pages,4figures
Disorder-induced stress-flow misalignment in soft glassy materials revealed using multi-directional shear
New Submission | Soft Condensed Matter (cond-mat.soft) | 2025-08-08 20:00 EDT
Frédéric Blanc, Guillaume Ovarlez, Adam Trigui, Kirsten Martens, Romain Mari
Controlling the mechanical response of soft glassy materials, such as emulsions, foams, and colloidal suspensions, is key for many industrial processes. While their steady-state flow behavior is reasonably well understood, their response to complex flow histories, as encountered in operations like pumping or mixing, remains poorly known. Using a custom multi-axis shear apparatus that enables arbitrary changes in flow direction, we investigate how shear history influences the mechanical behavior of a model soft glassy system. We uncover a transient shear response orthogonal to the applied shear direction, together with an anisotropic yield surface. These effects point to an underlying anisotropic distribution of internal stresses imprinted by previous deformation. To rationalize this behavior, we use a mesoscopic elasto-plastic model, demonstrating that local mechanical disorder governs the emergence of macroscopic stress-flow misalignment. Our findings offer a new route to experimentally probe the distribution of local yield stresses in soft glassy materials.
Soft Condensed Matter (cond-mat.soft), Materials Science (cond-mat.mtrl-sci)
On Random Displacements in Critical Rydberg Atom Arrays
New Submission | Disordered Systems and Neural Networks (cond-mat.dis-nn) | 2025-08-08 20:00 EDT
Xingyu Li, Shuyan Zhou, Xue Chen, Chengshu Li, Hanteng Wang
Rydberg atom arrays promise high-fidelity quantum simulations of critical phenomena with flexible geometries. Yet experimental realizations inevitably suffer from disorder due to random displacements of atoms, leading to departures from the expected behavior. Here, we study how such positional disorder influences the Ising criticality. Since disorder breaks the $ \mathbb{Z}_2$ symmetry, one might expect the system to flow to an infinite-strength disordered fixed point, erasing all nontrivial critical features in low spatial dimensions. Remarkably, we find instead that disorder in Rydberg systems is subjected to nontrivial local constraints, making the physics markedly different from systems with more conventional spatially short-range correlated or long-range correlated disorder. This leads to new classes of criticalities even at dimensions where conventional disorder would destroy criticality altogether. We then demonstrate as a consequence how a novel pseudo-criticality emerges in mesoscopic Rydberg chains, and show that the renormalization group flow is governed by a locally constrained $ \mathbb{Z}_2$ -breaking perturbation. Our findings uncover new disorder-driven phenomena and underscore the importance of carefully treating disorder effects in quantum simulators.
Disordered Systems and Neural Networks (cond-mat.dis-nn), Quantum Gases (cond-mat.quant-gas), Strongly Correlated Electrons (cond-mat.str-el)
7 pages, 3 figures + Supplementary Materials 4 pages, 2 figures
Quantum many-body scarring from Kramers-Wannier duality
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2025-08-08 20:00 EDT
Weslei B. Fontana, Fabrizio G. Oliviero, Yi-Ping Huang
Kramers-Wannier duality, a hallmark of the Ising model, has recently gained renewed interest through its reinterpretation as a non-invertible symmetry with a state-level action. Using sequential quantum circuits (SQC), we argue that this duality governs the stability of quantum many-body scar (QMBS) states in a nonintegrable model, depending on whether the dual preserves the embedding conditions for scarring. This is supported by striking agreement between first-order perturbation theory and numerics, which capture scar dynamics despite chaotic spectra. Our results suggest that non-invertible dualities provide both a generative mechanism for new QMBS and a diagnostic for their stability.
Strongly Correlated Electrons (cond-mat.str-el), Other Condensed Matter (cond-mat.other), Quantum Physics (quant-ph)
6+7 pages, 3+4 figures. Comments are welcome
Global Tensor Network Renormalization for 2D Quantum systems: A new window to probe universal data from thermal transitions
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2025-08-08 20:00 EDT
Atsushi Ueda, Sander De Meyer, Adwait Naravane, Victor Vanthilt, Frank Verstraete
We propose a new tensor network renormalization group (TNR) scheme based on global optimization and introduce a new method for constructing the finite-temperature density matrix of two-dimensional quantum systems. Combining these two into a new algorithm called thermal tensor network renormalization (TTNR), we obtain highly accurate conformal field theory (CFT) data at thermal transition points. This provides a new and efficient route for numerically identifying phase transitions, offering an alternative to the conventional analysis via critical exponents.
