CMP Journal 2025-04-15
Statistics
Nature Materials: 1
Nature Nanotechnology: 1
Nature Physics: 2
Physical Review Letters: 10
Physical Review X: 2
arXiv: 106
Nature Materials
Skyrmion nanodomains in ferroelectric-antiferroelectric solid solutions
Original Paper | Ferroelectrics and multiferroics | 2025-04-14 20:00 EDT
Weijie Zheng, Xingyue Ma, Zhentao Pang, Yifeng Ren, Hongying Chen, Jibo Xu, Chunyan Zheng, Jianyi Liu, Xiaohui Liu, Yu Deng, Yuefeng Nie, Di Wu, Laurent Bellaiche, Yurong Yang, Zheng Wen
Polar skyrmions have demonstrated rich physics and exotic properties for developing novel functionalities. However, so far, skyrmion nanodomains exist only in a few material systems, such as ferroelectric/dielectric superlattices, free-standing PbTiO3/SrTiO3 epitaxial bilayers and ultrathin Pb(Zr,Ti)O3/SrTiO3/Pb(Zr,Ti)O3 sandwiches. These heterostructures are fabricated with elaborately designed boundary conditions to meet the delicate energy balance for stabilizing topological phases. This requirement limits the broad applications of skyrmions in electronic devices. Here we show widespread skyrmion nanodomains in ferroelectric-antiferroelectric solid solutions, composed of ferroelectric PbTiO3 and one antiferroelectric PbSnO3 (Pb(Ti1-xSnx)O3), PbHfO3 (Pb(Ti1-xHfx)O3) or PbZrO3 (Pb(Ti1-xZrx)O3). The skyrmionic textures are formed by engineering dipole-dipole and antiferrodistortive-dipole couplings in competition between ferroelectric and antiferroelectric polar orderings, allowing the stabilization of topological phases. A phase diagram is built for the three solid solution series, revealing the stabilization regions of skyrmion nanodomains. In addition, the non-trivial domains also exhibit improved switching character, reversible writing/erasure and long-term retention for the electrical manipulation of polar configurations. These findings open an avenue for the investigation and exploitation of polar skyrmions in ferroelectric-based materials, providing opportunities in topological electronics.
Ferroelectrics and multiferroics
Nature Nanotechnology
Gold-modified nanoporous silicon for photoelectrochemical regulation of intracellular condensates
Original Paper | Biomaterials | 2025-04-14 20:00 EDT
Jing Zhang, Pengju Li, Jiping Yue, Lingyuan Meng, Wen Li, Chuanwang Yang, Saehyun Kim, Zhe Cheng, Ananth Kamath, Samira Siahrostami, Bozhi Tian
Nano-enabled catalysis at the interface of metals and semiconductors has found numerous applications, but its role in mediating cellular responses is still largely unexplored. Here we explore the territory by examining the once elusive mechanism through which a nanoporous silicon-based photocatalyst facilitates the two-electron oxidation of water to generate hydrogen peroxide under physiological conditions. We achieve precise modulation of intracellular stress granule formation by the controlled photoelectrochemical production of hydrogen peroxide in the extracellular environment, thereby enhancing cellular resilience to significant oxidative stress. This photoelectrochemical strategy has been evaluated for its efficacy in treating myocardial ischaemia-reperfusion injury in an ex vivo rodent model. Our data suggest that a pretreatment regimen involving photoelectrochemical generation of hydrogen peroxide at mild concentrations mitigates myocardial ischaemia-reperfusion-induced functional decline and infarction. These findings suggest a viable wireless therapeutic intervention for managing ischaemic disease and highlight the biomedical potential of nanostructured semiconductor-based catalytic devices.
Biomaterials, Biomedical engineering, Nanobiotechnology, Tissue engineering and regenerative medicine
Nature Physics
Impact of impurities on crystal growth
Original Paper | Chemical physics | 2025-04-14 20:00 EDT
Qiong Gao, Huang Fang, Dong Xiang, Yanshuang Chen, Hajime Tanaka, Peng Tan
Impurities critically influence crystallization, a process fundamental to both physical sciences and industrial engineering. However, understanding how impurity transport affects crystallization presents substantial experimental challenges. Here we visualized crystallization at the single-particle level for a relatively high concentration of impurities. We observed a bifurcation in growth modes–continuous growth or melting and recrystallization–governed by the ability of the system to remove impurity particles from the growth front. The initial nucleation configuration determines the crystal grain size and growth-front morphology, which in turn influence impurity transport. Small grains promote lateral impurity transport to grain boundaries, thus reducing impurity concentration and favouring continuous growth, whereas larger grains accumulate impurities, leading to melting and recrystallization. We reveal that the latter arises from the competition between crystallization and vitrification, which is a form of devitrification. This study provides insights into the relation between impurity concentration and crystallization pathways and highlights how the initial configuration shapes the final crystal morphology.
Chemical physics, Colloids, Phase transitions and critical phenomena, Structure of solids and liquids
Hamiltonian engineering of collective XYZ spin models in an optical cavity
Original Paper | Atomic and molecular interactions with photons | 2025-04-14 20:00 EDT
Chengyi Luo, Haoqing Zhang, Anjun Chu, Chitose Maruko, Ana Maria Rey, James K. Thompson
Quantum simulations offer opportunities both for studying many-body physics and for generating useful entangled states. However, existing platforms are usually restricted to specific types of interaction, fundamentally limiting the models they can mimic. Here we realize an all-to-all interacting model with an arbitrary quadratic Hamiltonian, thus demonstrating an infinite-range tunable Heisenberg XYZ model. This was accomplished by engineering cavity-mediated four-photon interactions between an ensemble of 700 rubidium atoms with a pair of momentum states serving as the effective qubit degree of freedom. As one example of the versatility of this approach, we implemented the so-called two-axis counter-twisting model, a collective spin model that can generate spin-squeezed states that saturate the Heisenberg limit on quantum phase estimation. Furthermore, our platform allows for including more than two relevant momentum states by simply adding additional dressing laser tones. This approach opens opportunities for quantum simulation and quantum sensing with matter-wave interferometers and other quantum sensors, such as optical clocks and magnetometers.
Atomic and molecular interactions with photons, Matter waves and particle beams, Quantum metrology, Quantum optics, Quantum simulation
Physical Review Letters
Threefold Way for Typical Entanglement
Research article | Quantum entanglement | 2025-04-14 06:00 EDT
Haruki Yagi, Ken Mochizuki, and Zongping Gong
A typical quantum state with no symmetry can be realized by letting a random unitary act on a fixed state, and the subsystem entanglement spectrum follows the Laguerre unitary ensemble (LUE). For integer-spin time reversal symmetry, we have an analogous scenario where we prepare a time-reversal symmetric state and let random orthogonal matrices act on it, leading to the Laguerre orthogonal ensemble (LOE). However, for half-integer-spin time reversal symmetry, a straightforward analog leading to the Laguerre symplectic ensemble (LSE) is no longer valid because that time-reversal symmetric state is forbidden by the Kramers’ theorem. We devise a system in which the global time reversal operator is fractionalized on the subsystems, and show that LSE arises in the system. Extending this idea, we incorporate general symmetry fractionalization into the system, and show that the statistics of the entanglement spectrum is decomposed into a direct sum of LOE, LUE, and/or LSE. Here, various degeneracies in the entanglement spectrum may appear, depending on the non-Abelian nature of the symmetry group and the cohomology class of the nontrivial projective representation on the subsystem. Our work establishes the entanglement counterpart of Dyson’s threefold way for Hamiltonians with symmetries.
Phys. Rev. Lett. 134, 150401 (2025)
Quantum entanglement, Symmetry protected topological states, Topological field theories, Random matrix theory
Dwarf Galaxies Imply Dark Matter is Heavier than $2.2\times{}{10}^{- 21}\text{ }\text{ }\mathrm{eV}$
Research article | Particle dark matter | 2025-04-14 06:00 EDT
Tim Zimmermann, James Alvey, David J. E. Marsh, Malcolm Fairbairn, and Justin I. Read
Through data-driven reconstructions of the dark matter density profiles within the Leo II dwarf Milky Way satellite galaxy, a rigorous lower bound of 2.2×10-21 eV is set on the mass of a hypothetical bosonic dark matter particle.
