CMP Journal 2026-02-17
Statistics
Nature Physics: 1
Nature Reviews Materials: 1
arXiv: 130
Nature Physics
Discontinuous transition to shear flow turbulence
Original Paper | Fluid dynamics | 2026-02-16 19:00 EST
Bowen Yang, Yi Zhuang, Gökhan Yalnız, Vasudevan Mukund, Elena Marensi, Björn Hof
Depending on the type of flow, the transition to turbulence can take one of two forms: either turbulence arises from a sequence of instabilities or from the spatial proliferation of transiently chaotic domains, a process analogous to directed percolation. The former scenario is commonly referred to as a supercritical transition and frequently encountered in flows destabilized by body forces, whereas the latter subcritical transition is common in shear flows. Both cases are inherently continuous in a sense that the transformation from ordered laminar to fully turbulent fluid motion is only accomplished gradually with flow speed. Here we show that these established transition types do not account for the more general setting of shear flows subject to body forces. The combination of the two continuous scenarios leads to the attenuation of spatial coupling; with increasing forcing amplitude, the transition becomes increasingly sharp and eventually discontinuous. We argue that the suppression of laminar-turbulent coexistence and the approach towards a discontinuous phase transition potentially apply to a broad range of situations including flows subject to, for example, buoyancy, centrifugal or electromagnetic forces.
Fluid dynamics, Phase transitions and critical phenomena
Nature Reviews Materials
Many-body entanglement in solid-state emitters
Review Paper | Optical materials and structures | 2026-02-16 19:00 EST
Emma Daggett, Christian M. Lange, Bennet Windt, Arshag Danageozian, Alexander Senichev, Jordi Arnau Montañà-López, Chanchal, Kinjol Barua, Xingyu Gao, Zhaoyun Zheng, Vijin Kizhake Veetil, Souvik Biswas, Jonas M. Peterson, Na Liu, Chuchuan Hong, Teri Odom, Matthew Pelton, Tongcang Li, Jelena Vučković, Vladamir M. Shalaev, Alexandra Boltasseva, Sophia E. Economou, Jonathan D. Hood, Valentin Walther, Rahul Trivedi, Libai Huang
The preparation and control of quantum states lie at the heart of quantum information science. Recent advances in solid-state quantum emitters (QEs) and nanophotonics have transformed the landscape of quantum photonic technologies, enabling scalable generation of quantum states of light and matter. A new frontier in solid-state quantum photonics is the engineering of many-body interactions between QEs and photons to achieve robust coherence and controllable many-body entanglement. These entangled states, including photonic graph and cluster states, superradiant emission and emergent quantum phases, are promising for quantum computation, sensing and simulation. However, intrinsic inhomogeneities and decoherence in solid-state platforms pose considerable challenges in realizing such complex entangled states. This Review provides an overview of fundamental many-body interactions and dynamics at the light-matter interfaces of solid-state QEs and discusses recent advances in mitigating decoherence and harnessing robust many-body coherence.
Optical materials and structures, Quantum physics
arXiv
A model of thermophoresis of colloidal proteins in water using non-Fickian diffusion currents
New Submission | Soft Condensed Matter (cond-mat.soft) | 2026-02-17 20:00 EST
Mayank Sharma, Angad Singh, A. Bhattacharyay
In 1928, Chapman generalised Einstein’s theory of diffusion for non-uniform fluids to show the presence of a non-Fickian diffusion current, which he considered important in thermodiffusion (Ludwig-Soret effect). In 1941, Kiyosi Itô proposed the formal methods of stochastic calculus in the presence of spatially dependent diffusion, yielding the same non-Fickian diffusion current as shown by Chapman. The phenomenon of thermodiffusion and thermophoresis happens in the presence of a temperature gradient, which makes diffusion space-dependent. The role of solvation forces in thermophoresis will only be clearer once that of diffusion is understood properly. In this paper, we investigate the importance of Chapman’s non-Fickian diffusion current on the thermophoretic motion of colloidal particles in water (with weak salt concentration). We show that all the general features of variations of the Soret coefficient $ S_T$ with temperature can be captured using Chapman’s non-Fickian diffusion current. We compare our theoretical results with experimental plots of the Soret coefficients for three polypeptides in aqueous solution: Lysozyme, BLGA, and Poly-L-Lysine, and find a strong match. We emphasise that, in addition to the yet-to-be-understood details of solvation forces, Chapman’s non-Fickian diffusion current is an indispensable element that needs to be taken into account for a complete understanding of thermophoresis and thermodiffusion.
Soft Condensed Matter (cond-mat.soft), Statistical Mechanics (cond-mat.stat-mech), Biological Physics (physics.bio-ph)
12 pages, 6 figures
Strain-rate, temperature and size effects on the mechanical behavior of fiber bundles
New Submission | Soft Condensed Matter (cond-mat.soft) | 2026-02-17 20:00 EST
The mechanical characteristics of fibers (of various materials), as well as of fiber bundles, are of primary importance for the design and the mechanical behavior of textiles, or of fibrous and composite materials. These characteristics are classically determined from strain-rate controlled tensile testing, generally assuming a negligible role of thermal activation on damage and fracturing processes. Under this assumption, the distribution of individual fiber strengths can be deduced from a downscaling of the macroscopic mechanical behavior at the bundle scale. There are however many experimental evidences of strain-rate and temperature effects on the mechanical behavior of individual fibers or bundles, which can also creep under constant applied load. This indicates a strong role of thermal activation on these processes. Here, these effects are analyzed from a fiber-bundle model with equal-load-sharing, in which thermal activation of fiber breakings is introduced from a kinetic Monte-Carlo algorithm adapted for time-varying stresses. This allows to rationalize these rate or temperature effects, such as a decrease of bundle strength, strain at peak stress, and apparent Young’s modulus with decreasing strain-rate and/or increasing temperature. This also shows that the classical downscaling procedure used to estimate the distribution of individual fiber strengths from the mechanical behavior at the bundle scale should be considered with caution. If mechanical testing of the bundle is performed under conditions favoring the role of thermal activation (e.g. low applied strain-rate), this procedure can strongly underestimate the intrinsic (athermal) Weibull’s parameters of the fiber strengths distribution. The same model is used as well to explore size (number of fibers) effects on bundle mechanical response.
Soft Condensed Matter (cond-mat.soft), Materials Science (cond-mat.mtrl-sci), Statistical Mechanics (cond-mat.stat-mech)
8 figures
Shape, confinement and inertia effects on the dynamics of a driven spheroid in a viscous fluid
New Submission | Soft Condensed Matter (cond-mat.soft) | 2026-02-17 20:00 EST
Aditya Bhowmik, Kevin Stratford, Oliver Henrich, Sumesh P. Thampi
The dynamics of anisotropic particles in viscous flows underpin a wide range of processes in soft matter, microfluidics, and targeted drug delivery. Here, we investigate the motion of externally driven prolate and oblate spheroids suspended in a Newtonian fluid and confined within a square microchannel. Using lattice Boltzmann simulations, complemented by far-field hydrodynamic theory based on superposition of wall interactions, we systematically quantify how particle aspect ratio, strength of confinement, and fluid inertia influence the dynamics of a spheroid. For unconfined spheroids, we show that the translational velocity is maximized not for a sphere but for a prolate (end-on) or oblate (broadside-on) spheroid of a specific aspect ratio. Under confinement, the optimal aspect ratio shifts toward oblate shapes due to the dominant contribution of wall-induced frictional resistance. Off-center positioning introduces strong translation-rotation coupling, giving rise to two families of oscillatory trajectories - glancing and reversing - whose existence and structure are captured as closed orbits in phase space. Weak fluid inertia breaks these closed loops: glancing trajectories spiral outward and merge with reversing trajectories, and new stable fixed points emerge. Together, these results reveal how modest deviations from sphericity or creeping-flow conditions profoundly alter the dynamics of driven particles in confined geometries. The predictions offer guidelines for optimizing particle shape in microfluidic transport and highlight the rich nonlinear behavior accessible in confined suspensions of nonspherical colloids.
Soft Condensed Matter (cond-mat.soft), Fluid Dynamics (physics.flu-dyn)
StrAPS: Structural Angular Power Spectrum for Discovering Novel Morphologies in Block Copolymers
New Submission | Soft Condensed Matter (cond-mat.soft) | 2026-02-17 20:00 EST
Dominic M. Robe, Elnaz Hajizadeh
The morphologies of phase separating systems have formal distinctions such as symmetry groups, but the analysis protocol for labeling a particular phase field with a morphology requires manual expertise, arbitrary thresholds, or established signatures. In this work, it is investigated if the angular power spectrum of the 3D structure factor can discriminate between morphologies. The 3D structure factor is computed on configurations of phase separating block copolymers generated by coarse-grained molecular dynamics simulations. The shell of structure factor values containing the primary peaks is isolated. This 2D field on a sphere is decomposed into spherical harmonic modes of even polynomial degree $ \ell\le 12$ , then further reduced to the rotationally invariant angular power spectrum. It is found that these few coefficients for low $ \ell$ discriminate robustly between different morphologies. This analysis serves as an automatic tool for flagging novel structures, without a need to enumerate the plausible morphologies in advance.
Soft Condensed Matter (cond-mat.soft), Computational Physics (physics.comp-ph)
Probing near-field EM fluctuations in superparamagnetic CoFeB with NV quantum dephasometry
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2026-02-17 20:00 EST
Shoaib Mahmud, Wei Zhang, Pronoy Das, Angshuman Deka, Wenbo Sun, Zubin Jacob
Superparamagnetism in nanoscale magnetic layers is a critical property for a wide range of spintronic-based sensor and computing applications. While conventional magnetization measurements can detect superparamagnetic signatures, they often require the application of high perturbative fields and are difficult to implement for magnetic layers integrated within functional devices. In this study, we non-invasively investigate the superparamagnetic spin dynamics of a nanoscale CoFeB layer of thickness 1.1 nm, deposited on a diamond substrate, by probing its low-frequency near-field electromagnetic (EM) fluctuations using nitrogen-vacancy (NV) centers-based quantum dephasometry. Our measurements reveal an unconventional, non-monotonic temperature dependence of the dephasing time of NV centers, which we attribute to EM fluctuations produced by thermally driven superparamagnetic domain flipping in CoFeB. Our findings are further supported by the theoretical interpretation of the dephasing dynamics of NV centers and the complementary SQUID-based magnetization characterizations of the CoFeB layer. Additionally, exploiting the technique of NV dephasometry, we extract the spectral density of the EM fluctuations in CoFeB, which is used to isolate different components of the EM fluctuations acting on NV centers. We also measure the CoFeB-to-NV distance-dependent coherence times of NV centers to investigate the effect of the dimensionality of the CoFeB layer on the generated near-field EM fluctuations. These results provide critical insight into the magnetization dynamics and near-field EM environment of nanoscale magnetic layers. It also has significant implications for the development of hybrid quantum spintronic devices and applications involving nanoscale opto-magnetic materials.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Quantum Physics (quant-ph)
Velocity Weakening in Anisotropic Friction on a Tilted Titania Nanorod Forest
New Submission | Soft Condensed Matter (cond-mat.soft) | 2026-02-17 20:00 EST
Debottam Datta, Enrico Gnecco, J. P. Singh, Nitya Nand Gosvami
In this study, we demonstrate velocity-dependent directional friction on a surface structured with tilted (~57°) titania nanorods using standard and colloidal probe force microscopy. Friction is measured at four different sliding speeds in two configurations, along and opposite to the tilt and perpendicular to the tilt direction, exhibiting anisotropic friction. Furthermore, friction decreases logarithmically with increasing sliding speed, which is attributed to the viscoelastic bending of the nanorods caused by stress-induced defect migration. The velocity weakening is more pronounced in the direction perpendicular to the tilt than along and opposite to it. The experimental findings are corroborated by creep measurements, which are well-reproduced by the Standard Linear Solid (SLS) model of viscoelasticity. Our results may be applied to the development of direction- and velocity-dependent sensors for microscale sliding motion as a robust alternative to structured interfaces based on polymeric materials.
Soft Condensed Matter (cond-mat.soft), Materials Science (cond-mat.mtrl-sci)
29 pages, 9 figures
Tuning Optoelectronic Properties and Photoelectrochemical Performance of \b{eta}-TaON via Vanadium Doping
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-02-17 20:00 EST
Mirabbos Hojamberdiev, Ronald Vargas, Lorean Madriz, Dilshod Nematov, Ulugbek Shaislamov, Hajime Wagata, Yuta Kubota, Kunio Yubuta, Katsuya Teshima, Nobuhiro Matsushita
The application of beta-TaON for solar-driven water splitting is hindered by limitations in phase purity, stoichiometry, crystallinity, visible-light absorption, carrier mobility, and high recombination rates. This study investigates the impact of vanadium doping (0-25 at.% V) on the structural, optoelectronic, and photoelectrochemical properties of beta-TaON using both experimental and density functional theory (DFT) approaches. Phase-pure beta-TaON is retained up to 10 at.% V, beyond which secondary phases (Ta2O5 and VN) form, indicating a threshold of ~10 at.% under the applied synthesis conditions. All samples exhibit a porous microstructure. Increasing vanadium content induces a redshift in the absorption edge, reducing the bandgap from 2.72 eV (undoped) to 2.38 eV at 25 at.% V for the main beta-TaON phase, in agreement with DFT results. X-ray photoelectron spectroscopy confirms substitutional incorporation of V5+ for Ta5+ in the beta-TaON lattice. DFT calculations reveal reduced electron effective mass, enhanced n-type conductivity, and favorable band edge shifts enabling spontaneous overall water splitting at <=10 at.% V. Photoelectrochemical measurements show improved photocurrent and more negative onset potentials for 5-10 at.% V, while higher V doping degrades performance due to phase segregation, which likely increases recombination and hinders interfacial charge transport. Vanadium doping (<=10 at.% V) is an effective strategy for tuning the electronic structure and enhancing the optical properties and photoelectrochemical performance of beta-TaON.
Materials Science (cond-mat.mtrl-sci)
Small 2026, 0:e10276
Room Temperature RF Sputtering of Mixed Ionic and Electronic Conductor Nd2Ni0.8Cu0.2O4+d films
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-02-17 20:00 EST
N. Coppola, M. Paone, H.S. Ur Rehman, S. Scarnicci, G. Carapella, A. Guarino, M. Tkalcevic, L. Calcagnile, G. Quarta, A. Galdi, L. Maritato
Lowering the operating temperature of Solid Oxide Fuel Cells (SOFCs) is essential for improving durability and enabling large scale commercialization. Mixed ionic-electronic conductors (MIECs) of the Ruddlesden-Popper family, such as Nd$ 2$ Ni$ {1-x}$ Cu$ x$ O$ {4+\delta}$ (NNCO), offer attractive cathode properties due to their high oxygen transport and favourable defect chemistry. In this work, we investigate the fabrication of Nd$ 2$ Ni$ {0.8}$ Cu$ {0.2}$ O$ {4+\delta}$ thin films using a room temperature RF sputtering process followed by moderate temperature annealing. To simplify deposition, a single stoichiometric target was employed, despite the compositional challenges posed by elements with different sputtering yields. We examine the effect of sputtering power density on phase formation and film stoichiometry through X-ray diffraction, Rutherford Backscattering Spectrometry, Energy Dispersive X-ray Spectroscopy, and temperature dependent resistivity measurements. Increasing the sputtering power density strongly reduces the presence of spurious phases and promotes stabilization of the desired n=1 Ruddlesden-Popper phase. Films deposited at 230 W (3.1 W cm$ ^{-2}$ ) exhibit a predominant NNCO structure, elemental ratios close to nominal composition, and resistivity values consistent with bulk materials. These findings demonstrate that high power sputtering combined with ex situ annealing enables the production of NNCO thin films suitable for SOFC cathodes. The results support the potential of PVD based approaches for scalable fabrication of advanced SOFC components.
Materials Science (cond-mat.mtrl-sci)
12 pages, 5 figures
Adaptive Pseudoboson Density-Matrix Renormalization Group for Dilute 2D Systems
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2026-02-17 20:00 EST
Fabian J. Pauw, Thomas Köhler, Ulrich Schollwöck, Sebastian Paeckel
Simulating strongly correlated systems in two dimensions is notoriously challenging due to rapid entanglement growth and frustration. Here, we introduce the adaptive projected-purified pseudoboson density-matrix renormalization group (A3P-DMRG) tailored to explore the ground states of dilute lattice models. The method compresses cluster Hilbert spaces by retaining only the most probable low-occupation Fock states, identified via probabilistic bounds and refined through a self-consistent mean-field basis optimization. We demonstrate that A3P-DMRG is advantageous in low-filling and weak-coupling regimes for large system sizes where conventional DMRG struggles. This establishes the method as a versatile tool for studying dilute quantum many-body systems relevant to ultra-cold atom quantum simulators, photonic lattices, Moiré materials and quantum chemistry.
Strongly Correlated Electrons (cond-mat.str-el), Quantum Physics (quant-ph)
14 pages, 6 figures
Dynamical metastability and transient topological magnons in interacting driven-dissipative magnetic systems
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2026-02-17 20:00 EST
Vincent P. Flynn, Lorenza Viola, Benedetta Flebus
Metastability, i.e., partial relaxation to long-lived, quasi-stationary states before true asymptotic equilibrium sets in, emerges ubiquitously in classical and quantum dynamical systems as a result of timescales separation. In open quantum systems, an intrinsically nonequilibrium analogue, dynamical metastability, can originate from the spectral geometry of a non-Hermitian operator. In noninteracting models, this mechanism produces boundary-sensitive anomalous relaxation, transient amplification, and topologically mandated long-lived edge modes, all of which are enhanced as system size grows. Here we extend dynamical metastability into the nonlinear, interacting regime and identify magnetic heterostructures as a natural platform for its exploration. We introduce an interacting spin Lindbladian whose linearized magnon dynamics map onto a dynamically metastable Hatano-Nelson chain, and show that dynamical metastability in the noninteracting limit seeds genuinely nonlinear phenomena, including size-dependent spin dipping and anomalous attraction to unstable equilibria. Long-lived edge states associated to topologically mandated Dirac bosons persist under nonlinearities and disorder. We further analyze the magnetization dynamics in magnetic multilayers within the classical Landau-Lifshitz-Gilbert-Slonczewski framework, identifying Dzyaloshinskii-Moriya interaction, nonlocal damping, and spin-transfer torque as control parameters governing bulk-boundary stability mismatch and band topology. While all the distinctive dynamical phenomena previously identified reappear in this experimentally relevant setting, the LLGS framework also supports multistability and limit cycles that are absent in the quantum model. Our results constitute the first systematic study of dynamical metastability in nonlinear dynamics, directly relevant to spin-torque oscillator arrays, magnonic devices, and beyond.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Quantum Physics (quant-ph)
29 pages, 19 figures
Exact dimer ground state and quantum phase transitions in a coupled spin ladder
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2026-02-17 20:00 EST
Manas Ranjan Mahapatra, Rakesh Kumar
Spin ladders are key models that act as intermediaries between one-dimensional and two-dimensional spin systems. In this study, we examine a coupled spin-$ 1/2$ ladder, where frustrated ladders with leg, rung, and diagonal interactions are linked through a horizontal coupling. By introducing a spatially anisotropic third-nearest-neighbor interaction along the horizontal direction, the model was found to possess an exact dimer ground state, characterized by a product of singlets forming a columnar dimer phase. The model is analyzed using bond-operator mean-field theory (BOMFT) and the density matrix renormalization group (DMRG). BOMFT reveals three distinct phases: a double-stripe ordered phase, a Néel ordered phase, and a quantum disordered dimerized phase. The critical points for the transitions are $ J_1 = -0.81$ (double-stripe to dimerized) and $ J_1 = 2.81$ (dimerized to Néel phase). DMRG results corroborate the exact ground state and refine the critical points to $ J_1 = -0.79$ and $ J_1 = 2.29$ for the respective transitions. Additionally, another transition is identified as the Néel order vanishes for $ J_1 > 4.5$ . The static spin structure factor further corroborates the nature of the ordered phases.
Strongly Correlated Electrons (cond-mat.str-el)
Evolutionary design of thermodynamic logic gates and their heat emission
New Submission | Statistical Mechanics (cond-mat.stat-mech) | 2026-02-17 20:00 EST
Landauer’s principle bounds the heat generated by logical operations, but in practice the thermodynamic cost of computation is dominated by the control systems that implement logic. CMOS gates dissipate energy far above the Landauer bound, while laboratory demonstrations of near-Landauer erasure rely on external measurement or feedback systems whose energy costs exceed that of the logic operation by many orders of magnitude. Here we use simulations to show that a genetic algorithm can program a thermodynamic computer to implement logic operations in which the total heat emitted by the control system is of a similar order of magnitude to that of the information-bearing degrees of freedom. Moreover, the computer can be programmed so that heat is drawn away from the information-bearing degrees of freedom and dissipated within the control unit, suggesting the possibility of computing architectures in which heat management is an integral part of the program design.
Statistical Mechanics (cond-mat.stat-mech), Neural and Evolutionary Computing (cs.NE)
Eco-Friendly Supercapacitor Architecture Based on Cotton Textile Waste and Biopolymer-Based Electrodes
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-02-17 20:00 EST
Luis Torres Quispe, Clemente Luyo Caycho, Javier Quino-Favero, Silvia Ponce, Abel Gutarra
This study presents an eco-friendly and bio-based symmetric supercapacitor using cotton textile waste-derived hydrogels as electrolytes and chitosan-based carbon electrodes as metal-free charge-storage components. Cotton-derived hydrogels were synthesized via an alkaline dissolution-gelation route and modified with ammonium thiocyanate (NH4SCN) to enhance ionic conductivity. The ionic modification increased the hydrogel conductivity from 17.1 to 37.8 mS cm^-1, confirming a nearly twofold improvement in ion transport efficiency. The resulting hydrogel exhibited improved thermal stability, homogeneous ionic transport, and strong polymer-ion interactions confirmed by FTIR and TGA analyses. In a symmetric device, the ion-modified hydrogel enables reduced equivalent series resistance, faster charge-transfer kinetics, and a short time constant (tau = 3.2 s), comparable to commercial energy-storage systems. After 1000 cycles, the device exhibits a 12.3% increase in specific capacitance, confirming stable proof-of-concept operation. Cycling leads to a moderate increase in R_ESR (18 to 22 ohm) and tau (3.2 to 4.1 s), indicating slower charge-ion redistribution. Notably, this R_ESR includes the contribution of the test-cell setup; in compact coin-type configurations, the resistance would be considerably lower. EIS reveals a concurrent rise in interfacial resistive terms, consistent with post-cycling hydrogel darkening and FTIR evidence of Fe-SCN coordination, suggesting that resistance buildup mainly originates from minor Fe-SCN interactions when the expelled liquid reaches the stainless-steel collector, rather than from loss of capacitive functionality. Overall, these results demonstrate the viability of cotton waste-derived hydrogels and chitosan-based electrodes as sustainable components for green energy storage, offering a recyclable and eco-friendly alternative to conventional systems.
