CMP Journal 2025-10-11
Statistics
Physical Review Letters: 2
arXiv: 79
Physical Review Letters
Coupling between a Si/SiGe Resonant Exchange Qubit and a High-Impedance Microwave Resonator
Article | Quantum Information, Science, and Technology | 2025-10-10 06:00 EDT
Shun-Li Jiang, Tian-Yi Jiang, Shu-Kun Ye, Ran-Ran Cai, Tian-Yue Hao, Yong-Qiang Xu, Zong-Hu Li, Yuan Kang, Bao-Chuan Wang, Hai-Ou Li, Guang-Can Guo, Xiang-Xiang Song, Gang Cao, and Guo-Ping Guo
Strong coupling between a Si/SiGe resonant exchange qubit and a high impedance microwave resonator is a step forward in achieving long range qubit scaling in silicon based quantum computation.
Phys. Rev. Lett. 135, 150604 (2025)
Quantum Information, Science, and Technology
Nonlocal Symmetries of Planar Feynman Integrals
Article | Particles and Fields | 2025-10-10 06:00 EDT
Florian Loebbert, Lucas Rüenaufer, and Sven F. Stawinski
We prove the invariance of scalar Feynman graphs of any planar topology under the Yangian level-one momentum symmetry given certain constraints on the propagator powers. The proof relies on relating this symmetry to a planarized version of the conformal simplices of Bzowski, McFadden, and Skenderis.…
Phys. Rev. Lett. 135, 151603 (2025)
Particles and Fields
arXiv
General expression for the energy and the equation of state for polycrystalline solids
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-10-10 20:00 EDT
O. Bystrenko, B. Ilkiv, S. Petrovska, T. Bystrenko, O. Foia, O. Khyzhun (Frantsevich Institute for problems of materials science, Kyiv, Ukraine)
On the basis of the extended classical elasticity theory, we propose universal semi-empirical analytical expressions for the energy and the equation of state for poly-crystalline solids. The validation of the relations has been made by means of first principle density functional theory simulations with the use of pseudo-potential approach and generalized gradient approximation for the exchange-correlation energy. The calculations performed for a large number of inorganic crystalline compounds with metal, covalent and ionic bonding (including diamond, Mg, sphalerite, B, magnesium carboboride, topaz, rocksalt, etc.) within the pressure range from -20 GPa to 300 GPa demonstrated an excellent agreement with the predictions of the analytical theory. The proposed relations can be used to describe the behavior of poly-crystalline solids at high pressure, in particular, to predict pressure-induced phase transitions.
Materials Science (cond-mat.mtrl-sci)
11 pages, 12 figures
Learning to predict superconductivity
New Submission | Superconductivity (cond-mat.supr-con) | 2025-10-10 20:00 EDT
Omri Lesser, Yanjun Liu, Natalie Maus, Aaditya Panigrahi, Krishnanand Mallayya, Leslie M. Schoop, Jacob R. Gardner, Eun-Ah Kim
Predicting the superconducting transition temperature ($ T_c$ ) of materials remains a major challenge in condensed matter physics due to the lack of a comprehensive and quantitative theory. We present a data-driven approach that combines chemistry-informed feature extraction with interpretable machine learning to predict $ T_c$ and classify superconducting materials. We develop a systematic featurization scheme that integrates structural and elemental information through graphlet histograms and symmetry vectors. Using experimentally validated structural data from the 3DSC database, we construct a curated, featurized dataset and design a new kernel to incorporate histogram features into Gaussian-process (GP) regression and classification. This framework yields an interpretable $ T_c$ predictor with an $ R^2$ value of 0.93 and a superconductor classifier with quantified uncertainties. Feature-significance analysis further reveals that GP $ T_c$ predictor can achieve near-optimal performance only using four second-order graphlet features. In particular, we discovered a previously overlooked feature of electron affinity difference between neighboring atoms as a universally predictive descriptor. Our graphlet-histogram approach not only highlights bonding-related elemental descriptors as unexpectedly powerful predictors of superconductivity but also provides a broadly applicable framework for predictive modeling of diverse material properties.
Superconductivity (cond-mat.supr-con), Materials Science (cond-mat.mtrl-sci)
9+13 pages, 5+3 figures
Emergent spacetime supersymmetry at 2D fractionalized quantum criticality
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2025-10-10 20:00 EDT
Zhengzhi Wu, Zhou-Quan Wan, Shao-Kai Jian, Hong Yao
While experimental evidence for spacetime supersymmetry (SUSY) in particle physics remains elusive, condensed matter systems offer a promising arena for its emergence at quantum critical points (QCPs). Although there have been a variety of proposals for emergent SUSY at symmetry-breaking QCPs, the emergence of SUSY at fractionalized QCPs remains largely unexplored. Here, we demonstrate emergent space-time SUSY at a fractionalized QCP in the Kitaev honeycomb model with Su-Schrieffer-Heeger (SSH) spin-phonon coupling. Specifically, through numerical computations and analytical analysis, we show that the anisotropic SSH-Kitaev model hosts a fractionalized QCP between a Dirac spin liquid and an incommensurate/commensurate valence-bond-solid phase coexisting with $ \mathbb{Z}_2$ topological order. A low-energy field theory incorporating phonon quantum fluctuations reveals that this fractionalized QCP features an emergent $ \mathcal{N}=2$ spacetime SUSY. We further discuss their universal experimental signatures in thermal transport and viscosity, highlighting the concrete lattice realization of emergent SUSY at a fractionalized QCP in 2D.
Strongly Correlated Electrons (cond-mat.str-el), Statistical Mechanics (cond-mat.stat-mech), High Energy Physics - Theory (hep-th)
4 pages, 1 figure
Localization of information driven by stochastic resetting
New Submission | Statistical Mechanics (cond-mat.stat-mech) | 2025-10-10 20:00 EDT
The dynamics of extended many-body systems are generically chaotic. Classically, a hallmark of chaos is the exponential sensitivity to initial conditions captured by positive Lyapunov exponents. Supplementing chaotic dynamics with stochastic resetting drives a sharp dynamical phase transition: we show that the Lyapunov spectrum, i.e., the complete set of Lyapunov exponents, abruptly collapses to zero above a critical resetting rate. At criticality, we find a sudden loss of analyticity of the velocity-dependent Lyapunov exponent, which we relate to the transition from ballistic scrambling of information to an arrested regime where information becomes exponentially localized over a characteristic length diverging at criticality with an exponent $ \nu = 1/2$ . We illustrate our analytical results on generic chaotic dynamics by numerical simulations of coupled map lattices.
Statistical Mechanics (cond-mat.stat-mech), Chaotic Dynamics (nlin.CD)
5 pages
Measuring intrinsic relaxation rates in superconductors using nonlinear response
New Submission | Superconductivity (cond-mat.supr-con) | 2025-10-10 20:00 EDT
Wei-En Tseng, Rahul Nandkishore
We discuss intrinsic relaxation rates in superconductors, and how they may be measured using non-linear optical (terahertz) response. We consider both $ s$ and $ d$ -wave superconductors, both with and without a phenomenological (energy dependent) damping. Intrinsic relaxation rates of interest include the Higgs mode decay rate, the quasiparticle redistribution rate ($ 1/T_1$ ) and the quasiparticle dephasing rate ($ 1/T_2$ ), where the latter two rates are zero in the pure BCS model, but non-zero in the presence of damping. Using the Anderson pseudospin formalism, we illustrate how these intrinsic relaxation rates are related to measurable quantities such as the time-dependent gap function and the non-linear current (a.k.a. third harmonic generation). Hence, we show how intrinsic relaxation rates may be experimentally extracted and discuss what one may thereby learn about the underlying damping. We also discuss the effects of polarization control (viz. non-linear response to light polarized in different directions), which offers a useful experimental knob, especially for $ d$ -wave superconductors, enabling selective excitation of modes in different irreducible representations (and readout of their corresponding relaxation rates).
Superconductivity (cond-mat.supr-con), Strongly Correlated Electrons (cond-mat.str-el)
Attention to Order: Transformers Discover Phase Transitions via Learnability
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-10-10 20:00 EDT
Phase transitions mark qualitative reorganizations of collective behavior, yet identifying their boundaries remains challenging whenever analytic solutions are absent and conventional simulations fail. Here we introduce learnability as a universal criterion, defined as the ability of a transformer model containing attention mechanism to extract structure from microscopic states. Using self-supervised learning and Monte Carlo generated configurations of the two-dimensional Ising model, we show that ordered phases correspond to enhanced learnability, manifested in both reduced training loss and structured attention patterns, while disordered phases remain resistant to learning. Two unsupervised diagnostics, the sharp jump in training loss and the rise in attention entropy, recover the critical temperature in excellent agreement with the exact value. Our results establish learnability as a data-driven marker of phase transitions and highlight deep parallels between long-range order in condensed matter and the emergence of structure in modern language models.
Materials Science (cond-mat.mtrl-sci), Disordered Systems and Neural Networks (cond-mat.dis-nn), Artificial Intelligence (cs.AI), Machine Learning (cs.LG)
Pareto-optimality of Majoranas in hybrid platforms
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2025-10-10 20:00 EDT
Juan Daniel Torres Luna, Sebastian Miles, A. Mert Bozkurt, Chun-Xiao Liu, Antonio L. R. Manesco, Anton R. Akhmerov, Michael Wimmer
To observe Majorana bound states, and especially to use them as a qubit, requires careful optimization of competing quality metrics. We systematically compare Majorana quality in proximitized semiconductor nanowires and quantum dot chains. Using multi-objective optimization, we analyze the fundamental trade-offs between topological gap and localization length, two key metrics that determine MBS coherence and operational fidelity. We demonstrate that these quantities cannot be simultaneously optimized in realistic models, creating Pareto frontiers that define the achievable parameter space. Our results show that QD chains achieve both comparable quality as nanowires and a regime with a much shorter localization length, making them particularly promising for near-term quantum computing applications where device length and disorder are limiting factors.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
Superfluidity in Fermi systems within the framework of Density Functional Theory
New Submission | Superconductivity (cond-mat.supr-con) | 2025-10-10 20:00 EDT
This review is based on lectures given by the author at the Enrico Fermi Summer School in Varenna. It presents the basics of Density Functional Theory (DFT) for Fermi superfluids, with particular emphasis on nuclear systems. Special attention is given to the foundations of both DFT and time-dependent DFT (TDDFT). The review explores the advantages and challenges involved in the practical application of TDDFT to superfluid systems, as well as the typical approximations employed. Various applications of the TDDFT framework to the description of phenomena related to nonequilibrium superfluidity in atomic nuclei, neutron stars, and ultracold atoms are discussed.
Superconductivity (cond-mat.supr-con), Quantum Gases (cond-mat.quant-gas), Nuclear Theory (nucl-th)
37 pages, 6 figures
From two dimensions to wire networks in a dice-lattice Josephson array
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2025-10-10 20:00 EDT
J. D. Bondar, L. Banszerus, W. Marshall, T. Lindemann, T. Zhang, M. J. Manfra, C. M. Marcus, S. Vaitiekėnas
We investigate Josephson arrays consisting of a dice-lattice network of superconducting weak links surrounding rhombic plaquettes of proximitized semiconductor. Josephson coupling of the weak links and electron density in the plaquettes are independently controlled by separate electrostatic gates. Applied magnetic flux results in an intricate pattern of switching currents associated with frustration, $ f$ . For depleted plaquettes, the switching current is nearly periodic in $ f$ , expected for a phase-only description, while occupied plaquettes yield a decreasing envelope of switching currents with increasing $ f$ . A model of flux dependence based on ballistic small-area junctions and diffusive large-area plaquettes yields excellent agreement with experiment.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
9 pages, 4+6 figures
Bayesian Optimization of Multi-Bit Pulse Encoding in In2O3/Al2O3 Thin-film Transistors for Temporal Data Processing
New Submission | Disordered Systems and Neural Networks (cond-mat.dis-nn) | 2025-10-10 20:00 EDT
Javier Meza-Arroyo, Benius Dunn, Weijie Xu, Yu-Chieh Chen, Jen-Sue Chen, Julia W.P. Hsu
Utilizing the intrinsic history-dependence and nonlinearity of hardware, physical reservoir computing is a promising neuromorphic approach to encode time-series data for in-sensor computing. The accuracy of this encoding critically depends on the distinguishability of multi-state outputs, which is often limited by suboptimal and empirically chosen reservoir operation conditions. In this work, we demonstrate a machine learning approach, Bayesian optimization, to improve the encoding fidelity of solution-processed Al2O3/In2O3 thin-film transistors (TFTs). We show high-fidelity 6-bit temporal encoding by exploring five key pulse parameters and using the normalized degree of separation (nDoS) as the metric of output state separability. Additionally, we show that a model trained on simpler 4-bit data can effectively guide optimization of more complex 6-bit encoding tasks, reducing experimental cost. Specifically, for the encoding and reconstruction of binary-patterned images of a moving car across 6 sequential frames, we demonstrate that the encoding is more accurate when operating the TFT using optimized pulse parameters and the 4-bit optimized operating condition performs almost as well as the 6-bit optimized condition. Finally, interpretability analysis via Shapley Additive Explanations (SHAP) reveals that gate pulse amplitude and drain voltage are the most influential parameters in achieving higher state separation. This work presents the first systematic method to identify optimal operating conditions for reservoir devices, and the approach can be extended to other physical reservoir implementations across different material platforms.