Phys. Rev. Lett. 134, 151001 (2025)
Particle dark matter, Axion-like particles, Axions, Galaxies, Mass
Observational Signatures of Highly Magnified Gravitational Waves from Compact Binary Coalescence
Research article | Gravitational lenses | 2025-04-14 06:00 EDT
Rico K. L. Lo, Luka Vujeva, Jose María Ezquiaga, and Juno C. L. Chan
Gravitational lensing has empowered telescopes to discover astronomical objects that are otherwise out of reach without being highly magnified by foreground structures. While we expect gravitational waves (GWs) from compact binary coalescences to also experience lensing, the phenomenology of highly magnified GWs has not been fully exploited. In this Letter, we fill this gap and explore the observational signatures of these highly magnified GWs. We find that these signatures are robust against modeling details and can be used as smoking-gun evidence to confirm the detection of lensing of GWs without any electromagnetic observation. Additionally, diffraction becomes important in some cases, which limits the maximum possible magnification and gives waveform signatures of lensing that can only be observed by GW detectors. Even with current-generation observatories, we are already sensitive to these rare, highly magnified GWs and could use them to probe the high-redshift Universe beyond the usual horizon.
Phys. Rev. Lett. 134, 151401 (2025)
Gravitational lenses, Gravitational waves
Search for a Hidden Sector Scalar from Kaon Decay in the Dimuon Final State at ICARUS
Research article | Axions | 2025-04-14 06:00 EDT
F. Abd Alrahman et al. (ICARUS Collaboration)
We present a search for long-lived particles (LLPs), produced in kaon decays, that decay to two muons inside the ICARUS neutrino detector. This channel would be a signal of hidden sector models that can address outstanding issues in particle physics such as the strong CP problem and the microphysical origin of dark matter. The search is performed with data collected in the Neutrinos at the Main Injector (NuMI) beam at Fermilab corresponding to $2.41\times{}{10}^{20}$ protons-on-target. No new physics signal is observed, and we set world leading limits on heavy QCD axions, as well as for the Higgs portal scalar among dedicated searches. Limits are also presented in a model-independent way applicable to any new physics model predicting the process $K\rightarrow \pi +S(\rightarrow \mu \mu )$, for a LLP $S$. This result is the first search for new physics performed with the ICARUS detector at Fermilab. It paves the way for the future program of LLP searches at ICARUS.
Phys. Rev. Lett. 134, 151801 (2025)
Axions, Particle dark matter, Axion-like particles, Hypothetical scalars, Neutrino detection
Final Search for Short-Baseline Neutrino Oscillations with the PROSPECT-I Detector at HFIR
Research article | Neutrino oscillations | 2025-04-14 06:00 EDT
M. Andriamirado et al. (PROSPECT Collaboration)
The PROSPECT experiment is designed to perform precise searches for antineutrino disappearance at short distances (7–9 m) from compact nuclear reactor cores. This Letter reports results from a new neutrino oscillation analysis performed using the complete data sample from the PROSPECT-I detector operated at the High Flux Isotope Reactor in 2018. The analysis uses a multiperiod selection of inverse beta decay neutrino interactions with reduced backgrounds and enhanced statistical power to set limits on electron neutrino disappearance caused by mixing with sterile neutrinos with $0.2–20\text{ }\text{ }{\mathrm{eV}}^{2}$ mass splittings. Inverse beta decay positron energy spectra from six different reactor-detector distance ranges are found to be statistically consistent with one another, as would be expected in the absence of sterile neutrino oscillations. The data excludes at 95% confidence level the existence of sterile neutrinos in regions above $3\text{ }\text{ }{\mathrm{eV}}^{2}$ previously unexplored by terrestrial experiments, including all space below $10\text{ }\text{ }{\mathrm{eV}}^{2}$ suggested by the recently strengthened Gallium Anomaly. The best-fit point of the Neutrino-4 reactor experiment’s claimed observation of short-baseline oscillation is ruled out at more than 5 standard deviations.
Phys. Rev. Lett. 134, 151802 (2025)
Neutrino oscillations, Sterile neutrinos
Quantum Electrodynamics in Strong Electromagnetic Fields: Substate Resolved $\mathrm{K}\alpha $ Transition Energies in Heliumlike Uranium
Research article | Atomic spectra | 2025-04-14 06:00 EDT
Ph. Pfäfflein et al.
Using novel metallic magnetic calorimeter detectors at the CRYRING@ESR, we recorded x-ray spectra of stored and electron cooled heliumlike uranium (${\mathrm{U}}^{90+}$) with an unmatched spectral resolution of close to 90 eV. This allowed for an accurate determination of the energies of all four components of the $\mathrm{K}\alpha $ transitions in ${\mathrm{U}}^{90+}$. We find good agreement with state-of-the-art bound-state QED calculations for the strong-field regime. Our results do not support any systematic deviation between experiment and theory in heliumlike systems, the presence of which was subject of intense debates in recent years.
Phys. Rev. Lett. 134, 153001 (2025)
Atomic spectra, Electronic structure of atoms & molecules, Ions, Spectroscopy, X-ray techniques
Experimental Observation of Dirac Exceptional Points
Research article | Quantum control | 2025-04-14 06:00 EDT
Yang Wu, Dongfanghao Zhu, Yunhan Wang, Xing Rong, and Jiangfeng Du
The discovery of a Dirac exceptional point in a nitrogen-vacancy center in diamond is associated with an exotic band topology that provides lossless quantum control with applications to various photonic, phononic, mechanical, and quantum systems.
Phys. Rev. Lett. 134, 153601 (2025)
Quantum control, Exceptional points, Nitrogen vacancy centers in diamond, Non-Hermitian systems
Autoresonant Removal of Fusion Products in Mirror Machines
Research article | Fast particle effects in plasmas | 2025-04-14 06:00 EDT
Eli Gudinetsky, Tal Miller, Ilan Be’ery, and Ido Barth
Magnetic confinement fusion reactors produce fusion byproduct particles that must be removed for efficient operation. It is suggested to use autoresonance (a continuous phase locking between anharmonic motion and a chirped drive) to remove the fusion products from a magnetic mirror, the simplest magnetic confinement configuration. An analogy to the driven pendulum is established via the guiding center approximation. The full 3D dynamics is simulated for $\alpha $ particles [the products of deuterium-tritium (DT) fusion] in agreement with the approximated 1D model. Monte Carlo simulations sampling the phase space of initial conditions are used to quantify the method’s efficiency. The DT fuel particles are out of the bandwidth of the chirped drive and, therefore, stay in the mirror for ongoing fusion. The method is also applicable for advanced aneutronic reactors, such as $\mathrm{p}\text{- }^{11}\mathrm{B}$.
Phys. Rev. Lett. 134, 155101 (2025)
Fast particle effects in plasmas, Magnetic confinement fusion, Nonlinear resonance, Magnetic mirrors & traps, Magnetically confined plasmas
Multipath Signal-Selective Metasurface: Passive Time-Varying Interlocking Mechanism to Vary Spatial Impedance for Signals with the Same Frequency
Research article | Dielectric properties | 2025-04-14 06:00 EDT
Kaito Tachi, Kota Suzuki, Kairi Takimoto, Shunsuke Saruwatari, Kiichi Niitsu, Ryo Ikeya, Tayaallen Ramachandran, Atsuko Nagata, Peter Njogu, and Hiroki Wakatsuchi
A new passive metasurface filter is capable of selectively transmitting only the first incident wave while rejecting time-delayed signals at the same frequency.
Phys. Rev. Lett. 134, 157001 (2025)
Dielectric properties, Impedance, Optical & microwave phenomena, Nonlinear time-delay systems, RF, microwave, & terahertz sources
Dielectric Properties of Aqueous Electrolytes at the Nanoscale
Research article | Dielectric properties | 2025-04-14 06:00 EDT
Maximilian R. Becker, Roland R. Netz, Philip Loche, Douwe Jan Bonthuis, Dominique Mouhanna, and Hélène Berthoumieux
Despite the ubiquity of aqueous electrolytes, the effect of salt on water organization remains controversial. We introduce a nonlocal and nonlinear field theory for the nanoscale polarization of ions and water and derive the electrolyte dielectric response as a function of salt concentration to first order in a loop expansion. By comparison with molecular dynamics simulations, we show that rising salt concentration induces a dielectric permittivity decrement and Debye screening in the longitudinal susceptibility but leaves the water structure remarkably unchanged.