Materials Science (cond-mat.mtrl-sci)
21 pages, 7 figures, 2 tables. Submitted to Energy Advances
Hidden Density-Wave Instability in the Trimer Ruthenate Ba4Ru3O10
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2026-02-17 20:00 EST
Gang Cao, Hengdi Zhao, Adrienne Bond, Tristan R. Cao, Gabriel Schebel, Arabella Quane, Yifei Ni, Yu Zhang, Logan Wall, Rahul Nandkishore, Pedro Schlottmann, Feng Ye
We report a hidden density-wave instability in the trimer-based ruthenate Ba4Ru3O10, previously regarded as a pure antiferromagnet with a phase transition at TA=100 K. This transition is manifested in lattice parameters, transport, thermodynamics, and magnetic susceptibility, yet remains remarkably insensitive to magnetic fields up to at least 14 T, indicating an electronically driven reconstruction. At much lower temperatures T\ast= 20 K, charge transport becomes strongly nonlinear, exhibiting distinct depinning thresholds, negative differential resistance, pronounced current- and frequency-dependence, and slow collective dynamics in the Hertz range. While each feature is characteristic of density-wave transport, their simultaneous occurrence in an antiferromagnetic oxide is unprecedented. All nonlinear signatures vanish upon only 3% Ir substitution, which preserves the crystal structure and insulating state, ruling out Joule heating or extrinsic artifacts. The wide separation between the electronic reconstruction at TA and the emergence of nonlinear dynamics at T\ast identifies Ba4Ru3O10 as a rare correlated system hosting a strongly pinned collective electronic state intertwined with antiferromagnetism.
Strongly Correlated Electrons (cond-mat.str-el), Quantum Physics (quant-ph)
5 figures
Shunt-controlled resistive state of superconducting wires
New Submission | Superconductivity (cond-mat.supr-con) | 2026-02-17 20:00 EST
Khalil Harrabi, Zain Alzoubi, Leonardo Cadorim, Milorad Milosevic
The use of resistive shunts in superconducting electronics is vast and versatile, to dampen oscillations in junctions, stabilize switching behavior, aid current sensing, divert current during quenches, and protect both the superconductor and the circuit from damage. In single-photon detection by superconducting nanowires, the shunt is crucial for the timely relaxation of the sensor between the events to detect. Here we step out from the superconducting state and discuss the effect of the shunt resistor on the resistive state of a superconducting wire, at elevated currents still below the critical current for the transition to the normal state. We reveal how the shunt resistance controls the system dynamics and the onset of different resistive phases that include hot-spot and phase-slippage events. The accompanying dynamic current redistribution in the circuit also affects the local heating properties and additionally contributes to the control of the resistive state, particularly important at the elevated operation temperatures.
Superconductivity (cond-mat.supr-con)
5 pages, 3 figures. Accepted in IEEE Transactions on Applied Superconductivity
A Minimal Nonlocal Theory of Thixotropic Flow
New Submission | Soft Condensed Matter (cond-mat.soft) | 2026-02-17 20:00 EST
Saghar Zolfaghari, Safa Jamali
Dense amorphous materials exhibit both nonlocal flow cooperativity and pronounced history dependence, yet existing continuum models capture only one of these features at a time. Nonlocal rheologies are intrinsically memoryless, while thixotropic models remain local. Here we introduce a coupling between structural memory and nonlocal fluidity to include aging and rejuvenation in nonlocal granular fluidity. The resulting model reproduces hysteresis in shear-rate sweeps and delayed yielding in creep, while preserving nonlocal flow profiles. By introducing memory augmented non local granular fluidity, MNGF, we show that nonlocality alone cannot encode history, and memory alone cannot encode spatial cooperativity, but their coupling is essential and minimal. These results demonstrate that memory and nonlocality must be treated jointly to describe history dependent flows, and provide a unified framework for modeling time-dependent rheology in dense amorphous materials.
Soft Condensed Matter (cond-mat.soft), Applied Physics (physics.app-ph)
Trion transfer in mixed-dimensional heterostructures
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2026-02-17 20:00 EST
N. Fang, U. Erkilic, Y. R. Chang, S. Fujii, D. Yamashita, C. F. Fong, S. Morito, K. Kanahashi, T. Taniguchi, K. Watanabe, K. Ueno, K. Nagashio, Y. K. Kato
Charged excitons, or trions, offering unique spin and charge degrees of freedom, have primarily been investigated in doped systems where charges are long considered indispensable. Here, we present an alternative route to ultra-efficient trion emission from an intrinsic, defect-free semiconductor via a transfer mechanism. By exciting trions in two-dimensional tungsten-diselenide donors and transferring them into one-dimensional carbon-nanotube acceptors in mixed-dimensional heterostructures, we circumvent the usual carrier requirement, overcoming intrinsic Auger-quenching limitations. Benefitting from a reservoir effect induced by dimensional heterogeneity, this process achieves trion emission efficiencies increased by over 100-fold compared to conventional doping-based approaches, and remains robust across diverse doping conditions. Our findings extend the exciton transfer paradigm to the three-body quasiparticles, offering a new platform for advancing excitonic physics and trion-based optoelectronic/spintronic applications.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
11 pages, 5 figures
Metal hydrides achieve high-Tc superconductivity at low pressure by mimicking high-pressure H3S chemical bonding
New Submission | Superconductivity (cond-mat.supr-con) | 2026-02-17 20:00 EST
Wendi Zhao, Shumin Guo, Chengda Li, Abhiyan Pandit, Tian Cui, Defang Duan, Maosheng Miao
Compressed hydrides are promising candidates for high-temperature superconductivity, yet achieving simultaneous structural stability and high-Tc at low pressures remains challenging. Here, we introduce a new mechanism for accomplishing this goal by mimicking the bonding characteristics of high-pressure H3S within metal hydrides. Using Li3CuH4 as an example, its Cu-H covalent interaction effectively mimics the core function of the S-H bonding in H3S. This interaction not only induces a high hydrogen-derived electronic density of states at the Fermi level, but also softens the hydrogen phonon modes, thereby significantly enhancing the electron-phonon coupling. Furthermore, embedding the strongly ionic Li3H lattice into the covalent Cu-H framework stabilizes the structure at significantly low pressures via a chemical-template effect, while maintaining high-Tc. Li3CuH4 exhibits excellent thermodynamic stability at 20 GPa, with a Tc of 39.25 K at 12 GPa. Further comprehensive high-throughput studies on Li3MH4 (M = transition metal) compounds uncover general principles applicable to a broader range of compounds. This work establishes a new paradigm for the simultaneous optimization of the stability and high-temperature superconductivity of metal hydrides through complementary sublattice interactions, thus advancing the search for practical and viable superconducting materials.
Superconductivity (cond-mat.supr-con)
17 pages, 5 figures
Altermagnetism, ARPES, symmetry, non-relativistic band splitting
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-02-17 20:00 EST
Jiayu Liu, Xun Ma, Xinnuo Zhang, Wenchuan Jing, Zhengtai Liu, Dawei Shen
Altermagnetism arises from composite real-space and spin-space symmetries, combining zero net magnetization with pronounced momentum-dependent spin splitting. This review highlights the pivotal role of angle-resolved photoemission spectroscopy (ARPES), along with its spin-resolved (SARPES) and circular-dichroism (CD-ARPES) variants, in directly visualizing nonrelativistic band splitting and spin textures in altermagnets. Within the spin-group framework, we distinguish ferromagnetic, antiferromagnetic, and altermagnetic orders and elucidate the symmetry origin of spin polarization. We then systematically review representative systems: the debated d-wave prototype RuO2, layered d-wave altermagnets KV2Se2O and Rb1-delta V2Te2O, and a series of g-wave compounds including MnTe (domain-tunable) and CrSb (topological), together with the noncoplanar antiferromagnet MnTe2 and other emerging candidate platforms. Overall, ARPES has become a key probe for resolving symmetry-driven spin splitting. Future advances in micro/nano-beam and in-situ spectroscopies, combined with strain and domain engineering, heterostructure design, and exploration of broader unconventional magnetic states, are expected to drive the joint evolution of altermagnetism and photoemission spectroscopy, paving the way for spintronic and correlated quantum research.
Materials Science (cond-mat.mtrl-sci)
57 pages, 10 figures
Josephson-like magnetic tunnel junction – transition from classical to quantum regime
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2026-02-17 20:00 EST
V.V.Yurlov, P.N. Skirdkov, K.A. Zvezdin, A.K. Zvezdin
We theoretically propose and analyze a Josephson-like magnetic tunnel junction (MTJ) structure that exhibits quantum spin dynamics analogous to those in superconducting Josephson junctions. By exploiting the isomorphism between the equations of motion for low-dissipation MTJs with easy-plane anisotropy and the Josephson phase dynamics, we construct a theoretical framework for realizing spintronic qubits. Within this framework, we identify the physical parameters – such as anisotropy constants, Gilbert damping, spin current amplitude, and geometric factors – that govern the transition from classical to quantum behavior. We show that different types of spintronic qubits, including analogs of charge, flux, and transmon superconducting qubits, can be implemented depending on the hierarchy of energy scales. A Hamiltonian formalism is developed for each regime, enabling an analytical treatment of the two-level quantum dynamics and estimation of coherence times. In particular, we demonstrate that the spin current can be used not only to excite but also to stabilize the qubit states through dissipation control. These findings provide a route toward integrating spintronic qubits into CMOS-compatible architectures and lay the groundwork for a fully spintronic platform for quantum computation.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Applied Physics (physics.app-ph)
Electronic Structure of Multilayer Graphene with Arbitrary Stackings
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2026-02-17 20:00 EST
Stacking geometry in multilayer graphene (MLG) provides an interesting degree of freedom to engineer its electronic structure near the Fermi level, wherein the linear bands in single layer graphene could retain or evolve into parabolic or flat bands. Using a tight-binding model, we carried out a detailed analytical analysis of the electronic band structures for arbitrarily stacked MLGs. We show that their low energy band dispersions near the Fermi level may be deduced from its substacks in isolation. The analytical solutions of the momenta with zero eigenvalue for an AA stacking allows us to generalize the results of the zero energy momenta for arbitrarily stacked MLGs. Moreover, we find that an interplay of parallel and rhombohedral stackings allows for flat band engineering and enhancement in arbitrarily stacked MLGs. The existence of flat bands in MLGs might offer another interesting platform for exploring the superconductivity in graphene systems beyond the twisted bilayer graphene.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Strongly Correlated Electrons (cond-mat.str-el)
13 pages, 7 figures
Magnonic spontaneous oscillation induced by parametric pumping
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2026-02-17 20:00 EST
Yi Li, Carissa Kiehl, Jinho Lim, Cliff Abbott, Pratap K. Pal, Alex J. Szymczak, Juliang Li, Ralu Divan, Clarence L. Chang, Charudatta Phatak, Dmytro A. Bozhko, Axel Hoffmann, Valentine Novosad
Spontaneous dynamic systems have attracted significant attention for their rich underlying physics such as phase-locking and synchronization. In this work, we report a new mechanism of generating magnetic spontaneous oscillation via parametric pumping. By applying a pump tone to excite propagating spin waves in a yttrium iron garnet delay line, four-wave mixing converts the pump mode into two phase-autonomous propagating magnon modes, i.e. a spontaneous mode with nearly twice the wavenumber of the pump mode and an idler mode with nearly zero wavenumber. This allows us to reliably generate ultrasharp spin wave dynamics with broad frequency tunability from the pump and magnetic field. We show that the spontaneous mode can be phase-locked to a probe tone, similar to an auto-oscillator. Furthermore, the spontaneous dynamics can be used to implement a high-gain magnonic parametric amplifier with a gain up to 40 dB. Our results open a new avenue for studying nonlinear magnonics and synchronization physics in propagating magnon geometry and for developing new magnonic devices.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
Anisotropic Core-Shell Swift Heavy Ion Tracks in beta-Ga2O3
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-02-17 20:00 EST
Huan He, Jiayu Liang, Shaowei He, Yanwen Zhang, Jiahui Zhang, Ziqi Cai, Tan Shi, Hang Zang, Flyura Djurabekova, Chaohui He, Junlei Zhao
Swift heavy ion (SHI) irradiation generates nanoscale ion tracks through intense electronic excitation, yet the microscopic mechanisms governing their morphology and phase stability in low symmetry oxides remain poorly understood. Here, a multiscale atomistic simulation framework is employed to investigate SHI-induced track formation and recovery in monoclinic beta-Ga2O3 over a wide range of electronic energy losses (Se) and crystallographic orientations. A sequence of distinct structural responses is identified with increasing Se: complete lattice recovery at low Se, recrystallization into a metastable gamma-Ga2O3 phase at intermediate Se, and the formation of core-shell ion tracks at high Se, consisting of an amorphous core surrounded by a recrystallized gamma-phase shell. Despite the essentially isotropic initial energy deposition, the final ion-track morphology exhibits pronounced crystallographic anisotropy, governed by orientation-dependent recovery dynamics. The superior recrystallization along [010] direction is attributed to its exceptionally high elastic stiffness. Notably, SHI irradiation perpendicular to the (100) plane induces a more severe structural response at low Se (less than 10 keV/nm), however, at higher Se, it yields a smaller residual ion track compared with the other orientations. The simulated ion-track sizes show excellent quantitative agreement with available experimental measurements over a broad range of Se values. These findings establish a unified atomic-scale picture of core-shell track formation and anisotropic recovery in beta-Ga2O3.
Materials Science (cond-mat.mtrl-sci)
Ballistic transport in nanodevices based on single-crystalline Cu thin film
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2026-02-17 20:00 EST
Yongjin Cho, Su Jae Kim, Min-Hyoung Jung, Yousil Lee, Hu Young Jeong, Young-Min Kim, Hu-Jong Lee, Seong-Gon Kim, Se-Young Jeong, Gil-Ho Lee
In ballistic transport, the movement of charged carriers is essentially unimpeded by scattering events. In this limit, microscopic parameters such as crystal momentum, spin and quantum phases are well conserved, allowing electrons to maintain their quantum coherence over longer distances. Nanoscale materials, like carbon nanotubes, graphene, and nanowires, exhibit ballistic transport. However, their scalability in devices is significantly limited. While deposited metal films offer excellent scalability for nanodevices, achieving ballistic transport in these films poses a challenge due to their short electronic mean free path. Here, we investigated the electronic transport in cross-geometry devices fabricated with 90 nm-thick copper films without grain boundaries. We observed ballistic transport in devices with channel width smaller than 150 nm below 85 K by measuring negative bend resistance. Our findings would open the opportunity for probing intrinsic quantum properties of Cu, and for realizing scalable low-loss signal transmission and high-quality interconnects in semiconductor devices.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Materials Science (cond-mat.mtrl-sci)
Evolution of magnetic correlation in doped Hubbard model with altermagnetic spin splitting
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2026-02-17 20:00 EST
Yinlong Li, Rana Imran Mushtaq, Ji Liu, Wing Chi Yu, Xiaosen Yang, Cho-Tung Yip, Ho-Kin Tang
The evolution of magnetic correlation in strongly correlated electron systems with altermagentic spin splitting remains largely unexplored. Here we investigate how spin splitting generated by spin-dependent next-nearest-neighbor hopping $ t’$ reshapes the Fermi surface nesting and van Hove singularities in the two-dimensional square-lattice Hubbard model, leading evolution of magnetic instabilities. Using the constrained-path quantum Monte Carlo method, we find the dominant magnetic correlation as functions of the filling and $ t’/t$ by computing the momentum-resolved spin structure factor. The analysis reveals a transition from antiferromagnetic $ (\pi,\pi)$ order in the isotropic, half-filled system to non-collinear spiral $ (\pi,q)$ order upon increasing the spin-dependent anisotropy or doping away from half-filling, ultimately entering a short-range correlation regime where stripe and spiral correlation coexist. These findings highlight a possible route to realizing spiral correlation in altermagnetic systems, potentially providing a platform for spintronic devices that exploit non-collinear spin textures.
Strongly Correlated Electrons (cond-mat.str-el)
14 figures
Operationalizing the Arrow of Time in mesoscopic: A Unified Framework for Non-equilibrium Matter
New Submission | Statistical Mechanics (cond-mat.stat-mech) | 2026-02-17 20:00 EST
Yikun Ren, Feixiang Xu, Ming Lin
What sustains a non-equilibrium system against fluctuations from within - as witnessed in non-equilibrium steady states, glassy relaxation, and even living organisms? Here we show that the arrow of time itself can be operationalized into a measurable physical quantity on mesoscopic particles - the eigen-phase displacement. This displacement gives rise to a non-local generalized force, the thermodynamic inertia force, which emerges from the integrated contribution of local constraints rather than as a conventional local force. It actively counteracts fluctuations and its algebraic structure is a semi-group, fundamentally distinct from the Lie group of Newton inertia, thereby encoding the irreversibility of time’s arrow. Building on this foundation, we construct a unified Microstate-Sequence-Mode-Coupling (MSS-MCT) theory. Its thermodynamic limit is defined by Microstate Sequence (MSS) theory, and its dynamical action is captured by a consequent mode-coupling theory (MCT). From this single first-principles framework, we simultaneously resolve two long-standing puzzles: it predicts the giant non-Gaussian parameter(1~10), closing the order-of-magnitude gap with experiments that standard mode-coupling theory could not explain; and it delivers a first-principles, non-fitting derivation of the universal polymer constant $ C_{1} \approx 16.7$ with merely 1 percent error - the most accurate theoretical prediction to date, dramatically surpassing the Adam-Gibbs and others. Our work establishes thermodynamic inertia as a foundational principle for non-equilibrium matter, bridging thermodynamic and dynamic descriptions from glassy relaxation to the maintenance of life.
Statistical Mechanics (cond-mat.stat-mech)
Localized-basis formulation of interacting Hamiltonians in flat topological bands: coherent states and coherent-like states for fractional physics
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2026-02-17 20:00 EST
In topological bands, it is impossible to construct exponentially localized Wannier functions while preserving the symmetries. Instead, in quantum Hall systems, one can define an overcomplete basis of spatially localized coherent states. In this work, we propose a unified framework for understanding the quantum Hall effect and Chern insulators from the perspective of localized bases, by extending the overcomplete basis of coherent states to Chern bands in terms of coherent-like states. Specifically, by representing both coherent states and coherent-like states as wave packets defined on a band, the difference between them can be encoded solely in the functional form of the wave packet in momentum space. Furthermore, for filling factor $ \nu=1/3$ , we define a local repulsive interaction Hamiltonian based on these bases and discuss properties of its ground states. In particular, by relating this Hamiltonian to previously studied models, we show that in quantum Hall systems it possesses exactly zero-energy ground states with topological degeneracy, thereby confirming that it serves as a model for fractional quantum Hall systems. In addition, we numerically verify that the Hamiltonian possesses topological degeneracy for representative Chern insulator models. An advantage of this formulation is that it allows fractional quantum Hall systems and various fractional Chern insulator systems to be discussed within a unified framework using the same Hamiltonian form. In addition, we discuss that coherent-like states can also be defined in $ \mathbb{Z}_2$ topological insulators. Corresponding to the fermionic time-reversal symmetry of the system, Kramers-degenerate coherent-like states can be naturally defined. The localized basis constructed from coherent-like states is expected to be useful for describing strongly correlated topological phases in flat-band systems.
Strongly Correlated Electrons (cond-mat.str-el), Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Materials Science (cond-mat.mtrl-sci)
14 pages, 5 figures
Disorder-Induced Topological Phases in a Two-Dimensional Chern Insulator with Strong Magnetic Disorder
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2026-02-17 20:00 EST
Devesh Vaish, Michael Potthoff
Strong directional disorder in local magnetic moments coupled to a Chern insulator gives rise to topological phases that cannot be continuously connected to the clean limit and are therefore genuinely disorder-driven. We demonstrate this in a spinful Qi-Wu-Zhang model of a two-dimensional Chern insulator coupled to disordered classical spins of unit length. The topological phase diagram is computed numerically using two complementary approaches: twisted boundary conditions and the topological Hamiltonian technique. Our results show that strong disorder can act as a fundamental topological mechanism rather than merely a perturbation. For strong exchange coupling, tuning the mass parameter reveals a transition between phases with different Chern numbers $ C$ . Remarkably, this transition is driven by zeros, rather than poles, of the disorder-averaged Green’s function crossing the chemical potential, and has no analogue in any clean system. We further identify a strong-coupling phase with $ C = 0$ that is nonetheless topologically nontrivial, characterized by a distinct Chern number $ C^{(\mathrm{S})} \neq 0$ over the manifold of classical spin configurations. This phase is also disorder-driven, as $ C^{(\mathrm{S})} = 0$ in the clean limit.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
15 pages, 10 figures
Quantitative models for excess carrier diffusion and recombination in STEM-EBIC experiments on semiconductor nanostructures
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2026-02-17 20:00 EST
Tobias Meyer, Christoph Flathmann, David A. Ehrlich, Patrick Paap-Peretzki, Jonas Lindner, Christian Jooß, Michael Seibt
The increased complexity and reduced size of (opto-)electronic devices demands for quantitative descriptions of excess carrier transport and recombination via various mechanisms. In addition, experimental methods capable of resolving carrier dynamics on the nanometer scale are required. In this paper, we present a quantitative model of a confined geometry including recombination at two surfaces, which is very generic for electron beam induced current measurements in a scanning transmission electron microscope - a method which offers atomic scale spatial resolution. The model is based on analytical considerations as well as finite element simulations and underlying assumptions are subjected to an in-depth discussion. Finally, the successfull application to experimental data obtained on the complex oxide SrTi0.995Nb0.005O3 demonstrates the practicality and robustness of the approach, which enables the precise determination of its bulk diffusion length of L = 10.2 +- 0.1 nm.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Materials Science (cond-mat.mtrl-sci), Applied Physics (physics.app-ph)
Polar unidirectional magnetotransport in $p-$type tellurene from quantum geometry
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2026-02-17 20:00 EST
Claudio Iacovelli, Pierpaolo Fontana, Victor Velasco, Chang Niu, Peide D. Ye, Marcus V. O. Moutinho, Caio Lewenkopf, Marcello B. Silva Neto
Unidirectional magnetoresistance, or electric magnetochiral anisotropy (eMChA), is a nonlinear magnetotransport phenomenon that arises in noncentrosymmetric conductors , where changes in resistance $ R(B)$ are: (i) chiral, $ \Delta R(B)/R(0)=2,\chi, {\bf I}\cdot{\bf B}$ , or (ii) polar, $ \Delta R(B)/R(0)=2,\gamma, {\bf I}\cdot({\bf P}\times{\bf B})$ , with eMChA coefficients $ \chi$ and $ \gamma$ . In [Phys. Rev. Lett. 135, 106602 (2025)], we showed that the eMChA in the conduction band of tellurene is polar ($ \chi=0$ , $ \gamma\neq 0$ ) and emerges from the quantum metric dipole due to its Weyl node and from the lone pair polarization $ {\bf P}$ . Here, we extend our work to the valence band of tellurene, where the eMChA is usually said to be chiral ($ \chi \neq 0, \gamma = 0$ ). We show that also a polar coefficient $ \gamma \neq 0$ emerges naturally through a downfolding procedure, in which remote Weyl-node containing bands induce momentum-space gradients of the quantum metric in the low-energy levels, activating finite metric dipoles. Combining semiclassical Boltzmann transport with a $ {\bf k}\cdot{\bf p}$ description of tellurene, our numerical calculations agree quantitatively with doping ($ \mu$ ) dependent second-harmonic measurements of the longitudinal voltage $ V^{2\omega}\parallel(\mu)$ in perpendicular field. The combined chiral and polar characters ($ \chi\neq0, \gamma\neq 0)$ of the eMChA in tellurene also explains the shift in the angular ($ \phi$ ) dependence of $ V^{2\omega}\parallel(\phi)$ for in plane fields. Our results demonstrate that the polar eMChA can arise in topologically trivial bands through multiband effects and establishes tellurene as a platform for quantum-geometric rectification in both electron and hole regimes.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
21 pages, 10 figures
MLIP-MC: A Framework for Adsorption Simulations using Machine-Learned Interatomic Potentials
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-02-17 20:00 EST
Connor W. Edwards, Fengxu Yang, Konstantin Stracke, Jack D. Evans
Grand canonical Monte Carlo (GCMC) simulations are essential for screening metal-organic frameworks (MOFs) for gas adsorption, yet their accuracy is limited by underlying interatomic potentials. Universal machine-learned interatomic potentials (MLIPs), trained on diverse chemical datasets, promise zero-shot prediction without system-specific training. We introduce MLIP-MC, an open-source Python framework to conduct GCMC simulations with MLIPs, and use this framework to benchmark a series of universal models, including MACE-MP-0, ORB-v3, and fairchem ODAC, for CO2 adsorption on ZIF-8, ZIF-4, and Mg-MOF-74. All universal models exhibit systematic biases, consistently over- or underestimating adsorption energetics. Crucially, accuracy depends on training data composition: only models trained on MOF-adsorbate interactions achieve reasonable agreement with a density functional theory derived reference. Errors grow linearly with CO2 uptake, reflecting compounding inaccuracies in adsorbate-adsorbate interactions. Our results demonstrate that current universal MLIPs require finetuning for quantitative adsorption predictions and demonstrate the power of MLIP-MC to rapidly test models.