Strongly Correlated Electrons (cond-mat.str-el), Statistical Mechanics (cond-mat.stat-mech)
Universal relations between thermoelectrics and noise in mesoscopic transport across a tunnel junction
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2025-08-08 20:00 EDT
Andrei I. Pavlov, Mikhail N. Kiselev
We develop a unified theory of weakly probed differential observables for currents and noise in transport experiments. Our findings uncover a set of universal transport relations between thermoelectric and noise properties of a system probed through a tunnel contact, with the Wiedemann-Franz law being just one example of such universality between charge and heat currents. We apply this theory to various quantum dot systems, including multichannel Kondo, quantum Hall and Sachdev-Ye-Kitaev quantum dots, and demonstrate that each of the microscopic theories is characterized by a set of universal relations connecting conductance and thermoelectrics with noise. Violations of these relations indicate additional energy scales emerging in a system.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Strongly Correlated Electrons (cond-mat.str-el)
Heat and super-diffusive melting fronts in unsaturated porous media
New Submission | Soft Condensed Matter (cond-mat.soft) | 2025-08-08 20:00 EDT
Eirik G. Flekkøy, Erika Eiser, Alex Hansen
When water is present in a medium with pore sizes in a range around 10nm the corresponding freezing point depression will cause long range broadening of a melting front. Describing the freezing-point depression by the Gibbs-Thomson equation and the pore size distribution by a power law, we derive a non-linear diffusion equation for the fraction of melted water. This equation yields super-diffusive spreading of the melting front with a diffusion exponent which is given by the spatial dimension and the exponent describing the pore size distribution. We derive this solution analytically from energy conservation in the limit where all the energy is consumed by the melting and explore the validity of this approximation numerically. Finally, we explore a geological application of the theory to the case of one-dimensional sub-surface melting fronts in granular or soil systems. These fronts, which are produced by heating of the surface, spread at a super-diffusive rate and affect the subsurface to significantly larger depths than would a system without the effects of freezing point depression.
Soft Condensed Matter (cond-mat.soft)
Single-shot optical precessional magnetization switching of Pt/Co/Pt ferromagnetic trilayers
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-08-08 20:00 EDT
Rui Xu, Chen Xiao, Xiangyu Zheng, Renyou Xu, Xiaobai Ning, Tianyi Zhu, Dinghao Ma, Kangning Xu, Fei Xu, Youguang Zhang, Boyu Zhang, Jiaqi Wei
Ultra-fast magnetization switching triggered by a single femtosecond laser pulse has gained significant attention over the last decade for its potential in low-power consumption, high-speed memory applications. However, this phenomenon has been primarily observed in Gd-based ferrimagnetic materials, which are unsuitable for storage due to their weak perpendicular magnetic anisotropy (PMA). In this work, we demonstrated that applying a single laser pulse and an in-plane magnetic field can facilitate magnetic switching in a Pt/Co/Pt ferromagnetic trilayers stack within a specific laser power window. To further understand this phenomenon, we introduce a Cu layer to accelerates the re-establishment time of the anisotropy field of Pt/Co/Pt trilayers, which leads to bullseye-patterned magnetic switching. We have mapped state diagrams for these phenomena, and through micromagnetic simulations, we have determined that these switchings are influenced by thermal anisotropy torque, which can be modulated through PMA. These findings indicate that single-shot optical precessional magnetization reversal is feasible in a broader range of materials, opening avenues for the development of optical-magnetic memory devices.
Materials Science (cond-mat.mtrl-sci)
Symmetry Resolved Entanglement Entropy in a Non-Abelian Fractional Quantum Hall State
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2025-08-08 20:00 EDT
Mark J. Arildsen, Valentin Crépel, Nicolas Regnault, Benoit Estienne
Symmetry-resolved entanglement entropy provides a powerful framework for probing the internal structure of quantum many-body states by decomposing entanglement into contributions from distinct symmetry sectors. In this work, we apply matrix product state techniques to study the bosonic, non-Abelian Moore-Read quantum Hall state, enabling precise numerical evaluation of both the full counting statistics and symmetry-resolved entanglement entropies. Our results reveal an approximate equipartition of entanglement among symmetry sectors, consistent with theoretical expectations and subject to finite-size corrections. The results also show that these expectations for symmetry-resolved entanglement entropy remain valid in the case of a non-Abelian state where the topological sectors cannot be distinguished by the Abelian $ \mathrm{U}(1)$ symmetry alone, and where neutral and charged modes possess distinct velocities. We additionally perform a detailed comparison of the entanglement spectrum with predictions from the Li-Haldane conjecture, finding remarkable agreement, and enabling a more precise understanding of the effects of the distinct neutral and charged velocities. This not only provides a stringent test of the conjecture but also highlights its explanatory power in understanding the origin and structure of finite-size effects across different symmetry sectors.