Phys. Rev. Lett. 134, 158001 (2025)
Dielectric properties, Water
Physical Review X
Classification of Joint Quantum Measurements Based on Entanglement Cost of Localization
Research article | Quantum algorithms & computation | 2025-04-14 06:00 EDT
Jef Pauwels, Alejandro Pozas-Kerstjens, Flavio Del Santo, and Nicolas Gisin
A powerful framework allows scientists to understand and classify joint quantum measurements–procedures essential for many quantum technologies.
Phys. Rev. X 15, 021013 (2025)
Quantum algorithms & computation, Quantum communication, protocols & technology, Quantum computation, Quantum correlations, foundations & formalism, Quantum field theory, Quantum information processing, Quantum information theory
From Existing and New Nuclear and Astrophysical Constraints to Stringent Limits on the Equation of State of Neutron-Rich Dense Matter
Research article | Equations of state | 2025-04-14 06:00 EDT
Hauke Koehn, Henrik Rose, Peter T. H. Pang, Rahul Somasundaram, Brendan T. Reed, Ingo Tews, Adrian Abac, Oleg Komoltsev, Nina Kunert, Aleksi Kurkela, Michael W. Coughlin, Brian F. Healy, and Tim Dietrich
For neutron stars, a combination of nuclear experiments, astrophysical data, and gravitational waves narrows the uncertainty of radii measurements to 0.5 km and predicts a maximum mass of about 2.3 solar masses.
Phys. Rev. X 15, 021014 (2025)
Equations of state, Equations of state of nuclear matter, Nuclear astrophysics, Nuclear matter in neutron stars, Neutron stars & pulsars
arXiv
Exact mobility line and mobility ring in the complex energy plane of a flat band lattice with a non-Hermitian quasiperiodic potential
New Submission | Disordered Systems and Neural Networks (cond-mat.dis-nn) | 2025-04-15 20:00 EDT
Guang-Xin Pang, Zhi Li, Shan-Zhong Li, Yan-Yang Zhang, Jun-Feng Liu, Yi-Cai Zhang
In this study, we investigate the problem of Anderson localization in a one-dimensional flat band lattice with a non-Hermitian quasiperiodic on-site potential. First of all, we discuss the influences of non-Hermitian potentials on the existence of critical states. Our findings show that, unlike in Hermitian cases, the non-Hermiticity of the potential leads to the disappearance of critical states and critical regions. Furthermore, we are able to accurately determine the Lyapunov exponents and the mobility edges. Our results reveal that the mobility edges form mobility lines and mobility rings in the complex energy plane. Within the mobility rings, the eigenstates are extended, while the localized states are located outside the mobility rings. For mobility line cases, only when the eigenenergies lie on the mobility lines, their corresponding eigenstates are extended this http URL, as the energy approaches the mobility edges, we observe that, differently from Hermitian cases, here the critical index of the localization length is not a constant, but rather varies depending on the positions of the mobility edges.
Disordered Systems and Neural Networks (cond-mat.dis-nn), Quantum Gases (cond-mat.quant-gas)
13 pages, 9 figures
Dew harvesting grass: role of epicuticular wax in regulating condensation dynamics
New Submission | Soft Condensed Matter (cond-mat.soft) | 2025-04-15 20:00 EDT
Bashra Mahamed, Francis James Dent, Robert Simpson, Nicola Weston, Fanny Nascimento Costa, Sepideh Khodaparast
Identification and characterization of natural dew collecting models is instrumental for the inspiration, design and development of engineered dew harvesting systems. Short low growing grass is one of the most ubiquitous and proficient examples of natural dew harvesting, owing to its large surface area, small thermal capacity, structured rough surface and proximity to ground level. Here, we provide a closer look at the formation, growth, and dynamics of microscale dew droplets on the surface of wheatgrass leaves, investigating the role of epicuticular wax. The wheatgrass leaf exhibits biphilic properties emerging from the hydrophilic lamina covered by hydrophobic wax microsculptures. As a result, the regulation of the dew formation and condensation dynamics is largely governed by the arrangement and density of epicuticular wax micromorphologies. At moderate subcooling levels (4-10 $ ^{\circ}$ C below the dew point), we observe drop-wise condensation on the superhydrophobic adaxial side, while significant flooding and film condensation usually appear on abaxial surfaces with lower wax coverage. On the adaxial side of the leaves, the fairly uniform coverage of the hydrophobic epicuticular wax crystals on the hydrophilic background promotes drop-wise condensation nucleation while facilitating droplet mobility. Frequent coalescence of multiple droplets of 5 - 20 $ {\mu}$ m diameter results in self-propelled departure events, creating free potential sites for new nucleation. The findings of this study advance our understanding of dew formation on natural surfaces while providing inspiration and guidance for the development of sustainable functional microstructured coatings for various drop-wise condensation applications.
Soft Condensed Matter (cond-mat.soft)
Towards scientific machine learning for granular material simulations – challenges and opportunities
New Submission | Soft Condensed Matter (cond-mat.soft) | 2025-04-15 20:00 EDT
Marc Fransen, Andreas Fürst, Deepak Tunuguntla, Daniel N. Wilke, Benedikt Alkin, Daniel Barreto, Johannes Brandstetter, Miguel Angel Cabrera, Xinyan Fan, Mengwu Guo, Bram Kieskamp, Krishna Kumar, John Morrissey, Jonathan Nuttall, Jin Ooi, Luisa Orozco, Stefanos-Aldo Papanicolopulos, Tongming Qu, Dingena Schott, Takayuki Shuku, WaiChing Sun, Thomas Weinhart, Dongwei Ye, Hongyang Cheng
Micro-scale mechanisms, such as inter-particle and particle-fluid interactions, govern the behaviour of granular systems. While particle-scale simulations provide detailed insights into these interactions, their computational cost is often prohibitive. Attended by researchers from both the granular materials (GM) and machine learning (ML) communities, a recent Lorentz Center Workshop on “Machine Learning for Discrete Granular Media” brought the ML community up to date with GM challenges.
This position paper emerged from the workshop discussions. We define granular materials and identify seven key challenges that characterise their distinctive behaviour across various scales and regimes, ranging from gas-like to fluid-like and solid-like. Addressing these challenges is essential for developing robust and efficient digital twins for granular systems in various industrial applications. To showcase the potential of ML to the GM community, we present classical and emerging machine/deep learning techniques that have been, or could be, applied to granular materials. We reviewed sequence-based learning models for path-dependent constitutive behaviour, followed by encoder-decoder type models for representing high-dimensional data. We then explore graph neural networks and recent advances in neural operator learning. Lastly, we discuss model-order reduction and probabilistic learning techniques for high-dimensional parameterised systems, which are crucial for quantifying uncertainties arising from physics-based and data-driven models.
We present a workflow aimed at unifying data structures and modelling pipelines and guiding readers through the selection, training, and deployment of ML surrogates for granular material simulations. Finally, we illustrate the workflow’s practical use with two representative examples, focusing on granular materials in solid-like and fluid-like regimes.
Soft Condensed Matter (cond-mat.soft), Machine Learning (cs.LG), Computational Physics (physics.comp-ph)
35 pages, 17 figures
Anomalous interference drives oscillatory dynamics in wave-dressed active particles
New Submission | Soft Condensed Matter (cond-mat.soft) | 2025-04-15 20:00 EDT
Austin M. Blitstein, Rodolfo R. Rosales, Pedro J. Sáenz
A recent surge of discoveries has sparked significant interest in active systems where a particle moves autonomously due to a resonant interaction with its self-generated wave field, leading to notable wave-mediated effects including new propulsion mechanisms, spontaneous oscillatory dynamics, and quantum-like phenomena. Drawing from an archetypical model of wave-dressed active particles, we unveil a wave-mediated non-local force driving their dynamics, arising from the particle’s path memory and an unconventional form of wave interference near jerking points, locations where the particle’s velocity changes rapidly. In contrast to the typical case of constructive interference at points of stationary phase, waves excited by the particle near jerking points avoid cancellation through rapid changes in frequency. Through an asymptotic analysis, we derive the wave force from jerking points, revealing it as an elusive but crucial remnant of the particle’s past motion that allows us to rationalize mechanistically in-line speed oscillations, wave-like statistics in potential wells, and non-specular reflections. The results we derive follow from generic wave superposition principles, suggesting their applicability to a broad class of wave-dressed active particles.