Disordered Systems and Neural Networks (cond-mat.dis-nn), Materials Science (cond-mat.mtrl-sci), Machine Learning (cs.LG)
Electric susceptibility of antiferromagnetic multiferroics with cycloidal spin order at magnetoelectric effect associated with collinear component of spins
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-10-10 20:00 EDT
The contribution of magnetoelectric effect to Landau–Lifshitz-Gilbert equation is considered in case when medium polarization is caused by parallel component of neighboring spins. The result is presented for ferromagnetic and antiferromagnetic materials. A comparison is given with the contribution of magnetoelectric effect to Landau–Lifshitz-Gilbert equation when medium polarization is caused by perpendicular component of spins. The dispersion dependence of spin waves in antiferromagnets with cycloidal equilibrium spin order is derived. The electric susceptibility and permittivity of antiferromagnetic multiferroics in which magnetoelectric effect is caused by collinear component of spins is obtained analytically.
Materials Science (cond-mat.mtrl-sci)
8 pages
Effects of skewing collision cells on transport properties in multiparticle collision dynamics simulations
New Submission | Soft Condensed Matter (cond-mat.soft) | 2025-10-10 20:00 EDT
Jinny Cha, Wilfred Kwabena Darko, Jeremy C. Palmer, Michael P. Howard
Multiparticle collision dynamics (MPCD) is a mesoscale simulation technique that uses a simplified solvent to model hydrodynamic interactions. Rather than interact through pairwise forces, MPCD solvent particles undergo momentum-exchanging collisions within spatially localized cells according to prescribed rules. The conventional MPCD algorithm employs cubic collision cells, but this choice is not optimal for systems that are most naturally described using skewed simulation boxes. Here, we investigate the behavior of a modified MPCD scheme in which the collision cells are aligned with the vectors that define a triclinic (parallelepiped) simulation box. We find that skewing the collision cells has a small but statistically significant impact on the transport properties of the pure solvent. Similar, but more pronounced, effects are found for nearly hard spheres in solution, including a significant decrease in their nominal self-diffusion coefficient and unphysical anisotropy in their self-diffusion tensor. Thus, our analysis indicates that skewed MPCD collision cells may result in spurious behavior and should be used with caution. We posit that these artifacts may be mitigated by grid-free schemes for placing particles into collision cells.
Soft Condensed Matter (cond-mat.soft)
Quantum Filtering of Hydrogen Isotopes through Graphene
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2025-10-10 20:00 EDT
Joshua Hale, Theja N. De Silva
Driven by the growing demand in the energy, medical, and industrial sectors, we investigate a hydrogen isotope separation technique that offers both a high separation factor and economic feasibility. Our findings reveal that filtering isotopes through two-dimensional graphene layers provides an exceptionally efficient quantum-mechanical method for isotope separation. Using a recently developed analytical pairwise potential between hydrogen isotopes and carbon atoms in graphene, we examine the classical trajectories of isotopes near the graphene layer, as well as the quantum-mechanical tunneling properties of isotopes through the graphene layer. Using various quantum-mechanical methods, we calculate both the isotope tunneling probabilities and the quantum-mechanical isotope sticking probabilities. Our study shows that quantum filtering through graphene layers can be an effective technique for enriching deuterium by separating it from protium.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Materials Science (cond-mat.mtrl-sci), Quantum Physics (quant-ph)
10 pages with 11 figures
J. Appl. Phys. 138, 144301 (2025)
Ultrathin bismuth-yttrium iron garnet films with tunable and compensated magnetic anisotropy
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-10-10 20:00 EDT
Hanchen Wang, William Legrand, Davit Petrosyan, Min-Gu Kang, Emir Karadža, Hiroki Matsumoto, Richard Schlitz, Michaela Lammel, Myriam H. Aguirre, Pietro Gambardella
We report on the epitaxial growth of nm-thick films of bismuth-substituted yttrium iron garnet (BiYIG) by high-temperature off-axis radio-frequency magnetron sputtering. We demonstrate accurate control of the magnetic properties by tuning of the sputtering parameters and epitaxial strain on various (111)-oriented garnet substrates. BiYIG films with up to -0.80% lattice mismatch with the substrate remain fully strained up to 60nm-thick, maintaining a high crystalline quality. Transmission electron microscopy and energy-dispersive X-ray spectroscopy confirm coherent epitaxial growth, the absence of defects, and limited interdiffusion at the BiYIG/substrate interface. Varying the tensile or compressive strain between -0.80% and +0.56% in BiYIG allows for accurate compensation of the total magnetic anisotropy through magneto-elastic coupling. The effective magnetic anisotropy of sputtered BiYIG films can be further tuned via the off-axis deposition angle and the oxygen flow during growth, which determine the cation stoichiometry. Under optimized growth conditions, a ferromagnetic resonance (FMR) linewidth of 1mT at 10GHz is reliably obtained even for thicknesses as low as 10nm. We also report small FMR linewidths in ultrathin (2-5~nm) BiYIG films grown on diamagnetic substrate yttrium scandium gallium garnet. These findings highlight the promise of low-damping, strain-engineered nm-thick BiYIG films for implementing advanced functionalities in spin-orbitronic and magnonic devices. Specifically, the magnetic-anisotropy compensation and low damping enable large cone-angle magnetization dynamics immune to magnon-magnon nonlinear scattering.
Materials Science (cond-mat.mtrl-sci), Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
Dissipative Generation of Currents by Nonreciprocal Local and Global Environments
New Submission | Quantum Gases (cond-mat.quant-gas) | 2025-10-10 20:00 EDT
We investigate the mechanisms necessary for the stabilization of complex quantum correlations by exploring dissipative couplings to nonreciprocal reservoirs. We analyze the role of locality in the coupling to the environment of the quantum system of interest, as we consider either local couplings throughout the system, or a single global coupling. We contrast the results obtained for two scenarios in which a chain of strongly interacting hardcore bosonic atoms is coupled directly to Markovian kinetic dissipative processes, or experiences effective dissipation through the mediation of the field of a lossy optical cavity. To investigate the dissipative dynamics of the many-body quantum systems considered we perform numerical simulations employing matrix product states numerical methods. We show that by coupling atomic tunneling terms to the global field of a dissipative cavity we can stabilize at long times both finite currents and current-current correlations throughout the atomic chain. This is in contrast to the setup in which dissipation acts directly via local tunneling processes, where currents arise in a small portion of the system and the current-current correlations are rapidly decaying.
Quantum Gases (cond-mat.quant-gas), Quantum Physics (quant-ph)
Efficiency of the superconducting diode effect of pair-density-wave states in two-dimensional $d$-wave altermagnets
New Submission | Superconductivity (cond-mat.supr-con) | 2025-10-10 20:00 EDT
Igor de M. Froldi, Hermann Freire
We systematically study the efficiency of the intrinsic superconducting diode effect of several pair-density-wave states that can emerge in two-dimensional $ d$ -wave metallic altermagnets. To this end, we investigate several scenarios using an effective minimal microscopic model and Ginzburg-Landau analysis in order to derive the corresponding pairing phase diagrams. In addition, we examine also whether the presence of a Rashba spin-orbit coupling and an applied external magnetic field are beneficial to this effect in these systems. As a consequence, our results add further support to the fact that altermagnetic materials indeed provide a good platform for the pursuit of finite-momentum superconductivity, which can lead to an optimization of the diode efficiency in some physically interesting situations. The latter phenomenon has been recently proposed to be key in improving the applicability of new energy-efficient quantum electronic devices.
Superconductivity (cond-mat.supr-con), Strongly Correlated Electrons (cond-mat.str-el)
14 pages, 6 figures
Thermodynamically Consistent Continuum Theory of Magnetic Particles in High-Gradient Fields
New Submission | Statistical Mechanics (cond-mat.stat-mech) | 2025-10-10 20:00 EDT
Marko Tesanovic, Daniel M. Markiewitz, Marcus L. Popp, Martin Z. Bazant, Sonja Berensmeier
Magnetic particles underpin a broad range of technologies, from water purification and mineral processing to bioseparations and targeted drug delivery. The dynamics of magnetic particles in high-gradient magnetic fields-encompassing both their transport and eventual capture-arise from the coupled interplay of field-driven drift, fluid advection, and particle-field feedback. These processes remain poorly captured by existing models relying on empirical closures or discrete particle tracking. Here, we present a thermodynamically consistent continuum theory for collective magnetic particle transport and capture in high-gradient fields. The framework derives from a free-energy functional that couples magnetic energy, entropic mixing, and steric interactions, yielding a concentration-dependent susceptibility via homogenization theory. The resulting equations unify magnetism, mass transport, and momentum balances without ad hoc shut-off criteria, allowing field shielding, anisotropic deposition, and boundary-layer confinement to emerge naturally. Simulations predict canonical capture morphologies-axially aligned plumes, crescent-shaped deposits, and nonlinear shielding-across field strengths and flow regimes, consistent with trends reported in prior experimental and modeling studies. By organizing captured particle mass data into a dimensionless phase diagram based on the Mason number, we reveal three distinct regimes-thermodynamically controlled, transitional, and dynamically controlled. This perspective provides a predictive platform for in silico optimization and extension to three-dimensional geometries, and informing digital twin development for industrial-scale high-gradient magnetic separation processes.
Statistical Mechanics (cond-mat.stat-mech), Fluid Dynamics (physics.flu-dyn)
Anomalous proteinaceous shells with octagonal local order
New Submission | Soft Condensed Matter (cond-mat.soft) | 2025-10-10 20:00 EDT
Sergei B. Rochal, Aleksey S. Roshal, Olga V. Konevtsova, Rudolf Podgornik
Proteinaceous shells useful for various biomedical applications exhibit a wide range of anomalous structures that are fundamentally different from icosahedral viral capsids described by the Caspar-Klug paradigmatic model. Exploring the Protein Data Bank, we have identified nine different types of anomalous shells structurally close to flat octagonal quasicrystals. As we show, these numerous shells have cubic nets cut from short-period approximants of an octagonal tiling composed of square and rhombic tiles. The approximants and parent tiling are easily obtained within the Landau density wave approach, while the nonequilibrium assembly of them can be simulated using the pair potentials derived from critical density waves. Gluing a polyhedron net and mapping it onto a spherical surface induces tile distortions, and to reduce them, we introduce and minimize the effective elastic energy of the system. Thus, we return quasi-equivalence to previously equivalent tiles. Possible cubic faceting of the octagonal spherical tilings is discussed in terms of the topological charge distribution over the tiling vertices. The proposed structural models describe numerous proteinaceous shells including about half of the known symmetrical enzymes. Our results constitute a fundamental basis for further applications of identified octagonal assemblies and can help to discover and study similar systems in the future.
Soft Condensed Matter (cond-mat.soft), Biological Physics (physics.bio-ph)
12 pages, 6 figures, accepted to Phys. Rev. E
What is the most optimal diffusion?
New Submission | Statistical Mechanics (cond-mat.stat-mech) | 2025-10-10 20:00 EDT
What is the fastest possible “diffusion”? A trivial answer would be “a process that converts a Dirac delta-function into a uniform distribution infinitely fast”. Below, we consider a more reasonable formulation: a process that maximizes differential entropy of a probability density function (pdf) $ f(\vec{x}, t)$ at every time $ t$ , under certain restrictions. Specifically, we focus on a case when the rate of the Kullback-Leibler divergence $ D_{\text{KL}}$ is fixed. If $ \Delta(\vec{x}, t, d{t}) = \frac{\partial f}{ \partial t} d{t}$ is the pdf change at a time step $ d{t}$ , we maximize the differential entropy $ H[f + \Delta]$ under the restriction $ D_{\text{KL}}(f + \Delta || f) = A^2 d{t}^2$ , $ A = \text{const} > 0$ . It leads to the following equation: $ \frac{\partial f}{ \partial t} = - \kappa f (\ln{f} - \int f \ln{f} d{\vec{x}})$ , with $ \kappa = \frac{A}{\sqrt{ \int f \ln^2{f} d{\vec{x}} - \left( \int f \ln{f} d{\vec{x}} \right)^2 } }$ . Notably, this is a non-local equation, so the process is different from the Itô diffusion and a corresponding Fokker-Planck equation. We show that the normal and exponential distributions are solutions to this equation, on $ (-\infty; \infty)$ and $ [0; \infty)$ , respectively, both with $ \text{variance} \sim e^{2 A t}$ , i.e. diffusion is highly anomalous. We numerically demonstrate for sigmoid-like functions on a segment that the entropy change rate $ \frac{d H}{d t}$ produced by such an optimal “diffusion” is, as expected, higher than produced by the “classical” diffusion.
Statistical Mechanics (cond-mat.stat-mech)
Nonreciprocal Spin-Wave Dynamics in Crescent-Shaped Ferromagnetic Nanowires
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2025-10-10 20:00 EDT
Uladzislau Makartsou, Mateusz Gołębiewski, Attila Kákay, Olena Tartakivska, Maciej Krawczyk
Recent progress in the study of spin-wave propagation in ferromagnetic waveguides has highlighted the role of nonreciprocity arising from both the interfacial Dzyaloshinskii-Moriya interaction and the chiral nature of dipolar interactions. In this paper, we examine how a nanowire with a crescent-shaped cross-section affects spin-wave propagation along its long axis when a bias magnetic field is applied perpendicular to the axis. Employing micromagnetic simulations supported by analytical modeling, we systematically analyze the effects of geometry and external magnetic field strength on the magnetization dynamics and spin-wave amplitude distribution. The results demonstrate that these factors modify the dispersion relation of spin waves and influence its nonreciprocity, which can vary depending on the mode type. This work advances the fundamental understanding of spin-wave dynamics in curved geometries and offers new perspectives for designing magnonic waveguides with tailored properties.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
Quantizing Bosonized Fermi Surfaces
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2025-10-10 20:00 EDT
Sihan Chen, Luca V. Delacretaz
Bosonization describes Fermi surface dynamics in terms of a collective field that lives on a part of phase space. While sensible semiclassically, the challenge of treating such a field quantum mechanically has prevented bosonization from providing as powerful a nonperturbative tool as in one dimension. We show that general Fermi surfaces can be exactly described by a particular $ N\to \infty$ limit of a $ U(N)_1$ WZW model, with a tower of irrelevant corrections. This matrix-valued description encodes the noncommutative nature of phase space, and its (solvable) strongly coupled dynamics resolves the naive overcounting of degrees of freedom of the collective field without the need to cut the Fermi surface into patches. This approach furthermore provides a quantitative tool to systematically study power-law corrections to Fermi surface dynamics.