Strongly Correlated Electrons (cond-mat.str-el), High Energy Physics - Theory (hep-th)
28 pages, 21 figures, 6 tables
The use of open boundaries in stochastic hydrodynamic models of nucleation
New Submission | Statistical Mechanics (cond-mat.stat-mech) | 2025-08-08 20:00 EDT
Stochastic hydrodynamics is a central tool in the study of first order phase transitions at a fundamental level. Combined with sophisticated free energy models, e.g. as developed in classical Density Functional Theory, complex processes such as crystallization can be modeled and information such as free energy barriers, nucleation pathways and the unstable eigenvector and eigenvalues determined. The latter are particularly interesting as they play key roles in defining the natural (unbiased) order parameter and the nucleation rate respectively. As is often the case, computational realities restrict the size of system that can be modeled and this makes it difficult to achieve experimental conditions for which the volume is effectively infinite. In this paper, the use of open boundary conditions is discussed. By using an open system, the calculations become much closer to experimental conditions however, the introduction of open boundary conditions raises a number of questions concerning the stochastic model such as whether the fluctuation-dissipation relation is preserved and whether stationary points on the free energy surface remain stationary points of the dynamics.
Statistical Mechanics (cond-mat.stat-mech), Chemical Physics (physics.chem-ph), Computational Physics (physics.comp-ph)
Ta2Pd3Te8: A potential candidate of 1D van der Waals stacked thermoelectric materials
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-08-08 20:00 EDT
Shi Chen, Aijun Hong, Junming Liu
Discovering new thermoelectric (TE) materials is an eternal goal in the TE field. Excellent TE materials have ranged from 3D stacked to 2D stacked bulk. However, the 1D stacked receives little attention due to the scarcity in quantity. In this work, it is predicted that 1D van der Waals (vdW) stacked Ta2Pd3Te8 crystal is a compelling candidate for TE applications by combining first-principles calculations with phonon and electron Boltzmann transport equations and molecular dynamics methods. We find that Ta2Pd3Te8 crystal has mechanical, dynamical, and thermal stabilities, and its TE properties are featured by strong anisotropy, high power factor (PF) and low lattice thermal conductivity. The results indicate the ZT values of n-type Ta2Pd3Te8 at 900 K along a, b and c axes reach 0.48, 0.39 and 0.22, respectively. We propose that enlarging the bandgap can weaken the bipolar effect and thus significantly increases ZT to 1.11. The findings in the work not only stimulate more theoretical works on 1D vdW stacked TE materials, but also provide valuable information for experimentally improving TE materials.
Materials Science (cond-mat.mtrl-sci)
Negative differential conductance in triangular molecular assemblies
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2025-08-08 20:00 EDT
Chao Li, Vladislav Pokorný, Prokop Hapala, Martin Žonda, Ping Zhou, Silvio Decurtins, Shi-Xia Liu, Fengqi Song, Rémy Pawlak, Ernst Meyer
We report the creation and characterization of a molecular-scale negative differential conductance (NDC) device by assembling a triangular trimer of 4,5,9,10-tetrabromo-1,3,6,8-tetraazapyrene (TBTAP) molecules on a superconducting Pb(111) substrate. Using low-temperature scanning tunneling spectroscopy, we observe robust NDC behavior manifesting as a decrease in current with increasing voltage between 0.7-0.9 V arising from the interplay of Coulomb blockade and strong inter-molecular capacitive coupling within the molecular cluster. Gate-controlled charging and discharging processes are directly visualized via two-dimensional differential conductance mapping, which reveals the emergence of Coulomb rings and spatial regions of NDC. Theoretical modeling using a three-impurity Anderson model and master equation approach quantitatively reproduces the experimental observations and demonstrates that the NDC emerges purely from electron correlations, independent of the underlying superconductivity. By tuning the geometry to a hexamer structure, we further show that cluster topology provides versatile control over electronic properties at the molecular scale. These results establish a functional platform for implementing multifunctional molecular devices and highlight a strategy toward programmable and scalable nanoelectronics.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
Nonreciprocal inertial spin-wave dynamics in twisted magnetic nanostrips