Soft Condensed Matter (cond-mat.soft), Fluid Dynamics (physics.flu-dyn)
6 pages, 5 figures
Molecular Dynamics (MD) simulation of silicon nanoparticle crystallization during laser-induced forward transfer (LIFT) printing
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-04-15 20:00 EDT
Laser-induced forward transfer (LIFT) printing is a versatile technique to realize micro/nano-scale additive manufacturing of functional materials, including metals, and semiconductors. However, the crystallization phenomena during LIFT printing have not been well understood. In this work, we attempt to gain a comprehensive understanding of silicon crystallization during LIFT printing. Specifically, molecular dynamics (MD) simulation is used to investigate the size effect on the melting and crystallization of Si nanoparticles during transportation in air. We found with the decrease in nanoparticle size, crystallization becomes rare, even with a low cooling rate. The nucleation location of different particles is also analyzed and almost always starts at a sub-surface location (below 5 Å). The atomic structure evolution during solidification is also monitored to provide guidance for LIFT printing of Si. Our simulation results indicate that nano-confinement can lead to single-crystal structure formation, which may shed light on single-crystal additive manufacturing.
Materials Science (cond-mat.mtrl-sci)
Twist-Induced Effects on Weyl Pairs in Magnetized Graphene Nanoribbons
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2025-04-15 20:00 EDT
Semra Gurtas Dogan, Kobra Hasanirokh, Omar Mustafa, Abdullah Guvendi
This paper presents an analytical investigation into the dynamics of Weyl pairs within magnetized helicoidal graphene nanoribbons. By embedding a curved surface into flat Minkowski space-time, we derive a fully covariant two-body Dirac equation specific to this system. We begin by formulating a non-perturbative wave equation that governs the relative motion of the Weyl pairs and obtain exact solutions. Our results demonstrate the influence of the uniform magnetic field and the number of twists on the dynamics of Weyl pairs in graphene nanoribbons, providing precise energy values that lay a robust foundation for future research. Furthermore, we examine the material’s response to perturbation fields by calculating the polarization function and investigating how twisting and magnetic fields affect this response. Our findings indicate that, in principle, the material’s properties, which are crucial for practical applications, can be effectively controlled by precisely tuning the magnetic field and the number of twists in graphene nanoribbons.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Materials Science (cond-mat.mtrl-sci), High Energy Physics - Theory (hep-th), Quantum Physics (quant-ph)
7 pages, 8 figures
Imbibition of Oil in Dry and Prewetted Calcite Nanopores
New Submission | Soft Condensed Matter (cond-mat.soft) | 2025-04-15 20:00 EDT
Ejaz Ahmed (1), Huajie Zhang (1), Mert Aybar (1), Bikai Jin (2), Shihao Wang (2), Rui Qiao (1) ((1) Department of Mechanical Engineering, Virginia Tech, Blacksburg, USA, (2) Chevron Energy Technology Co., Houston, USA)
Fluid imbibition into porous media featuring nanopores is ubiquitous in applications such as oil recovery from unconventional reservoirs and material processing. While the imbibition of pure fluids has been extensively studied, the imbibition of fluid mixture is little explored. Here we report the molecular dynamics study of the imbibition of model crude oil into nanometer-wide mineral pores, both when pore walls are dry and prewetted by a residual water film. Results show the fastest imbibition and quickest propagation of molecularly thin precursor films ahead of the oil meniscus in the dry pore system. The presence of a thin water film on pore walls corresponding to an environmental relative humidity of 30% slows down but still allows the spontaneous imbibition of single-component oil. Introducing polar components into the oil slows down the imbibition into dry nanopores, due partly to the clogging of the pore entrance. Strong selectivity toward nonpolar oil is evident. The slowdown of imbibition by polar oil is less significant in the prewetted pores than in dry pores, but the selectivity toward nonpolar oil remains strong.
Soft Condensed Matter (cond-mat.soft), Atomic Physics (physics.atom-ph), Fluid Dynamics (physics.flu-dyn)
24 pages, 8 figures, Submitted to Physics of Fluids, Rui Qiao: To whom correspondence should be addressed. Email: ruiqiao@vt.edu
Banana DNA derivatives as homeotropic alignment layers in optical devices
New Submission | Soft Condensed Matter (cond-mat.soft) | 2025-04-15 20:00 EDT
Rafał Węgłowski, Anna Spadło, Dorota Węgłowska
In this study, deoxyribonucleic acid (DNA) from bananas was extracted and functionalized and used for the first time as a homeotropic alignment layer for liquid crystals (LCs). Our research was aimed at extracting and investigating DNA from bananas via the synthesis and study of DNA complexes with various surfactants to examine the usefulness of such a complex as an alignment layer in electro-optical transducers. We proposed a simple and eco-friendly synthesis of the DNA complexes isolated from bananas with surfactants, so we transformed the DNA isolated from bananas into a functionalized alignment layer. A biopolymer alignment layer like deoxyribonucleic acid (DNA) from a banana complexed with a cationic surfactant is an excellent alternative to a commonly used but toxic polyimide alignment layer. DNA-based materials are promising for photonic applications and biosensors because of their excellent optical and physical properties, biodegradability, and low production cost. The novelty of the research lies in the potential use of these materials as biodegradable biopolymer alignment layers for optical devices instead of conventional polymers, which are usually harmful for the environment.
Soft Condensed Matter (cond-mat.soft), Materials Science (cond-mat.mtrl-sci), Biological Physics (physics.bio-ph)
This work was supported by the National Centre of Science MINIATURA 6 2022/06/X/ST5/00508 and UGB 22-720 and 22723. The authors thank Mateusz Mrukiewicz for performing ionic conductivity measurements
Soft Matter, 2024,20, 8561-8569
Enhanced Classical Nucleation Theory for Cavitation Inception in the Presence of Gaseous Nuclei
New Submission | Soft Condensed Matter (cond-mat.soft) | 2025-04-15 20:00 EDT
Mazyar Dawoodian, Ould el Moctar
This paper introduces an enhanced Classical Nucleation Theory model to predict the cavitation inception pressure and to describe the behavior of nanoscale gaseous nuclei during cavitation. Validation is achieved through molecular dynamics simulations. The findings highlight the significant role of nanoscale gaseous nuclei in lowering the tensile strength required for cavitation initiation. The results show that our enhanced CNT model predicts lower cavitation pressures than the Blake threshold, closely matching molecular dynamics simulations. Finally, our results illustrate that differences between cavitation pressures using the Van der Waals and ideal gas models are greatest for smaller nuclei and lower temperatures.