Strongly Correlated Electrons (cond-mat.str-el), High Energy Physics - Theory (hep-th)
45 pages, 5 figures
Magnetotransport in Topological Materials and Nonlinear Hall Effect via First-Principles Electronic Interactions and Band Topology
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-10-10 20:00 EDT
Dhruv C. Desai, Lauren A. Tan, Jin-Jian Zhou, Shiyu Peng, Jinsoo Park, Marco Bernardi
Topological effects arising from the Berry curvature lead to intriguing transport signatures in quantum materials. Two such phenomena are the chiral anomaly and nonlinear Hall effect (NLHE). A unified description of these transport regimes requires a quantitative treatment of both band topology and electron scattering. Here, we show accurate predictions of the magnetoresistance in topological semimetals and NLHE in noncentrosymmetric materials by solving the Boltzmann transport equation (BTE) with electron-phonon ($ e$ -ph) scattering and Berry curvature computed from first principles. We apply our method to study magnetotransport in a prototypical Weyl semimetal, TaAs, and the NLHE in strained monolayer WSe$ _2$ , bilayer WTe$ _2$ and bulk BaMnSb$ _2$ . In TaAs, we find a chiral contribution to the magnetoconductance which is positive and increases with magnetic field, consistent with experiments. We show that $ e$ -ph interactions can significantly modify the Berry curvature dipole and its dependence on temperature and Fermi level, highlighting the interplay of band topology and electronic interactions in nonlinear transport. The computed nonlinear Hall response in BaMnSb$ _2$ is in agreement with experiments. By adding the Berry curvature to first-principles transport calculations, our work advances the quantitative analysis of a wide range of linear and nonlinear transport phenomena in quantum materials.
Materials Science (cond-mat.mtrl-sci)
8 pages, 3 figures
Magnetically Responsive Microprintable Soft Nanocomposites with Tunable Nanoparticle Loading
New Submission | Soft Condensed Matter (cond-mat.soft) | 2025-10-10 20:00 EDT
Rachel M. Sun, Andrew Y. Chen, Yiming Ji, Daryl W. Yee, Carlos M. Portela
Magnetic remote actuation of soft materials has been demonstrated at the macroscale using hard-magnetic particles for applications such as transforming materials and medical robots. However, due to manufacturing limitations, few microscale magnetically responsive devices exist – light-based additive manufacturing methods, which are ideal for realizing microscale features, struggle with light scattering induced by the magnetic particles. Moreover, large hard-magnetic microparticles prevent high-resolution features from being manufactured altogether, and soft-magnetic nanoparticles require impractically high loading and high magnetic gradients, incompatible with existing printing techniques. Among successfully fabricated microscale soft-magnetic composites, limited control over magnetic-particle loading, distribution, and matrix-phase stiffness has hindered their functionality. Here, we combine two-photon lithography with iron-oxide nanoparticle co-precipitation to fabricate 3D-printed microscale nanocomposites having features down to 8 um with spatially tunable nanoparticle distribution. Using uniaxial compression experiments and vibrating sample magnetometry, we characterize the mechanical and magnetic properties of the composite, achieving millimeter-scale elastic deformations. We control nanoparticle content by modulating laser power of the print to imbue complex parts with magnetic functionality, demonstrated by a soft robotic gripper and a bistable bit register and sensor. This approach enables precise control of structure and functionality, advancing the development of microscale metamaterials and robots with tunable mechanical and magnetic properties.
Soft Condensed Matter (cond-mat.soft)
28 pages, 6 figures, 6 supplementary figures
Unified microscopic theory of equilibrium thermodynamics and ion association in aqueous and non-aqueous electrolytes with explicit hard-core size
New Submission | Soft Condensed Matter (cond-mat.soft) | 2025-10-10 20:00 EDT
Within the framework of a functional integral formalism incorporating ionic charge and hard-core (HC) interactions on an equal footing, we formulate a unified theory of equilibrium thermodynamics and ion association in charged solutions. Via comparison with recent Monte-Carlo (MC) simulation results (J. Forsman et al., PCCP 26, 19921 (2024)), it is shown that our approach is able to predict with quantitative precision the pair distributions of monovalent ions with the typical hydrated sizes d = 3.0 A and 4.0 A up to the molar concentration ni = 2.0 M. Moreover, comparison with additional simulation data from the literature indicates that within the characteristic regime of ionic packing fraction eta <0.1, the formalism can accurately account for the ion size dependence of the excess energy and pressure from d = 14.3 A down to d = 1.6 A. Via the adjustment of the hydration radius, the theory can also reproduce the non-monotonic salt dependence of the experimentally measured osmotic coefficients of various aqueous and non-aqueous solutions. In accordance with AFM experiments involving non-aqueous electrolytes, the underlying sharp competition between the opposite charge attraction and the excluded volume constraint is shown to limit the occurrence of substantial ionic pair formation to the submolar concentration regime ni <50 mM; at larger concentrations, HC repulsion hinders ion association and results in the quasi-saturation of the pair fraction curves.
Soft Condensed Matter (cond-mat.soft)
Low-Temperature Skyrmions and Spiral Reorientation Processes in Chiral Magnets with Cubic Anisotropy: Guidelines for Bridging Theory and Experiment
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2025-10-10 20:00 EDT
A. O. Leonov, G. Gödecke, J. Grefe, S. Süllow, D. Menzel
We revisit the phenomenological Dzyaloshinskii framework, a central theoretical approach for describing magnetization processes in bulk chiral magnets, and demonstrate how magnetocrystalline cubic anisotropy reshapes the phase diagrams of states and provides the key mechanism stabilizing low-temperature skyrmion phases. We show that, for magnetic field directions along the easy anisotropy axes, the phase diagrams feature stable skyrmion pockets for both signs of the anisotropy constant. We further analyze the nature of the transitions at the critical field $ H_{c1}$ , associated with the reorientation of stable and metastable spirals along the field. We also examine the transition at $ H_{c2}$ , where the conical state closes into the homogeneous state accompanied by a deviation of the wave vector from the field direction. By mapping characteristic anisotropy-dependent parameters in the theoretical phase diagrams, we provide guidelines for connecting theory with experiment and for estimating the cubic anisotropy constant in Fe$ _{1-x}$ Co$ _x$ Si and MnSi. Our results indicate that samples Fe$ _{1-x}$ Co$ _x$ Si with small $ x \sim 0.1$ possess sufficiently strong cubic anisotropy to stabilize a low-temperature skyrmion phase. Overall, these theoretical findings establish a quantitative framework for predicting and interpreting skyrmion stability in other cubic helimagnets as well.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
13 pages, 8 figures
Superconducting meander-line surface coil for NMR spectroscopy of nanoscale thin films
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2025-10-10 20:00 EDT
Louis Beaudoin, Aimé Verrier, Youcef A. Bioud, Mathieu Massicotte, Bertrand Reulet, Jeffrey A. Quilliam
Nuclear magnetic resonance (NMR) spectroscopy is a powerful technique to study local magnetism in a variety of materials. However, the inherently low sensitivity of conventional inductively detected solid state NMR typically requires a large number of spins, reducing its applicability to two-dimensional (2D) materials and nanoscale thin films. To overcome this experimental challenge, we introduce a novel probe based on a superconducting meander-line surface coil that significantly enhances the NMR sensitivity for thin samples. Using a NbN meander with an optimized geometry, we demonstrate the sensitivity of this technique by detecting the NMR signal of a 150-nm-thick boron film containing only $ \sim 2\times10^{16}$ $ ^{11}$ B nuclear spins. Spin-echo measurements and theoretical modeling offer insight into the parameters limiting the coil’s performance. This work lays the foundation for developing highly sensitive NMR probes, potentially unlocking new opportunities for studying atomically thin materials.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
Submitted to Physical Review Applied
Thermoelectric Enhancement of Series-Connected Cross-Conjugated Molecular Junctions
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2025-10-10 20:00 EDT
We investigate the thermoelectric response of single-molecule junctions composed of acyclic cross-conjugated molecules, including dendralene analogues and related iso-poly(diacetylene) (iso-PDA) motifs, in which node-possessing repeat units are connected in series. Using many-body quantum transport theory, we show that increasing the number of repeat units leaves the fundamental gap essentially unchanged while giving rise to a split-node spectrum whose cumulative broadening dramatically enhances the thermopower. This form of quantum enhancement can exceed other interference-based mechanisms, such as the coalescence of nodes into a supernode, suggesting new opportunities for scalable quantum-interference-based materials. Although illustrated here with cross-conjugated systems, the underlying principles apply broadly to series-connected architectures hosting multiple interference nodes. Finally, we evaluate the scaling of the electronic figure of merit ZT and the maximum thermodynamic efficiency. Together, these results highlight the potential for split-node-based materials to realize quantum-enhanced thermoelectric response.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Materials Science (cond-mat.mtrl-sci), Other Condensed Matter (cond-mat.other), Chemical Physics (physics.chem-ph)
18 pages, 5 figures
Entropy 2025, 27(10), 1040
Chromium-doped uranium dioxide fuels: A review
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-10-10 20:00 EDT
Mack Wesley Cleveland, Andrew Nelson, Ericmoore Jossou
UO2 doped with parts per million Cr2O3 powder is considered a potential near term accident tolerant fuel candidate. Here, the results of decades of industry and academic research into Cr-doped UO2 are analyzed and their shortcomings are critiqued. Focusing on the incorporation mechanisms of Cr into the fuel matrix, we explore a mechanistic understanding of the characteristic properties of Cr-doped UO2, notably, enhanced fission gas retention attributed to enlarged grain sizes following sintering, along with marginal improvements in the thermophysical properties. The findings of recent X-ray Adsorption Near Edge Spectroscopy studies were compared and put into conversation with historic data regarding the incorporation of Cr in UO2. On the basis of defect mechanisms, the case is made for the substitutional incorporation of Cr governing the lattice solubility but not the enhanced U diffusivity. Instead, Cr/Cr2O3 redox chemistry in a well-defined oxygen potential explains the differences in the U diffusivity and O/M ratio. The primary mechanism of doping-enhanced grain growth is found to be liquid assisted sintering due to a CrO(l) eutectic phase at the grain boundaries. The role of inhomogeneities in Cr concentration in UO2 at various length scales across the materials microstructure is highlighted and connected to promising experimental and modeling work to fill in the gaps in the current understanding of Cr-doped UO2. The review ends with an outline of future works that combine meticulous irradiation studies and high resolution experiments with next generation modeling and simulations techniques empowered by machine learning advances to accelerate the fabrication and adoption of Cr-doped UO2 light water reactors.
Materials Science (cond-mat.mtrl-sci)
Surface band-selective moiré effect induces flat band in mixed-dimensional heterostructures
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2025-10-10 20:00 EDT
Shuming Yu, Zhentao Fu, Dingkun Qin, Enting Li, Hao Zhong, Xingzhe Wang, Keming Zhao, Shangkun Mo, Qiang Wan, Yiwei Li, Jie Li, Jianxin Zhong, Hong Ding, Nan Xu
In this work, we reveal a curious type of moiré effect that selectively modifies the surface states of bulk crystal. We synthesize mixed-dimensional heterostructures consisting of a noble gas monolayer grow on the surface of bulk Bi(111), and determine the electronic structure of the heterostructures using angle-resolved photoemission spectroscopy. We directly observe moiré replicas of the Bi(111) surface states, while the bulk states remain barely changed. Meanwhile, we achieve control over the moiré period in the range of 25 Å to 80 Å by selecting monolayers of different noble gases and adjusting the annealing temperature. At large moiré periods, we observe hybridization between the surface band replicas, which leads to the formation of a correlated flat band. Our results serve as a bridge for understanding the moiré modulation effect from 2D to 3D systems, and provide a feasible approach for the realization of correlated phenomena through the engineering of surface states via moiré effects.
Strongly Correlated Electrons (cond-mat.str-el), Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Materials Science (cond-mat.mtrl-sci)
5 pages, 4 figures
Probing Phase Diagrams of Ordered Two-Dimensional Ice
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-10-10 20:00 EDT
Bingzheng Wu, Jianming Wu, Sai Duan, Xin Xu
Water, a ubiquitous and fundamental substance, plays a critical role across a wide range of disciplines from physics and chemistry to biology and engineering. Despite theoretical predictions of several phases of two-dimensional (2D) ice confined between idealized hydrophobic walls, experimental validation has been limited to the square phase, whose structural origin remains controversial. Here, we propose a realistic nanoconfinement setup using wide-bandgap hexagonal boron nitride (h-BN) as the capping layer and Cu(111) as the substrate. This protocol enables scanning tunneling microscope (STM) to resolve the atomic-scale arrangement of water molecules beneath the h-BN layer, overcoming the limitations of conventional techniques. Simulated STM images unambiguously identify all ordered flat 2D ice phases, as well as coexisting phases, and effectively distinguish them from potential contaminants. These findings establish a robust framework for experiment to systematically probe the phase structures of 2D ice, opening an avenue for studying nanoconfined water under ambient conditions.