Materials Science (cond-mat.mtrl-sci)
15 pages, 4 figures
Interplay between non-Fermi liquid and non-Hermiticity: A multi-method study of non-Hermitian multichannel Kondo model
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2026-02-17 20:00 EST
Wei-Zhu Yi, Yun Chen, Jun-Jun Pang, Hong Chen, Baigeng Wang, Rui Wang
Non-Hermitian multichannel Kondo problems host both non-Fermi liquid and non-Hermitian physics, which provide a prototypical model to explore exotic collective quantum phenomena driven by the two different ingredients. Here, we first propose an experimental setup that realizes this model with exact channel symmetry as well as a controllable PT symmetry. Then, we perform a multi-method study of this model, focusing on the low-energy spectrum, the thermodynamic quantities, and the transport properties associated with different fixed points. Using the Bethe ansatz approach, we identify existence of the Yu-Shiba-Rusinov-like state previously found in the non-Hermitian single-channel Kondo model. Then, based on non-Hermitian numerical renormalization group calculations, we reveal clear numerical signatures of the Yu-Shiba-Rusinov state emerging in the relatively strong non-Hermiticity regime of the PT-asymmetric model. Furthermore, our boundary conformal field theory, which is found to be applicable for the PT-symmetric model, uncovers an anomalous temperature dependence of the Kondo conductance, which is beyond conventional Hermitian Kondo systems.
Strongly Correlated Electrons (cond-mat.str-el)
Coulomb Interaction in Atomically Thin Semiconductors and Density-Independent Exciton-Scattering Processes
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2026-02-17 20:00 EST
Henry Mittenzwey, Andreas Knorr, Thorsten Deilmann
In quantum-kinetic approaches to the dynamics of Coulomb-bound many-body correlations such as excitons, trions, biexcitons or higher-order correlations, a detailed knowledge of the many-body Coulomb Hamiltonian serving as a starting point is important. In this manuscript, the second-quantized description of the Coulomb interaction between Bloch electrons in a Heisenberg-equation-of-motion approach in atomically thin semiconductors is derived and reviewed. Emphasis is put on a discussion of Umklapp processes and the dielectric screening including all local-field effects. A link between \textit{ab initio} methods of screening and few-band models in effective-mass approximations for the quantum kinetics is established and all important Coulomb scattering processes contributing to the exciton energy landscape and density-independent exciton scattering are discussed.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
Non-monotonic Irreversibility in Polytropic Steering
New Submission | Statistical Mechanics (cond-mat.stat-mech) | 2026-02-17 20:00 EST
Cong Fu, Youhui Lin, Shanhe Su, Yu-Han Ma
The efficient manipulation of thermodynamic states within the finite time is fundamentally constrained by the intrinsic dissipative cost. While the slow-driving regime is well-characterized by a universal $ 1/\tau$ -scaling of irreversibility, the physics governing fast, non-adiabatic transitions remains elusive. Here, we propose the polytropic steering protocols that provide an exact analytical bridge between the isothermal and adiabatic limits for Brownian particles far-from-equilibrium. We demonstrate that for any protocol duration $ \tau$ , the system can be precisely steered along a prescribed polytropic trajectory, revealing a striking non-monotonic dependence of irreversibility on the driving rate. Contrary to the near-equilibrium paradigm where faster driving necessitates higher energetic costs, we identify a most-irreversible timescale, beyond which dissipation is anomalously suppressed by rapid driving. By mapping these protocols onto a broad class of controllable thermodynamic cycle, we establish power-efficiency tradeoffs and position the polytropic index as a genuine thermodynamic control knob for the rational design of high-speed, high-performance microscopic thermal machines.
Statistical Mechanics (cond-mat.stat-mech)
11 pages, 3 figures, comments are welcome
Relativistic spin-momentum locking in ferromagnets
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-02-17 20:00 EST
Xujia Gong, Amar Fakhredine, Carmine Autieri
The relativistic spin-momentum locking has been proven in time-reversal-breaking classes of materials with zero net magnetization in the non-relativistic limit, such as altermagnets and other non-collinear magnets. Using density functional theory calculations, we aim to show relativistic spin-momentum locking in ferromagnets, focusing on a broad class of ferromagnetic materials with magnetic sites connected by rotational symmetry, and compare with fcc Ni. In SrRuO3, the antisymmetric exchange interaction produces a spin canting orthogonal to the easy axis, while in all other cases, spin canting is forbidden. Even when the canted magnetic moment in real space is forbidden, relativistic spin-momentum locking shows sizable contributions in k-space. Using prototypical ferromagnets such as orthorhombic SrRuO3, hexagonal CrTe and CrAs with the NiAs crystal structure, half-Heusler MnPtSb, and fcc Ni, we demonstrate that relativistic spin-momentum locking can generate strong effects in ferromagnets. Subdominant components of centrosymmetric ferro-magnetic materials with magnetic sites connected by rotational symmetry host spin-momentum locking similar to altermagnets, while noncentrosymmetric MnPtSb hosts relativistic p-wave due to the spin-orbit coupling. Fcc Ni shows a more complex behavior with a combination of two spin-momentum locking patterns characteristic of altermagnets. Because ferromagnets typically have larger bandwidths than altermagnets, they provide a promising platform for observing even-wave relativistic spin-momentum locking and associated emergent phenomena. From an application standpoint, relativistic spin-momentum locking governs symmetry-allowed spin Hall currents, spin photocurrents, and other momentum-dependent spin responses in k-space.
Materials Science (cond-mat.mtrl-sci), Strongly Correlated Electrons (cond-mat.str-el)
10 pages, 5 figures in the main text
Measuring Spin-Charge Separation by an Off-diagonal Dissipative Response
New Submission | Quantum Gases (cond-mat.quant-gas) | 2026-02-17 20:00 EST
Fractionalization of symmetry - exemplified by spin-charge separation in the 1D Hubbard model and fractional charges in the fractional quantum Hall effect - is a typical strongly correlated phenomena in quantum many-body systems. Despite the success in measuring velocity differences, however, it is still quite challenging in probing emergent excitations’ anomalous dimensions experimentally. We propose a off-diagonal dissipative response protocol, leveraging dissipative response theory (DRT), to directly detect spin-charge separation. By selectively dissipating spin-$ \downarrow$ particles and measuring the spin-$ \uparrow$ response, we uncover a universal temporal signature: the off-diagonal response exhibits a crossover from cubic-in-time ($ t^3$ ) growth at short times to linear-in-time ($ t$ ) decay at long times. Crucially, the coefficients $ \varkappa^s$ (short-time) and $ \varkappa^l$ (long-time) encode the distinct anomalous dimensions and velocities of spinons and holons, providing unambiguous evidence of fractionalization. This signal vanishes trivially without spin-charge separation. Our predictions, verified numerically via tDMRG, with microscopic parameters linking with Luttinger parameters by Bethe ansatz, establish off-diagonal dissipative response as a probe of quantum fractionalization in synthetic quantum matter.
Quantum Gases (cond-mat.quant-gas), Strongly Correlated Electrons (cond-mat.str-el)
6 pages, 2 figures
Tuning magnetic, lattice, and transport properties in CoNb3S6 via Fe doping
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-02-17 20:00 EST
Deepu Kumar, Joydev Khatua, Mukesh Suthar, Rajesh Kumar Ulaganathan, Jeonghun Kang, Hengbo Cui, Sihun Seong, Seo Hyoung Chang, Kee Hoon Kim, Raman Sankar, Maeng-Je Seong, Kwang-Yong Choi
We present a comprehensive investigation of the effects of Fe doping on the lattice dynamics, magnetic ordering, and magneto-transport properties of the intercalated van der Waals antiferromagnets Co1-xFexNb3S6 (x = 0.1 and 0.3). Temperature- and polarization-dependent Raman scattering measurements reveal a pronounced blue shift of the 180 cm-1 phonon mode with increasing Fe concentration, indicating enhanced sensitivity of lattice vibrations to Fe-induced structural and mass effects. While the temperature evolution of the phonon modes is dominated by conventional anharmonic phonon softening, subtle anomalies observed near the Néel temperature for x = 0.1 point to weak spin-phonon coupling. Electrical transport and magnetic susceptibility data show clear signatures of the antiferromagnetic phase transitions at TN ~ 20.5-23.7 K for x = 0.1 and TN ~ 32.0 K for x = 0.3. Out-of-plane magnetization measurements reveal hysteretic behavior with two field-induced transitions for x =0.1, which evolve into a single hysteresis loop at x =0.3, signaling a subtle reconstruction of the magnetic ground state. Magneto-transport measurements for x = 0.1 further display a butterfly-shaped hysteretic magnetoresistance and a weak topological Hall effect; however, both features are strongly suppressed at x = 0.3. These results illustrate the critical role of Fe-induced magnetic structure reconstruction in fine-tuning topological and magnetic transport phenomena in intercalated van der Waals antiferromagnets.
Materials Science (cond-mat.mtrl-sci)
Non-Hermiticity Induced Universal Anomalies in Kondo Conductance
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2026-02-17 20:00 EST
Wei-Zhu Yi, Yun Chen, Jun-Jun Pang, Hong Chen, Baigeng Wang, Rui Wang
Strong correlation, when combined with dissipation in open systems, can lead to a variety of exotic quantum phenomena. Here, we study nontrivial interplays between non-Fermi liquid behaviors emerging from strong correlation and non-Hermiticity arising from open systems. We propose a practical physical setup that realizes a non-Hermitian multichannel Kondo model. We identify a weak-coupling local moment fixed point and a strong-coupling non-Fermi liquid fixed point under PT symmetry, both are enriched by the non-Hermitian effect. Remarkably, universal unconventional Kondo conductance behaviors are found for both cases, which are distinct from all previously studied Kondo systems. Particularly, we show that an anomalous upturn of conductance could take place with increasing the temperature, originating from the interplay between non-Fermi liquid and non-Hermiticity. Our results identify a novel class of transport phenomena unrecognized before, driven by intertwined effects of correlation and dissipation.
Strongly Correlated Electrons (cond-mat.str-el)
Quantitative measurements of the lift force acting on a sphere sliding along a liquid-liquid interface
New Submission | Soft Condensed Matter (cond-mat.soft) | 2026-02-17 20:00 EST
Hao Zhang, Zaicheng Zhang, Abdelhamid Maali
This work explores the lift force experienced by a particle moving in a viscous fluid near a liquid-liquid interface. The lift force is induced by the interaction between the viscous flow generated by the particle’s motion and the deformation of the soft interface. The factors influencing the lift force including the velocity, the viscosity, and the sphere radius, and the separation distance were systematically studied. The experiments demonstrate that the lift force intensifies as the particle approaches the interface, and saturates at shorter distances. These findings are consistent with predictions made using soft lubrication theory and numerical calculations, providing strong validation for the theoretical framework.
Soft Condensed Matter (cond-mat.soft)
Ion Implantation Enhanced Nucleation Facilitates Heat Transport across Atomically-Sharp Semiconductor Interfaces
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2026-02-17 20:00 EST
Jinwen Liu, Zifeng Huang, Lina Yang, Yachao Zhang, Xingqiang Zhang, Kun Zhang, Xufei Guo, Yuxiang Wang, Hong Zhou, Jincheng Zhang, Wei Wang, Yue Hao, Zhe Cheng
Overheating is a critical bottleneck limiting the performance and reliability of next-generation high-power and high-frequency electronics. Interfacial thermal resistance constitutes a significant portion of the total thermal resistance. In this study, we report an ultrahigh thermal boundary conductance (TBC) of approximately 800 MW/m2-K at the atomically-sharp AlN-SiC interface, achieved through an ion implantation-enhanced nucleation epitaxy technique. This value is among the highest TBC values reported for semiconductor interfaces, confirmed by structural characterizations which show an ultrahigh-quality interface. Atomistic Green Function calculations reveal that elastic phonon transmission dominates the interface, with nearly half of the acoustic modes (0-15 THz) exhibiting near-unity transmission due to the atomically sharp structure. Furthermore, using high-energy-resolution electron energy loss spectroscopy, we probe vibrational properties with nanometer spatial resolution and identify unique interfacial phonon modes connecting the mismatched phonon spectra, confirmed by molecular dynamics simulations. The ultrahigh TBC is attributed to both the high elastic phonon transmission due to the high quality interfaces and the inelastic phonon scattering channel due to interfacial phonon modes. These findings not only advance the fundamental understanding of interfacial thermal transport but also provide a pathway for effective thermal management in emerging electronic devices.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Materials Science (cond-mat.mtrl-sci)
Influence of Disorder on Exciton Transfer in a Quantum Dot Chain with Short-Range Interaction and a Side-Coupled Defect
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2026-02-17 20:00 EST
Aleksey Vlasov, Pavel Golovinski
This paper considers the propagation of excitons in linear chains of QDs with a side defect, located on a dielectric substrate. This configuration is suitable for spatially selective excitation of the system by pulsed optical radiation through the side defect. The dynamics of excitation in the chain is governed by structural disorder, caused by technological variations in the parameters of the QDs themselves and their mutual arrangement. To describe the quantum properties of excitons in the QD chain, a model Hamiltonian is used, taking into account the coupling of neighboring QDs due to dipole-dipole interaction. The localization of stationary states is calculated depending on the magnitude of disorder and the chain length. A criterion is introduced that determines the boundaries of the phase transition from the localized to the delocalized excitation phase. The dynamics of exciton transfer along the QD chain is calculated depending on its length and degree of disorder for linear excitation of the system by a laser pulse. It is shown that dynamic localization emerging in the system corresponds to the stationary localization properties of the states of the chain with a side defect.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
12 pages, 4 figures
Non-exponential relaxation without dynamic heterogeneity in van der Waals liquids above the melting point
New Submission | Soft Condensed Matter (cond-mat.soft) | 2026-02-17 20:00 EST
Rolf Zeißler, Niklas Pfeiffer, Thomas Blochowicz
We investigate the influence of dynamic heterogeneity on the spectral shape of structural relaxation in van der Waals liquids above the melting point by means of depolarized dynamic light scattering. To this end, we study optically anisotropic probe molecules both in the bulk and when diluted in an optically isotropic solvent. Strikingly, the relaxation shape of the probe molecules in dilution is indistinguishable from that of the pure liquid composed of the probe molecules. By contrast, when explicit dynamic heterogeneity is introduced, e.g., through internal degrees of freedom or a distribution of probe molecule sizes, the relaxation shape becomes sensitive to the solvent concentration. These findings indicate that dynamic heterogeneity has a negligible influence on the rotational dynamics of single component van der Waals liquids above the melting point, despite the pronounced non-exponential character of their relaxation shape.
Soft Condensed Matter (cond-mat.soft)
From interface-limited to Auger-dominated carrier dynamics in $π$-SnS
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-02-17 20:00 EST
Hugo Laurell, Kevin Xiong, Nedjma Ouahioune, Thomas Kjellberg Jensen, Jonah R. Adelman, Kylie J. Gannan, Rafael Quintero-Bermudez, Lior Verbitsky, Han K. D. Le, Anders Mikkelsen, Peidong Yang, Carl Hägglund, Stephen R. Leone
Metastable cubic tin(II) sulfide ($ \pi$ -SnS) is an earth-abundant semiconductor whose three-dimensionally bonded chiral lattice may overcome the short minority-carrier lifetime of orthorhombic SnS while maintaining a near-ideal bandgap for tandem photovoltaics. Despite its promise, ultrafast carrier cooling and recombination mechanisms over illumination density remain poorly constrained. We use core-level extreme-ultraviolet attosecond transient absorption spectroscopy at the Sn $ 4d$ edge to track carrier injection, cooling, and recombination in $ \pi$ -SnS with element- and orbital-specific sensitivity. Following femtosecond near-infrared excitation, the Sn $ 4d\rightarrow$ CB onset exhibits conduction-band state filling and a carrier-induced edge shift, enabling extraction of density-dependent kinetics. The transient response follows a biexponential decay with a fast hot-carrier cooling component and a slower recombination component. At low carrier densities, recombination is consistent with interface-limited processes, whereas above $ \sim1\times10^{20}$ cm$ ^{-3}$ both cooling and recombination accelerate, indicating a crossover to carrier-carrier interaction-dominated dynamics. Coherent phonon oscillations with a period of $ \sim188$ fs reveal coupling between electronic excitation and lattice motion. These results provide a comprehensive picture of nonequilibrium carrier and phonon dynamics in cubic SnS, reveal a change of mechanisms over a range of carrier densities, and establish the value of using attosecond transient absorption spectroscopy to study ultrafast processes in complex semiconductors that have optoelectronic and energy-conversion applications.
Materials Science (cond-mat.mtrl-sci)
Machine Learning-integrated Multiscale Simulation Framework: Bridging Scales in Associative Polymer-Colloid Suspensions
New Submission | Soft Condensed Matter (cond-mat.soft) | 2026-02-17 20:00 EST
Jalal Abdolahi, Dominic M. Robe, Ronald G. Larson, Elnaz Hajizadeh
Predicting the rheological behavior of associative polymers bridging colloidal particles into transient networks is fundamentally challenging because the coupled spatiotemporal scales prevent efficient molecular-fidelity modeling. We address this through a novel, unified multiscale simulation framework for telechelic polymer-colloid suspensions integrating: explicit-chain Brownian dynamics resolving polymer-particle association kinetics; active learning metamodels compressing kinetics into efficient surrogates; and Population Balance-Brownian Dynamics (Pop-BD) computing network-scale dynamics from metamodel predictions. Validated against explicit-chain Brownian dynamics, our framework accurately reproduces time-and frequency-dependent stress relaxation moduli, enabling simulations of larger systems over longer timescales. Systematic investigations reveal that network connectivity exhibits critical transitions at specific chain-to-particle ratios, with bond density and lifetime correlating to enhanced relaxation times and moduli. Higher particle volume fractions yield more persistent bonds and slower relaxation. This framework connects chain-level dynamics to macroscopic rheology, enabling computationally efficient rational design of associative colloidal materials for waterborne coatings and soft-matter applications.
Soft Condensed Matter (cond-mat.soft), Materials Science (cond-mat.mtrl-sci)
Bulk-boundary correspondence in topological two-dimensional non-Hermitian systems: Toeplitz operators and singular values
New Submission | Statistical Mechanics (cond-mat.stat-mech) | 2026-02-17 20:00 EST
In contrast to eigenvalue-based approaches, we formulate the bulk-boundary correspondence for two-dimensional non-Hermitian quadratic lattice Hamiltonians in terms of Toeplitz operators and singular values, which correctly capture the stability, localization, and scaling of edge and corner modes. We show that singular values, rather than eigenvalues, provide the only stable foundation for topological protection in non-Hermitian systems because they remain robust under translational-symmetry-breaking perturbations that destabilize the eigenvalue spectrum, rendering it unsuitable for topological classification. Building on Toeplitz operator theory, we establish general results for non-Hermitian Hamiltonians defined on half and quarter planes, relating the topological indices of the associated Toeplitz operators to the number of finite-size singular values that are separated from the bulk singular-value spectrum and vanish in the thermodynamic limit. This yields a precise bulk-boundary correspondence for edge and corner modes, including higher-order topological phases, without requiring crystalline symmetries. We illustrate our general results with detailed examples exhibiting topologically protected families of edge states, coexisting edge and corner modes, and phases with both gapped bulk and edges supporting only stable corner modes. The latter is exemplified by a non-Hermitian generalization of the Benalcazar-Bernevig-Hughes model.