Soft Condensed Matter (cond-mat.soft), Chemical Physics (physics.chem-ph)
Tuning Charge Density Wave in the Transition from Magnetically Frustrated Conductor to Ferrimagnetic Insulator in Carbon Nanowire within Boron Nitride Nanotube
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2025-04-15 20:00 EDT
Chi Ho Wong, Zong Liang Guo, King Cheong Lam, Chun Pong Chau, Wing Yu Chan, Chak-yin Tang, Yuen Hong Tsang, Leung Yuk Frank Lam, Xijun Hu
The emergence of exotic charge density wave (CDW) alongside ferrimagnetism materials opens exciting new possibilities for quantum switching, particularly in field-tuning CDW electronics. However, these two phenomena often compete and rely heavily on strong electronic correlations. While carbon nanowire arrays have been experimentally shown to exhibit ferromagnetism above 400 K, our research shows that encapsulating a linear carbon chain (LCC) within zigzag boron nitride nanotubes (BNT) induces a short-range CDW state under a competing effect of ferrimagnetism and magnetic frustrations. However, for this exotic feature to occur, the LCC needs to break the symmetry along the circular plane of the BNT. Then we utilize a Monte Carlo model to identify the optimal length of LCC@BNT to tackle its size effect, while also comparing the stability of chains provided by carbon nanotubes. The shorter LCC@BNT displays a more prominent long-range CDW pattern with a tunneling barrier of 2.3 eV on the Fermi surface, transitioning into an unconventional insulator. Meanwhile, magnetic frustrations disappear, and ferrimagnetism remains stable up to 280 K. Our discovery of ferrimagnetic CDW carbyne insulators, which function without conventional periodic lattice distortion, spin-orbit coupling, or complex d and f hybridization represents a groundbreaking shift in thinking, which demonstrates that such exotic properties are not exclusive to transition metal elements. We anticipate that spin fluctuations in LCC@BNT could enable fine-tuning of the CDW pattern, and applying an electric excitation of 2.3 eV triggers an abrupt insulator-to-conductor transition for quantum switching applications.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Quantum Physics (quant-ph)
The temperature dependent thermal vector potential in spinor Boltzmann equation
New Submission | Statistical Mechanics (cond-mat.stat-mech) | 2025-04-15 20:00 EDT
The thermal scalar and vector potential were introduced to investigate the thermal transport under a temperature gradient in terms of linear response theory[1,2]. However, the microscopic origin of these phenomenological thermal potentials had not been addressed clearly. In this manuscript, we try to derive a temperature dependent damping force based on the spinor Boltzmann equation (SBE), and relate it with the thermal gauge potential, which is exactly the temperature dependent thermal scalar and vector potential. It is shown that the thermal potential originates from the scattering of conduction electrons and impurity or other scattering mechanisms. We also derive a temperature dependent inverse relaxation time, which depends on momentum, it is different from the usual constant relaxation time. We evaluate the temperature dependent damping force by an approximated analytical solution of SBE. The other physical observable such as charge current and spin current are also explored.
Statistical Mechanics (cond-mat.stat-mech), Quantum Physics (quant-ph)
6 figures
PolyConf: Unlocking Polymer Conformation Generation through Hierarchical Generative Models
New Submission | Soft Condensed Matter (cond-mat.soft) | 2025-04-15 20:00 EDT
Fanmeng Wang, Wentao Guo, Qi Ou, Hongshuai Wang, Haitao Lin, Hongteng Xu, Zhifeng Gao
Polymer conformation generation is a critical task that enables atomic-level studies of diverse polymer materials. While significant advances have been made in designing various conformation generation methods for small molecules and proteins, these methods struggle to generate polymer conformations due to polymers’ unique structural characteristics. The scarcity of polymer conformation datasets further limits progress, making this promising area largely unexplored. In this work, we propose PolyConf, a pioneering tailored polymer conformation generation method that leverages hierarchical generative models to unlock new possibilities for this task. Specifically, we decompose the polymer conformation into a series of local conformations (i.e., the conformations of its repeating units), generating these local conformations through an autoregressive model. We then generate corresponding orientation transformations via a diffusion model to assemble these local conformations into the complete polymer conformation. Moreover, we develop the first benchmark with a high-quality polymer conformation dataset derived from molecular dynamics simulations to boost related research in this area. The comprehensive evaluation demonstrates that PolyConf consistently generates high-quality polymer conformations, facilitating advancements in polymer modeling and simulation.
Soft Condensed Matter (cond-mat.soft), Artificial Intelligence (cs.AI)
Breaking better: Imperfections increase fracture resistance in architected lattices
New Submission | Soft Condensed Matter (cond-mat.soft) | 2025-04-15 20:00 EDT
Alessandra Lingua, Antoine Sanner, François Hild, David S. Kammer
Architected materials offer unique opportunities to tailor fracture properties through local structural modifications. In this study, we investigate how the failure of architected materials with triangular lattice topology is affected by the removal of individual struts, which represent well-controlled and localized imperfections. Using a combination of macroscopic mechanical testing and digital image correlation (DIC), we analyze both global response and local crack propagation. We observe that the designed imperfections do not alter the failure initiation site nor the peak tensile load but significantly increase the work to failure. DIC-based tracking reveals that this increase correlates with deviations in the crack path and may also involve mechanisms such as crack bridging or temporary pinning near defects. These results demonstrate that small, well-characterized imperfections, when properly mastered, can be harnessed to improve failure resistance and expand the design space of architected materials beyond regular, periodic structures.
Soft Condensed Matter (cond-mat.soft), Materials Science (cond-mat.mtrl-sci)
Entropically Driven Agents
New Submission | Statistical Mechanics (cond-mat.stat-mech) | 2025-04-15 20:00 EDT
Populations of agents often exhibit surprising collective behavior emerging from simple local interactions. The common belief is that the agents must posses a certain level of cognitive abilities for such an emerging collective behavior to occur. However, contrary to this assumption, it is also well known that even noncognitive agents are capable of displaying nontrivial behavior. Here we consider an intermediate case, where the agents borrow a little bit from both extremes. We assume a population of agents performing random-walk in a bounded environment, on a square lattice. The agents can sense their immediate neighborhood, and they will attempt to move into a randomly selected empty site, by avoiding this http URL, the agents will temporary stop moving when they are in contact with at least two other agents. We show that surprisingly, such a rudimentary population of agents undergoes a percolation phase transition and self-organizes in a large polymer like structure, as a consequence of an attractive entropic force emerging from their restricted-valence and local spatial arrangement.
Statistical Mechanics (cond-mat.stat-mech), Adaptation and Self-Organizing Systems (nlin.AO), Data Analysis, Statistics and Probability (physics.data-an)
16 pages, 9 figures
International Journal of Modern Physics C, 2025
Unveiling Berry curvature contributions to Hall current in $C_4K$ materials
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2025-04-15 20:00 EDT
T. Farajollahpour, R. Ganesh, K. V. Samokhin
We identify a new contribution to the conventional Hall effect that emerges in materials with $ C_4K$ symmetry. This contribution originates from the modification of phase space density due to the Berry curvature, as we demonstrate using semiclassical equations of motion for band electrons. As an illustration, we build a minimal two-band tight-binding model with altermagnetic order that breaks $ C_4$ and $ K$ symmetries while preserving $ C_4K$ . The resulting Hall conductivity shows a square-root feature at the altermagnetic phase transition, which is due to the novel Berry curvature-driven contribution emerging below the critical temperature. This effect may offer a simple transport-based signature of an altermagnetic phase transition.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
6 pages + 10 pages supplementary materials
Measurement-induced phase transitions in quantum inference problems and quantum hidden Markov models
New Submission | Statistical Mechanics (cond-mat.stat-mech) | 2025-04-15 20:00 EDT
Sun Woo P. Kim, Curt von Keyserlingk, Austen Lamacraft
Recently, there is interest in coincident ‘sharpening’ and ‘learnability’ transitions in monitored quantum systems. In the latter, an outside observer’s ability to infer properties of a quantum system from measurements undergoes a phase transition. Such transitions appear to be related to the decodability transition in quantum error correction, but the precise connection is not clear. Here, we study these problems under one framework we call the general quantum inference problem. In cases as above where the system has a Markov structure, we say that the inference is on a quantum hidden Markov model. We show a formal connection to classical hidden Markov models and that they coincide for certain setups. For example, we prove this for those involving Haar-random unitaries and measurements. We introduce the notion of Bayes non-optimality, where parameters used for inference differs from true ones. This allows us to expand the phase diagrams of above models. At Bayes optimality, we obtain an explicit relation between ‘sharpening’ and ‘learnability’ order parameters, explicitly showing that the two transitions coincide. Next, we study concrete examples. We review quantum error correction on the toric and repetition code and their mapping to 2D random-bond Ising model (RBIM) through our framework. We study the Haar-random U(1)-symmetric monitored quantum circuit and tree, mapping each to inference models that we call the planted SSEP and planted XOR, respectively, and expanding the phase diagram to Bayes non-optimality. For the circuit, we deduce the phase boundary numerically and analytically argue that it is of a single universality class. For the tree, we present an exact solution of the entire phase boundary, which displays re-entrance as does the 2D RBIM. We discuss these phase diagrams, with their interpretations for quantum inference problems and rigorous arguments on their shapes.