Materials Science (cond-mat.mtrl-sci), Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Applied Physics (physics.app-ph)
29 pages, 7 figures
Elucidation of the Correlation between Molecular Conformation and Shear Viscosity of Polymer Melts under Steady-State Shear Flow
New Submission | Soft Condensed Matter (cond-mat.soft) | 2025-10-10 20:00 EDT
Yuhi Sakamaki, Shota Goto, Kang Kim, Nobuyuki Matubayasi
The rheological behavior of polymer melts is strongly influenced by parameters such as chain length, chain stiffness, and architecture. In particular, shear thinning, characterized by a power-law decrease in shear viscosity with increasing shear rate, has been widely investigated through molecular dynamics simulations. A central question is the connection between molecular conformation under steady flow and the resulting shear-thinning response. In this study, we employ coarse-grained molecular dynamics simulations of linear and ring polymers with varying chain stiffness to examine this relationship, with chain conformations quantified by the gyration tensor. We identified a strong correlation between the velocity-gradient direction component of the gyration tensor and shear viscosity, which exhibits a clear scaling relationship. This indicates that chain extension along the velocity-gradient direction governs the effective frictional force. Notably, this behavior emerges as a general feature, independent of chain architecture and chain stiffness. In addition, shear viscosity was found to correlate with the component of the gyration tensor that is not directly influenced by advective effects of shear flow. Because advection is absent in the direction, polymer chains can be regarded as diffusing freely, and the extent of this diffusion appears to be controlled by the shear viscosity.
Soft Condensed Matter (cond-mat.soft)
6 pages, 5 figures
Dimension- and Facet-Dependent Altermagnetic Triferroics and Biferroics in CrSb
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-10-10 20:00 EDT
Altermagnets have recently garnered significant interest due to their vanishing net magnetic moment and non-relativistic momentum-dependent spin splitting. However, altermagnetic (AM) multiferroics especially triferroics remain scarce. We investigate the experimentally synthesized non-van der Waals CrSb as a model system to explore the effects of dimensionality and facet orientation on its ferroic properties. NiAs, MnP, wurtzite (WZ), zincblende (ZB), and rocksalt (RS) phases are considered. Using first-principles calculations, we predict the altermagnetism of CrSb in MnP phase which has comparable stability with experimental NiAs phase. Both NiAs- and MnP-phase (110) facets exhibit AM-ferroelastic (FC) biferroics, while the WZ-phase bulk and (001) facets host ferromagnetic (FM) or AM-ferroelectric (FE) biferroics. Notably, the WZ-phase (110) facets are identified as FM/AM-FE-FC triferroics, with moderate energy barriers of 0.129 and 0.363 eV atom-1 for FE and FC switching, respectively. Both FE and FC switching can reverse the AM spin splitting in antiferromagnetic (AFM) configurations while preserving the high spin polarization in FM states. The magnetic anisotropy is highly tunable, exhibiting either uniaxial or in-plane behavior depending on the phase, dimension, and facet. This work establishes a framework for designing AM multiferroics through polymorphic, dimensional, and facet engineering, offering promising avenues for multifunctional spintronic applications.
Materials Science (cond-mat.mtrl-sci), Computational Physics (physics.comp-ph)
31 pages, 12 figures
Chiral Edge Excitations of Fractional Chern Insulators
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2025-10-10 20:00 EDT
Xiao-Han Yang, Ji-Yao Chen, Xiao-Yu Dong
Edge excitations are the defining signature of chiral topologically ordered systems. In continuum fractional quantum Hall (FQH) states, these excitations are described by the chiral Luttinger liquid ($ \chi$ LL) theory. Whether this effective description remains valid for fractional Chern insulators (FCIs) on discrete lattices has been a longstanding open question. Here we numerically demonstrate that the charge-one edge spectral function of a $ \nu=1/2$ FCI on an infinitely long strip with width $ L_y=10$ quantitatively follows the predictions of $ \chi$ LL theory. The edge spectrum is gapless, chiral, and linear, with spectral weight increasing linearly with both momentum and energy. We further analyze the influence of lattice size, particle number, trapping potential, and charge sector of excitations on the edge properties. Our results establish a clear correspondence between lattice FCIs and continuum FQH systems and provide guidance for future experimental detection of chiral edge modes.
Strongly Correlated Electrons (cond-mat.str-el), Quantum Physics (quant-ph)
Non-Kramers State Transitions in a Synthetic Toggle Switch Biosystem
New Submission | Statistical Mechanics (cond-mat.stat-mech) | 2025-10-10 20:00 EDT
Jianzhe Wei, Jingwen Zhu, Pan Chu, Liang Luo, Xiongfei Fu
State transitions are fundamental in biological systems but challenging to observe directly. Here, we present the first single-cell observation of state transitions in a synthetic bacterial genetic circuit. Using a mother machine, we tracked over 1007 cells for 27 hours. First-passage analysis and dynamical reconstruction reveal that transitions occur outside the small-noise regime, challenging the applicability of classical Kramers’ theory. The process lacks a single characteristic rate, questioning the paradigm of transitions between discrete cell states. We observe significant multiplicative noise that distorts the effective potential landscape yet increases transition times. These findings necessitate theoretical frameworks for biological state transitions beyond the small-noise assumption.
Statistical Mechanics (cond-mat.stat-mech), Cell Behavior (q-bio.CB), Molecular Networks (q-bio.MN)
5 pages, 3 figures in main text; 17 pages, 15 figures in supplemental information
Phase-controlled quantum transport signatures in a quantum dot-Majorana hybrid ring system
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2025-10-10 20:00 EDT
Sirui Yu, Junrong Wang, Huajin Zhao, Hong Mao, Jinshuang Jin
We investigate the quantum transport in a hybrid ring system consisting of a quantum dot (QD) coupled to two Majorana bound states (MBSs) hosted in a topological superconducting nanowire, threaded by a magnetic flux. Utilizing the dissipaton equation-of-motion approach, we demonstrate that the differential conductance shows periodic behavior and its periodicity depends on both the QD energy level and the MBS overlapping. A zero-bias peak (ZBP) emerges as a result of the balance between normal and anomalous tunneling processes, associated with the presence of a single MBS. Beyond the phase-dependent periodic behavior, the shot noise exhibits voltage-dependent transitions between sub-Poissonian ($ F = 0.5$ ), Poissonian ($ F = 1$ ), and super-Poissonian ($ F > 1$ ) regimes. Strikingly, we find a giant Fano factor ($ F\gg1$ ) emerging at the balance point, accompanied by a peak in the shot noise. This distinctive feature may serve as a supplementary signature for MBS detection. However, both ZBP in the differential conductance and shot noise peak are degraded by thermal effects.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
11 pages, 4 figures
J. Chem. Phys. 163, 144103 (2025)
Three-Dimensional Electrostatic and Quantum-Confinement Modeling of Silicon Nanowire Double Quantum Dots
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2025-10-10 20:00 EDT
Nilesh Pandey, Dipanjan Basu, Leonard F Register, Sanjay K Banerjee
We present a three-dimensional simulation study of silicon nanowire double quantum dots with leads, which extends beyond traditional effective-mass or quasi-1D and quasi-2D approaches typically applied to bulk or planar geometries. Using the Sentaurus QTX, we self-consistently couple a 3-D Poisson solver with two-dimensional Schrödinger solutions along the strongly confined width \ast thickness cross-sections normal to the transport direction, yielding bound-state energies and wavefunctions across the device cross-section. This method captures wavefunction evolution, subband formation, and valley splitting while retaining the full three-dimensional electrostatics of the device. Our results show that narrow quantum dots (width = 5 nm) provide strong confinement, enhanced valley splitting, and robust single-electron localization, whereas wider quantum dots (width = 20 nm) allow single-electron occupation at lower gate voltages but with shallower quantum wells and additional higher-order modes in the wavefunction. Importantly, the quantum dot width also plays a key role in tunnel coupling: smaller channel widths enhance wavefunction overlap across the barrier, resulting in higher tunnel coupling, whereas increasing the width reduces coupling, which eventually saturates once the width is approximately twice the plunger-gate length. By systematically varying the quantum dot width together with plunger- and barrier-gate lengths, we investigate their combined influence on the conduction-band profile and interdot coupling. Together, these simulations provide design guidelines for geometry-driven control of confinement, valley splitting, and tunnel coupling in silicon nanowire double quantum dots.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Applied Physics (physics.app-ph)
Simultaneous optimization of assembly time and yield in programmable self-assembly
New Submission | Soft Condensed Matter (cond-mat.soft) | 2025-10-10 20:00 EDT
Maximilian C. Hübl, Carl P. Goodrich
Rational design strategies for self-assembly require a detailed understanding of both the equilibrium state and the assembly kinetics. While the former is starting to be well understood, the latter remains a major theoretical challenge, especially in programmable systems and the so-called semiaddressable regime, where binding is often nondeterministic and the formation of off-target structures negatively influences the assembly. Here, we show that it is possible to simultaneously sculpt the assembly outcome and the assembly kinetics through the underexplored design space of binding energies and particle concentrations. By formulating the assembly process as a complex reaction network, we calculate and optimize the tradeoff between assembly speed and quality, and show that parameter optimization can speed up assembly by many orders of magnitude without lowering the yield of the target structure. Although the exact speedup varies from design to design, we find the largest speedups for nondeterministic systems where unoptimized assembly is the slowest, sometimes even making them assemble faster than optimized fully-addressable designs. Therefore, these results not only solve a key challenge in semiaddressable self-assembly, but further emphasize the utility of semiaddressability, where designs have the potential to be faster as well as cheaper (fewer particle species) and better (higher yield). More broadly, our results highlight the importance of parameter optimization in programmable self-assembly, and provide practical tools for simultaneous optimization of kinetics and yield in a wide range of systems.
Soft Condensed Matter (cond-mat.soft)
On the decoherence of Majorana zero modes mediated by gapless fermions
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2025-10-10 20:00 EDT
Sauri Bhattacharyya, Marco Grilli, Bernard van Heck
We study the decoherence of a collection of Majorana zero modes weakly coupled to a gapless reservoir of non-interacting fermions. Using the Born-Markov approximation, we derive a Lindblad master equation for the dissipative dynamics of the Majorana zero modes. Due to the long-range coupling between Majorana zero modes mediated by the gapless reservoir, the Lindblad jump operators are non-local linear combinations of the Majorana operators. We show that, as a consequence, the dissipative dynamics can exhibit long relaxation times, i.e. a slow decay of fermion parities. A spectral analysis of the Liouvillian shows that the slow-down is suppressed as a power law of the distance between Majorana zero modes. Finally, we validate the Lindblad equation by comparison with unbiased numerical simulations of the time evolution of the full density matrix. In particular, these illustrate that non-Markovian dynamics establishes non-local correlations at small times.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
21 pages, 8 figures
Topological Magnon-Plasmon Hybrids
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2025-10-10 20:00 EDT
Tomoki Hirosawa, Pieter M. Gunnink, Alexander Mook
We study magnon-plasmon coupling in effectively two-dimensional stacks of van der Waals layers in the context of the band structure topology. Invoking the quasiparticle approximation, we show that the magnetic dipole coupling between the plasmons in a metallic layer and the magnons in a neighboring magnetic layer gives rise to a Berry curvature. As a result, the hybrid quasiparticles acquire an anomalous velocity, leading to intrinsic anomalous thermal Hall and spin-Nernst effects in ferromagnets and antiferromagnets. We propose magnetic layers supporting skyrmion crystals as a platform to realize chiral magnon-plasmon edge states, inviting the notion of topological magnon-plasmonics.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Strongly Correlated Electrons (cond-mat.str-el)
6+15 pages
Ergodicity Breaking and High-Dimensional Chaos in Random Recurrent Networks
New Submission | Disordered Systems and Neural Networks (cond-mat.dis-nn) | 2025-10-10 20:00 EDT
Carles Martorell, Rubén Calvo, Adrián Roig, Alessia Annibale, Miguel A. Muñoz
The neural model introduced by Sompolinsky, Crisanti, and Sommers (SCS) nearly four decades ago has become a paradigmatic framework for studying complex dynamics in random recurrent networks. In its original formulation, with balanced positive and negative couplings, the model exhibits two phases: a quiescent regime, where all activity ceases, and a regime of ongoing irregular collective activity, termed asynchronous chaos (AC), in which state variables fluctuate strongly in time and across units but average to zero across the network. Building on recent work, we analyze an extension of the SCS model that breaks this coupling balance, yielding a richer phase diagram. In addition to the classical quiescent and AC phases, two additional regimes emerge, marked by spontaneous symmetry breaking. In the persistent-activity (PA) phase, each unit settles into a distinct, stable activation state. In the synchronous-chaotic (SC) phase, dynamics remain irregular and chaotic but fluctuate around a nonzero mean, generating sustained long-time autocorrelations. Using analytical techniques based on dynamical mean-field theory, complemented by extensive numerical simulations, we show how structural disorder gives rise to symmetry and ergodicity breaking. Remarkably, the resulting phase diagram closely parallels that of the Sherrington-Kirkpatrick spin-glass model, with the onset of the SC phase coinciding with the transition associated with replica-symmetry breaking. All key features of spin glasses, including ergodicity breaking, have clear counterparts in this recurrent network context, albeit with crucial idiosyncratic differences, highlighting a unified perspective on complexity in disordered systems.
Disordered Systems and Neural Networks (cond-mat.dis-nn)
Modulating thermal conductivity of bulk BAs based on targeted phonon excitation
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-10-10 20:00 EDT
Tianhao Li, Yangjun Qin, Dongkai Pan, Han Meng, Nuo Yang
This study proposes a reversible phonon excitation strategy to dynamically modulate the thermal conductivity of boron arsenide (BAs), addressing the opposing thermal conductivity requirements in electronics and thermoelectrics. Using first-principles calculations and Boltzmann transport equation, we demonstrate that selective excitation of specific phonon modes enables active control over thermal transport. At an excitation multiplier of 25, the thermal conductivity of BAs can be enhanced by up to 2% or suppressed by up to 35% relative to its intrinsic value of 2235 W m^-1 K^-1. At a lower multiplier of 5, thermal conductivity can be increased by 2% or decreased by 11%. The modulation effect depends on excitation frequency, multiplier, and intrinsic phonon properties, with certain frequencies exhibiting opposite trends under different excitation intensities. Mechanistic analysis shows that at low excitation levels, phonon splitting suppresses Umklapp scattering, reducing the scattering rate, while at high levels, it enhances Normal scattering, increasing the scattering rate. This approach offers a dynamic and reversible route to tuning thermal conductivity, with applications in thermal management and thermoelectric energy conversion.