Statistical Mechanics (cond-mat.stat-mech), Strongly Correlated Electrons (cond-mat.str-el), Mathematical Physics (math-ph), Quantum Physics (quant-ph)
29 pages
Ultrasensitive strain modulation of terahertz magnons at a magnetic phase transition
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-02-17 20:00 EST
Lichen Wang, Sajna Hameed, Yiran Liu, Manuel Knauft, Kazuki Higuchi, Maximilian Krautloher, Sonia Francoual, Giniyat Khaliullin, Huimei Liu, Matteo Minola, Bernhard Keimer
Antiferromagnets typically host spin-wave (magnon) excitations in the terahertz (THz) regime, offering a promising platform for high-speed magnonic information technologies. Harnessing these excitations requires sensitive control of their spectral properties. Here we use resonant x-ray diffraction and Raman scattering to demonstrate uniaxial-strain control of the antiferromagnetic (AFM) ground state and THz magnon excitations in the layered Mott insulator Ca$ _2$ RuO$ _4$ . Although the states separated by the strain-induced phase transition differ only by the sign of the weak and partially frustrated interlayer interaction, their magnon energies differ by more than 10% (~ 0.3 THz). Our theoretical analysis explains this surprising observation by tracing the origin of both the sign reversal of the interlayer coupling and the magnon energy to the spin-orbital composition of the Ru valence electrons. The extreme strain sensitivity of the THz magnon energy near a magnetic phase transition opens up pathways towards a new generation of transition-edge magnonic devices.
Materials Science (cond-mat.mtrl-sci)
Unified Phase-Field Framework for Antiferroelectric, Ferroelectric and Dielectric Phases: Application to HZO Thin Films
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-02-17 20:00 EST
P. Pankaj, Sandeep Sugathan, Si Joon Kim, Pil-Ryung Cha
Polycrystalline hafnia-based thin films exhibit mixed ferroelectric (FE), antiferroelectric (AFE), and dielectric (DE) behavior, with switching characteristics strongly influenced by microstructure and phase distribution. Here, we develop a unified grain-resolved three-dimensional phase-field framework for metal-insulator-metal capacitors that simultaneously captures ferroic phase characteristics in realistic polycrystalline microstructures by explicitly incorporating grain topology and crystallographic orientation. Antipolar sublattice kinetics are represented via the coupled evolution of macroscopic and staggered polarization order parameters. All thermodynamic and kinetic parameters are calibrated to experimental P-E hysteresis loops and held fixed across all simulations. The results show that phase fractions primarily determine hysteresis character, while vertical segregation of AFE- and FE-rich regions systematically reduces the effective coercive field (Ec) under identical electrical loading. Grain-resolved analysis reveals that this reduction arises from microstructure-assisted switching pathways and electrostatic coupling between layers. These findings demonstrate that vertical phase arrangement provides a viable strategy to engineer switching behavior in hafnia-based ferroic capacitors and highlight the importance of explicit microstructural resolution for quantitative phase-field modeling.
Materials Science (cond-mat.mtrl-sci)
Phason-Driven Diversity of Nucleation Pathways in Icosahedral Quasicrystals
New Submission | Soft Condensed Matter (cond-mat.soft) | 2026-02-17 20:00 EST
Gang Cui, Lei Zhang, Pingwen Zhang, An-Chang Shi, Kai Jiang
The nucleation of quasicrystals remains a fundamental puzzle, primarily due to the absence of a periodic translational template. Here, we demonstrate that phasons - hidden degrees of freedom unique to quasiperiodic order - drive diverse nucleation pathways in icosahedral quasicrystals (IQCs). Combining a Landau free-energy model with the spring pair method, we compute distinct critical nuclei and their corresponding minimum energy paths. At low temperatures, a direct, symmetry-preserving pathway dominates. In contrast, higher temperatures promote a “symmetry detour” that reduces the nucleation barrier via a lower-symmetry critical nucleus. Remarkably, while the resulting bulk IQCs exhibit distinct real-space symmetries, they remain thermodynamically degenerate with identical diffraction patterns. We resolve this paradox within the high-dimensional projection framework, showing that phason shifts modulate real-space symmetry without altering bulk thermodynamics. Our findings establish phasons as the structural origin of pathway diversity, offering a new physical picture for the emergence of quasiperiodic order.
Soft Condensed Matter (cond-mat.soft), Computational Physics (physics.comp-ph)
Ion Concentration and Voltage Imaging with Fluorescent Nanodiamonds
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2026-02-17 20:00 EST
Patrick Voorhoeve, Hiroshi Abe, Takeshi Ohshima, Anita Quigley, Rob Kapsa, Nikolai Dontschuk, Philipp Reineck
The nitrogen-vacancy (NV) center in diamond exists in different charge states with distinct photoluminescence properties, which are sensitive to the nanoscale electrochemical environment. Hence, the NV charge state is emerging as a powerful all-optical platform for nanoscale sensing and imaging. Although significant progress has been made in engineering near-surface NV centers in bulk diamond, controlling the NV charge state in fluorescent nanodiamonds (FNDs) has proven challenging, limiting the sensitivity and reliability of FND-based charge state sensing. Here, we demonstrate reliable, reversible switching between the fluorescent NV$ ^0$ and non-fluorescent NV$ ^+$ charge states in sub-30 nm FNDs via surface oxidation and hydrogenation, respectively, for single particles and particle powder. In aqueous electrochemical cells, we demonstrate voltage and ion concentration imaging based on the NV charge state in self-assembled FND layers on transparent substrates. Applied voltages reliably modulate the FND PL with a sensitivity of up to 16 mV Hz$ ^{-1/2}$ . Importantly, FND PL is also modulated by local changes in salt concentration with a sensitivity of up to 1.8% per millimolar NaCl, enabling all-optical imaging of ion concentration gradients at the microscale. Our results represent a significant step toward realizing fast, stable, and scalable nanoscale charge- and voltage-imaging technologies with sub-micrometer spatial resolution.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
Coexistence of Topological Anderson Insulator and Multifractal Critical Phase in a Non-Hermitian Quasicrystal
New Submission | Disordered Systems and Neural Networks (cond-mat.dis-nn) | 2026-02-17 20:00 EST
The interplay of topology, disorder, and non-Hermiticity gives rise to phenomena beyond the conventional classification of quantum phases. We propose a one-dimensional non-Hermitian Su-Schrieffer-Heeger model with quasiperiodically modulated nonreciprocal intracell hopping. We show that quasiperiodic modulation can substantially enhance topological robustness and, remarkably, induce a non-Hermitian topological Anderson insulator (TAI) phase. Beyond the topological transition, increasing nonreciprocity drives a cascade of localization transitions in which all bulk eigenstates evolve from extended to multifractal critical and ultimately to localized states. Strikingly, the extended-to-critical transition coincides exactly with a real-complex spectral transition. We establish complete phase diagrams and derive exact analytical boundaries for both topological and localization transitions, uncovering an unanticipated coexistence of TAI and multifractal critical phases. Finally, we propose a feasible implementation in topolectrical circuits. Our results reveal a new paradigm for the cooperative effects of topology, quasiperiodicity, and non-Hermiticity.
Disordered Systems and Neural Networks (cond-mat.dis-nn)
7 pages, 4 figures
A Magnon-Based Electric Field Controlled Magnetoelectric Device for Energy-Efficient Logic-in-Memory
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-02-17 20:00 EST
Rongqing Cong, Sajid Husain, Yumin Su, Sasikanth Manipatruni, Naveed Ahmed, Dmitri E. Nikonov, Ramamoorthy Ramesh, Kaiyuan Yang, Zhi Jackie Yao
We demonstrate a non-volatile magnetoelectric magnonic memory (MEMM) that enables fully electrical write/read via direct magnon-driven sensing in an insulating antiferromagnet. A fabricated SrIrO3/La-BiFeO3/SrIrO3 trilayer exhibits sub-100 ps switching, a remnant polarization of 20 uC/cm2, and a readout voltage contrast close to 1mV between high and low-resistance states. To connect device physics to circuit behavior, we develop and experimentally validate a compact circuit model that captures spin Hall injection and spin transport. Simulations with optimized material parameters predict output voltages > 100mV, enabling cascading without external amplification. Using this framework, we design MEMM-based memory and logic blocks, including a 1T1R array, two inverter implementations (complementary two-device and single-device), and a three-input majority gate, and evaluate deep-pipelined operation. The model projects switching energies down to 1 aJ per operation and logic propagation delays of 30-60 ps, indicating MEMM as a promising platform for energy-constrained, high throughput computing.
Materials Science (cond-mat.mtrl-sci)
Interaction-Enabled Two- and Three-Fold Exceptional Points
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2026-02-17 20:00 EST
We propose a novel type of exceptional points, dubbed interaction-enabled $ n$ -fold exceptional points [EP$ n$ s ($ n=2,3$ )] – EP$ n$ s protected by topology that are prohibited at the non-interacting level. Specifically, we demonstrate that both bosonic and fermionic systems host such interaction-enabled EP$ n$ s ($ n=2,3$ ) in parameter space that are protected by charge U(1), pseudo-spin-parity, and $ PT$ symmetries. The interaction-enabled EP2s are protected by zero-dimensional topology and give rise to qualitative changes in the loss rate, an experimentally measurable quantity for cold atoms. Furthermore, we reveal that interactions enable EP3s protected by one-dimensional topology beyond the point-gap topological classifications, suggesting the potential presence of a broader class of interaction-enabled non-Hermitian degeneracies.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Strongly Correlated Electrons (cond-mat.str-el), Quantum Physics (quant-ph)
7+11 pages, 3+6 figures
NMR study on equilateral triangular lattice antiferromagnet Ba2La2CoTe2O12
New Submission | Statistical Mechanics (cond-mat.stat-mech) | 2026-02-17 20:00 EST
Keito Morioka, Takayuki Goto, Masari Watanabe, Yuki Kojima, Nobuyuki Kurita, Hidekazu Tanaka, Satoshi Iguchi, Takahiko Sasaki
We report a 139La-NMR study of Ba2La2CoTe2O12, S = 1/2 equilateral triangular-lattice antiferromagnet with easy-plane anisotropy at low temperatures. This compound undergoes a magnetic phase transition at TN = 3.26 K into an ordered state with the 120 degree spin structure. Under magnetic fields above 3T, TN splits into TN1 and TN2, which correspond to the transitions from the paramagnetic phase to the up-up-down (uud) phase and from the uud phase to the triangular coplanar phase, respectively. The NMR spin-lattice relaxation rate 1/T1 exhibits a critical divergence at TN1, indicating the onset of long-range magnetic order. At TN2, the NMR-linewidth measured at 5.4 T exhibits an anomalous decrease, which we attribute to a change in the spin structure from the uud to the triangular coplanar phase.
Statistical Mechanics (cond-mat.stat-mech)
J. Low. Temp. Phys. 222, 47 (2026)
Dynamical screening effects on formation of swift heavy ions damage in GaN
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-02-17 20:00 EST
S. V. Moskalets, R. A. Rymzhanov, A. E. Volkov
We used a multiscale model to study the damage caused by swift heavy ions in GaN. The model combines Monte Carlo and molecular dynamics simulations to analyze the material response to the excitation initiated by a projectile. We found that the most appropriate simulation approach couples the dynamical screening of charges of target atoms during the scattering of fast electrons with the Tersoff-Brenner interatomic potential describing atomic dynamics in the excited target. The simulations demonstrate the formation of damaged ion tracks with an amorphous core, containing voids filled with nitrogen. The core is surrounded by a damaged crystalline region containing edge dislocations, consistent with experimental observations.
Materials Science (cond-mat.mtrl-sci)
22 pages, 11 figures, 1 table
Synergism in radiation effects in condensed matter. Fundamental and application aspects
New Submission | Other Condensed Matter (cond-mat.other) | 2026-02-17 20:00 EST
Boris Oksengendler, Muhsin Ashurov, Sultan Suleymanov, Nigora Turayeva, Farida Iskandarova, Gulnoza Akhmatova, Rahmatillo Ibrohimov
The impressive success achieved by condensed matter radiation physics over its 170-year development period is related to the solution of problems in three areas, the emergence of new materials, the development of new sources of radiation, and the formulation of new concepts with a wide range of applications. In the borderlands of the 20th and 21st centuries, significant changes occurred in each of these aspects (not-so-catastrophic disasters, R. Tom). A major role was played by the emergence of a new ideology - Complexity, which led to the birth of four paradigms, self-organization, dynamic chaos, self-organized criticality and nonadditivity (the first three are related to the concept of synergetics, the fourth - synergism). This article is devoted to radiation synergism, with an emphasis on combinations of radiation and other effects. It presents methods of graphical techniques to identify the specific issue of synergism effects, which is the non-additivity of the overall radiation effect. A parameter expression is proposed to account for the non-additivity of the radiation effect in the experiment, which can be compared to the q parameter introduced by Tsallis in the general science of Complexity, opening up new possibilities in condensed matter radiation physics for both living and non-living objects.
Other Condensed Matter (cond-mat.other)
Delocalisation explains efficient transport and charge generation in neat Y6 organic photovoltaics
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-02-17 20:00 EST
Daniel Balzer, Paul A. Hume, Geoffrey R. Weal, Justin M. Hodgkiss, Ivan Kassal
Non-fullerene acceptors (NFA), such as Y6, have significantly improved the efficiency of organic photovoltaic devices (OPVs). However, the fundamental processes behind the high efficiencies of NFA devices have remained incompletely understood, with the high efficiencies persisting without the large energetic offsets often thought to be required for charge separation. Even more surprising has been the efficient charge generation in neat Y6 devices, where there is no energetic offset at all. Here, we simulate charge transport and separation in Y6 using delocalised kinetic Monte Carlo (dKMC) parameterised using atomistic calculations, thus taking into account the often-neglected ingredients of delocalisation, disorder, and polaron formation. Including delocalisation predicts higher carrier mobilities and exciton diffusion coefficients than is possible with classical simulations, bringing them into agreement with experimental values. Delocalisation also predicts higher charge-generation efficiencies in neat Y6, in agreement with experimental measurements. Finally, this work establishes dKMC as a realistic, predictive tool for understanding next-generation OPVs.
Materials Science (cond-mat.mtrl-sci), Chemical Physics (physics.chem-ph)
Nonlinear effects in a strongly coupled Nanoelectromechanical System
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2026-02-17 20:00 EST
Narges Tarakameh Samani, Farhad Shahbazi, Mehdi Abdi
Controlling nonlinear effects in micro- and nano-electro-mechanical systems is essential for unlocking their full potential in sensing, signal processing, and frequency control. In this study, we develop a voltage-dependent Hamiltonian framework for a nanoelectromechanical resonator with two strongly coupled vibrational modes, representative of a nanostring platform. The mode frequencies and couplings of the system are tuned electrostatically using a DC voltage, which also controls the strength of the interactions. Our theoretical model reproduces the experimentally observed avoided crossing in the absence of an AC drive and generates tunable frequency-comb spectra when a parametric drive is applied. By scanning the DC voltage, we generate a phase diagram that links comb formation and sharp regime boundaries to underlying bifurcations, multi-stability, and attractor switching. Phase-resolved diagnostics based on a Kuramoto order parameter, together with autocorrelation and Poincaré analyses, quantify coherence and critical slowing down near these transitions. We further explore the relationship between nonlinear coupling, parametric excitation, and stability transitions within a single device of experimental relevance and establish a dynamical framework for engineering nanoelectromechanical resonators that offer enhanced tunability, functionality, and a predictive link to experimental outcomes.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
11 pages, 10 figures, Accepted in Physical Review E (PRE)
Exchange interactions and finite-temperature magnetism in (111)-oriented (LaMnO$3$)${2n}$|(SrMnO$_3$)$_n$ superlattices
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2026-02-17 20:00 EST
Shivalika Sharma, Julio do Nascimento, Imran Ahamed, Fabrizio Cossu, Heung-Sik Kim, Igor Di Marco
We present a first-principles investigation of magnetic exchange interactions and critical behavior in (111)-oriented (LaMnO$ _3$ )$ _{2n}$ |(SrMnO$ _3$ )$ n$ superlattices for $ n=2,4,6$ . For all superlattices under investigation, we find robust half-metallic ferromagnetism extending across all the layers of both component regions. Changing octahedral tilt patterns is found to have negligible effects on the magnetic properties, despite determining the presence or absence of small Jahn-Teller distortions. The analysis of the response of the magnetic coupling to a variation of the Coulomb interaction parameters demonstrates that ferromagnetism is driven by a double-exchange mechanism involving itinerant $ e_g$ electrons, while its final strength is hampered by antiferromagnetic contributions due to the superexchange of localized $ t{2g}$ electrons. Multi-scale simulations based on atomistic spin dynamics show that the thinnest superlattices, $ n=2,4$ , possess an ordering temperature that is at least comparable to that of La$ _{2/3}$ Sr$ _{1/3}$ MnO$ _3$ . Conversely, as thickness increases, a two-phase behavior emerges, where the SrMnO$ _3$ region loses long-range order faster than the LaMnO$ _3$ region. While the global ordering temperature increases together with thickness, we argue that the high-temperature regime for the observed two-phase behavior is not representative of the real physical system, which will undergo a combined electronic, magnetic and structural phase transition as soon as the long-range order is lost inside the SrMnO$ _3$ region. This study provides insights into the emergent magnetic phases and transition temperatures relevant to oxide heterostructures.
Strongly Correlated Electrons (cond-mat.str-el), Materials Science (cond-mat.mtrl-sci)
Magnetic skyrmion lattice disclinations in pentagon- and heptagon-shaped FeGe crystals
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-02-17 20:00 EST
Thibaud Denneulin, Nikolai S. Kiselev, Vladyslav M. Kuchkin, Rafal E. Dunin-Borkowski
Magnetic skyrmions in chiral magnets typically arrange into hexagonal lattices, with their structural order influenced by factors such as temperature, external magnetic fields and geometric constraints. While translational defects in skyrmion lattices such as dislocations have been extensively studied, individual angular defects, or disclinations, remain largely unexplored. Here, we report on the stabilization of five-fold and seven-fold disclinations in pentagon- and heptagon-shaped FeGe nanocrystals created using focused ion beam milling. The magnetic and elastic structures of the disclinated lattices are investigated using Fresnel imaging and off-axis electron holography in a transmission electron microscope. The results are supported by micromagnetic simulations and analytical models based on linear elasticity theory.
Materials Science (cond-mat.mtrl-sci)
Stacking-Tunable Electronic Properties in Recently Synthesized Hydrogen-Substituted Graphdiyne
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-02-17 20:00 EST
Guilherme S. L. Fabris, Raphael B. de Oliveira, Bruno Ipaves, Marcelo L. Pereira Junior, Douglas S. Galvao
Recent progress in porous carbon materials has highlighted the importance of structural design in controlling emergent physicochemical properties. In this context, hydrogen-substituted graphdiyne (HsGDY), a three-dimensional framework derived from graphdiyne (GDY), has recently emerged as a promising architecture whose stacking-dependent behavior remains largely unexplored. Here, we present a comprehensive first-principles investigation of the structural, electronic, and optical properties of HsGDY across distinct stacking sequences. Our results identify the AA and ABC configurations as the most energetically favorable, with AA corresponding to the global minimum, consistent with recent experimental observations. Electronic-structure analysis reveals that HsGDY is an indirect semiconductor with an electronic band gap of 0.89 eV (optB88-vdW), primarily governed by interlayer coupling and van der Waals interactions. The optical response exhibits pronounced absorption features spanning the visible to ultraviolet regions, highlighting strong potential for optoelectronic applications. \textit{Ab initio} molecular dynamics (AIMD) simulations at 700 K confirm the thermal robustness of the framework, with negligible structural distortions. Collectively, these findings elucidate the stacking-dependent stability and semiconducting character of HsGDY, providing a solid theoretical foundation for its integration into next-generation nanoelectronic and energy-harvesting technologies.
Materials Science (cond-mat.mtrl-sci)
Disorder-driven stochastic dynamics in Mott resistive-switching systems
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2026-02-17 20:00 EST
David J. Alspaugh, Lorenzo Fratino, Nareg Ghazikhanian, Ivan K. Schuller, Marcelo Rozenberg
Controlled disorder in correlated materials provides a new route to emergent stochastic dynamics in neuromorphic hardware. Here we show that focused ion beam irradiation in VO$ _{2}$ - and V$ _{2}$ O$ _{3}$ -based resistive-switching oscillators induces a transition from regular periodic oscillations to strongly irregular stochastic firing, while simultaneously reducing the required switching energy by orders of magnitude. Under an applied electric field, these materials undergo a volatile insulator-to-metal transition characterized by the formation of percolating metallic filaments within an insulating bulk. Using numerical simulations based on the Mott resistor network, we demonstrate that defect-induced modifications to filament nucleation and stability drive these devices into stochastic oscillatory regimes. These results are validated by experimental measurements on irradiated VO$ _{2}$ and V$ _{2}$ O$ _{3}$ devices.
Strongly Correlated Electrons (cond-mat.str-el)
The Sokoban Random Walk: A Trapping Perspective
New Submission | Statistical Mechanics (cond-mat.stat-mech) | 2026-02-17 20:00 EST
Prashant Singh, Eli Barkai, David A Kessler
We study caging/trapping in Sokoban-type models, featuring a random walker moving through a disordered medium of obstacles and capable of pushing some obstacles blocking its path. In one-dimension, we allow the walker to push up to an arbitrary $ N_{\rm P}$ number of obstacles. For $ N_{\rm P}\gg 1$ , we use large-deviation theory to show that the survival probability to remain uncaged exhibits crossover from an exponential decay with time at intermediate times to a stretched-exponential decay at long times, with an exponent $ 1/3$ independent of $ N_{\rm P}$ . The long-time exponent matches the Balagurov–Vaks–Donsker–Varadhan (BVDV) theory of the classical trapping problem, while the exponential decay is qualitatively distinct from the Rosenstock’s intermediate-time theory for classical trapping. Similarly, in two dimensions, numerical simulations reveal that both the Sokoban model and its generalized version exhibit long-time stretched-exponential relaxation with exponent $ 1/2$ , again consistent with the BVDV theory. Finally, in two dimensions, we find that the mean trap size is nonmonotonic in $ \rho$ : it is small at both low and high densities, but reaches a peak at a characteristic density $ \rho_\ast$ . We estimate $ \rho_\ast \approx 0.55$ for the Sokoban model and $ \rho_\ast \approx 0.675$ for the generalized Sokoban model.
Statistical Mechanics (cond-mat.stat-mech)
Composite Boson Theory of Fractional Chern Insulators
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2026-02-17 20:00 EST
The understanding of fractional Chern insulators (FCIs) has been deeply guided by band topology and quantum geometry. Here, we introduce a real-space theoretical framework in which FCIs are understood in terms of composite bosons, local objects consisting of electrons bound to their energetically excluded surrounding orbitals. The central element of our framework is the construction of a radially ordered set of maximally localized basis for Chern bands without requiring continuous rotational symmetry. Within this basis, the complex many-body problem simplifies to a real-space organizing principle: a stable FCI occurs if the orbitals excluded around central electrons are those maximizing the two-body interaction energy. We validate this with direct numerical evidence for composite boson formation in the Haldane model, demonstrating that our criterion reliably characterizes FCIs. Importantly, our analysis illustrates that the composite boson framework bridges the fractional quantum Hall effect in continuum and lattice paradigms, providing a unified and intuitive real-space interpretation for distinct correlated phases. It thus establishes a foundation for diagnosing and guiding the design of both Abelian and non-Abelian topologically ordered phases across distinct platforms.