Statistical Mechanics (cond-mat.stat-mech), Disordered Systems and Neural Networks (cond-mat.dis-nn), Quantum Physics (quant-ph)
24 pages of main text, 23 pages of appendix, 9 figures
How quantum fluctuations freeze a classical liquid and then melt it into a topological one
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2025-04-15 20:00 EDT
Hao Chen, Dan Mao, Andrea Kouta Dagnino, Glenn Wagner, Mark H. Fischer, Juraj Hasik, Eun-Ah Kim, Titus Neupert
Topologically ordered quantum liquids are highly sought-after quantum phases of matter and recently, fractional Chern insulators (FCIs) joined the few experimental realizations of such phases. Here, we ask whether a gapped classical, highly degenerate liquid can be the birthplace of FCIs upon the addition of suitable quantum fluctuations. Two competing tendencies can be anticipated: (i) following the quantum order-by-disorder paradigm, quantum fluctuations could induce symmetry-breaking (charge) order, or (ii) the classical liquid builds up long-range entanglement and turns into a quantum liquid. We study spinless fermions on a honeycomb lattice subject to cluster-charging interactions and introduce quantumness through a Haldane kinetic term. Based on extensive exact diagonalization calculations and high-order perturbation theory, we find that neither scenario (i) or (ii) prevails, but (i) and (ii) manifest sequentially as the kinetic energy is increased. We demonstrate how the gradual lifting of kinematic constraints gives rise to this sequence of phases. Our results relate to the regime of intermediate-scale interactions present in moiré systems, where band projections are not suitable to model FCIs and competing charge-ordered phases have been identified.
Strongly Correlated Electrons (cond-mat.str-el)
14 pages, 10 figures
Gate-tunable electroresistance in a sliding ferroelectric tunnel junction
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2025-04-15 20:00 EDT
Bozo Vareskic, Finn G. Kennedy, Takashi Taniguchi, Kenji Watanabe, Kenji Yasuda, Daniel C. Ralph
We fabricate and measure electrically-gated tunnel junctions in which the insulating barrier is a sliding van der Waals ferroelectric made from parallel-stacked bilayer hexagonal boron nitride and the electrodes are single-layer graphene. Despite the nominally-symmetric tunnel-junction structure, these devices can exhibit substantial electroresistance upon reversing the ferroelectric polarization. The magnitude and sign of tunneling electroresistance are tunable by bias and gate voltage. We show that this behavior can be understood within a simple tunneling model that takes into account the quantum capacitance of the graphene electrodes, so that the tunneling densities of states in the electrodes are separately modified as a function of bias and gate voltage.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
Magnetic order and physical properties of the Kagome metal UNb$_6$Sn$_6$
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2025-04-15 20:00 EDT
Z. W. Riedel, W. Simeth, C. S. Kengle, S. M. Thomas, J. D. Thompson, A. O. Scheie, F. Ronning, C. Lane, Jian-Xin Zhu, P. F. S. Rosa, E. D. Bauer
The $ RM_6X_6$ family of materials ($ R$ = rare-earth, $ M$ = transition metal, $ X$ = Ga, Si, Ge, Sn) produces an array of emergent phenomena, such as charge density waves, intrinsic Hall effects, and complex magnetic order, due to its Kagome net of transition metal atoms, its local-moment magnetic anisotropies, and its extensive chemical tunability. Here, we report a new ``166” material containing both an actinide (uranium) and a 4$ d$ transition metal (niobium) to investigate the properties of a 5$ f$ -4$ d$ electron 166 system. UNb$ 6$ Sn$ 6$ crystallizes in the hexagonal $ P$ 6/$ mmm$ space group with a small degree of disorder due to shifts in the size of the CoSn-like cages along the $ c$ axis. Upon cooling at zero magnetic field, the material undergoes two magnetic phase transitions at $ T\mathrm{2}$ = 46 K and $ T\mathrm{N}$ = 43 K. The low-temperature, zero-field phase is an antiferromagnet with ordered uranium moments and a $ \textbf{k}$ =(0,0,1/2) propagation vector determined by neutron diffraction. Remarkably, with a magnetic field applied along the $ c$ axis, five additional magnetic transitions occur, evidenced by magnetization and resistivity data, before the moment saturates at 2.62 $ {\mu}_{\mathrm{B}}$ /U at 2 K and $ \ge$ 13.6 T. In two magnetic phase regions, the Hall resistivity of UNb$ _6$ Sn$ _6$ significantly deviates from the magnetization, suggesting that the phases have a large Berry curvature or a change in the Fermi surface. The unknown magnetic ordering of the field-dependent phases of UNb$ _6$ Sn$ _6$ demonstrates the complexity of the 5$ f$ -4$ d$ 166 system and encourages further study of its properties.
Strongly Correlated Electrons (cond-mat.str-el), Materials Science (cond-mat.mtrl-sci)
28 pages, 23 figures
Tunable Magnon Polaritons via Eddy-Current-Induced Dissipation in Metallic-Banded YIG Spheres
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2025-04-15 20:00 EDT
Tatsushi Uno, Shugo Yoshii, Sotaro Mae, Ei Shigematsu, Ryo Ohshima, Yuichiro Ando, Masashi Shiraishi
We demonstrate a robust method to dynamically tune magnon dissipation in yttrium iron garnet spheres by equipping a metallic band around the sphere’s equator, enabling precise control over magnon-photon coupling states. The collective magnetization dynamics in the YIG sphere induce circular eddy currents in the metallic band, whose magnitude can be systematically varied by adjusting the angle between the metallic band plane and an external static magnetic field. This angular dependence yields a pronounced modulation of the ferromagnetic resonance (FMR) linewidth, facilitating seamless transitions between the Purcell and strong coupling regimes without altering photon cavity parameters. Systematic FMR and cavity spectroscopy measurements confirm that eddy-current-induced losses govern the primary mechanism behind the observed tunable damping. By achieving extensive periodic-angular dependence of magnon relaxation rate, we precisely control the magnon-photon coupling state, approaching the critical coupling condition. These results establish the YIG-metallic-band platform as a versatile and practical approach for engineering tunable magnon-polariton systems and advancing magnonic applications, including those exploring non-Hermitian magnonics.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Quantum Physics (quant-ph)
5 figures
Insights into Nb2C and Nb2CO2 as high-performance anodes for sodium- and lithium-ion batteries: An ab initio investigation
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-04-15 20:00 EDT
Nishat Sultana, Abdullah A. Amin, Eric J. Payton, Woo Kyun Kim
In this study, we employ first-principles density functional theory (DFT) calculations to investigate the electrochemical properties of Nb2C and Nb2CO2 MXenes as potential anode materials for sodium-ion (SIBs) and lithium-ion batteries (LIBs). Our findings reveal that Li and Na intercalation primarily modifies the electronic properties of Nb2C without inducing significant structural distortions, as indicated by Raman intensity variations. Adsorption energy calculations show that the T4 and H3 sites are the most favorable for metal intercalation, with Nb2CO2 exhibiting stronger adsorption due to oxygen functionalization. We find that Nb2C offers lower diffusion barriers, especially for Na ions, making it a promising candidate for fast-charging SIBs. In contrast, Nb2CO2 enhances charge retention through stronger electrostatic interactions but introduces higher migration resistance. Electronic structure analysis confirms the metallic nature of both MXenes, ensuring efficient electron transport. Open-circuit voltage (OCV) calculations indicate that Nb2CO2 exhibits higher OCV values than Nb2C, highlighting the role of surface functionalization in tuning electrochemical performance. Our study suggests that, while Li-based systems achieve slightly higher theoretical capacities, Na-based systems exhibit comparable performance, reinforcing the viability of sodium-ion batteries as a cost-effective alternative. Overall, our results demonstrate that Nb2C is better suited for rapid ion transport, whereas Nb2CO2 offers enhanced charge retention. These insights provide a foundation for the optimization of MXene-based electrodes for next-generation high performance energy storage applications.