Materials Science (cond-mat.mtrl-sci), Computational Physics (physics.comp-ph)
Phase Transitions Without Instability: A Universal Mechanism from Non-Normal Dynamics
New Submission | Statistical Mechanics (cond-mat.stat-mech) | 2025-10-10 20:00 EDT
Virgile Troude, Didier Sornette
We identify a new universality class of phase transitions that arises in non-normal systems, challenging the classical view that transitions require eigenvalue instabilities. In traditional bifurcation theory, critical phenomena emerge when spectral stability is lost; here, we show that transitions can occur even when all equilibria are spectrally stable. The key mechanism is the transient amplification induced by non-orthogonal eigenvectors: noise-driven dynamics are enhanced not by lowering energy barriers, but by increasing the effective shear of the flow, which renormalizes fluctuations and acts as an emergent temperature. Once the non-normality index $ \kappa$ exceeds a critical threshold $ \kappa_c$ , stable equilibria lose practical relevance, enabling escapes and abrupt transitions despite preserved spectral stability. This pseudo-criticality generalizes Kramers’ escape beyond potential barriers, providing a fundamentally new route to critical phenomena. Its implications are broad: in biology, DNA methylation dynamics reconcile long-term epigenetic memory with rapid stochastic switching; in climate, ecology, finance, and engineered networks, abrupt tipping points can arise from the same mechanism. By demonstrating that phase transitions can emerge from non-normal amplification rather than eigenvalue instabilities, we introduce a predictive, compact framework for sudden transitions in complex systems, establishing non-normality as a defining principle of a new universality class of phase transitions.
Statistical Mechanics (cond-mat.stat-mech)
Short letter (8 pages, 1 box and 1 figure) + supplementary document of 21 pages and 5 figures
Higher-order epitaxy: A pathway to suppressing structural instability and emergent superconductivity
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-10-10 20:00 EDT
Yuki Sato, Soma Nagahama, Shunsuke Kitou, Hajime Sagayama, Ilya Belopolski, Ryutaro Yoshimi, Minoru Kawamura, Atsushi Tsukazaki, Naoya Kanazawa, Takuya Nomoto, Ryotaro Arita, Taka-hisa Arima, Masashi Kawasaki, Yoshinori Tokura
Molecular beam epitaxy enables the growth of thin film materials with novel properties and functionalities. Typically, the lattice constants of films and substrates are designed to match to minimise disorders and strains. However, significant lattice mismatches can result in higher-order epitaxy, where commensurate growth occurs with a period defined by integer multiples of the lattice constants. Despite its potential, higher-order epitaxy is rarely used to enhance material properties or induce emergent phenomena. Here, we report single-crystalline FeTe films grown via 6:5 commensurate higher-order epitaxy on CdTe(001) substrates. Scanning transmission electron microscopy reveals self-organised periodic interstitials near the interface, arising from higher-order lattice matching. Synchrotron x-ray diffraction shows that the tetragonal-to-monoclinic structural transition in bulk FeTe is strongly suppressed. Remarkably, these films exhibit substrate-selective two-dimensional superconductivity, likely due to suppressed monoclinic distortion. These findings demonstrate the potential of higher-order epitaxy as a tool to control materials and inducing emergent phenomena.
Materials Science (cond-mat.mtrl-sci), Strongly Correlated Electrons (cond-mat.str-el), Superconductivity (cond-mat.supr-con)
Compounding formula approach to chromatin and active polymer dynamics
New Submission | Soft Condensed Matter (cond-mat.soft) | 2025-10-10 20:00 EDT
Takahiro Sakaue, Enrico Carlon
Active polymers are ubiquitous in nature, and often kicked by persistent noises that break detailed balance. In order to capture the out-of-equilibrium dynamics of such active polymers, we propose a simple yet reliable analytical framework based on a compounding formula. Connecting polymeric dynamics to the isolated monomeric behavior via the notion of tension propagation, the formula allows us to clarify rich scaling scenarios alongside corresponding intuitive physical pictures. We demonstrate distinctive transient and steady-state scalings due to the non-Markovian nature of the active noise. Aside from a paradigmatic example of an active Rouse polymer, we expect the framework to be applicable to wide variety of spatially extended systems including more general polymers (crumpled globule, semiflexible polymers etc), fluctuation of growing interface, and an array of particles in single-file configuration.
Soft Condensed Matter (cond-mat.soft), Statistical Mechanics (cond-mat.stat-mech)
5 pages, 5 figures and SI file
Atomically resolved electron reflectivity at a metal/semiconductor interface
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2025-10-10 20:00 EDT
Ding-Ming Huang, Jian-Huan Wang, Jie-Yin Zhang, Yuan Yao, H. Q. Xu, Jian-Jun Zhang
An atomically flat interface is achieved between face-centered cubic Al and diamond lattice Ge via molecular beam epitaxy (MBE). Based on the measurements of scanning tunneling microscopy (STM), we demonstrate an atomically resolved lateral periodic change of the electron reflectivity at the Al/Ge interface. The variation of electron reflectivity is up to 24% in lateral 2 nm. We speculate that the change of reflectivity results from the local electronic states at the Al/Ge interface. This phenomenon provides an atomically non-destructive method for detecting the buried interfacial states in hetero-structures by STM.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Materials Science (cond-mat.mtrl-sci)
24 pages, 12 figures
Magnetic-Field Control of Tomonaga-Luttinger Liquids in Ta2Pd3Te5 Edge States
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2025-10-10 20:00 EDT
Xingchen Guo Anqi Wang, Xiutong Deng, Yupeng Li, Guoan Li, Zhiyuan Zhang, Xiaofan Shi, Xiao Deng, Ziwei Dou, Guangtong Liu, Fanming Qu, Zhijun Wang, Tian Qian, Youguo Shi, Li Lu, Jie Shen
Ta2Pd3Te5 is a quasi-one-dimensional transition-metal telluride whose heavy atoms endow the material with strong spin-orbit coupling, while the Fermi level inside the bulk gap makes the low-energy electronic structure highly this http URL and early experiments have already identified a wealth of emergent phases in this platform: an excitonic insulator driven by electron-hole binding, a second-order topological insulator protected by crystalline symmetry, a potential topological-protected quantum-spin-Hall edge, and proximity-induced edge supercurrents when coupled to a conventional s-wave superconductor. These properties make it a promising platform for hosting Majorana zero modes and quantum computation, provided that time-reversal symmetry can be broken by a Zeeman gap. In this work, we demonstrate that the one-dimensional edge channels of exfoliated Ta2Pd3Te5 host a robust and tunable Tomonaga-Luttinger liquid by electrostatic gating because it shifts the chemical potential across the bulk gap without changing the gap size. More importantly, the application of a magnetic field introduces a Zeeman gap that systematically increases the TLL power-law exponent alpha. Furthermore, rotating the field reveals a pronounced twofold anisotropy–alpha is maximal for a field parallel to the edge and minimal for a perpendicular orientation–originating from an orientation-dependent edge g-factor that is likely amplified by quantum-confinement-induced orbital-angular-moment quenching. The existence of gate-tunable edge supercurrents together with the field-controlled Zeeman gap provides a direct route to break time-reversal symmetry in a particle-hole-symmetric superconducting gap and thus to engineer a topological superconducting phase, paving the way towards Majorana-based quantum devices.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Materials Science (cond-mat.mtrl-sci)
Magnon-mediated Radiation and Phonon-driven Quenching of Excitons in a Layered Semiconductor
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-10-10 20:00 EDT
Yingchen Peng, Yanan Ge, Zihan Wang, Kang Wang, Kezhao Du, Xingzhi Wang, Ye Yang
Layered van der Waals (vdW) magnetic semiconductors open a new avenue for exploring intertwined excitonic and magnetic phenomena. Here, we investigate this interplay in the vdW MnPS3 antiferromagnet, uncovering an exceptionally long exciton lifetime (~100 {\mu}s) below the Néel temperature (T_N). We demonstrate that the exciton lifetime is governed by phonon-mediated nonradiative recombination and thus exhibits a strong temperature dependence. On the contrary, the radiative recombination rate shows a distinct temperature dependence, which is dominated by magnon-assisted emission mechanism below T_N and by short-range spin correlations and phonons above T_N. These findings not only establish MnPS3 as a compelling candidate for excitonic devices due to its long-lifetime and correlation with magnetic orders but also provide crucial insights into the interplay between excitons, spins, and lattice in vdW magnetic semiconductors.
Materials Science (cond-mat.mtrl-sci)
Gate Voltage Tunable Second Harmonic Generation in Mono- and Bi-layer Black Phosphene
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2025-10-10 20:00 EDT
Yan Meng, Kainan Chang, Yanyan Qian, Luxia Wang, Jin Luo Cheng
Black phosphorene (BP) has emerged as a promising platform for tunable nonlinear photonics due to its layer-dependent bandgap, high carrier mobility, and remarkable in-plane anisotropy. This study investigates the second-harmonic generation (SHG) of monolayer and bilayer BP under an external static electric field, with describing the electronic states by a tight-binding model and the dynamics by semiconductor Bloch equations. Our results reveal that BP exhibits large second-order nonlinear optical response along the armchair direction, with significant resonant enhancement when the incident photon energy approaches half of its bandgap. Under an applied electric field of $ 10^7$ V/m, the effective second-order nonlinear susceptibility of BP can be as large as $ 10^3$ pm/V, surpassing that of the conventional nonlinear crystal AgGaSe$ _2$ by more than an order of magnitude. With respect to the static electric field induced by gate voltage, we discuss the relation between the electric-field-induced second harmonic (EFISH) generation and conventional SHG – under lower gate voltage, the EFISH approach agrees well with the SHG solutions, whereas the former is no longer applicable under higher gate voltage. Specifically, as the increasing gate voltage, monolayer BP exhibits the bandgap expansion and the corresponding blue-shift in the SHG resonant peak. In contrast, bilayer BP undergoes a semiconductor-to-semimetal transition, forming Dirac cone and generating divergent SHG spectra as photon energy goes to zero. Additionally, the chemical potential allows for precise control over interband and intraband nonlinear responses. This work provides important theoretical foundations for the development of BP-based tunable nonlinear photonic devices and expands the application potential of anisotropic two-dimensional materials in nonlinear optics.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
Twist-tuned exchange and hysteresis in a bilayer van der Waals magnet
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-10-10 20:00 EDT
Priyanka Mondal, Sonu Verma, Wenze Lan, Lukas Krelle, Ryan Tan, Regine von Klitzing, Kenji Watanabe, Takashi Taniguchi, Kseniia Mosina, Zdenek Sofer, Akashdeep Kamra, Bernhard Urbaszek
Moiré superlattices in twisted bilayers enable profound reconstructions of the electronic bandstructure, giving rise to correlated states with remarkable tunability. Extending this paradigm to van der Waals magnets, twisting creates spatially varying interlayer exchange interactions that stabilize emergent spin textures and the coexistence of ferromagnetic and antiferromagnetic domains. Here, we demonstrate the emergence of robust magnetic hysteresis in bilayer CrSBr upon twisting by an angle of ~ 3°. This is observed as the corresponding hysteretic evolution of the exciton energy, that directly correlates with the bilayer magnetic state, in magnetic field dependent photoluminescence measurements. A two-sublattice model captures this behavior, attributing it to the twist-induced reduction of interlayer exchange that stabilizes both parallel and antiparallel spin configurations across a broad field range. Comparison with experiment enables quantitative extraction of the effective exchange strength. Remarkably, the system exhibits coherent averaging across the moiré supercell, yielding an effective monodomain response characterized by switching into the antiferromagnetic state, rather than forming spin textures or fragmented domains. Spatially resolved measurements further uncover local variations in hysteresis loops, consistent with position-dependent modulation of the average exchange interaction. Our results establish twist engineering as a powerful route to programmable magnetic memories in two-dimensional magnets, harnessing the robustness of antiferromagnetic order.
Materials Science (cond-mat.mtrl-sci)
Main and Supplement
Exact solution for the current generated by dissipative master equation in single-band tight-binding systems subject to time-dependent uniform electric fields
New Submission | Statistical Mechanics (cond-mat.stat-mech) | 2025-10-10 20:00 EDT
J. M. Alendouro Pinho, B. Amorim, J. M. Viana Parente Lopes
The theory of open quantum systems is one of the most essential tools for the development of quantum technologies. A particular area of interest is in the optical response of solid state systems, where dissipation is introduced phenomenologically through the relaxation time approximation and its effects are usually gauged perturbatively. Analytical exact results for driven systems under this approximation are scarce and tipically pertain only to the stationary regime. Here, we obtain the analytical solution for the current response of general single-band tight-binding system driven by a uniform electric field with generic time-dependence under the relaxation time approximation. We explore the effects of dissipation in two limiting cases: A monochromatic field, where we analytically deduce the effect of dissipation on High Harmonic Generation, and a constant electric field, where a generalization for the Esaki-Tsu equation is presented for any single-band tight-binding system. We specify the results for a simple 2D nearest neighbours tight-binding lattice to emphasize the effect of the scale competition introduced by the two different neighbours in both the monochromatic and constant field cases. Finally, we compare our exact result for the constant field to the one obtained from the usual perturbation theory calculation to probe the validity of the latter.