Strongly Correlated Electrons (cond-mat.str-el), Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
5 pages, 2 figures
Upper critical field in few-layer Ising superconductors
New Submission | Superconductivity (cond-mat.supr-con) | 2026-02-17 20:00 EST
Lena Engström, Andrej Mesaros, Pascal Simon
The N-layer 2H-stacked transition metal dichalcogenides 2H-NbSe2 and 2H-TaS2 are superconductors in which each quasi-two-dimensional layer breaks inversion symmetry. In this paper, we show that, as for the individual monolayers, it is crucial to include all pockets at the Fermi surface to accurately determine the upper critical field. Furthermore, we propose an experiment where a distinct scaling with a varying displacement field is predicted for an intralayer spin-singlet order in a bilayer. The scaling of the upper critical field with external tuning parameters can thus be used to extract information about the spin-symmetry of the superconducting order. We also explore the possibility of a mixed-parity spin-singlet and -triplet order parameter. In that case, we predict that the experimentally observable scaling would remain that of the spin-singlet component.
Superconductivity (cond-mat.supr-con)
15 pages, 7 figures
Optical transport of cold atoms to quantum degeneracy
New Submission | Quantum Gases (cond-mat.quant-gas) | 2026-02-17 20:00 EST
Yanqing Tao, Yufei Wang, Ligeng Yu, Bo Song
Efficient transport of cold atoms is essential for continuous operation, enabling applications ranging from atomic lasers to continuously operated qubits. However, deep potentials required to overcome vibrations, axial trap nonuniformity and insufficient cooling have limited transport of cold atoms near quantum degeneracy. Here we demonstrate rapid optical transport of cold atoms to Bose-Einstein condensation using a moving optical lattice formed by two Bessel beams. A gas of $ 3 \times 10^5$ ytterbium atoms at a temperature of $ 340,$ nK is transported over $ 34,$ cm in $ 350,$ ms with efficiency over $ 60%$ . Furthermore, a degenerate gas of $ 1 \times 10^5$ atoms with a $ 40%$ condensate fraction emerges from the phase synchronization process driven by atomic interactions. This demonstration enables the fast preparation of ultracold atomic beams and large-scale atom arrays for quantum sensing, simulation and computing.
Quantum Gases (cond-mat.quant-gas), Atomic Physics (physics.atom-ph), Quantum Physics (quant-ph)
10 pages, 10 figures
Topology optimization of type-II superconductors with superconductor-dielectric/vacuum interfaces based on Ginzburg-Landau theory under Weyl gauge
New Submission | Superconductivity (cond-mat.supr-con) | 2026-02-17 20:00 EST
Geometry design is a crucial and challenging strategy for improving the performance of type-II superconductors. Topology optimization is one of the most powerful approaches used to determine structural geometries. Therefore, a topology optimization approach is presented to inversely design structural geometries of both low- and high-temperature type-II superconductors with superconductor-dielectric/vacuum interfaces. In the presented approach, the magnetic response of type-II superconductors is modeled using the Ginzburg-Landau theory, where the temporal evolution of the order parameter and vector potential is described by the time-dependent Ginzburg-Landau equations under the Weyl gauge.
Superconductivity (cond-mat.supr-con), Mathematical Physics (math-ph), Optimization and Control (math.OC), Computational Physics (physics.comp-ph), Quantum Physics (quant-ph)
Magnetocardiography measurements using an optically pumped magnetometer under ambient conditions
New Submission | Statistical Mechanics (cond-mat.stat-mech) | 2026-02-17 20:00 EST
Kushal Patel, Kesavaraja C, Pranab Dutta, Korak Biswas
In this work, we report the development of a rubidium-based single-beam scalar optically pumped magnetometer (OPM) and demonstrate its application in measuring human cardiac magnetic fields in an unshielded environment. The developed magnetometers exhibit a noise floor below 15 pT/sqrt(Hz) in the frequency range of 1 to 35 Hz, with a measurement bandwidth of 100 Hz. When operated in a gradiometric configuration, the noise floor is further reduced to below 3 pT/sqrt(Hz) over the same frequency range. Magnetocardiography (MCG) signals were recorded at five different locations across the thorax. A clear polarity reversal of the QRS complex was observed across these measurement positions, confirming the spatial sensitivity of the system. The proposed system shows strong potential for clinical diagnostics, offering valuable physiological information through non-contact MCG measurements
Statistical Mechanics (cond-mat.stat-mech), Medical Physics (physics.med-ph)
Enhancement of mechanical properties of graphene oxide fibers via liquid crystalline phase formation and flake size optimization
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-02-17 20:00 EST
M. Zhezhu, G. Baghdasaryan, G. Gevorgyan, S. Gyozalyan, Y. Grigoryan, K. Margaryan, H. Gharagulyan
Graphene oxide (GO) fibers are promising materials for lightweight, high-strength applications due to their unique structural tunability and mechanical performance. However, the properties of GO fibers strongly depend on the ordering of GO flakes during the assembly process. In this work, we demonstrate that GO fibers spun from a liquid crystalline (LC) GO dispersion exhibit significantly enhanced mechanical properties compared to those produced from non-LC GO dispersions. The improved tensile strength is attributed to the larger GO flake size and highly ordered alignment achieved in the LC phase. The LC-derived fibers demonstrated a Young’s modulus of 12.3 GPa, a tensile strength of 146.8 MPa, and an elongation at break of 2.5%. These findings emphasize the critical role of flake size and LC ordering in enhancing the performance of GO-based fibers and suggest a straightforward pathway toward scalable fabrication of strong yet flexible carbon-based materials.
Materials Science (cond-mat.mtrl-sci)
Materials Letters Volume 410, 1 May 2026, 140242
Propagation processing of short pulses in Rydberg exciton medium under blockade conditions
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2026-02-17 20:00 EST
Sylwia Zielińska-Raczyńska, David Ziemkiewicz
Propagation of short pulses through Cu$ _2$ O crystal containing Rydberg excitons is studied with the use of density matrix formalism and FDTD method. Saturation effects related to the so-called Rydberg blockade are studied extensively, exploring not only reduction of absorption (bleaching) but also power-dependent changes of the dispersive properties of the medium. The role of exciton lifetime and coherent population oscillations in the dynamics of the system is investigated. A pump-probe setup with two pulses is also studied, showing good agreement with recent experimental studies.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
11 pages, 13 figures
Dirac Spin Liquid Candidate in a Rydberg Quantum Simulator
New Submission | Quantum Gases (cond-mat.quant-gas) | 2026-02-17 20:00 EST
Guillaume Bornet, Marcus Bintz, Cheng Chen, Gabriel Emperauger, Daniel Barredo, Shubhayu Chatterjee, Vincent S. Liu, Thierry Lahaye, Michael P. Zaletel, Norman Y. Yao, Antoine Browaeys
We experimentally investigate a frustrated spin-exchange antiferromagnet in a quantum simulator, composed of N = 114 dipolar Rydberg atoms arranged into a kagome array. Motivated by a recent theoretical proposal of a gapless U(1) Dirac spin liquid ground state, we use local addressing to adiabatically prepare low-energy states. We measure the local polarization and spin-spin correlations over this adiabatic protocol, and observe our system move from a staggered product state, through an intermediate magnetic crystal, and finally into a disordered, correlated liquid. We estimate the entropy density of this atomic liquid to be similar to that of frustrated magnetic insulators at liquid nitrogen temperatures. We compare the correlations in our liquid to those of a simple, parameter-free ansatz for the Dirac spin liquid, and find good agreement in the sign structure and spatial decay. Finally, we probe the static susceptibility of our system to a local field perturbation and to a geometrical distortion. Our results establish Rydberg atom arrays as a promising platform for the preparation and microscopic characterization of quantum spin liquid candidates.
Quantum Gases (cond-mat.quant-gas), Strongly Correlated Electrons (cond-mat.str-el), Atomic Physics (physics.atom-ph), Quantum Physics (quant-ph)
5+5 pages, 5+6 figures
Pattern recognition with superconducting wirelet neurons
New Submission | Superconductivity (cond-mat.supr-con) | 2026-02-17 20:00 EST
Khalil Harrabi, Leonardo Cadorim, Milorad Milosevic
Neuromorphic computing aims to reproduce the energy efficiency and adaptability of biological intelligence in hardware. Superconducting devices are an attractive platform due to their ultra-low dissipation and fast switching dynamics. Here we introduce a shunted superconducting wirelet as an artificial neuron, representing the simplest possible superconducting neuron implementation. This minimal design, a single superconducting channel with a resistive shunt, enables straightforward fabrication, electronic control, and high scalability. The neuron exhibits spiking voltage behavior driven by the interplay of resistive switching and relaxation, with key properties such as threshold, firing frequency, and refractory time tunable via applied current, temperature, and shunt resistance. We further show that the resulting temporal voltage signals can be incorporated into a training algorithm to achieve accurate pattern recognition, demonstrating suitability for neuromorphic tasks. Finally, we discuss on-chip training using similar wirelets with gated synaptic weights, establishing a scalable, energy-efficient building block for cryogenic artificial intelligence hardware, integrable with other emergent superconducting technologies.
Superconductivity (cond-mat.supr-con)
29 pages, 7 figures
Supersonic Microparticle Impact Experiments at Temperatures Approaching 2000 °C
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2026-02-17 20:00 EST
Jamshid Ochilov, Isaac Faith Nahmad, Intekhab Alam, Peter Yip, vand Suraj Ravindran
Experiments at extreme strain rates and temperatures are critical for characterizing materials in high-speed applications. In this study, we develop a laser-driven particle impact platform capable of accelerating microparticles to supersonic velocities and impacting targets heated to temperatures approaching 2000 °C. The conventional laser-induced particle impact testing (LIPIT) system has been modified to enable high-temperature experiments through the integration of a resistive heating system and the development of a robust launch pad assembly suitable for accelerating particles in high-temperature environments. To eliminate the oxidation of materials at elevated temperatures, an optically accessible portable vacuum chamber has been developed and integrated into the setup. The capabilities of the system are demonstrated through a study of the temperature dependent particle impact cratering behavior of POCO graphite. With this new platform, high-velocity, high-temperature impact experiments can be performed in a controlled environment, supporting the investigation of materials under extreme conditions.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
Probing atom-surface interactions from tunneling-time measurements via rotation-transport on an atom chip
New Submission | Quantum Gases (cond-mat.quant-gas) | 2026-02-17 20:00 EST
J-B. Gerent, R. Veyron, V. Mancois, R. Huang, E. Beraud, S. Bernon
We propose a novel method to measure the interaction between an ultracold gas of neutral atoms and a surface. This solution combines an optical dipole trap reflected by the surface, a magnetic trap formed by current carrying wires embedded below the surface, and a rotation of the surface itself. It allows to adiabatically transport a $ ^{87}$ Rb BEC from few $ \mu$ m to few hundred nm of the surface. At such distances, atom-surface interaction strongly affects the trapping potential, causing an increase of the tunneling rate towards the surface. In this paper, we show that the measurement of the lifetime of the cloud and its comparison to a tunneling model will allow to extract the Casimir-Polder (CP) force coefficient in the retarded regime ($ c_4$ ). Our model includes noise-induced heating, calibration biases of experimentally controlled parameters and accuracy of the atom lifetime measurement. Using typical trapping parameters and experimental uncertainties, we numerically estimate the relative uncertainty of $ c_4$ to be 10%. This method can be implemented with any atomic species that can be magnetically and optically trapped.
Quantum Gases (cond-mat.quant-gas), Quantum Physics (quant-ph)
10 pages, 4 figures
Dislocation dynamics on deformable surfaces
New Submission | Soft Condensed Matter (cond-mat.soft) | 2026-02-17 20:00 EST
Marcello De Donno, Luiza Angheluta, Marco Salvalaglio
We develop a fully coupled theoretical description of dislocation dynamics on deformable crystalline surfaces, using continuum modeling and the amplitude-phase-field crystal (APFC) framework extended to curved geometries. We derive a general kinematic expression for dislocation velocity directly from the complex-amplitude evolution equations, which is also applicable to deformed surfaces through curvature-modified differential operators. From numerical simulations, we show that even small out-of-plane deformations reshape the phenomenology of defect motion through curvature-induced self-propulsion, modified glide directions, and non-classical defect-defect interactions. Our results show how surface geometry profoundly influences defect dynamics and establish the surface-APFC model as a powerful framework for predicting and interpreting curvature-defect coupling across a wide range of systems, from stiff but deformable layers to soft matter surfaces and membranes that retain crystalline order.
Soft Condensed Matter (cond-mat.soft), Materials Science (cond-mat.mtrl-sci)
13 pages, 3 figures
Polymer Brushes and Grafted Polymers: AI/ML-Driven Synthesis, Simulation, and Characterization towards autonomous SDL
New Submission | Soft Condensed Matter (cond-mat.soft) | 2026-02-17 20:00 EST
Rigoberto C. Advincula, Jihua Chen
Polymer brushes and grafted polymers have attracted significant interest at the intersection of polymers, interfacial chemistry, colloidal science, and nanostructuring. The confinement of high-density grafted polymers and differences in swelling regimes govern the synthetic challenges and the interesting physics underlying their macromolecular dynamics. In this article, we focus on another intersection, artificial intelligence and machine learning (AI/ML), and how workflows will enhance the microstructure and composition of these systems. It will also accelerate potential applications through high-throughput experimentation (HTE) and data-driven intelligence, enabling scientific discovery and optimization. Applications in microfluidics, sensors, bioimplants, drug delivery, and related areas may yet offer more opportunities for ML-driven optimization. There is also interest in applying these studies with self-driving laboratories (SDLs) that can leverage autonomous systems for synthesis screening, characterization, and application evaluation.
Soft Condensed Matter (cond-mat.soft)
512 pages, 5 figures
Ilmenite-Type Ca$_x$IrO$_3$ via Topochemical Ion Exchange: Stacking Faults and Low-Temperature Magnetic Anomaly
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-02-17 20:00 EST
Haruki Kira, Yuya Haraguchi, Wataru Yokoshima, Daisuke Nishio-Hamane, Hiroko Aruga Katori
We report the synthesis of an ilmenite-type polymorph of Ca$ x$ IrO$ 3$ distinct from the known post-perovskite and perovskite phases, via low-temperature topochemical Ca$ ^{2+}$ /2Na$ ^+$ exchange from Na$ 2$ IrO$ 3$ . Powder X-ray diffraction is indexable in $ R\bar{3}$ , and whole pattern modelling that includes layer glide faults indicates that the selective broadening can be captured by a first order Markov stacking description based on stochastic switching between two symmetry equivalent lateral stacking steps, with explicit model dependence and an uncertainty of at least several percent. A freezing-like bulk magnetic anomaly is suggested at $ T^\ast \sim 25$ K (defined by the onset of a ZFC/FC bifurcation at $ \mu{0}H = 10$ mT), accompanied by a broad heat capacity feature and Curie-Weiss behavior with a large negative Weiss temperature of $ \theta_W \sim -98$ K. The effective moment $ \mu{\rm eff} = 1.68 \mu{\rm B}$ per Ir is consistent with $ J{\rm eff} = 1/2$ for an Ir$ ^{4+}$ . SEM-EDX suggests an A-site content below unity (Ca/Ir $ <$ 1); accordingly, we describe the ion-exchanged product using the nonstoichiometric formula Ca$ _x$ IrO$ _3$ . These results identify ilmenite-type CaIrO$ _3$ as a honeycomb iridate in which stacking disorder can be quantified (with caveats regarding model and instrument correlations) and related to its low-temperature magnetic behavior.
Materials Science (cond-mat.mtrl-sci), Strongly Correlated Electrons (cond-mat.str-el)
12 pages, 6 figures, accepted in Journal of Solid State Chemistry
M-CODE: Materials Categorization via Ontology, Dimensionality and Evolution
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-02-17 20:00 EST
Vsevolod Biryukov, Kamal Choudhary, Timur Bazhirov
The rapid advancement of artificial intelligence in materials science requires data standards and data management practices that can capture the complexity of real-world structures, including surfaces, interfaces, defects, and dimensionality reduction. We present M-CODE - Materials Categorization via Ontology, Dimensionality and Evolution - a compact categorization system that links materials-science-specific terminology to a set of reusable concepts as building blocks and provenance-aware transformations. M-CODE classifies structures by dimensionality, structural complexity (from pristine to compound pristine, defective, and processed), and variants that capture common structure creation and evolution approaches. A practical implementation of the categorization is provided in an open-source codebase that includes JSON schemas, examples, and Python and TypeScript types/interfaces, designed to support reproducible dataset generation, validation, and community contributions.
Materials Science (cond-mat.mtrl-sci), Digital Libraries (cs.DL), Computational Physics (physics.comp-ph)
13 pages, 2 figures, 5 tables
Reversible tuning of magnetic order and intrinsic superconductivity in strained FeTe thin films via stoichiometry control
New Submission | Superconductivity (cond-mat.supr-con) | 2026-02-17 20:00 EST
Hao Xu, Jing Jiang, Xuesong Gai, Rui-Qi Cao, Xiao-Xiao Man, Kaiwei Chen, Haicheng Lin, Peng Deng, Ke He, Kai Liu, Dapeng Zhao, Zhong-Yi Lu, Kai Chang, Chong Liu
FeTe is a prototypical parent compound of iron-based superconductors. While bulk FeTe is non-superconducting with a long-range bicollinear antiferromagnetic order, superconductivity has been achieved in thin films. However, the approaches usually involve complex oxygen incorporation or interfacial effects, the microscopic mechanisms of which remain elusive. Here, we prepare high-purity, bare FeTe thin films on SrTiO3 and investigate their magnetic and superconducting states combining both microscopic and macroscopic characterizations. By reducing the interstitial Fe impurities, we successfully suppress the long-range antiferromagnetic order, enhance the quasiparticle coherence and induce superconductivity at ~10 K. Moreover, this process is readily reversible by tuning the Fe concentration. Our findings reveal that precise stoichiometric control is sufficient to induce intrinsic superconductivity in strained FeTe thin films. This work provides insights into the competition between magnetism and superconductivity in iron chalcogenides, and supplies a robust pathway for developing stable, high-purity superconducting FeTe films.
Superconductivity (cond-mat.supr-con), Strongly Correlated Electrons (cond-mat.str-el)
5 figures,1 table
Programming active-molecule dynamics via intramolecular nonreciprocity
New Submission | Soft Condensed Matter (cond-mat.soft) | 2026-02-17 20:00 EST
Ye Zhang, Meng Xiao, Duanduan Wan
The dynamics of a self-propelled particle are typically hard-wired by its microscopic construction, limiting the range of behaviors accessible without redesigning the particle itself. Here we show that intramolecular nonreciprocity provides a minimal and versatile mechanism to overcome this constraint. We construct active molecules from short chains of two species of self-propelled particles whose propulsion directions are coupled nonreciprocally according to a prescribed internal sequence. At the single-molecule level, homogeneous sequences exhibit standard persistent random-walk dynamics, whereas heterogeneous sequences produce distinct trajectories inaccessible to either constituent species alone. At the collective level, using motility-induced phase separation (MIPS) as a representative example, we find that modifying the internal sequence shifts the MIPS onset by multiple orders of magnitude in propulsion strength, without altering particle-level interactions. These results demonstrate that intramolecular nonreciprocity among a small set of active components enables sequence-level programmability from single-molecule dynamics to emergent collective behavior, providing a minimal mechanism to encode and control active-matter dynamics across scales.
Soft Condensed Matter (cond-mat.soft)
Convergent-Beam X-ray Crystallography
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-02-17 20:00 EST
Chufeng Li, Margarita Zakharova, Mauro Prasciolu, Jia Chyi Wong, Holger Fleckenstein, Nikolay Ivanov, Wenhui Zhang, Mansi Butola, J. Lukas Dresselhaus, Ivan De Gennaro Aquino, Dmitry Egorov, Philipp Middendorf, Alessa Henkel, Bjarne Klopprogge, Lars Klemeyer, Tobias Beck, Oleksandr Yefanov, Miriam Barthelmess, Janina Sprenger, Dominik Oberthuer, Saša Bajt, Henry N. Chapman
Molecular and polymeric crystals show a wide range of functional properties that arise from the interplay between the atomic-scale structure of their constituent molecules and the organization of these molecules within the crystal lattice at macroscopic length scales. X-ray diffraction can provide structural information at these disparate length scales, but usually only through experiments that address one or the other of molecular (or unit-cell) structure versus crystal structure. Consequently, the accuracy of determined molecular or polymer structures may be limited by unaccounted crystal inhomogeneities of the crystal lattice and the characterization of crystalline materials might not reveal the underlying causes of crystal morphology. Here we introduce X-ray convergent-beam diffraction to obtain spatially-resolved structural information from crystals by projection topographic imaging. Using highly focusing X-ray multilayer Laue lenses, we show that Bragg reflections can be mapped into tomographic images of the crystal, for the characterization of strain and defects at high resolution. We demonstrate how the crystal morphology obtained this way can be accounted for when determining structure factors as a function of position in the crystal. The approach may assist in studies such as diffusion and binding in MOFS, protein-drug binding, crystal growth, and the mechanical responses of photo-reactive or thermally driven dynamic crystals.
Materials Science (cond-mat.mtrl-sci), Applied Physics (physics.app-ph), Biological Physics (physics.bio-ph), Optics (physics.optics)
RF field characterization and rectification effects in spin pumping and spin-torque FMR for spin-orbitronics
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-02-17 20:00 EST
Melissa Yactayo, Michel Hehn, J.-C. Rojas-Sánchez, Sébastien Petit-Watelot
Quantifying spin-orbital-to-charge conversion efficiency is crucial for spin-orbitronics. Two widely used methods for determining these efficiencies are based on ferromagnetic resonance (FMR), spin pumping FMR for the inverse effect, and spin-torque FMR for the direct effect. A key parameter to achieve accurate quantification, especially for spin-pumping FMR, is the RF field strength, $ h_{\mathrm{RF}}$ . We present a comprehensive theoretical model and experimental protocol that allow a correct quantification of $ h_{\mathrm{RF}}$ . It was validated by extensive experimental results and it was rigorously tested across various antennas geometries and ferromagnetic systems. We demonstrate that odd-symmetric Lorentzian voltages-which perfectly mimic spin-pumping or spin-torque FMR signals-can arise purely from rectification effects (due to anisotropic magnetoresistance) when $ h_{\mathrm{RF}}$ orientation is parallel to the ferromagnetic surface. Through a systematic study of various 10-nm-thick ferromagnetic layers, such as Ni, NiFe, Fe, and CoFeB, we find that while Fe and CoFeB exhibit minimal rectification, Ni and NiFe generate strong rectified signals that must be corrected. We further demonstrate that these rectification effects become negligible for ferromagnetic thicknesses $ \leq$ 6 nm, as validated in NiFe/Pt bilayers, providing an important guideline for the design of future heterostructures.