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2025-08-08 20:00 EDT
Massimiliano d’Aquino, Riccardo Hertel
We develop a theoretical framework for inertial spin-wave dynamics in three-dimensional twisted soft-magnetic nanostrips, where curvature and torsion couple with magnetic inertia to generate terahertz (THz) magnetic oscillations. The resulting spin-wave spectra exhibit pronounced nonreciprocity due to effective symmetry breaking arising from geometric chirality and inertial effects. We show that this behavior is governed by a curvature-induced geometric (Berry) phase, which we analytically capture through compact expressions for dispersion relations and spectral linewidths in both nutational (THz) and precessional (GHz) regimes. Topological variations, including Möbius and helical geometries, impose distinct wavenumber quantization rules, elucidating the role of topology in spin-wave transport. These results position twisted magnetic strips as a viable platform for curvilinear THz magnonics and nonreciprocal spintronic applications.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
7 pages, 5 figures
Unveiling the Lithium-Ion Transport Mechanism in Li2ZrCl6 Solid-State Electrolyte via Deep Learning-Accelerated Molecular Dynamics Simulations
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-08-08 20:00 EDT
Hanzeng Guo, Volodymyr Koverga, Selva Chandrasekaran Selvaraj, Anh T. Ngo
Lithium zirconium chlorides (LZCs) present a promising class of cost-effective solid electrolyte for next-generation all-solid-state batteries. The unique crystal structure of LZCs plays a crucial role in facilitating lithium-ion mobility, which is central to their electrochemical performance. To understand the underlying mechanism governing ion transport, we employed deep learning-accelerated molecular dynamics simulation on Li2ZrCl6 (trigonal {\alpha}- and monoclinic \b{eta}-LZC), focusing specifically on the zirconium coordination environment. Our results reveal that disordered {\alpha}-LZC exhibits the highest ionic conductivity, while \b{eta}-LZC demonstrates significantly lower conductivity, closely aligning with experimental findings. Detailed analysis shows substantial differences in lithium-ion dynamics: {\alpha}-LZC phases display pronounced collective diffusion driven anisotropic interlayer transport, whereas lithium mobility in \b{eta}-LZC is largely determined by isotropic translations and individual diffusion dominated by intralayer migration. Across all phases, lithium migration proceeds via site-to-site hopping mechanism, where variations in site residence times critically impact the overall ionic conductivity. Local structure organizations analysis confirms that particular zirconium arrangements in LZC phases create varied ion channel energy barriers, influencing dynamic behaviors: In {\alpha}-LZC phases, the interlayer hopping barrier is lower than the intralayer barrier, facilitating faster ion transport. Disordered {\alpha}-LZC, with its loose zirconium arrangement, presents the lowest energy barrier, enhancing conductivity. Conversely, \b{eta}-LZC features a higher overall barrier, with intralayer hopping favored over interlayer, resulting in slower ion migration.
Materials Science (cond-mat.mtrl-sci)
it has supporting information
Pressure-induced decomposition of Bi14WO24
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-08-08 20:00 EDT
E. Karaca, D. Santamaria-Perez, A. Otero-de-la-Roza, R. Oliva, K.S. Rao, S.N. Achary, C. Popescu, D. Errandonea
We present a study of the high-pressure behaviour Bi14WO24, a high oxide ion conductor member of the Bi2O3-WO3 binary system. The tetragonal polymorph of Bi14WO24 was studied under high-pressure conditions using synchrotron powder X-ray diffraction. It was found that in contrast to isostructural Bi14CrO24 and Bi14MoO24 which experience a phase transition around 5 GPa, in our study Bi14WO24 undergoes an irreversible chemical decomposition into Bi2O3 and WO3 at 2.85(5) GPa. The pressure dependence of the unit-cell parameters of Bi14WO24 was also determined, and hence the linear compressibility along different axes and room-temperature pressure-volume equation of state were derived. Bulk modulus of tetragonal Bi14WO24 was found to be 49.8(2.6) GPa, and the linear compressibility of the two crystallographic axes, \k{appa}a and \k{appa}c were 6.94(2) 10-3 GPa-1 and = 3.73(1) 10-3 GPa-1, respectively. The pressure induced decomposition can be attributed to the favourable increasing density of the system to accommodate the pressure induced stress.
Materials Science (cond-mat.mtrl-sci), Applied Physics (physics.app-ph)
18 pages, 6 figures, 2 tables
Results in Physics 70, 2025, 108170