Statistical Mechanics (cond-mat.stat-mech)
12 pages, 6 figures
Finite element models for Self-Deployable Miura-folded origami
New Submission | Soft Condensed Matter (cond-mat.soft) | 2025-10-10 20:00 EDT
Suraj Singh Gehlot, Siddhanth Gautam, Sanhita Das
Origami-inspired self-deployable structures offer lightweight, compact, and autonomous deployment capabilities, making them highly attractive for aerospace and defence applications, such as solar panels, antennas, and reflector systems. This paper presents finite element frameworks for simulating Miura-origami units in ABAQUS, focusing on two deployment mechanisms: elastic strain energy release and thermally activated shape-memory polymers (SMPs). Validation against experimental data for elastic deployment demonstrates that the model accurately captures fold trajectories and overall kinematics. Parametric studies reveal the influence of hinge stiffness and damping on deployment efficiency. SMP-based simulations qualitatively reproduce stress-strain-temperature behaviour and realistic shape recovery ratios. The study establishes that predictive numerical models can effectively guide the design of origami-based deployable structures for aerospace and defence applications, while highlighting the challenges associated with hinge modelling, damping effects, and thermomechanical actuation.
Soft Condensed Matter (cond-mat.soft)
Amplification and Detection of Single Itinerant Microwave Photons
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2025-10-10 20:00 EDT
Lukas Danner (1 and 2), Max Hofheinz (3), Nicolas Bourlet (3), Ciprian Padurariu (2), Joachim Ankerhold (2), Björn Kubala (1 and 2) ((1) German Aerospace Center (DLR), Institute of Quantum Technologies, Ulm, Germany, (2) Institute for Complex Quantum Systems and IQST, University of Ulm, Ulm, Germany, (3) Institut Quantique, Université de Sherbrooke, Sherbrooke, Québec, Canada)
Single-photon detectors are an essential part of the toolbox of modern quantum optics for implementing quantum technologies and enabling tests of fundamental physics. The low energy of microwave photons, the natural signal path for superconducting quantum devices, makes their detection much harder than for visible light. Despite impressive progress in recent years and the proposal and realization of a number of different detector architectures, the reliable detection of a single itinerant microwave photon remains an open topic.
Here, we investigate and simulate a detailed protocol for single-photon multiplication and subsequent amplification and detection. At its heart lies a Josephson-photonics device which uses inelastic Cooper-pair tunneling driven by a dc bias in combination with the energy of an incoming photon to create multiple photons, thus compensating for the low-energy problem. Our analysis provides clear design guidelines for utilizing such devices, which have previously been operated in an amplifier mode with a continuous wave input, for counting photons. Combining a formalism recently developed by Mølmer to describe the full quantum state of in- and outgoing photon pulses with stochastic Schrödinger equations, we can describe the full multiplication and detection protocol and calculate performance parameters, such as detection probabilities and dark count rates. With optimized parameters, a high population of a single output mode can be achieved that can then be easily distinguished from vacuum noise in heterodyne measurements of quadratures with a conventional linear amplifier. Realistic devices with two multiplication stages with multiplication of $ 16$ reach for an impinging Gaussian pulse of length $ T$ a detection probability of $ 84.5%$ with a dark count rate of $ 10^{-3}/T$ , and promise to outperform competing schemes.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Superconductivity (cond-mat.supr-con), Quantum Physics (quant-ph)
15 pages, 9 figures
Far-field radiation of bulk, edge and corner eigenmodes from a finite 2D Su-Schrieffer-Heeger plasmonic lattice
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2025-10-10 20:00 EDT
Álvaro Buendía, José Luis Pura, Vincenzo Giannini, José Antonio Sánchez Gil
Subwavelength arrays of plasmonic nanoparticles allow us to control the behaviour of light at the nanoscale. Here, we develop an eigenmode analysis, employing a coupled electromagnetic dipole formalism, which permits us to isolate the contribution to the far-field radiation of each array mode. Specifically, we calculate the far-field radiation patterns by bulk, edge and corner out-of-plane eigenmodes in a finite 2D Su-Schrieffer-Heeger (SSH) array of plasmonic nanoparticles with out-of-plane dipolar resonances. The breaking of symmetries in multipartite unit cells is exploited to tailor the optical properties and far-field radiation of the resonant modes. We prove that the antisymmetric modes are darker and have higher Q-factors than their symmetric counterparts. Also, the out-of-plane nature of the dipolar resonances imposes that all bulk $ \Gamma$ -modes are dark, while corner and edge states need extra in-plane symmetries to cancel the far-field radiation; radiation patterns in turn become more complex and concentrated along the array plane with increasing array size.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Optics (physics.optics)
14 pages, 8 figures
Surface-Localized Magnetic Order in RuO2 Thin Films Revealed by Low-Energy Muon Probes
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2025-10-10 20:00 EDT
Akashdeep Akashdeep, Sachin Krishnia, Jae-Hyun Ha, Siyeon An, Maik Gaerner, Thomas Prokscha, Andreas Suter, Gianluca Janka, Günter Reiss, Timo Kuschel, Dong-Soo Han, Angelo Di Bernardo, Zaher Salman, Gerhard Jakob, Mathias Kläui
Ruthenium dioxide (RuO2) has recently emerged as a candidate altermagnet, yet its intrinsic magnetic ground state, particularly in thin films, remains debated. This study aims to clarify the nature and spatial extent of the magnetic order in RuO2 thin films grown under different conditions. Thin films of RuO2 with thicknesses of 30 nm and 33 nm are fabricated by pulsed laser deposition and sputtering onto TiO2(110) and Al2O3(1-102) substrates, respectively. Low-energy muon spin rotation/relaxation (LE-muSR) with depth-resolved sensitivity measurements is performed in transverse magnetic fields (TF) from 4 K to 290 K. The muSR data collected with a muon implantation energy of 1 keV reveal that magnetic signals originate from the near-surface region of the film (<10 nm), and the affected volume fraction is at most about 8.5%. The localized magnetic response is consistent across different substrates, growth techniques, and parameter sets, suggesting a common origin related to surface defects and dimensionality effects. The combined use of TF-muSR and the study of depth-dependent implantation with low-energy muons provides direct evidence for surface-confined, inhomogeneous static magnetic order in RuO2 thin films, helping reconcile discrepancies. These findings underscore the importance of considering reduced-dimensional contributions and motivate further investigation into the role of defects, strain, and stoichiometry on the magnetic properties of RuO2, especially at the surface.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Materials Science (cond-mat.mtrl-sci)
Faraday patterns, spin textures, spin-spin correlations and competing instabilities in a driven spin-1 antiferromagnetic Bose-Einstein condensate
New Submission | Quantum Gases (cond-mat.quant-gas) | 2025-10-10 20:00 EDT
Vaishakh Kargudri, Sandra M. Jose, Rejish Nath
We study the formation of transient Faraday patterns and spin textures in driven quasi-one-dimensional and quasi-two-dimensional spin-1 Bose-Einstein condensates under the periodic modulation of $ s$ -wave scattering lengths $ a_0$ and $ a_2$ , starting from the anti-ferromagnetic phase. This phase is characterized by a Bogoliubov spectrum consisting of three modes: one mode is gapped, while the other two are gapless. When $ a_0$ is modulated and half of the modulation frequency lies below the gapped mode, density and spin Faraday patterns emerge. In that case, in quasi-one-dimension, the spin texture is characterized by periodic domains of opposite $ z$ -polarizations. When driven above the gap, the spin texture is characterized by random orientations of spin vectors along the condensate axis. Qualitatively new features appear in the driven quasi-two-dimensional condensate. For instance, when driven above the gap, the spin textures are characterized by anomalous vortices and antivortices that do not exhibit phase winding in individual magnetic components. Below the gap, the spin texture exhibits irregular ferromagnetic patches with opposite polarizations. The spatial spin-spin correlations in quasi-one-dimension exhibit a Gaussian envelope, whereas they possess a Bessel function dependence in quasi-two-dimension. Under the $ a_2$ -modulation, the density patterns dominate irrespective of the driving frequency, unless the spin-dependent interaction strength is sufficiently smaller than that of the spin-independent interaction. The intriguing scenario of competing instability can emerge when both scattering lengths are simultaneously modulated. Finally, we show that the competing instabilities result in a complex relationship between the population transfer and the strength of the quadratic Zeeman field, while keeping all other parameters constant.
Quantum Gases (cond-mat.quant-gas), Pattern Formation and Solitons (nlin.PS), Quantum Physics (quant-ph)
11 pages, 12 figures
Unveiling Intrinsic Triplet Superconductivity in Noncentrosymmetric NbRe through Inverse Spin-Valve Effects
New Submission | Superconductivity (cond-mat.supr-con) | 2025-10-10 20:00 EDT
F. Colangelo, M. Modestino, F. Avitabile, A. Galluzzi, Z. Makhdoumi Kakhaki, A. Kumar, J. Linder, M. Polichetti, C. Attanasio, C. Cirillo
NbRe is a non-centrosymmetric superconductor that has been proposed as a candidate for intrinsic spin-triplet pairing. However, a conclusive demonstration of triplet pairing in NbRe is yet to be found. To probe the presence of equal-spin triplet Cooper pairs, we fabricated Py/NbRe/Py trilayers capped with an antiferromagnetic layer. Magnetic and electrical measurements reveal an inverse spin-valve effect, which could indicate equal-spin triplet superconductivity. The minimal sample structure and the lack of ad hoc engineered interfaces clearly associate our observation to intrinsic triplet correlations of NbRe. The availability of NbRe in thin-film form and the simplicity of the heterostructure highlight its potential as a scalable platform for superconducting spintronics.
Superconductivity (cond-mat.supr-con)
Accepted for publication in Physical Review Letters
Rare-Earth Engineering of NaAlO3 Perovskites Unlocks Unified Optoelectronic, Thermoelectric, and Spintronic Functionalities
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-10-10 20:00 EDT
Muhammad Imran, Sikander Azam, Qaiser Rafiq, Amin Ur Rahman
Perovskite oxides are promising for energy and quantum technologies, but wide-gap hosts such as NaAlO3 suffer from deep-UV absorption and limited carrier transport. Using first-principles GGA+U+SOC calculations, we investigate Eu3+-, Gd3+-, and Tb3+-doped NaAlO3 and evaluate their electronic, optical, elastic, and thermoelectric properties. Rare-earth substitution is thermodynamically favorable (formation energies 1.2-1.6 eV) and induces strong f-p hybridization, reducing the pristine band gap (about 6.2 eV) to about 3.1 eV for Tb. Spin-resolved band structures reveal Gd-driven half-metallicity, Eu-induced spin-selective metallicity, and Tb-stabilized p-type semiconducting behavior. The optical spectra show a red-shifted absorption edge (about 2.0-2.2 eV), a large static dielectric response (epsilon1(0) about 95 for Eu), and plasmonic resonances near 4 eV, enabling visible-light harvesting. Elastic analysis indicates mild lattice softening with preserved ductility (Pugh ratio B/G about 1.56-1.57). Thermoelectric performance is enhanced, with Seebeck coefficients greater than 210 uV/K for Eu and Tb and ZT about 0.45 at 500 K. These results identify rare-earth-doped NaAlO3 as a multifunctional perovskite platform for photovoltaics, photocatalysis, thermoelectrics, and spintronics.
Materials Science (cond-mat.mtrl-sci), Computational Physics (physics.comp-ph)
Odd-frequency Pairing in Josephson Junctions Coupled by Magnetic Textures
New Submission | Superconductivity (cond-mat.supr-con) | 2025-10-10 20:00 EDT
Ignacio Sardinero, Jorge Cayao, Rubén Seoane Souto, Pablo Burset
Josephson junctions coupled through magnetic textures provide a controllable platform for odd-frequency superconductivity and Majorana physics. Within a tight-binding Green function framework, induced pair correlations and spectral properties are analyzed under various magnetic and geometric conditions. When the junction is in the topologically trivial regime, even-frequency singlet pairing is dominant, whereas the topological phase is characterized by the coexistence of Majorana bound states and robust odd-frequency equal-spin triplet pairing at the interface edges. The odd-frequency polarized triplets reveal a divergent $ 1/\omega$ behavior when the Majorana states are decoupled, which is intrinsically connected to their self-conjugation property. The zero-frequency divergence evolves into shifted resonances and linear low-frequency behavior once hybridization occurs. A nonmagnetic interruption in the texture separates the topological superconductor into two topological segments and generates additional inner Majorana modes. When the nonmagnetic barrier is comparable to the inner Majorana states localization length, they hybridize and modify their associated odd-frequency triplet pairing, while the outer edge modes preserve their self-conjugated nature. Tuning the superconducting phase difference further controls the onset of the topological regime and the stability of localized Majorana states. The results highlight the central role of odd-frequency triplet correlations as a probe of topological superconductivity in magnetically engineered Josephson junctions.
Superconductivity (cond-mat.supr-con), Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
14 pages, 9 figures
Multimodal Topological Textures Arising from Coupled Structural Orders in SrTiO$_3$
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-10-10 20:00 EDT
Fernando Gómez-Ortiz, Louis Bastogne, Philippe Ghosez
Magnetic spin topological textures recently found their electrical counterparts in polar topologies emerging from the condensation of inhomogeneous polar atomic distortions. Here, we further extend the concept to other non-polar atomic degrees of freedom. Taking SrTiO$ 3$ as a prototypical example, we investigate from second-principles atomistic simulations, the equilibrium domain structures and topological textures associated with the natural antiferrodistortive rotations of its oxygen octahedra. %
Besides the common 90$ ^\circ$ antiferrodistortive domain walls (twin boundaries), we identify new metastable 180$ ^\circ$ domain walls oriented along the $ \lbrace100\rbrace\mathrm{pc}$ direction, when compressive epitaxial strain is applied. These domains exhibit complex antiferrodistortive Bloch- and Néel-like configurations with the later being the most favorable. We also stabilize antiferrodistortive vortex and antivortex structures which are accompanied by co-localized polarization vortices and a complex pattern of the local strain field, giving rise to a trimodal topological structures. Our results extends the concept of topological ordering to non-polar structural degrees of freedom and highlights the role of lattice-mediated couplings in stabilizing complex textures in perovskite oxides.