Materials Science (cond-mat.mtrl-sci)
11 pages, 7 figures, 1 table plus 5 pages of appendix
Phonon Echo from Multi-Level Systems and Many-Body Interactions in Low-Temperature Glasses
New Submission | Disordered Systems and Neural Networks (cond-mat.dis-nn) | 2026-02-17 20:00 EST
At low temperatures, glasses exhibit distinctive properties compared to crystalline solids. A notable example is the phonon echo, a phenomenon that motivated the two-level-system (TLS) model. This model has successfully explained many universal anomalies in glasses. Here, we extend the TLS framework to a multi-level system and show that phonon echoes persist when nonlinear energy structures and disorder are included. By incorporating virtual phonon exchange, we introduce many-body interactions between these multi-level systems, leading to nonlinear eigen-energies that enhance the echo signal. Meanwhile, finite-temperature thermal fluctuations cause dephasing, resulting in a decay of echo amplitude over time. The analytical and numerical results are consistent across semi-classical and quantum regimes. Our work validates the multi-level-system model and underscores the role of many-body interactions in low-temperature glassy dynamics.
Disordered Systems and Neural Networks (cond-mat.dis-nn)
20 pages, 6 figures
Self-Viscophoresis: Autonomous Motion by Biasing Thermal Fluctuations via Self-Generated Viscosity Asymmetry
New Submission | Soft Condensed Matter (cond-mat.soft) | 2026-02-17 20:00 EST
Bokusui Nakayama, Yusuke Takagi, Ryoya Hirose, Masatoshi Ichikawa, Marie Tani, Ibuki Kawamata, Eiji Yamamoto, Akira Kakugo
Microscale transport often relies on ubiquitous yet intrinsically random thermal fluctuations. Understanding how such fluctuations can be biased into directed motion has long been a central theme of nonequilibrium physics. Here, we introduce self-viscophoresis, a mechanism of autonomous motion based on the rectification of thermal fluctuations in a self-generated nonequilibrium viscosity field. Asymmetric colloidal particles dispersed in a thermoresponsive polymer solution induce local heating under uniform illumination, producing a spatially asymmetric viscosity profile around the particle and resulting in persistent directed motion. To elucidate the physical origin of this behavior, we develop a minimal Langevin model coupling isotropic thermal fluctuations to a dynamically updating temperature-viscosity field. The model shows that viscosity asymmetry anisotropically damps stochastic dynamics, effectively biasing thermal fluctuations into a net drift. It thus reproduces the observed directed motion without invoking deterministic propulsion terms associated with effective potentials or environmental fluid flows. Our results distinguish self-viscophoresis from conventional self-propulsion mechanisms and establish it as a general framework enabling reversible control of both the direction and dimensionality of motion.
Soft Condensed Matter (cond-mat.soft), Applied Physics (physics.app-ph)
main manuscript: 13 pages including 5 figures, supplemental material: 9 pages including 7 figures and 4 movies (.mp4)
Altermagnetic Even-Odd Effects in CsV$_2$Te$_2$O Josephson Junctions
New Submission | Superconductivity (cond-mat.supr-con) | 2026-02-17 20:00 EST
Chuang Li, Jin-Xing Hou, Shuai-Ling Zhu, Hao Zheng, Yu Song, Yang Liu, Song-Bo Zhang, Lun-Hui Hu
The interplay between conventional superconductivity and unconventional magnetism offers an exciting platform for realizing exotic superconducting phenomena. Here, we investigate Josephson effects in planar and vertical junctions based on CsV$ _2$ Te$ _2$ O-family materials, which host hidden $ d$ -wave altermagnetism with G-type antiferromagnetic order. In monolayer-based planar junctions, the quasi-1D, nearly flat, spin-polarized bands of the altermagnet, when coupled to $ s$ -wave superconductors, produce a \textit{fully} spin-polarized supercurrent with strong directional anisotropy – a spin-selective Josephson effect. In multilayers, we uncover an \textit{altermagnetic even-odd effect}: spin-polarized supercurrents persist only in odd-layer planar junctions but cancel exactly in even layers. Thus, layer parity acts as a switch for spin-polarized supercurrent. In vertical junctions, odd-layer barriers enhance equal-spin triplet transport while even layers favor opposite-spin transport, yielding a robust period-two oscillation in the total supercurrent with layer number. These layer-parity-dependent responses represent a general even-odd effect in hidden altermagnets, applicable to diverse magnetic and transport phenomena.
Superconductivity (cond-mat.supr-con)
Reentrant Superconductivity in Zeeman Fields
New Submission | Superconductivity (cond-mat.supr-con) | 2026-02-17 20:00 EST
Tomoya Sano, Kota Tabata, Satoshi Ikegaya, Yasuhiro Asano
We propose a theoretical model for a superconductor that exhibits the reentrant superconductivity in Zeeman fields. The Bogoliubov-de Gennes Hamiltonian includes three vectors in spin space: a $ d$ vector of a spin-triplet superconducting state, a potential representing spin-orbit interactions, and a Zeeman field. When the three vectors are perpendicular to one another, the spin-orbit interaction suppresses superconductivity in weak Zeeman fields and enhances superconductivity in strong Zeeman fields. The instability (stability) of superconducting state is characterized by the appearance of odd-frequency (even-frequency) Cooper pairs.
Superconductivity (cond-mat.supr-con)
6 pages, 2 figures
Zr-based bulk metallic glass clamp cell for high-pressure inelastic neutron scattering
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-02-17 20:00 EST
S. Hayashida, T. Wada, M. Ishikado, K. Munakata, K. Iida, K. Kamazawa, R. Kajimoto, Y. Inamura, M. Nakamura, K. Iwasa, K. Ohoyama, H. Kato, H. Kira, M. Matsuura, Y. Uwatoko
We report the fabrication and characterization of a Zr-based bulk metallic glass (Zr-BMG) clamp cell designed for high-pressure inelastic neutron scattering (INS) measurements. The INS spectra of the empty cell exhibit broad and featureless backgrounds, reflecting the amorphous structure of the Zr-BMG. Test measurements using a reference sample, CsFeCl$ _{3}$ , confirm that the neutron transmission of the Zr-BMG cell is significantly higher than that of a conventional monobloc CuBe clamp cell. These results demonstrate that the Zr-BMG clamp cell provides both enhanced neutron transparency and a clean background profile, thereby advancing high-pressure INS studies.
Materials Science (cond-mat.mtrl-sci), Strongly Correlated Electrons (cond-mat.str-el)
Magnetic fluctuations driven by quantum geometry
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2026-02-17 20:00 EST
Makoto Shimizu, Chang-guen Oh, Youichi Yanase
Using quantum distance, magnetic susceptibility in the non-interacting limit can be rigorously split into two contributions: one arising solely from band dispersion, while the other stems from quantum geometric contributions. In this Letter, we apply this decomposition to two materials, LaFeAsO and Pb$ _9$ Cu(PO$ _4$ )$ _6$ O, and demonstrate that their dominant magnetic fluctuations originate from the geometric contribution. In LaFeAsO, stripe-type antiferromagnetic fluctuations arise primarily from quantum geometry, while in Pb$ _9$ Cu(PO$ _4$ )$ _6$ O the geometric term suppresses antiferromagnetic fluctuations and stabilizes ferromagnetic fluctuations. Our findings highlight the essential role of quantum geometry in governing magnetic fluctuations in multi-band systems, and provide a unique and quantitative framework to disentangle band-structure and wavefunction-geometry effects that have often been discussed collectively as multi-orbital effects.
Strongly Correlated Electrons (cond-mat.str-el)
Universal observable as a signal of chiral anomaly in lattice Weyl fermions
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2026-02-17 20:00 EST
The Adler-Bell-Jackiw chiral anomaly is shown to retain its Lorentz-invariant form, $ \partial_\mu J^\mu_5 \propto \mathbf{E} \cdot \mathbf{B}$ , in lattice Weyl systems beyond moderate magnetic fields, where neither Lorentz nor rotational symmetry is present. We show that the longitudinal and Hall magnetoconductivities factorize into a product of a universal part, governed by the chiral anomaly, and a non-universal part that depends on the density of states at the Fermi level. A rotationally invariant observable $ \varkappa = \sigma (c_V/T)^2$ is introduced as a robust signature of the anomaly, where $ \sigma$ denotes the Euclidean norm of the longitudinal and Hall conductivities and $ c_V$ is the specific heat density. This quantity follows a universal $ B^2$ dependence and scales as $ |\cos\Theta|$ , with $ \Theta$ being the angle between $ \mathbf{E}$ and $ \mathbf{B}$ . Through analytical derivation and full numerical simulation, we establish that $ \varkappa$ remains universal independent of system parameters and of the orientation of the magnetic or electric field for fixed $ \Theta$ . The emergent SO(3) symmetry in $ \varkappa$ persists despite the absence of isotropy in both the microscopic model and the low-energy effective theory.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
6 pages, 3 figures
Quantifying Strain and its Effect on Charge Transport in Ge/Si Core/Shell Nanowires
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2026-02-17 20:00 EST
Aswathi K. Sivan, Nicolas Forrer, Aakash Shandilya, Yang Liu, Janica Böhler, Alexander Vogel, Arianna Nigro, Pierre Chevalier Kwon, Artemii Efimov, Ilya Golokolenov, Gerard Gadea, Riccardo Rurali, Andreas Baumgartner, Dominik M. Zumbühl, Ilaria Zardo
Strain engineering in semiconductor nanostructures offers a promising route to optimize electronic and optical properties for advanced quantum technologies. This study explores the relationship between core and shell thicknesses and strain distribution in Ge/Si core/shell nanowires, targeting their application as hosts for spin qubits. Nanowires were synthesized using an Au-catalyzed chemical vapor deposition technique, achieving control over core and shell dimensions. High-resolution transmission electron microscopy and elemental mapping confirmed structural integrity, while Geometric Phase Analysis and Raman spectroscopy provided quantitative insights into strain variations driven by core and shell dimensions. Furthermore, polarization resolved $ \mu$ -Raman measurements allowed us to quantify the longitudinal and transverse phonon mode splitting as a function of strain in the Ge core. The strain dependent electronic properties were investigated by hole mobility measurements. Finally, we observe a record high hole mobility of 25,500 cm$ ^2$ V$ ^{-1}$ s$ ^{-1}$ , underscoring the potential of these core/shell nanowire structures for the realization of high-fidelity spin qubits. Our findings highlight the critical role of geometry in strain tuning and provide valuable design guidelines for optimizing Ge/Si nanowires in scalable quantum device architectures.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
Main: 25 pages, 6 Figures Supporting: 8 pages, 6 figures
Realization of a Synthetic Hall Torus with a Spinor Bose-Einstein Condensate
New Submission | Quantum Gases (cond-mat.quant-gas) | 2026-02-17 20:00 EST
T. -H. Chien, S. -C. Wu, Y. -H. Su, L. -R. Liu, N. -C. Chiu, M. Sarkar, Q. Zhou, Y. -J. Lin
We report the first experimental realization of a synthetic Hall torus using a spinor Bose-Einstein condensate confined in a ring-shaped trap with in situ imaging. By cyclically coupling three hyperfine spin states via Raman and microwave fields, we impose a periodic boundary condition in the synthetic dimension, which together with a real-space ring trap, realizes a toroidal geometry with a synthetic magnetic flux. This flux induces azimuthal density modulations in the condensate, whose periodicity is uniquely determined by the quantized toroidal magnetic flux-a hallmark of the Hall torus geometry. By varying the relative phase between the couplings across repeated experimental runs, we control the location of the density extrema, emulating the behavior of Thouless charge pump in a toroidal geometry. We further investigate the onset of these modulations as the system transitions from a cylindrical to a toroidal topology. Our results establish a versatile platform for investigating quantum Hall physics and topological phenomena in synthetic curved spaces.
Quantum Gases (cond-mat.quant-gas)
Magnetic excitations in the Kitaev material Na$_2$IrO$_3$ studied by neutron scattering
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2026-02-17 20:00 EST
Alexandre Bertin, Hengdi Zhao, Gang Cao, Andrea Piovano, Paul Steffens, Alexandre Ivanov, Markus Braden
Inelastic neutron scattering experiments with a large set of comounted Na$ _2$ IrO$ _3$ crystals reveal the low-energy magnon dispersion in this candidate material for Kitaev physics. The magnon gap amounts to 1.7(1) meV and can be interpreted similarly to the sister compound $ \alpha$ -RuCl$ _{3}$ to stem from the zone boundaries in the antiferromagnetic zigzag structure. The neutron experiments find no evidence for low-energy excitations with ferromagnetic character, which contrasts to the findings in $ \alpha$ -RuCl$ _{3}$ . Our results are consistent with a recently proposed microscopic model that involves an antiferromagnetic Heisenberg nearest-neighbor exchange in Na$ _2$ IrO$ _3$ in contrast to the ferromagnetic one considered for $ \alpha$ -RuCl$ _{3}$ . Although the magnetic response shows the signatures of bond-directional anisotropy in both materials the different relative signs of Kitaev and Heisenberg interaction result in different deviations from the initial Kitaev model. Low-energy ferromagnetic fluctuations cannot be considered as a fingerprint of ferromagnetic Kitaev interaction.
Strongly Correlated Electrons (cond-mat.str-el)
11 pages, 6 figures
Compositional Metrology of Atom Probe Applied to non-Metallic Materials
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-02-17 20:00 EST
Enrico Di Russo, François Vurpillot, Lorenzo Rigutti
Two decades after its introduction, laser-assisted Atom Probe Tomography (La-APT) has demonstrated a unique potential for the study of the 3D distribution of atomic species in semiconductor materials and devices, and in a growing list of inorganic non-metallic solids. A crucial and often underestimated issue with APT is its accuracy in compositional measurements of non-metallic systems. This work introduces the principles of APT as an experimental technique, recalling the aspects potentially leading to compositional biases and underlining in particular the role of the surface electric field in governing the different physical-chemical phenomena that enable the measurement. It reviews the possible mechanisms of specific losses, as well as the methods for assessing a compositional bias and proposing possible correction methods. Finally, it establishes a state of the art on compositional biases in APT of non-metallic materials, on the basis of which it will be possible to conclude on specific recommendations for best practices, and the perspective of application of APT to new materials.
Materials Science (cond-mat.mtrl-sci), Instrumentation and Detectors (physics.ins-det)
Review article and user guide. 30 Figures
Non-commutative Dynamic Approaches to the Kibble-Zurek Scaling Limit with an Initial Gapless Order
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2026-02-17 20:00 EST
Zhe Wang, Chengxiang Ding, Dongxu Liu, Fuxiang Li, Zheng Yan, Shuai Yin
Nonequilibrium many-body physics is one of the core problems in modern physics, while the dynamical scaling from a gapless phase to the critical point is a most important challenge with very few knowledge so far. In the driven dynamics with a tuning rate $ R$ across the quantum critical point (QCP) of a system with size $ L$ , the finite-time scaling shows that the square of the order parameter $ m^2$ obeys a simple scaling relation $ m^2\propto R^{2\beta/\nu r}$ in the Kibble-Zurek (KZ) scaling limit with $ RL^r\gg1$ . Here, by studying the driven critical dynamics from a gapless ordered phase in the bilayer Heisenberg model, we unveil that the approaches to the scaling region dominated by the KZ scaling limit with $ RL^r\gg1$ are {\it non-commutative}: this scaling region is inaccessible for large $ R$ and finite medium $ L$ , while merely accessible for large $ L$ and moderately finite $ R$ . We attribute this to the memory effect induced by the finite-size correction in the gapless ordered phase. This non-commutative property makes $ m^2$ still strongly depends on the system size and deviates from $ m^2\propto R^{2\beta/\nu r}$ even for large $ R$ . We further show that a similar correction applies to the imaginary-time relaxation dynamics. Our results establish an essential extension of nonequilibrium scaling theory with a gapless ordered initial state.
Strongly Correlated Electrons (cond-mat.str-el)
13 pages, 10 figures
DFT and MLIP study of solute segregation to coherent and semi-coherent α-Fe/Fe$_3$C interfaces
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-02-17 20:00 EST
Amin Reiners-Sakic, Ronald Schnitzer, David Holec
Solute segregation to interfaces significantly impacts material behavior. A large majority of theoretical works focus on grain boundaries and coherent interfaces. Studies on semi-coherent interfaces are usually prohibited by the structural complexity, yielding models beyond the practical capability of density functional theory (DFT), or chemical complexity, restricted by the availability of (classical) interatomic potentials. This work investigates solute segregation to the coherent and semi-coherent $ \alpha$ -Fe/Fe$ _3$ C interface in pearlite and its effect on mechanical properties using novel universal machine learning interatomic potentials (uMLIPs). DFT calculated solution enthalpies, segregation energetics, and changes in cohesion at the coherent interface are used to benchmark several state-of-the-art uMLIPs. We find that the GRACE-2L-OAM and GRACE-2L-OMAT models most accurately reproduce the quantum-mechanical predictions. While Cu has the strongest segregation energy of $ \approx$ -0.3 eV to the coherent interface among the investigated tramp and trace elements, all of them, As, Cr, Cu, Mo, Ni, P, Sb, and Sn, exhibit significantly more negative segregation values reaching below $ \approx$ -1.5 eV in the presence of the misfit dislocation at the semi-coherent interface. The deepest traps are identified in the vicinity of the dislocation core, although the spatial distribution of segregation energies differs markedly among the solute species. The cohesion of the coherent interface is strongly reduced by Sb, Sn, P, and As, and only mildly by Cu, whereas Ni shows a negligible effect, and Cr and Mo slightly enhance cohesion. In contrast, all investigated solutes (except for P) tend to embrittle the semi-coherent interface, with Sn and, especially, Sb having the strongest impact in tensile tests performed in the out-of-plane direction. Abstract shortened for ArXiv.
Materials Science (cond-mat.mtrl-sci)
Pearlite, Coherent and semi-coherent interfaces, Segregation, Cohesion, Universal machine learning interatomic potentials, DFT
Why is the $d$-Wave spin splitting in CuF$_2$ bulk-like?
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-02-17 20:00 EST
Muskan, Subhadeep Bandyopadhyay, Sayantika Bhowal
With the advent of nonrelativistic spin splitting in collinear compensated antiferromagnets, several candidate materials have also been proposed, among which the family of transition-metal difluorides stands out as a prominent example. Within this family, most members exhibit planar $ d$ -wave spin splitting, whereas CuF$ _2$ shows bulk $ d$ -wave splitting with an explicit $ k_z$ dependence. In this work, we show that this transition from planar to bulk $ d$ -wave splitting in CuF$ _2$ is primarily driven by the antipolar displacements of the F ions, which are absent in the tetragonal rutile structure of the other family members. Our calculations reveal that these additional structural distortions introduce an extra plane of anisotropic magnetization density, giving rise to an additional totally symmetric component of the magnetic octupole tensor. The $ k$ -space representation of this octupole component, consequently, dictates an additional direction of spin splitting, thereby transforming the $ d$ -wave spin splitting pattern from planar to bulk-like. We further analyze the effect of spin-orbit coupling on the magnetic octupoles and the resulting spin splitting in the band structure. Our work highlights the possibility of controlling the pattern of nonrelativistic spin splitting through structural modifications, for example, via the application of external pressure.
Materials Science (cond-mat.mtrl-sci), Other Condensed Matter (cond-mat.other)
13 pages and 10 figures
A scalable non-superconducting tunnel junction technology
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2026-02-17 20:00 EST
Juho Luomahaara, Kristupas Razas, Omid Sharifi Sedeh, Renan P. Loreto, Janne S. Lehtinen, Mingchi Xu, Armel A. Cotten, Aldo Tarascio, Peter Müller, Nikolai Yurttagül, Lassi Lehtisyrjä, Leif Grönberg, Christian P. Scheller, Jonathan R. Prance, Michael D. Thompson, Richard P. Haley, Mika Prunnila, Dominik M. Zumbühl
Tunnel junctions are one of the key elements of chip-scale microsystems serving various technologies from classical microelectronics to quantum information. Aluminium and its oxide (AlOx) have dominated cryogenic tunnel junction technology for decades due to the high quality of AlOx barriers and Al superconducting properties below 1.2 K. However, many applications require non-superconducting junctions, either standalone or in combination with superconducting technology, motivating efforts to suppress Al superconductivity through magnetic fields, doping, or proximity effects – approaches that so far suffered from integration compatibility and scalability issues. Here, we present a CMOS-compatible normal-metal tunnel junction technology based on TiW alloy and AlOx barriers. We demonstrate wafer-scale fabrication of TiW/Al-AlOx/TiW junctions and validate their performance in Coulomb blockade thermometers operating down to 20 mK, confirming robust normal-state behavior. This TiW-based architecture offers a scalable solution for non-superconducting tunnel junctions across a broad temperature range, enabling integration into advanced cryogenic, quantum and nanoelectronic chip-level systems.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Materials Science (cond-mat.mtrl-sci)
9 pages, 6 figures; equal contribution of J.L., K.R., O.S.S, and R.P.L
Data-Efficient Machine learning for Predicting Dopant Formation Energies in TiO$_2$ Monolayer
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-02-17 20:00 EST
Kati Asikainen, Matti Alatalo, Marko Huttula, Assa Aravindh Sasikala Devi
Machine learning models are increasingly applied in materials science, yet their predictive power is often constrained by data scarcity. Here, we show that accurate predictions can be achieved, even with a limited number of training examples, provided the dataset is compact and and grounded in physically relevant quantities. By combining density functional theory calculations with a machine-learning framework, we construct accurate descriptor-based models to predict the formation energies of doped lepidocrocite TiO$ _2$ monolayers. The predictive accuracy of machine-learning models was first evaluated for single-dopant Pt configurations, demonstrating that the selected structural and chemical descriptors reliably capture the key factors governing dopant stability. Chemical transferability is then examined by extending the dataset to include Ag-doped configurations. Predictive accuracy improved systematically as additional Ag-doped data points were included in the training, while the performance of Pt remains robust. These results highlight the potential of small and well-curated datasets combined with physically informed descriptors to enable not only accurate but also chemically transferable machine-learning-driven screening in doped TiO$ _2$ monolayer.