Materials Science (cond-mat.mtrl-sci)
High-Throughput Transition-State Searches in Zeolite Nanopores
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-04-15 20:00 EDT
Pau Ferri-Vicedo, Alexander J. Hoffman, Avni Singhal, Rafael Gómez-Bombarelli
Zeolites are important for industrial catalytic processes involving organic molecules. Understanding molecular reaction mechanisms within the confined nanoporous environment can guide the selection of pore topologies, material compositions, and process conditions to maximize activity and selectivity. However, experimental mechanistic studies are time- and resource-intensive, and traditional molecular simulations rely heavily on expert intuition and hand manipulation of chemical structures, resulting in poor scalability.
Here, we present an automated computational pipeline for locating transition states (TS) in nanopores and exploring reaction energy landscapes of complex organic transformations in pores. Starting from the molecular structure of potential reactant and products, the Pore Transition State finder (PoTS) locates gas-phase transition states using DFT, docks them in favorable orientations near active sites in nanopores, and leverages the gas-phase reaction mode to seed condensed-phase DFT calculations using the dimer method. The approach sidesteps tedious manipulations, increases the success rate of TS searches, and eliminates the need for long path-following calculations.
This work presents the largest ensemble of zeolite-confined transition states computed at the DFT level to date, enabling rigorous analysis of mechanistic trends across frameworks, reactions, and reactant types. We demonstrate the applicability of PoTS by analyzing 644 individual reaction steps for transalkylation of diethylbenzene in BOG, IWV, UTL and FAU zeolites, and in skeletal isomerization of 162 individual reaction steps in BEA, FER, FAU, MFI and MOR zeolites finding good experimental agreement in both cases. Lastly, we propose a path to address the limitations we observe regarding unsuccessful TS searches and insufficient theory in other reactions, like alkene cracking.
Materials Science (cond-mat.mtrl-sci), Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
Main Paper; 12 Pages, 7 Figures. Method; 4 Pages, 1 Figure. Supplementary Information; 123 Pages, 59 Figures
Spectral signatures of residual electron pairing in the extended-Hubbard-Su-Schrieffer-Heeger model
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2025-04-15 20:00 EDT
Debshikha Banerjee, Alberto Nocera, George A. Sawatzky, Mona Berciu, Steven Johnston
We study the electron addition spectrum of the one-dimensional extended Hubbard-Su-Schrieffer-Heeger (HSSH) model in the dilute limit using the density matrix renormalization group method. In addition to the expected renormalization to the band structure, we find that the electron-phonon (e-ph) interaction produces an anomalous spectral feature when electrons are added in the singlet channel but which is absent in the triplet channel. By comparing these results with those obtained from perturbation theory in the antiadiabatic limit, we demonstrate that this anomalous feature is a remnant of the strong electron-electron interaction mediated by the SSH coupling previously derived in the two-particle limit. By studying the evolution of this feature as a function of doping, we track the fate of this attraction to higher carrier concentrations and provide predictions for the spectral features to help guide future searches for strong e-ph mediated pairing.
Strongly Correlated Electrons (cond-mat.str-el)
7 figures
Worm-like emulsion droplets
New Submission | Soft Condensed Matter (cond-mat.soft) | 2025-04-15 20:00 EDT
Jatin Abacousnac, Wenjun Chen, Jasna Brujic, David G. Grier
Forming an interface between immiscible fluids incurs a free-energy cost that usually favors minimizing the interfacial area. An emulsion droplet of fixed volume therefore tends to form a sphere, and pairs of droplets tend to coalesce. Surfactant molecules adsorbed to the droplets’ surfaces stabilize emulsions by providing a kinetic barrier to coalescence. Here, we show that the bound surfactants’ osmotic pressure also competes with the droplet’s intrinsic surface tension and can reverse the sign of the overall surface free energy. The onset of negative surface tension favors maximizing surface area and therefore favors elongation into a worm-like morphology. Analyzing this system in the Gibbs grand canonical ensemble reveals a phase transition between spherical and worm-like emulsions that is governed by the chemical potential of surfactant molecules in solution. Predictions based on this model agree with the observed behavior of an experimental model system composed of lipid-stabilized silicone oil droplets in an aqueous surfactant solution.
Soft Condensed Matter (cond-mat.soft)
5 pages, 4 figures
Density-driven segregation of binary granular mixtures in a vertically vibrating drum the role of filling fraction
New Submission | Soft Condensed Matter (cond-mat.soft) | 2025-04-15 20:00 EDT
Anghao Li, Zaizheng Wang, Haoyu Shi, Min Sun, Decai Huang
This paper investigates the influence of filling fraction on segregation patterns of binary granular mixtures in a vertically vibrating drum through experiments and simulations. Glass and stainless steel spherical grains, which differ in mass density, are used to form density-driven segregation. The results reveal four segregation patterns, including the Brazil-nut-effect (BNE) segregation, counterclockwise two-eye-like segregation, dumpling-like segregation, and clockwise two-eye-like segregation. The theoretical analysis demonstrates that grains predominantly exhibit counterclockwise convection at low filling fractions, while clockwise convection dominates at high filling fractions. The competition between buoyancy and convection forces determines the final stable segregation pattern. These findings provide valuable insights into controlling segregation in granular systems, which is crucial for optimizing industrial processes in fields such as pharmaceuticals and chemical engineering.
Soft Condensed Matter (cond-mat.soft)
23 pages, 9 figures
Revisiting the Contact Model with Diffusion Beyond the Conventional Methods
New Submission | Statistical Mechanics (cond-mat.stat-mech) | 2025-04-15 20:00 EDT
Roberto da Silva, Eliseu Venites Filho, Henrique Almeida Fernandes, Paulo F. Gomes
The contact process is a non-equilibrium Hamiltonian model that, even in one dimension, lacks an exact solution and has been extensively studied via Monte Carlo simulations, both in steady-state and time-dependent scenarios. Although the effects of particle mobility/diffusion on criticality have been preliminarily investigated, they remain incompletely understood. In this work, we examine how the critical rate of the model varies with the probability of particle mobility. By analyzing different stochastic evolutions of the system, we employ two modern approaches: 1) Random Matrix Theory (RMT): By building on the success of RMT, particularly Wishart-like matrices, in studying statistical physics of systems with up-down symmetry via magnetization dynamics [R. da Silva, IJMPC 2022], we demonstrate its applicability to models with an absorbing state. 2) Optimized Temporal Power Laws: By using short-time dynamics, we optimize power laws derived from ensemble-averaged evolutions of the system. Both methods consistently reveal that the critical rate decays with mobility according to a simple Belehradek function. Additionally, a straightforward mean-field analysis supports the decay of the critical parameter with mobility, although it predicts a simpler linear dependence.
Statistical Mechanics (cond-mat.stat-mech)
10 pages, 5 figures
Controllable and Non-Dissipative Inertial Dynamics of Skyrmion in a Bosonic Platform
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2025-04-15 20:00 EDT
It has been understood in the past a decade or two that the dynamics of spin or magnetization in ultrafast regime necessarily involves inertial term that reflects the reluctance to follow abrupt or sudden change in the spin or magnetization orientation. The role of inertial spin dynamics in governing the motion of Skyrmion, a topological spin texture, is elucidated. Using nonequilibrium Green’s function Keldysh formalism, an equation of motion is derived in terms of collective coordinates for a Skyrmion coupled via a ‘’minimal coupling’’ to a bath of harmonic oscillators of frequency $ \omega$ . A deterministic and non-dissipative dynamics equation of motion is obtained with an explicit mass term for the Skyrmion emerging due the coupling, even within rigid Skyrmion picture. This results in a cyclotronic motion of Skyrmion, with a frequency that can go ultrafast, depending on that of the oscillator. Controlling the oscillator frequency can therefore guide the Skyrmion dynamics. Our theory bridges inertial dynamics and topology in magnetism and opens a pathway to ultrafast control of topological spin textures.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Strongly Correlated Electrons (cond-mat.str-el)
5.5 pages main text + 3.5pages supplementary materials. Comments are welcome
Quantum thermocouples: nonlocal conversion and control of heat in semiconductor nanostructures
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2025-04-15 20:00 EDT
Nanoscale conductors are interesting for thermoelectrics because of their particular spectral features connecting separated heat and particle currents. Multiterminal devices in the quantum regime benefit from phase-coherent phenomena, which turns the thermoelectric effect nonlocal, and from tunable single-particle interactions. This way one can define quantum thermocouples which convert an injected heat current into useful power in an isothermal conductor, or work as refrigerators. Additionally, efficient heat management devices can be defined. We review recent theoretical and experimental progress in the research of multiterminal thermal and thermoelectric quantum transport leading to proposals of autonomous quantum heat engines and thermal devices.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
Short review. 16 pages + references, 6 figures. Comments are welcome!