Materials Science (cond-mat.mtrl-sci)
Electronic structures and superconductivity in Nd-doped La$_3$Ni$_2$O$_7$
New Submission | Superconductivity (cond-mat.supr-con) | 2025-10-10 20:00 EDT
Cui-Qun Chen, Wenyuan Qiu, Zhihui Luo, Meng Wang, Dao-Xin Yao
The recent discovery of high-$ T_c$ superconductivity in Ruddlesden-Popper (RP) nickelates has motivated extensive efforts to explore higher $ T_c$ superconductors. Here, we systematically investigate Nd-doped La$ _3$ Ni$ 2$ O$ 7$ using density functional theory (DFT) and renormalized mean-field theory (RMFT). DFT calculations reveal that both the lattice constants and interlayer spacing decrease upon Nd substitution, similar to the effect of physical pressure. However, the in-plane Ni-O-Ni bond angle evolves non-monotonically with doping, increasing to a maximum at 70% (~2/3) Nd doping level and then falling sharply at 80%, which leads to a reduction in orbital overlap. Moreover, Nd doping has a more pronounced effect on the Ni-$ d{{z^2}}$ orbital, demonstrating an orbital-dependent effect of rare-earth substitution. Through the bilayer two-orbital t-J model, RMFT analysis further shows an $ s\pm$ -wave pairing symmetry, with $ T_c$ rising to a maximum at about 70% Nd substitution before declining, in agreement with the transport measurements. The variation in $ T_c$ can be traced to the competition between continuously enhanced interlayer superexchange coupling $ J\perp^z$ and a gradual decrease in particle density. These results highlight the delicate interplay among structural tuning, orbital hybridization, and superconductivity, providing important clues to design higher-$ T_c$ RP nickelate superconductors.
Superconductivity (cond-mat.supr-con), Strongly Correlated Electrons (cond-mat.str-el)
8 pages, 5 figures
Mechanical coupling of polar topologies and oxygen octahedra rotations in PbTiO$_3$/SrTiO$_3$ superlattices
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-10-10 20:00 EDT
Fernando Gómez-Ortiz, Louis Bastogne, Xu He, Philippe Ghosez
PbTiO$ _3$ /SrTiO$ _3$ artificial superlattices recently emerged as a prototypical platform for the emergence and study of polar topologies. While previous studies mainly focused on the polar textures inherent to the ferroelectric PbTiO$ _3$ layers, the oxygen octahedra rotations inherent to the paraelectric SrTiO$ _3$ layers have attracted much little attention. Here, we highlight a biunivocal relationship between distinct polar topologies – including $ a_1/a_2$ domains, polar vortices, and skyrmions – within the PbTiO$ _3$ layers and specific patterns of oxygen octahedra rotations in the SrTiO$ _3$ layers. This relationship arises from a strain-mediated coupling between the two materials and is shown to be reciprocal. Through second-principles atomistic simulations, we demonstrate that each polar texture imposes a corresponding rotation pattern, while conversely, a frozen oxygen octahedra rotation dictates the emergence of the associated polar state. This confirms the strong coupling between oxygen octahedra rotations in SrTiO$ _3$ and polarization in PbTiO$ _3$ , highlighting their cooperative role in stabilizing complex polar textures in related superlattices.
Materials Science (cond-mat.mtrl-sci)
Dominant scattering mechanisms and mobility peak in cryogenic 2D electron transport in Silicon (110) confinement by high-k oxides
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2025-10-10 20:00 EDT
Hsin-Wen Huang, Xi-Jun Fang, Edward Chen, Yuh-Renn Wu
The performance of silicon nano-devices at cryogenic temperatures is critical for quantum computing technologies. Through multi-valley Monte Carlo simulations of Si (110) systems, we reveal a fundamental shift in electron transport physics at low temperatures. Phonon scattering becomes negligible, and mobility is instead dictated by a competition between remote Coulomb scattering (RCS) at low carrier densities and surface roughness scattering (SRS) at high densities. This competition creates a distinct peak in electron mobility. Furthermore, we demonstrate a critical design trade-off for high-$ \kappa$ dielectrics like $ \mathrm{HfO_2}$ : while enhancing gate control, they introduce strong remote phonon scattering, which can suppress mobility. These findings provide essential guidelines for the material selection and design of next-generation cryogenic nano-devices.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Applied Physics (physics.app-ph)
4 pages, 4 figures
Observation of electromagnons in a monolayer multiferroic
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-10-10 20:00 EDT
Mohammad Amini, Tiago V. C. Antão, Liwei Jing, Ziying Wang, Antti Karjasilta, Robert Drost, Shawulienu Kezilebieke, Jose L. Lado, Adolfo O. Fumega, Peter Liljeroth
Van der Waals multiferroics have emerged as a promising platform to explore novel magnetoelectric phenomena. Recently, it has been shown that monolayer NiI$ _2$ hosts robust type-II multiferroicity down to the two-dimensional limit, a giant dynamical magnetoelectric coupling at terahertz frequencies, and an electrically switchable spin polarization. These developments present the possibility of engineering ultrafast, low-energy-consumption, and electrically-tunable spintronic devices based on the collective excitations of the multiferroic order, electromagnons. However, the direct visualization of these bosonic modes in real space and within the monolayer limit remains elusive. Here, we report the atomic-scale observation of electromagnons in monolayer NiI$ _2$ using low-temperature scanning tunneling microscopy. By tracking the thermal evolution of the multiferroic phase, we establish the energy scale and resolve coherent in-gap excitations of the symmetry-broken multiferroic state. Comparison with first-principles and spin-model calculations reveals that the low-energy modes originate from electromagnon excitations. Spatially resolved inelastic tunneling spectroscopy maps show a stripe-like modulation of the local spectral function at electromagnon energies, matching theoretical predictions. These results provide direct evidence of the internal structure of electromagnons and establish a methodology to probe these modes at the atomic scale, opening avenues for electrically tunable spintronics.
Materials Science (cond-mat.mtrl-sci), Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
Non-Hermitian many-body localization in asymmetric chains with long-range interaction
New Submission | Disordered Systems and Neural Networks (cond-mat.dis-nn) | 2025-10-10 20:00 EDT
Wen Wang, Han-Ze Li, Jian-Xin Zhong
Understanding the relationship between many-body localization and spectra in non-Hermitian many-body systems is crucial. In a one-dimensional clean, long-range interaction-induced non-Hermitian many-body localization system, we have discovered the coexistence of static and dynamic spectral real-complex phase transitions, along with many-body ergodic-localized phase transitions. The phase diagrams of these two types of transitions show similar non-monotonic boundary trends but do not overlap, highlighting properties distinct from conventional disorder-induced non-Hermitian many-body localization. We also propose a potential experimental realization of this model in cold-atom systems. Our findings provide valuable insights for further understanding the relationship between non-Hermitian many-body localization and non-Hermitian spectra in long-range interacting systems.
Disordered Systems and Neural Networks (cond-mat.dis-nn), Computational Physics (physics.comp-ph), Quantum Physics (quant-ph)
Any comments are welcome
Flow Coupling Alters Topological Phase Transition in Nematic Liquid Crystals
New Submission | Soft Condensed Matter (cond-mat.soft) | 2025-10-10 20:00 EDT
Jayeeta Chattopadhyay, Simon Guldager Andersen, Kristian Thijssen, Amin Doostmohammadi
We investigate how coupling to fluid flow influences defect-mediated transitions in two-dimensional passive nematic fluids using fluctuating nematohydrodynamic simulations. The system is driven by tuning the fluctuation strength, with increasing (decreasing) fluctuations defining the forward (backward) protocol. In the absence of flow coupling, the transition follows the Berezinskii–Kosterlitz–Thouless (BKT) scenario, governed by reversible binding and unbinding of $ \pm 1/2$ defect pairs. When hydrodynamics is included, the outcome is controlled by the flow–alignment parameter. For non-aligning nematics ($ \lambda=0$ ), the transition remains consistent with BKT. By contrast, for strain-rate–aligning nematics ($ \lambda\neq 0$ ), bend–splay walls emerge, lowering the defect nucleation threshold and preventing sustained recombination: once created, defects remain unbound across the full range of fluctuation strengths in both forward and backward protocols. These results identify flow alignment as a fundamental control parameter for topological phase behavior and suggest that the canonical BKT transition emerges only in the absence of flow alignment.
Soft Condensed Matter (cond-mat.soft), Statistical Mechanics (cond-mat.stat-mech)
9 pages, 4 figures
Modified Monte Carlo method with the heat bath algorithm for a model cuprate
New Submission | Superconductivity (cond-mat.supr-con) | 2025-10-10 20:00 EDT
Yu. D. Panov, V. A. Ulitko, D. N. Yasinskaya, A. S. Moskvin
The results of numerical simulation using a modified Monte Carlo method with a heat bath algorithm for the pseudospin model of cuprates are presented. The temperature phase diagrams are constructed for various degrees of doping and for various parameters of the model, and the effect of local correlations on the critical temperatures of the model cuprate is investigated. It is shown that, in qualitative agreement with the results of the mean field, the heat bath algorithm leads to a significant decrease in the estimate of critical temperatures due to more complete accounting of fluctuations, and also makes it possible to detect phase inhomogeneous states. The possibility of using machine learning to accelerate the heat bath algorithm is discussed.
Superconductivity (cond-mat.supr-con)
6 pages, 5 figures
The Phase Diagram for Percolating Free Surfaces in Disordered Assemblies of Faceted Grains
New Submission | Disordered Systems and Neural Networks (cond-mat.dis-nn) | 2025-10-10 20:00 EDT
Percolation in systems made up of randomly placed impermeable grains is often examined in the context of system spanning clusters of connected solids forming above a relatively low critical grain density $ \rho_{c1}$ or networks of interstitial void volumes ceasing to exist above a signficantly higher threshold $ \rho_{c2}$ . In this work, we interpret these percolation transitions as, respectively, the low and high density boundaries of percolating exposed surfaces which either ensheath clusters of impermeable particles or line tunnel-like voids. Moreover, we find in the thermodynamic limit exposed surfaces are either sheaths or tunnels with a second order phase transition from the former to the latter at a density threshold $ \rho_{c\ast}$ intermediate between $ \rho_{c1}$ and $ \rho_{c2}$ . We calculate critical inclusion densities with a new method which identifies exposed free surfaces in a geometrically exact manner with a computational cost scaling only linearly in the system volume. We obtain $ \rho_{c1}$ , $ \rho_{c2}$ , and $ \rho_{c\ast}$ for a variety of grain geometries, including each of the Platonic solids, truncated icosahedra, and structurally disordered inclusions formed from cubes subject to a random sequence of slicing planes. In the case of the latter, we find a limiting value of $ 5%$ for the critical porosity at the void percolation threshold as the number of sustained slices per cube becomes large.
Disordered Systems and Neural Networks (cond-mat.dis-nn)
6 pages, 5 figures
A nonequilibrium distribution for stochastic thermodynamics
New Submission | Statistical Mechanics (cond-mat.stat-mech) | 2025-10-10 20:00 EDT
The canonical distribution of Gibbs is extended to the case of systems outside equilibrium. The distribution of probabilities of a discrete energy levels system is used to provide a microscopic definition of work, along with a microscopic definition of the uncompensated heat of Clausius involved in nonequilibrium processes. The later is related to the presence of non-conservatives forces with regards to the variation of the external parameters. This new framework is used to investigate the nonequilibrium relations in stochastic thermodynamics. A new relation is derived for the random quantity of heat associated to the nonequilibrium work protocol. We finally show that the distributions of probabilities of work, heat and uncompensated heat are non-independent each other during a nonequilibrium process.
Statistical Mechanics (cond-mat.stat-mech)
14 pages; 20 references
Dynamics of individual active elastic filaments with chiral self-propulsion
New Submission | Soft Condensed Matter (cond-mat.soft) | 2025-10-10 20:00 EDT
Chanania Steinbock, Daniel A. Beller
We study the over-damped dynamics of individual one-dimensional elastic filaments subjected to a chiral active force which propels each point of the filament at a fixed angle relative to the tangent vector of the filament at that point. Such a model is a reasonable starting point for describing the behavior of polymers such as microtubules in gliding assay experiments. We derive sixth-order nonlinear coupled partial differential equations for the intrinsic properties of the filament, namely, its curvature and metric, and show that these equations are capable of supporting multiple different stationary solutions in a co-moving frame, i.e. that chiral active elastic filaments exhibit dynamic multi-stability in their shapes. A linear stability analysis of these solutions is carried out to determine which solutions are stable and a brief analysis of the time-dependent approach to stationary shape is considered. Finally, simulations are presented which confirm many of our predictions while also revealing additional complexity.