Materials Science (cond-mat.mtrl-sci), Computational Physics (physics.comp-ph)
Free-electron decoherence: Theory and applications
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-02-17 20:00 EST
Cruz I. Velasco, Valerio Di Giulio, F. Javier García de Abajo
Electron microscopy relies on the spatial coherence of electron beams to generate atomic-scale images using interference and diffraction, which can be degraded by inelastic scattering processes that induce decoherence. Here, we present a theoretical study of decoherence arising from the electromagnetic interaction of free electrons with bulk materials and planar surfaces. We show that bulk plasmons dominate decoherence in Al and Au, while electronic excitations above the band gap, supplemented by weaker coupling to phononic and guided modes, are the primary channels in ionic insulators such as LiF. A thermal population of electromagnetic modes leads to a divergence in the energy-loss probability at low frequencies, which in turn produces a pronounced temperature dependence. We show that this effect can be exploited for nanoscale thermometry, predicting that optimized energy-filtered holography enables $ \sim0.1%$ changes in fringe visibility for physically viable temperature variations in metals. Through these results, we establish a unified theoretical framework to describe free-electron decoherence in the bulk and surfaces of arbitrary materials.
Materials Science (cond-mat.mtrl-sci)
18 pages, 5 figures, 2 tables, 65 references
A self-consistent criterion for the range of validity of weakly driven processes
New Submission | Statistical Mechanics (cond-mat.stat-mech) | 2026-02-17 20:00 EST
One of the longstanding open questions in linear response theory concerns its true range of validity. Determining when the linear approximation can be trusted typically requires knowledge of second-order corrections, which are often difficult to compute explicitly. In this letter, I propose a self-consistent criterion for the validity of linear response, formulated in terms of a typical length scale that emerges from the fluctuation-response inequality within the theory itself. The result applies to classical open systems. I illustrate the criterion with explicit examples of Brownian particles in harmonic traps, and classical open systems presenting Kibble-Zurek mechanism. Finally, I discuss the physical meaning of this typical length, providing both thermodynamic and information-theoretic interpretations.
Statistical Mechanics (cond-mat.stat-mech)
7 pages, 2 figures
The cost of speed: Time-optimal thermal control of trapped Brownian particles
New Submission | Statistical Mechanics (cond-mat.stat-mech) | 2026-02-17 20:00 EST
Miguel Ibanez, Antonio Patron-Castro, Antonio Lasanta, Carlos A. Plata, Antonio Prados, Raul A. Rica-Alarcon
A thermal analogue of the classical brachistochrone problem, which minimizes the connection time between two equilibrium states of harmonically confined Brownian particles, has recently been solved theoretically. Here we report its experimental realization using two optically trapped microparticles subjected to a bang-bang effective temperature protocol. Despite their distinct relaxation times, both degrees of freedom are steered to their respective equilibrium states simultaneously in a finite minimal time. We provide a complete time-resolved characterization of the nonequilibrium dynamics through the evolution of the position variances and the entropy production within the framework of stochastic thermodynamics, enabling a quantitative comparison with direct relaxation and a suboptimal protocol. In addition, we employ information-geometric tools – recently referred to as thermal kinematics – to track the system’s path in state space with a single dynamical quantity. Our results show that faster equilibration requires a larger entropy production and an increased thermodynamic length, revealing a direct trade-off between temporal optimality and thermodynamic cost in multidimensional stochastic systems driven by a single intensive control parameter.
Statistical Mechanics (cond-mat.stat-mech), Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
The distinction of time-reversal-like degeneracy by electronic transport in a new compound
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2026-02-17 20:00 EST
Yi-Yan Wang, Ping Su, Kai-Yuan Hu, Yi-Ran Li, Na Li, Ying Zhou, Dan-Dan Wu, Yan Sun, Qiu-Ju Li, Xia Zhao, Hui Liang, Xue-Feng Sun
We report the discovery of a new compound, Ce$ _3$ MgBi$ _5$ , and reveal the hidden time-reversal-like degenerate states within it. Ce$ _3$ MgBi$ _5$ is an antiferromagnet with the distorted kagome lattice of Ce atoms, in which several fractional magnetization plateaus emerge with the increase of magnetic field. At the 1/2 magnetization plateau, obvious hysteresis has been observed in the magnetoresistance and Hall resistivity during the rise and fall of the magnetic field. However, hysteresis vanishes in the corresponding measurements of magnetization, indicating the existence of degenerate states with the same net magnetization but different electronic transport properties. The degenerate states can be connected by the time-reversal-like operation. In addition, by comparing with HoAgGe, it is suggested that the special crystal structure in Ce$ _3$ MgBi$ _5$ may have a shielding effect on the time-reversal-like operation, thereby affecting the distinction of degenerate states. Our work establishes Ce$ _3$ MgBi$ _5$ as an example of utilizing electronic transport properties to identify and distinguish hidden symmetries in frustrated magnetic systems.
Strongly Correlated Electrons (cond-mat.str-el)
Antiferromagnetic Barkhausen noise induced by weak random-field disorder
New Submission | Disordered Systems and Neural Networks (cond-mat.dis-nn) | 2026-02-17 20:00 EST
This study numerically investigates magnetisation reversal processes driven by an external magnetic field in three-dimensional antiferromagnetic spin models with weak random field disorder. Considering an extremely weak disorder and low temperature, we observe a step-wise hysteresis loop and the appearance of short magnetisation bursts of a characteristic triangular shape; the number of bursts increases with disorder, indicative of Barkhausen-type noise. These phenomena are attributed to the simultaneous reversal at a given external field of segments composed of spins with identical neighbourhoods. A local random field orients one or more spin neighbours, resulting in small, ferromagnetic-like clusters distributed throughout the system. As disorder increases, these clusters may merge to form a labyrinthine structure within the antiferromagnetic background, facilitating brief avalanche propagation. The results demonstrate that, compared with familiar random-field ferromagnets, the observed antiferromagnetic Barkhausen noise and the related avalanche sequence have a profoundly different structure, organised into peaks associated with the transition between magnetisation plateaus. They exhibit prominent cyclical trends and disorder-dependent multifractal fluctuations, with the singularity spectrum quantifying the degree of disorder. The activity avalanches exhibit scale invariance resembling that recently found in experiments with disordered ferr\textit{i}magnets and martensites, as well as in quantum Barkhausen noise, which are associated with active geometric regions rather than individual-spin dynamics. The observed scaling behaviour is interpreted in terms of self-organised critical dynamics.
Disordered Systems and Neural Networks (cond-mat.dis-nn), Statistical Mechanics (cond-mat.stat-mech)
20 pages, 4 figures
Variational preparation and characterization of chiral spin liquids in quantum circuits
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2026-02-17 20:00 EST
Zi-Yang Zhang, Donghoon Kim, Ji-Yao Chen
Quantum circuits have been shown to be a fertile ground for realizing long-range entangled phases of matter. While various quantum double models with non-chiral topological order have been theoretically investigated and experimentally implemented, the realization and characterization of chiral topological phases have remained less explored. Here we show that chiral topological phases in spin systems, i.e., chiral spin liquids, can be prepared in quantum circuits using the variational quantum eigensolver (VQE) framework. On top of the VQE ground state, signatures of the chiral topological order are revealed using the recently proposed tangent space excitation ansatz for quantum circuits. We show that, both topological ground state degeneracy and the chiral edge mode can be faithfully captured by this approach. We demonstrate our approach using the Kitaev honeycomb model, finding excellent agreement of low-energy excitation spectrum on quantum circuits with exact solution in all topological sectors. Further applying this approach to a non-exactly solvable chiral spin liquid model on square lattice, the results suggest this approach works well even when the topological sectors are not exactly known.
Strongly Correlated Electrons (cond-mat.str-el), Quantum Physics (quant-ph)
19 pages, 15 figures
Spin qubit shuttling between coupled quantum dots with inhomogeneous Landé g-tensors
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2026-02-17 20:00 EST
Zhi-Hai Liu, Xiao-Fei Liu, H. Q. Xu
By utilizing the site-dependent spin quantization axis in semiconductor quantum dot (QD) arrays, shuttling-based spin qubit gates have become an appealing approach to realize scalable quantum computing due to the circumvention of using high-frequency driving fields. The emergence of a spin deviation from the local quantization axis of one residing QD is the prerequisite to implement the qubit gates. In this work, we study the non-adiabatic dynamics of a spin qubit shuttling between coupled QDs with inhomogeneous Landé g-tensors and a small magnetic field. The spin dynamics is analyzed through solving the time-dependent Schrödinger equation of the qubit under the effects of spin-orbit interaction and rapid ramping inter-dot detuning. The precondition, imposed on the ramping time and the tunnel-coupling strength, to ensure a high-fidelity inter-dot transfer is estimated. We then calculate the change in the spin orientation of a transferred qubit, and study the dependences of the spin deviation on the difference in the quantization axes of the two QDs, the tunnel-coupling strength, and the ramping time. We also demonstrate that the effect of multiple rounds of inter-dot bidirectional shuttling can be captured by an operator matrix, and evaluate the idling times required for realizing the single-qubit Pauli-X and Pauli-Y gates. Intriguingly, it is confirmed that a generalized Hadamard gate can be achieved through tuning the idling times.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
16 pages, 7 figures
Physical Review B 113, 075302 (2026)
Exact Multi-Valley Envelope Function Theory of Valley Splitting in Si/SiGe Nanostructures
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2026-02-17 20:00 EST
Lasse Ermoneit, Abel Thayil, Thomas Koprucki, Markus Kantner
Valley splitting in strained Si/SiGe quantum wells is a central parameter for silicon spin qubits and is commonly described with envelope-function and effective-mass theories. These models provide a computationally efficient continuum description and have been shown to agree well with atomistic approaches when the confinement potential is slowly varying on the lattice scale. In modern Si/SiGe heterostructures with atomically sharp interfaces and engineered Ge concentration profiles, however, the slowly varying potential approximation underlying conventional (local) envelope-function theory is challenged. We formulate an exact multi-valley envelope-function model by combining Burt-Foreman-type envelope-function theory, which does not rely on the assumption of a slowly varying potential, with a valley-sector decomposition of the Brillouin zone. This construction enforces band-limited envelopes, which satisfy a set of coupled integro-differential equations with a non-local potential energy operator. Using degenerate perturbation theory, we derive the intervalley coupling matrix element within this non-local model and prove that it is strictly invariant under global shifts of the confinement potential (choice of reference energy). We then show that the conventional local envelope model generically violates this invariance due to spectral leakage between valley sectors, leading to an unphysical energy-reference dependence of the intervalley coupling. The resulting ambiguity is quantified by numerical simulations of various engineered Si/SiGe heterostructures. Finally, we propose a simple spectrally filtered local approximation that restores the energy-reference invariance exactly and provides a good approximation to the exact non-local theory.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Mathematical Physics (math-ph), Applied Physics (physics.app-ph), Computational Physics (physics.comp-ph), Quantum Physics (quant-ph)
Uniaxial strain tuned magnetism of the altermagnet candidate h-FeS
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-02-17 20:00 EST
Weiliang Yao, Feng Ye, Zachary J. Morgan, Douglas L. Abernathy, Ruixian Liu, Sijie Xu, Yuxiang Gao, Kevin Allen, Yuan Fang, Emilia Morosan, Qimiao Si, Pengcheng Dai
Altermagnets are collinear magnetic materials with ‘alter’nating local crystalline environments, characterized by joint spin and crystalline symmetries that enable ferromagnetic-like transport properties but with vanishing net magnetization. Hexagonal FeS (h-FeS) is a recently identified altermagnet candidate that shows a spontaneous anomalous Hall effect (AHE) accompanied by a tiny net magnetization. Here, we show that both the spontaneous AHE and magnetization can be effectively suppressed by an in-plane compressive strain. Since neutron diffraction measurements show that the applied uniaxial strain only modifies the in-plane domain population but does not affect the in-plane magnetic structure, the major effect of the applied strain is to tune the small $ c$ -axis ferromagnetic moment. Our results demonstrate a strong correlation between the tiny net magnetization and the spontaneous AHE in h-FeS, and show that uniaxial strain provides an effective knob to tune both properties in this altermagnet candidate for spintronic applications.
Materials Science (cond-mat.mtrl-sci), Strongly Correlated Electrons (cond-mat.str-el)
Strongly correlated Josephson junction: proximity effect in the single-layer Hubbard model
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2026-02-17 20:00 EST
We study the proximity effect in the Hubbard model coupled to BCS superconductors describing a single-layer strongly correlated electron system in a phase-biased Josephson junction. We find two distinct gapped solutions, one Mott-like insulating (M-phase) and one proximitized superconducting phase (S-phase), separated by first-order transition with hysteresis. In the M-phase the large correlation charge gap strongly suppresses the critical current, while the S-phase behaves as a $ 0$ -junction, with a proximitized gap that closes for $ \phi=\pi$ to yield a correlated metal. Phase bias and junction transparency can thus serve as tuning knobs to switch between conducting and insulating regimes. Working within the dynamical mean field theory using the numerical renormalization group as the impurity solver, we associate M- and S-phase solutions with the doublet and singlet fixed points of the underlying superconducting Anderson impurity problem. We obtain detailed insight into the spectral structure on all energy scales. In the M-phase, the self-energy has sub-gap resonances symmetrically located around the Fermi level resulting from the splitting of the ‘’mid-gap pole’’ found in Mott insulators; this structure accounts for phase insensitivity.
Strongly Correlated Electrons (cond-mat.str-el), Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Superconductivity (cond-mat.supr-con)
Radio-Frequency Gasket for Studies of Superconductivity in Diamond Anvil Cells
New Submission | Superconductivity (cond-mat.supr-con) | 2026-02-17 20:00 EST
Dmitrii V. Semenok, Di Zhou, Viktor V. Struzhkin
This work presents the development and testing of a novel radio-frequency (RF) gasket with a Lenz lens surface geometry for contactless measurements in diamond anvil cells (DACs). Conventional RF approaches, which fabricate the Lenz lens onto the diamond anvil itself, preclude the placement of electrical circuits. Our method overcomes this limitation by transferring the RF sensor to a composite Ta-based gasket. The sensor consists of single-turn microcoils that are formed by magnetron sputtering a gold film onto an insulating Ta$ _2$ O$ _5$ layer. The Lenz lens topology is then patterned using focused ion beam etching. We validated this technique using polycrystalline Cu1234 and Bi2212 high-$ \textit{T$ _c$ }$ superconductors at ambient and high pressures. The measurements consistently identified the superconducting transition temperature across carrier frequencies from 111 kHz to 200 MHz. This new gasket technique establishes a reliable and sensitive tool for contactless studies of superconductivity under high pressure.
Superconductivity (cond-mat.supr-con), Materials Science (cond-mat.mtrl-sci)
Unraveling the electronic structure of silicon vacancy centers in 4H-SiC
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-02-17 20:00 EST
Ali Tayefeh Younesi, Minh Tuan Luu, Christopher Linderälv, Vytautas Žalandauskas, Marianne Etzelmüller Bathen, Nguyen Tien Son, Takeshi Ohshima, Gergő Thiering, Lukas Razinkovas, Ronald Ulbricht
Point defects in silicon carbide (SiC), particularly the negatively-charged silicon vacancy ($ \mathrm{V_{Si}^{-}}$ ) in 4H-SiC, are leading candidates for scalable quantum technologies due to their favorable spin-optical properties and compatibility with industrial semiconductor fabrication processes. Comprehensive knowledge of a defect’s electronic structure is essential for interpreting spin-optical dynamics and for the reliable design and optimization of defect-based quantum devices. Despite extensive study, our knowledge of the electronic structure of $ \mathrm{V_{Si}^{-}}$ \ is limited since key excited-state manifolds have remained inaccessible to conventional steady-state spectroscopy. In this study, transient absorption spectroscopy is utilized to probe non-equilibrium electronic transitions of $ \mathrm{V_{Si}^{-}}$ \ and to uncover previously unobserved excited states. The first direct observation of the elusive V2’ quartet transition is presented, with its broad spectral signature attributed to nonadiabatic vibronic coupling. Within the spin-doublet manifold, which is central to optically detected magnetic resonance (ODMR) but has remained unresolved spectroscopically, multiple optical transitions are identified. The complete electronic level structure in the relevant energy range is elucidated by combining polarization-resolved spectroscopy, group-theoretical analysis, quantum embedding calculations and first-principles optical lineshape modeling. Collectively, these results provide a microscopic understanding of the $ \mathrm{V_{Si}^{-}}$ \ electronic structure. Our approach also establishes a general framework for resolving and understanding complex excited-state manifolds in wide-bandgap color centers.
Materials Science (cond-mat.mtrl-sci)
Fast and accurate quasi-atom method for simultaneous atomistic and continuum simulation of solids
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-02-17 20:00 EST
Artem Chuprov, Egor E. Nuzhin, Alexey A. Tsukanov, Nikolay V. Brilliantov
We report a novel hybrid method of simultaneous atomistic simulation of solids in critical regions (contacts surfaces, cracks areas, etc.), along with continuum modeling of other parts. The continuum is treated in terms of quasi-atoms of different size, comprising composite medium. The parameters of interaction potential between the quasi-atoms are optimized to match elastic properties of the composite medium to those of the atomic one. The optimization method coincides conceptually with the online Machine Learning (ML) methods, making it computationally very efficient. Such an approach allows a straightforward application of standard software packages for molecular dynamics (MD), supplemented by the ML-based optimizer. The new method is applied to model systems with a simple, pairwise Lennard-Jones potential, as well with multi-body Tersoff potential, describing covalent bonds. Using LAMMPS software we simulate collision of particles of different size. Comparing simulation results, obtained by the novel method, with full-atomic simulations, we demonstrate its accuracy, validity and overwhelming superiority in computational speed. Furthermore, we compare our method with other hybrid methods, specifically, with the closest one – AtC (Atomic to Continuum) method. We demonstrate a significant superiority of our approach in computational speed and implementation convenience. Finally, we discuss a possible extension of the method for modeling other phenomena.
Materials Science (cond-mat.mtrl-sci), Machine Learning (cs.LG)
Probing topological Floquet states in graphene with ultrafast terahertz scanning tunneling microscopy
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2026-02-17 20:00 EST
Nils Jacobsen, Michael Schüler, Angel Rubio, Martin Wolf, Melanie Müller, Michael A. Sentef
Floquet control of band topology is a central theme in ultrafast quantum materials science. Established experimental probes of light-induced topological states include ultrafast transport and time- and angle-resolved photoemission spectroscopy, each with important strengths but also well-known limitations. Here we propose ultrafast terahertz scanning tunneling microscopy (THz-STM) as a real space energy-resolved probe of Floquet physics. We show that THz-STM enables direct local detection of bulk Floquet gaps and distinct Floquet edge state signatures. We derive a nonequilibrium Green’s-function formalism for time-dependent tunneling that directly extends standard STM theory and provides an intuitive interpretation of rectified ultrafast tunneling currents. We apply the approach to bulk graphene and graphene nanoribbons of variable width. For the bulk, we show that THz-STM provides direct spectroscopic access to Floquet-induced gap openings, and we contrast pulsed pump-probe protocols with the continuous-wave Floquet steady-state limit. For finite ribbons, we demonstrate time- and space-resolved imaging of Floquet-induced topological edge states and identify the ribbon-width scale below which edge state protection breaks down. We further show how band structures of graphene nanoribbons and Floquet chiral edge modes can be reconstructed via Floquet quasiparticle interference. Finally we demonstrate that chiral impurities that break time-reversal symmetry induce characteristic spatial THz-STM signatures that can be used as a direct probe of Floquet edge state chirality.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
18 pages, 5 figures
Electron-phonon coupling in EuAl4 under hydrostatic pressure
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2026-02-17 20:00 EST
A. S. Sukhanov, S. Gebel, A.N. Korshunov, N. D. Andriushin, M.S. Pavlovskii, Y. Gao, K.M. Moya, K. Allen, E. Morosan, M. C. Rahn
In the intermetallid rare-earth tetragonal EuAl4 system, competing itinerant exchange mechanisms lead to a complex magnetic phase diagram, featuring a centrosymmetric skyrmion lattice. Previous inelastic x-ray scattering (IXS) experiments revealed that the incommensurate charge-density wave (CDW) transition in EuAl4 (TCDW = 142 K) is driven by momentum-dependent electron-phonon coupling (EPC). We present the results of IXS under high hydrostatic pressure induced by diaond anvils and show how the EPC in EuAl4 is renormalized and suppressed in the material’s temperature-pressure phase diagram. Our findings highlight the crucial role of momentum-dependent EPC in the formation of the CDW in EuAl4 and provide further insights into how external pressure can be used to tune charge ordering in quantum materials.
Strongly Correlated Electrons (cond-mat.str-el)
Physical Review B 111, 195150 (2025)
Drift-Diffusion Matching: Embedding dynamics in latent manifolds of asymmetric neural networks
New Submission | Disordered Systems and Neural Networks (cond-mat.dis-nn) | 2026-02-17 20:00 EST
Ramón Nartallo-Kaluarachchi, Renaud Lambiotte, Alain Goriely
Recurrent neural networks (RNNs) provide a theoretical framework for understanding computation in biological neural circuits, yet classical results, such as Hopfield’s model of associative memory, rely on symmetric connectivity that restricts network dynamics to gradient-like flows. In contrast, biological networks support rich time-dependent behaviour facilitated by their asymmetry. Here we introduce a general framework, which we term drift-diffusion matching, for training continuous-time RNNs to represent arbitrary stochastic dynamical systems within a low-dimensional latent subspace. Allowing asymmetric connectivity, we show that RNNs can faithfully embed the drift and diffusion of a given stochastic differential equation, including nonlinear and nonequilibrium dynamics such as chaotic attractors. As an application, we construct RNN realisations of stochastic systems that transiently explore various attractors through both input-driven switching and autonomous transitions driven by nonequilibrium currents, which we interpret as models of associative and sequential (episodic) memory. To elucidate how these dynamics are encoded in the network, we introduce decompositions of the RNN based on its asymmetric connectivity and its time-irreversibility. Our results extend attractor neural network theory beyond equilibrium, showing that asymmetric neural populations can implement a broad class of dynamical computations within low-dimensional manifolds, unifying ideas from associative memory, nonequilibrium statistical mechanics, and neural computation.
Disordered Systems and Neural Networks (cond-mat.dis-nn), Statistical Mechanics (cond-mat.stat-mech), Machine Learning (cs.LG), Neurons and Cognition (q-bio.NC)
23 pages, 15 figures
Identifying open-orbit topological surface states in dual topological semimetal TaSb$_2$
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-02-17 20:00 EST
Susmita Changdar, Heike Schlörb, Oleksandr Suvorov, Dimitry Efremov, Alexander Yaresko, Rui Lou, Alexander Fedorov, Bernd Büchner, Andy Thomas, Sergey Borisenko, Setti Thirupathaiah
TaSb$ _2$ , a member of the transition metal dipnictide family of materials, hosts the very rare dual topological phase - weak topological insulating state and topological crystalline insulating state along different crystallographic orientations. So far, studies on the electronic structure of transition metal dipnictides have focused on their overall electronic structure and the bulk open-orbit Fermi surfaces. Using angle-resolved photoemission spectroscopy, density functional theory calculations, and transport measurements, we distinguish the intertwined bulk and surface states on the weakly topological $ (20\bar{1})$ plane of TaSb$ _2$ . We identify multiple electron- and hole-like bulk bands, yielding a near-perfect carrier compensation. Crucially, we observe open-orbit FSs parallel to $ \bar{L}$ -$ \bar{Y}$ direction that are entirely of surface origin. Circular-dichroism ARPES reveals $ k \rightarrow -k$ spectral reversal, indicating spin-momentum locking and the topological nature of these surface states. Consistent with this, magnetotransport measurements display weak antilocalization, establishing TaSb$ _2$ as a platform for spin-polarized topological transport on a weakly topological surface.