Soft Condensed Matter (cond-mat.soft), Biological Physics (physics.bio-ph)
19 pages, 7 figures. Supplementary Movie available at this https URL
Topological surface magnon-polariton in an insulating canted antiferromagnet
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2025-10-10 20:00 EDT
Weixin Li, Rundong Yuan, Fenglin Zhong, Bo Peng, Jean-Philippe Ansermet, Haiming Yu
Excitation and control of antiferromagnetic magnon modes lie at the heart of coherent antiferromagnetic spintronics. Here, we propose a topological surface magnon-polariton as the potential means to excite antiferromagnetic magnons in the prototypical magnonic material hematite. We show that in an insulating canted antiferromagnet, where the magnons can strongly couple to photons using electrical on-chip layouts, a surface magnon-polariton mode exists in the gap of the bulk magnon-photon bands. The emergence of surface magnon-polariton mode is further attributed to the nontrivial topology of bulk magnon-photon bands. Magnon-photon coupling enhances the Berry curvature near the anticrossing points, leading to a topological bulk Chern band associated with the surface magnon-polaritons. Our work provides a general principle for the utilisation of optomagnetic properties in antiferromagnets, with an illustration of its feasibility in the particular case of hematite.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Materials Science (cond-mat.mtrl-sci), Optics (physics.optics)
21 pages, 3 figures
Impact of protein corona morphology on nanoparticle diffusion in biological fluids: insights from a mesoscale approach
New Submission | Soft Condensed Matter (cond-mat.soft) | 2025-10-10 20:00 EDT
Beatrice Cipriani, Hender Lopez
Nanoparticles (NPs) demonstrate considerable potential in medical applications, including targeted drug delivery and diagnostic probes. However, their efficacy depends on their ability to navigate through the complex biological environments inside living organisms. In such environments, NPs interact with a dense mixture of biomolecules, which can reduce their mobility and hinder diffusion. Understanding the factors influencing NP diffusion in these environments is key to improving nanomedicine design and predicting toxicological effects. In this study, we propose a computational approach to model NP diffusion in crowded environments. We introduce a mesoscale model that accounts for the combined effects of the Protein Corona (PC) and the crowded medium on NP movement. By including volume-exclusion interactions and modelling the PC both explicitly and implicitly, we identify key macromolecular descriptors that affect NP diffusion. Our results show that the morphology of the PC can significantly affect the diffusion of NPs, and the role of the occupied volume fraction and the size ratio between tracers and crowders are analysed. The results also show that approximating large macromolecular assemblies with a hydrodynamic single-sphere model leads to inexact diffusion estimates. To overcome the limitations of single-sphere representations, a strategy for an accurate parametrization of NP-PC systems using a single-sphere model is presented.
Soft Condensed Matter (cond-mat.soft)
Ultraviolet optical conductivity, exciton fine-structure and dispersion of freestanding monolayer h-BN
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-10-10 20:00 EDT
Jinhua Hong, Alberto Guandalini, Weibin Wu, Haiming Sun, Fuwei Wu, Shulin Chen, Chao Ma, Kazu Suenaga, Thomas Pichler, Francesco Mauri
Excitons govern the light-matter interaction in 2D gapped materials with intrinsically large binding energies. In spite of plentiful optical measurements in the visible for semiconducting transition-metal dichalcogenides, we still lack optical-absorption studies of the exciton structure of insulating 2D materials that requires UV light. Moreover, measurements of the momentum dispersion of excitons in the vicinity of optical limit are rare owing to low resolutions but hold the key to reveal quasiparticle interactions. To close this gap, we employ high momentum resolution electron energy loss spectroscopy ($ q$ -EELS) to explore exciton dispersions of mono- and few-layer hexagonal boron nitride. Surprisingly, we reveal a fine structure of the first bright exciton dispersion band composed by two features (A and A$ ‘$ ), visible only at small momentum, not predicted by Bethe-Salpeter calculations. Introducing an optical conductivity approximation (OCA), we extract from the experimental $ q$ -EELS spectra the ultraviolet (UV) optical conductivity at zero momentum, $ \sigma(\omega)$ , and discuss the exciton fine structure in $ \sigma(\omega)$ , consistent with previous photoluminescence observations. Our findings establish a general methodology to probe the fine structure of exciton dispersions, providing new insights into exciton-phonon sidebands and eventually polarons in low-dimensional materials.
Materials Science (cond-mat.mtrl-sci)
Enhanced thermal stability of inverted perovskite solar cells by bulky passivation with pyridine-functionalized triphenylamine
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-10-10 20:00 EDT
Ekaterina A. Ilicheva, Irina A. Chuyko, Lev O. Luchnikov, Polina K. Sukhorukova, Nikita S. Saratovsky, Anton A. Vasilev, Luiza Alexanyan, Anna A. Zarudnyaya, Dmitri Yu. Dorofeev, Sergey S. Kozlov, Andrey P. Morozov, Dmitry S. Muratov, Yuriy N. Luponosov, Danila S. Saranin
Despite competitive efficiency compared to Si solar cells and relevant stability at near room temperatures the rapid degradation at elevated temperatures remains the critical obstacle for exploitation of perovskite photovoltaics. In this work, a 4-(pyridin-4-yl)triphenylamine (TPA-Py) with pyridine anchor group was employed for inter-grain bulk modification of double-cation CsCH(NH2)2PbI3 perovskite absorbers to enhance thermal stability. Through coordination and dipole-dipole interactions, nitrogen-containing fragments (diphenylamine and pyridine) of TPA-Py passivate uncoordinated cations and improve the phase resilience of perovskite films against segregation. This resulted in a power conversion efficiency of 21.3% with a high open-circuit voltage of 1.14 V. Notable impact of self-assembled monolayer incorporated into the bulk of perovskite film manifested in huge improvement of thermal stability at 85°C (ISOS-D-2). TPA-Py modification improved extended the T80 lifetime to ~600 h compared to only 200 h for the reference under harsh heating stress in ambient conditions. In-depth analysis using photoinduced voltage transients and admittance spectroscopy after different stress periods revealed the screening of ion migration (0.45 eV) for devices with TPA-Py. This work offers an important understanding of the bulk modification of microcrystalline perovskite absorbers and guide for robust design of bulk and buried interfaces in highly efficient perovskite solar cells.
Materials Science (cond-mat.mtrl-sci), Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Applied Physics (physics.app-ph)
Microstructure and phase stability within the AlMoNbTiZr system: design tools and compositional boundaries for a high-entropy alloy
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-10-10 20:00 EDT
Mariano Casas-Luna, Dalibor Preisler, Jiří Kozlík, Josef Stráský
This study explores Ti-containing complex concentrated alloys (CCAs) within the AlMoNbTiZr system, focusing on compositions located in regions of the Bo-Md diagram characterized by low bond order (Bo) and d-orbital energy level (Md). Four alloys were designed near the line predicting stress-induced martensite formation in conventional Ti alloys, then cast, annealed at 1200°C, and water quenched. Their microstructures and phases were analyzed and compared against phase prediction tools commonly applied to high-entropy alloys (HEAs), namely empirical parameters and CALPHAD simulations. Results highlight the strong influence of chemical affinity, particularly the roles of Al, Mo, and Zr concentrations, on solid-solution stability. A maximum Al content of 10 at% was identified as the threshold for achieving a single-phase microstructure, observed in the 10Al15Mo10Nb35Ti30Zr alloy. This alloy exhibited a bcc/b2 structure with high compressive strength (above 1300 MPa), low Young’s modulus (28 GPa), and limited strain (<6%), but lacked the transformation-induced strengthening mechanisms expected for Ti alloys with comparable Bo-Md values.
Materials Science (cond-mat.mtrl-sci)
Trajectory-Dependent Electronic Energy Losses in Ion Range Simulations
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-10-10 20:00 EDT
Glen P. Kiely, Bruno Semião, Evgeniia Ponomareva, Rafael Nuñez-Palacio, Unna Arpiainen, Andrea E. Sand
The energy losses of energetic ions in materials depend on both nuclear and electronic interactions. In channeling geometries, the stopping effect of these interactions can be highly reduced, resulting in deeper ion penetration. Comprehensive, trajectory-dependent models for ion-material interactions are therefore crucial for the accurate prediction of ion range profiles. We present the implementation of a recent electron density-dependent energy-loss model in the efficient molecular dynamics-based MDRANGE code. The model captures \textit{ab initio} electron dynamics using a parametrized ion energy loss function, based on calculations for explicit trajectories using real-time time-dependent density functional theory. We demonstrate the efficient simulation of trajectory-dependent ion range profiles with this comprehensive model for electronic energy losses. Our results indicate that accurate trajectory-dependent ion range profiles can be simulated using well-fitted parametrizations of this model. This method offers a unique tool for validation of the fitted energy-loss functions using energetic ion ranges, which can be measured experimentally but are beyond the capability of full MD simulations due to the computational expense.
Materials Science (cond-mat.mtrl-sci)
8 pages, 6 figures
Anomalous Diffusion in Driven Electrolytes due to Hydrodynamic Fluctuations
New Submission | Soft Condensed Matter (cond-mat.soft) | 2025-10-10 20:00 EDT
The stochastic dynamics of tracers arising from hydrodynamic fluctuations in a driven electrolyte is studied using a self-consistent field theory framework in all dimensions. A plethora of scaling behaviour including two distinct regimes of anomalous diffusion is found, and the crossovers between them are characterized in terms of the different tuning parameters. A short-time ballistic regime is found to be accessible beyond two dimensions, whereas a long-time diffusive regime is found to be present only at four dimensions and above. The results showcase how long-ranged hydrodynamic interactions can dominate the dynamics of non-equilibrium steady-states in ionic suspensions and produce strong fluctuations despite the presence of Debye screening.
Soft Condensed Matter (cond-mat.soft), Statistical Mechanics (cond-mat.stat-mech), Chemical Physics (physics.chem-ph)
Fractional quantum Hall states under density decoherence
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2025-10-10 20:00 EDT
Zijian Wang, Ruihua Fan, Tianle Wang, Samuel J. Garratt, Ehud Altman
Fractional quantum Hall states are promising platforms for topological quantum computation due to their capacity to encode quantum information in topologically degenerate ground states and in the fusion space of non-abelian anyons. We investigate how the information encoded in two paradigmatic states, the Laughlin and Moore-Read states, is affected by density decoherence – coupling of local charge density to non-thermal noise. We identify a critical filling factor $ \nu_c$ , above which the quantum information remains fully recoverable for arbitrarily strong decoherence. The $ \nu=1/3$ Laughlin state and $ \nu = 1/2$ Moore-Read state both lie within this range. Below $ \nu_c$ both classes of states undergo a decoherence induced Berezinskii-Kosterlitz-Thousless (BKT) transition into a critical decohered phase. For Laughlin states, information encoded in the topological ground state manifold degrades continuously with decoherence strength inside this critical phase, vanishing only in the limit of infinite decoherence strength. On the other hand, quantum information encoded in the fusion space of non-abelian anyons of the Moore-Read states remains fully recoverable for arbitrary strong decoherence even beyond the BKT transition. These results lend further support to the promise of non-Abelian FQH states as platforms for topological quantum computation and raises the question of how errors in such states can be corrected.
Strongly Correlated Electrons (cond-mat.str-el), Quantum Gases (cond-mat.quant-gas), Statistical Mechanics (cond-mat.stat-mech), Quantum Physics (quant-ph)
19 pages + 8 pages appendix + 3 figures
Kinetic description of one-dimensional stochastic dynamics with small inertia
New Submission | Statistical Mechanics (cond-mat.stat-mech) | 2025-10-10 20:00 EDT
Denis S. Goldobin, Lyudmila S. Klimenko, Irina V. Tyulkina, Vasily A. Kostin, Lev A. Smirnov
We study single-variable approaches for describing stochastic dynamics with small inertia. The basic models we deal with describe passive Brownian particles and phase elements (phase oscillators, rotators, superconducting Josephson junctions) with an effective inertia in the case of a linear dissipation term and active Brownian particles in the case of a nonlinear dissipation. Elimination of a fast variable (velocity) reduces the characterization of the system state to a single variable and is formulated in four representations: moments, cumulants, the basis of Hermite functions, and the formal cumulant variant of the last. This elimination provides rigorous mathematical description for the overdamped limit in the case of linear dissipation and the overactive limit of active Brownian particles. For the former, we derive a low-dimensional equation system which generalizes the Ott-Antonsen Ansatz to systems with small effective inertia. In the latter case, we derive a Fokker-Planck-type equation with a forced drift term and an effective diffusion in one dimension, where the standard two-/three-dimensional mechanism is impossible. In the four considered representations, truncated equation chains are demonstrated to be utilitary for numerical simulation for a small finite inertia.
Statistical Mechanics (cond-mat.stat-mech), Adaptation and Self-Organizing Systems (nlin.AO)
24 pages, 5 figures
Classical to Quantum Diffusive Transport in Atomically Thin Semiconductors Capped with High-k Dielectric
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2025-10-10 20:00 EDT
Jaroslaw Pawlowski, Dickson Thian, Repaka Maheswar, Chai Jian Wei, Pawan Kumar, Sudhiranjan Tripathy, Hugh O.H. Churchill, Dharmraj Kotekar Patil
The dielectric environment surrounding semiconductors plays a crucial role in determining device performance, a role that becomes especially pronounced in atomically thin semiconductors where charge carriers are confined within a few atomic layers and strongly interact with their surroundings. High-k dielectrics, such as hafnium oxide (HfO2), have been shown to enhance the performance of two-dimensional (2D) materials by suppressing scattering from charged impurities and phonons, but most studies to date have focused on room-temperature transistor operation. Their influence on quantum transport properties at low temperatures remains largely unexplored. In this work, we investigate how capping monolayer molybdenum disulfide (MoS2) with HfO2 modifies its electronic behavior in the quantum regime. By comparing devices with and without HfO2 capping, we find that uncapped devices exhibit transport dominated by classical diffusive scattering, whereas capped devices show clear Fabry-Perot interference patterns, providing direct evidence of phase-coherent quantum transport enabled by dielectric screening. To gain further insight, we develop a tight-binding interferometer model that captures the effect of dielectric screening on conductive modes and reproduces the experimental trends. Our findings demonstrate that dielectric engineering provides a powerful route to control transport regimes in TMD devices.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Materials Science (cond-mat.mtrl-sci), Other Condensed Matter (cond-mat.other), Strongly Correlated Electrons (cond-mat.str-el)
4 figure, 6 supplemnetary figures