Materials Science (cond-mat.mtrl-sci)
8 pages, 4 figures
Competing states in the $S=1/2$ triangular-lattice $J_1$-$J_2$ Heisenberg model: a dynamical density-matrix renormalization group study
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2026-02-17 20:00 EST
Shengtao Jiang, Steven R. White, Steven A. Kivelson, Hong-Chen Jiang
Previous studies of the $ S=1/2$ triangular-lattice $ J_1$ –$ J_2$ Heisenberg antiferromagnet have inferred the existence of a non-magnetic ground-state phase for an intermediate range of $ J_2$ , but disagree concerning whether it is a gapped $ \mathbb{Z}_2$ quantum spin liquid (QSL), a gapless (Dirac) QSL, or a weakly symmetry-broken phase. Using an improved dynamical density-matrix renormalization group method, we investigate the relevant intermediate $ J_2$ regime for cylinders with circumferences from 6 to 9. Depending on the initial state and boundary conditions, we find two {\it distinct} variational states. The higher energy state is consistent with a Dirac QSL. In the lower-energy state, both the static and dynamical properties are qualitatively similar to the magnetically ordered state at $ J_2=0$ , suggestive of either a weakly magnetically ordered non-QSL or a gapped QSL proximate to a continuous transition to such an ordered state.
Strongly Correlated Electrons (cond-mat.str-el)
5+5+9 pages, 3+3+9 figures
Low-Temperature Sputtering and Polarity Determination of Vertically Aligned ZnO Nanocolumns
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-02-17 20:00 EST
A. Hamzi, L. Ouardas, M. Saleh, P. Leuasoongnoen, T. Sonklin, P. David, S. le Denmat, O. Leynaud, E. Mossang, B. Fernandez, S. Pojprapai, D. Mornex, R. Songmuang
We report the low temperature growth of vertically aligned ZnO nanocolumns on Si substrates by using reactive radio frequency magnetron this http URL sputtering pressure combined with low substrate temperatures induce a pronounced self shadowing effect,leading to the formation of isolated nanocolumns. In contrast, lower sputtering pressure promotes void filling in deposited films, favouring the growth of dense, low roughness columnar films. Modification of native SiOx on Si surfaces via substrate preheating prior to deposition, alters the initial nucleation stage, thereby determining dominant polarity and morphology of ZnO nanostructures. O polar columnar films and nanocolumns exhibit higher effective piezoelectric coefficient, corresponding to their higher differential resistance and reduced dielectric loss, suggesting suppressed carrier induced screening of piezoelectric charges. This low thermal budget, scalable sputtering approach provides an alternative route for integrating ZnO nanostructures onto thermal constrained substrates, including those used in flexible and wearable electronics.
Materials Science (cond-mat.mtrl-sci)
Sub-1-Angstrom-Resolution Imaging Reveals Phase Contrast Transition in Ice Ih Caused by Basal Stacking Faults
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-02-17 20:00 EST
Jingshan S. Du, Suvo Banik, Lehan Yao, Shuai Zhang, Subramanian K. R. S. Sankaranarayanan, James J. De Yoreo
Phase-contrast transmission electron microscopy (TEM) of hexagonal ice (Ih) along [0001] sometimes shows a honeycomb-like pattern, often interpreted as individual oxygen columns in single crystals. Here, we show that this pattern commonly arises from intrinsic basal stacking faults instead. A translational boundary separating domains of comparable thickness, with an in-plane offset of (2/3a + 1/3b), produces this honeycomb-like contrast. Stacking domains translated in nonequivalent directions yields patterns resembling cubic ice (Ic) along [0001] but with a 3-fold symmetry. We imaged this structure at a record-breaking line resolution of 89 picometers, finer than the O-H covalent bond length. These findings highlight the defect tolerance of ice’s molecular packing and clarify the structural relationships among hexagonal, stacking-disordered, and cubic ice phases. This resolution milestone opens new avenues for characterizing subtle structural perturbations of water in the solid state.
Materials Science (cond-mat.mtrl-sci), Chemical Physics (physics.chem-ph)
16 pages, 4 figures, and 2 appendices. Including a Supplemental Material with 2 figures
Ferrocene-functionalized covalent organic framework exceeding the ultimate hydrogen storage targets: a first-principles multiscale computational study
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-02-17 20:00 EST
Marcus Djokic, Jose L. Mendoza-Cortes
The development of efficient hydrogen storage materials is crucial for advancing the hydrogen economy and meeting the U.S. Department of Energy’s targets of 6.5 wt% and 50 g \ce{H2} L$ ^{-1}$ for automotive applications. We present a computational study of ferrocene-functionalized covalent organic frameworks (COFs) for hydrogen storage. Following the \textbf{M}ulti-binding \textbf{S}ites \textbf{U}nited in \textbf{C}ovalent-\textbf{O}rganic \textbf{F}ramework (MSUCOF) approach, we introduce MSUCOF-4-FeCp, designed by incorporating ferrocene (\ce{FeCp2}) moieties into IRCOF-102. Notably, it achieves exceptional performance with gravimetric and volumetric uptakes of 18.0 wt% and 72.6 g \ce{H2} L$ ^{-1}$ at 298 K and 700 bar. The material exhibits optimal binding energies (15–20 kJ$ \cdot$ mol$ ^{-1}$ ) ensuring both high storage capacity and deliverable hydrogen under practical conditions. This work establishes ferrocene functionalization as a cost-effective alternative to precious metal incorporation in COFs.
Materials Science (cond-mat.mtrl-sci), Other Condensed Matter (cond-mat.other), Statistical Mechanics (cond-mat.stat-mech), Chemical Physics (physics.chem-ph)
24 pages, 12 figures
From Classical to Quantum: Extending Prometheus for Unsupervised Discovery of Phase Transitions in Three Dimensions and Quantum Systems
New Submission | Disordered Systems and Neural Networks (cond-mat.dis-nn) | 2026-02-17 20:00 EST
Brandon Yee, Wilson Collins, Maximilian Rutkowski
We extend the Prometheus framework for unsupervised phase transition discovery from 2D classical systems to 3D classical and quantum many-body systems, addressing scalability in higher dimensions and generalization to quantum fluctuations. For the 3D Ising model ($ L \leq 32$ ), the framework detects the critical temperature within 0.01% of literature values ($ T_c/J = 4.511 \pm 0.005$ ) and extracts critical exponents with $ \geq 70%$ accuracy ($ \beta = 0.328 \pm 0.015$ , $ \gamma = 1.24 \pm 0.06$ , $ \nu = 0.632 \pm 0.025$ ), correctly identifying the 3D Ising universality class via $ \chi^2$ comparison ($ p = 0.72$ ) without analytical guidance. For quantum systems, we developed quantum-aware VAE (Q-VAE) architectures using complex-valued wavefunctions and fidelity-based loss. Applied to the transverse field Ising model, we achieve 2% accuracy in quantum critical point detection ($ h_c/J = 1.00 \pm 0.02$ ) and successfully discover ground state magnetization as the order parameter ($ r = 0.97$ ). Notably, for the disordered transverse field Ising model, we detect exotic infinite-randomness criticality characterized by activated dynamical scaling $ \ln \xi \sim |h - h_c|^{-\psi}$ , extracting a tunneling exponent $ \psi = 0.48 \pm 0.08$ consistent with theoretical predictions ($ \psi = 0.5$ ). This demonstrates that unsupervised learning can identify qualitatively different types of critical behavior, not just locate critical points. Our systematic validation across classical thermal transitions ($ T = 0$ to $ T > 0$ ) and quantum phase transitions ($ T = 0$ , varying $ h$ ) establishes that VAE-based discovery generalizes across fundamentally different physical domains, providing robust tools for exploring phase diagrams where analytical solutions are unavailable.
Disordered Systems and Neural Networks (cond-mat.dis-nn), Statistical Mechanics (cond-mat.stat-mech), Machine Learning (cs.LG)
Anisotropy-driven interfacial magnetism in Ru-deficient SrRuO$_3$ thin films
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-02-17 20:00 EST
Vítor A. de Oliveira Lima, Michael I. Faley, Asmaa Qdemat, Valeria Lauter, Haile Ambaye, Omar Concepción, Ankita Singh, Emmanuel Kentzinger, Milan Radovic, Shibrabata Nandi, Thomas Brückel, Connie Bednarski-Meinke
While stoichiometric SrRuO$ _3$ (SRO) is a metallic itinerant ferromagnet with relatively homogeneous magnetization, Ru deficiency provides a powerful route to alter its electronic transport and depth-dependent magnetic properties. Ru-deficient SRO thin films grown by radio-frequency high oxygen pressure sputtering were investigated using a combination of X-ray reflectivity, polarized neutron reflectometry, off-specular neutron scattering, scanning transmission electron microscopy with energy-dispersive X-ray spectroscopy, electrical transport, and magnetometry. Structural and compositional analyses reveal that Ru deficiency is intrinsic to the films, with an enhanced deficiency at the interfaces. As a result, coherent electronic transport is suppressed and the saturation magnetization is reduced, while the Curie temperature remains largely unaffected, placing Ru-deficient SRO in a regime consistent with ferromagnetic insulator-like behavior. Depth- and lateral-resolved magnetic measurements further show that the interfacial regions remain ferromagnetic but exhibit enhanced perpendicular magnetic anisotropy, which constrains the local magnetization to remain predominantly out-of-plane and strongly reduces its in-plane projection. Our results establish Ru deficiency as a key control parameter governing transport, magnetization, and anisotropy in SRO thin films and highlight defect and interface engineering as powerful routes to tailor interfacial magnetism in correlated oxide heterostructures.
Materials Science (cond-mat.mtrl-sci), Strongly Correlated Electrons (cond-mat.str-el)
41 pages, 14 figures (including Supplementary Material). Submitted to APL Materials
Stick-slip dynamics in an interleaved system with self-amplified friction
New Submission | Soft Condensed Matter (cond-mat.soft) | 2026-02-17 20:00 EST
A. Plati, F. Restagno, C. Poulard
Understanding how stick-slip dynamics manifests in diverse physical conditions is a crucial topic in tribology. Although it has been extensively studied in simple frictional configurations, the characterization of stick-slip behavior in complex assemblies is challenging. This work presents the first systematic investigation of stick-slip dynamics in a system with multiple contact surfaces undergoing friction amplification through conversion of traction forces into normal compression. Using interleaved paper blocks as a model system, we combine force measurements and image processing to characterize stick-slip events occurring when the two blocks are pulled apart at different detachment velocities. We find that both the peak force and the amplitude of the stick-slip events decrease along with the system’s detachment. By combining a previously designed model for friction amplification and the stick-slip dynamics predicted by a simple frictional spring-block system, we link the observed behavior to the evolving normal compression within the assembly. Through force measurements and imaging, we extract the effective stiffness of the system from stick-slip events at low velocities and relate it to the system’s normal compression. We then predict the observed decrease of the global stiffness as function of the detachment by considering the spatial distribution of normal forces within the assembly, which determines an effective number of sheets contributing to the system’s mechanical response. Our findings reveal a non-trivial interplay between internal stress distribution and mechanical response mediated by frictional forces, with implications for granular materials, textiles, fibrous systems, and mechanical metamaterials.
Soft Condensed Matter (cond-mat.soft)
16 pages, 13 figures (including appendices)
Optical and transport anisotropies in spin-textured altermagnets
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2026-02-17 20:00 EST
Spin textures are ubiquitous in antiferromagnets, yet their consequences for altermagnets remain largely unexplored. We show that spatial variations of the Néel order act on the low-energy electrons as effective gauge fields, leading to strong anisotropies in both dc transport and optical absorption, even without intrinsic spin-orbit coupling. As a concrete example, we analyze a coplanar spin helix and predict that the principal axes of the conductivity and linear dichroism are set by the helix wave vector and can be tuned by the texture geometry. Our results point to polarization-resolved optics and anisotropic transport as direct probes of textured altermagnetic states, and suggest a simple route to direction-selectivity.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
7 + 6 pages, 4 + 1 figures
Large Transverse Thermoelectric Effect in Weyl Semimetal TaIrTe$_4$ Engineered for Photodetection
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-02-17 20:00 EST
Morgan G. Blevins, Xianglin Ji, Vivian J. Santamaria-Garcia, Abhishek Mukherjee, Thanh Nguyen, Mingda Li, Svetlana V. Boriskina
Anomalous local photocurrent generation via second-order nonlinear and thermoelectric responses is a signature of many topological semimetals. The emergence of these photocurrents is inherently linked to symmetry breaking and anisotropy of their crystal lattices. Studies of type-II Weyl semimetals of group C$ _{2v}$ (WTe$ _2$ , MoTe$ _2$ , TaIrTe$ _4$ ) have reported anomalous, nonlocal photocurrents localized to crystals edges or far from electrodes, which are highly dependent on the geometry of the material sample. While originally attributed to a nonlinear charge current response, it was recently shown that these currents could instead be attributed to the anisotropic Seebeck coefficients of the materials. Here, we confirm that anomalous photocurrents observed in TaIrTe$ _4$ under either visible or far-infrared far-field illumination originate from the large transverse thermoelectric effect. We engineer the mutual orientation of crystal edges and electrodes as well as the thermal environment of TaIrTe$ _4$ to control and amplify its spatial photocurrent response. We show that substrate engineering can locally enhance photocurrent. This framework of thermal device engineering can enable broadband photo detection schemes by leveraging spectral and spatial dependence of photocurrents for applications like wavefront sensing, beam positioning, and edge detection.
Materials Science (cond-mat.mtrl-sci), Optics (physics.optics)
Practical and improved density functionals for computational catalysis on metal surfaces
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-02-17 20:00 EST
Benjamin X. Shi, Timothy Berkelbach
Density functional theory (DFT) has been critical towards our current atomistic understanding of catalysis on transition-metal surfaces. It has opened new paradigms in rational catalyst design, predicting fundamental properties, like the adsorption energy and reaction barriers, linked to catalytic performance. However, such applications depend sensitively on the predictive accuracy of DFT and achieving experimental-level reliability, so-called transition-metal chemical accuracy (13 kJ/mol), remains challenging for present density functional approximations (DFAs) or even methods beyond DFT. We introduce a new framework for designing DFAs tailored towards studying molecules adsorbed on transition-metal surfaces, building upon recent developments in non-self-consistent DFAs. We propose two functionals within this framework, demonstrating that transition-metal chemical accuracy can be achieved across a diverse set of 39 adsorption reactions while delivering consistent performance for 17 barrier heights. Moreover, we show that these non-self-consistent DFAs address qualitative failures that challenge current self-consistent DFAs, such as CO adsorption on Pt(111) and graphene on Ni(111). The resulting functionals are computationally practical and compatible with existing DFT codes, with scripts and workflows provided to use them. Looking ahead, this framework establishes a path toward developing more accurate and sophisticated DFAs for computational heterogeneous catalysis and beyond.
Materials Science (cond-mat.mtrl-sci), Chemical Physics (physics.chem-ph), Computational Physics (physics.comp-ph)
Nematostriction in frustrated two-dimensional Heisenberg models
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2026-02-17 20:00 EST
Olav F. Syljuåsen, Jens Paaske
We investigate the nematic phase transition in the Heisenberg $ J_1$ -$ J_2$ -model on square and triangular lattices, accounting for finite lattice compressibility and bond-length-dependent magnetic exchange. Using Nematic Bond Theory, a diagrammatic self-consistent method, we study the nematostriction that happens when the onset of nematic order in the spin-system drives a concomitant structural phase transition. We analyze the mechanisms by which the magnetoelastic couplings renormalize the critical temperature and modify the phonon spectrum. The magnetoelastic feeback can also alter fundamentally the nature of the phase transition. Specifically, on the square lattice, the transition shifts from continuous to weakly first-order (discontinuous) beyond a critical magnetoelastic coupling threshold. Conversely, on the triangular lattice, the transition remains discontinuous regardless of coupling strength.
Strongly Correlated Electrons (cond-mat.str-el)
Stacking-Engineered Thermal Transport and Phonon Filtering in Rhenium Disulfide
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-02-17 20:00 EST
Yongjian Zhou, Haoran Cui, Zefang Ye, Jung-Fu Lin, Yan Wang, Yaguo Wang
Cross-plane heat transport is a critical bottleneck for van der Waals (vdW) electronics, yet its microscopic governing principles remain elusive. We demonstrate that stacking order is an effective control knob for cross-plane phonon transport in multilayer Rhenium Disulfide (ReS2). Thickness-dependent thermal conductivity measurements reveal remarkably long cross-plane phonon mean free paths (MFPs) (>= 200-300 nm) and provide a direct experimental observation of the transition from quasi-ballistic transport to a thickness-independent ballistic limit. AA stacking exhibits nearly double the cross-plane thermal conductivity of AB stacking, driven by longer acoustic phonon lifetimes from a more “coherent” interlayer registry. Integrated deep neural-network molecular dynamics reveals that phonon filtering in ReS2 is fundamentally frequency-selective: weak vdW coupling acts as a low-pass filter, whereas stronger coupling broadens the transmission passband. These results establish ReS2 as a model system where stacking order and interlayer coupling can be engineered to tune heat conduction across diffusive, quasi-ballistic, and ballistic regimes, offering a new framework for thermal management in 2D electronics.
Materials Science (cond-mat.mtrl-sci)
23 pages, 5 figures
Signatures of Dynes superconductivity in the THz response of ALD-grown NbN thin films
New Submission | Superconductivity (cond-mat.supr-con) | 2026-02-17 20:00 EST
Frederik Bolle, Yayi Lin, Ozan Saritas, Martin Dressel, Ciprian Padurariu, Sahitya Varma Vegesna, Nitesh Yerra, Heidemarie Krüger, Marc Scheffler
The frequency-dependent complex optical conductivity reflects key properties of superconductors, such as the energy gap in the density of states (DOS) and the superfluid density. For disordered superconductors, the optical conductivity often can be described within Bardeen-Cooper-Schrieffer (BCS) theory, while in corresponding tunneling experiments, deviations in the observed DOS typically require modelling by the phenomenological Dynes formula. The implications of such Dynes DOS for optics were rarely discussed so far. Here we probe the terahertz conductivity of superconducting NbN thin films with thicknesses ranging from 4.5 to 20nm, which were grown by atomic layer deposition (ALD). Our frequency range from 0.3 to 2.1 THz covers energies below and above the spectral gap. For 20nm thick NbN, we find in the optical conductivity distinct deviations from the BCS model, including a step-like characteristic in the absorption at half the zero-temperature spectral gap. These observations can be fully captured by Dynes electrodynamics with a small and temperature-independent pair-breaking rate. For the other films, we also observe signs of Dynes electrodynamics, and we discuss the evolution of the energy gap, the superfluid density, and the pair-breaking rate as function of film thickness.
Superconductivity (cond-mat.supr-con)
Controlled Theory of Skyrmion Chern Bands in Moiré Quantum Materials: Quantum Geometry and Collective Dynamics
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2026-02-17 20:00 EST
Recent experiments in moiré quantum materials exhibit quantized Hall states without an external magnetic field, motivating continuum mechanisms based on smooth moiré-periodic pseudospin textures. We present a controlled theory of skyrmion Chern bands generated by such textures. An exact local $ SU(2)$ transformation reveals an emergent non-Abelian gauge field; for large branch splitting we perform an operator-level Schrieffer-Wolff expansion, yielding a single-branch Hamiltonian together with systematically dressed physical operators that define the projected interacting theory beyond strict adiabaticity. The leading dynamics is governed by a $ U(1)$ Berry connection whose flux is set by the skyrmion density, while controlled non-adiabatic corrections are fixed by the texture’s real-space quantum geometric tensor. In a Landau-level representation built from the averaged emergent field, moiré-periodic modulations induce Umklapp-resolved deformations of Girvin-MacDonald-Platzman kinematics and microscopic sources of excess optical quantum weight above the topological lower bound. Assuming a gapped Hall phase, we further derive a skyrmion-crystal effective field theory with a universal Berry-phase term and a noncommutative magnetophonon. Our results provide experimentally accessible signatures for twisted transition-metal dichalcogenide homobilayers and rhombohedral graphene aligned with hexagonal boron nitride.
Strongly Correlated Electrons (cond-mat.str-el), Mesoscale and Nanoscale Physics (cond-mat.mes-hall), High Energy Physics - Theory (hep-th), Quantum Physics (quant-ph)
63 pages
Majorana Signatures in Planar Tunneling through a Kitaev Spin Liquid
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2026-02-17 20:00 EST
Weiyao Li, Vitor Dantas, Wen-Han Kao, Natalia B. Perkins
We propose a planar tunneling setup to probe vacancy-bound Majorana modes in the chiral Kitaev spin liquid. In this geometry, the inelastic tunneling conductance can be expressed directly in terms of real-space spin correlations, establishing a link between measurable spectra and the underlying fractionalized excitations. We show that spin vacancies host localized Majorana states that generate sharp near-zero-bias features, well separated from the continuum of bulk spin excitations. Compared to local STM measurements, the planar configuration naturally enhances the signal by coherently summing over multiple vacancies, reducing spatial resolution requirements. Our results demonstrate a realistic and scalable route to detect Majorana excitations in Kitaev materials.
Strongly Correlated Electrons (cond-mat.str-el)
14 pages, 5 figures
3d Conformal Field Theories via Fuzzy Sphere Algebra
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2026-02-17 20:00 EST
Fuzzy sphere models conjecturally realize 3d CFTs in small systems of spinful fermions, but why they work so well is still not fully understood. Their Hamiltonians are built from electron density operators projected to the lowest Landau Level. We analyze the algebra of the density modes and verify that it satisfies the Jacobi identity. The fuzzy sphere geometry admits two thermodynamic limits: a local planar limit yielding the fuzzy plane, and a commutative limit yielding an ordinary sphere. In the planar limit, high-angular-momentum modes recover the Girvin-MacDonald-Platzman algebra, whereas in the commutative limit the low-angular-momentum modes become semiclassical. We further find an explicit representation of the conformal algebra so(3,2) in the minimal two-electron system and extend it to larger systems via an so(3) equivariant coproduct. Because the coproduct splits one so(3) representation into a tensor product, it is structurally mismatched with the thermodynamic limit of critical fuzzy sphere Hamiltonians.
Strongly Correlated Electrons (cond-mat.str-el), High Energy Physics - Theory (hep-th)