Research on the Crystal Growth, Band Structure and Luminescence Mechanism of (CH3NH3)2HgI4
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-04-15 20:00 EDT
Linlin Liu, Zuanquan Chen, Wensi Yang, Sen Zhang, Jiaqi Zhu
Nuclear radiation detectors play a crucial role in fields such as nuclear safety and medical imaging. The core of their performance lies in the selection of detection materials. Semiconductor detectors have become a hot topic in current research due to their advantages such as small size, good energy resolution, and high detection efficiency. As one of the most promising materials for fabricating room - temperature nuclear radiation semiconductor detectors, HgI2 exhibits excellent detection performance due to its high atomic number, large band gap, strong ray - stopping power, and high volume dark resistivity. However, issues such as poor chemical stability and low vacancy mobility of HgI2 limit its development. Therefore, researchers have carried out inorganic doping/organic hybridization on it. By introducing the organic ligand CH3NH3I, the synthesis of organic - inorganic hybrid compounds based on HgI2 is expected to significantly improve the stability of HgI2. Research on organic - inorganic hybrid metal halide crystals shows that this material has great application potential in the field of luminescent materials.
Materials Science (cond-mat.mtrl-sci)
Tunable Molecular Interactions Near an Atomic Feshbach Resonance: Stability and Collapse of a Molecular Bose-Einstein Condensate
New Submission | Quantum Gases (cond-mat.quant-gas) | 2025-04-15 20:00 EDT
Zhiqiang Wang, Ke Wang, Zhendong Zhang, Qijin Chen, Cheng Chin, K. Levin
Understanding and controlling interactions of ultracold molecules has been a central goal in quantum chemistry research. Recent experiments on atoms near a Feshbach resonance offer the key to prepare and investigate molecules in the quantum many-body regime. Just as Feshbach resonances allow tuning of the scattering length of bosonic atoms, we show that they also modify the scattering length of Feshbach molecules which are constituted from these atoms. Based on calculations of the compressibility, we determine the stability phase diagrams of molecular condensates and show that their instability can be associated with a sign change of the inter-molecular interactions. We derive universal expressions for the molecular scattering lengths, presented in terms of experimentally measurable quantities. These will enable control of interactions between Feshbach molecules as well as further studies of few- and many-body reactions involving Feshbach molecules in the quantum regime.
Quantum Gases (cond-mat.quant-gas), Atomic Physics (physics.atom-ph)
6 pages, 3 figures + Supplemental materials
Unsupervised learning of non-Abelian multi-gap topological phases
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2025-04-15 20:00 EDT
Xiangxu He, Ruo-Yang Zhang, Xiaohan Cui, Lei Zhang, C. T. Chan
Recent experiments have successfully realized multi-band non-Abelian topological insulators with parity-time symmetry. Their topological classification transcends the conventional ten-fold classification, necessitating the use of non-Abelian groups, manifesting novel properties that cannot be described using integer topological invariants. The unique non-commutative multiplication of non-Abelian groups, along with the distinct topological classifications in the context of homotopy with or without a fixed base point, makes the identification of different non-Abelian topological phases more nuanced and challenging than in the Abelian case. In this work, we present an unsupervised learning method based on diffusion maps to classify non-Abelian multi-gap topological phases. The automatic adiabatic pathfinding process in our method can correctly sort the samples in the same phase even though they are not connected by adiabatic paths in the sample set. Most importantly, our method can deduce the multiplication table of the non-Abelian topological charges in a data-driven manner without requiring \textit{a priori} knowledge. Additionally, our algorithm can provide the correct classifications for the samples within both the homotopy with and without a fixed base point. Our results provide insights for future studies on non-Abelian phase studies using machine learning approaches.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
Macroscopic fluctuation theory of correlations in hard rod gas
New Submission | Statistical Mechanics (cond-mat.stat-mech) | 2025-04-15 20:00 EDT
Recently, a theoretical framework known as ballistic macroscopic fluctuation theory has been developed to study large-scale fluctuations and correlations in many-body systems exhibiting ballistic transport. In this paper, we review this theory in the context of a one-dimensional gas of hard rods. The initial configurations of the rods are sampled from a probability distribution characterized by slowly varying conserved density profiles across space. Beginning from a microscopic description, we first formulate the macroscopic fluctuation theory in terms of the phase-space density of quasiparticles. In the second part, we apply this framework to compute the two-point, two-time correlation functions of the conserved densities in the Euler scaling limit. We derive an explicit expression for the correlation function, which not only reveals its inherent symmetries but is also straightforward to evaluate numerically for a given initial state. Our results also recover known expressions for space-time correlations in equilibrium for the hard rod gas.
Statistical Mechanics (cond-mat.stat-mech)
30 pages, 2 figures
Discovery of a Robust Non-Janus Hybrid MoSH Monolayer as a Two-Gap Superconductor via High-Throughput Computational Screening
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-04-15 20:00 EDT
Zhijing Huang, Hongmei Xie, Zhibin Gao, Longyuzhi Xu, Lin Zhang, Li Yang, Zonglin Gu, Shuming Zeng
The atomic-scale determination of hydrogen positions in MoSH monolayers remains experimentally challenging, and existing studies are confined to Janus-type configurations. Here, we combine high-throughput structural screening with first-principles calculations to predict a novel non-Janus Hybrid 1T$ ^{‘}$ -MoSH monolayer, which energetically surpasses all previously reported MoSH phases with a binding energy of -3.02 eV. This structure emerges as a hybrid of MoS$ _2$ and MoH$ _2$ , featuring alternating S and H atoms on both sides of the Mo layer. Comprehensive stability analyses confirm its robustness in energy, mechanics, dynamics, and thermodynamics (stable up to 1600 K). Remarkably, anisotropic Migdal-Eliashberg theory predicts Hybrid 1T$ ^{‘}$ -MoSH as a two-gap superconductor with a critical temperature T$ _c$ of 16.34 K, driven by strong electron-phonon coupling ($ \lambda$ =$ 1.39). Substituting Mo with Hf, Ta, or Ti drastically suppresses T$ _c$ $ \sim$ (0.53-2.42 K), highlighting Mo$ ^{‘}$ s unique role in enhancing superconductivity. Our work not only expands the family of 2D transition metal chalcogenides but also proposes a promising candidate for quantum technologies, bridging theoretical design to functional material discovery.
Materials Science (cond-mat.mtrl-sci)
Strain-induced polarization rotation in freestanding ferroelectric oxide membranes
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-04-15 20:00 EDT
Alban Degezelle, Razvan Burcea, Pascale Gemeiner, Maxime Vallet, Brahim Dkhil, Stéphane Fusil, Vincent Garcia, Sylvia Matzen, Philippe Lecoeur, Thomas Maroutian
Freestanding ferroelectric membranes have emerged as a versatile tool for strain engineering, enabling the exploration of ferroelectric properties beyond traditional epitaxy. The resulting ferroelectric domain patterns stem from the balance at the local scale of several effects playing a key role, i.e. piezoelectricity linked to strain, and flexoelectricity arising from strain gradients. To weight their respective contributions for a given membrane geometry, the strain profile has to be mapped with respect to the ferroelectric polarization landscape, a necessary step to allow for a controlled tailoring of the latter. In this study, we examine the effect of bending strain on a Pb(Zr,Ti)O3 membrane in a fold-like structure, observing a polarization rotation from out-of-plane to in-plane at the fold apex. Combining piezoresponse force microscopy, Raman spectroscopy, and scanning transmission electron microscopy, we map the ferroelectric polarization direction relative to the height profile of the membrane, and discuss the contributions of strain and strain gradients for this archetypal fold geometry. Our findings offer new insights into strain-engineered polarization configurations, and emphasize strain effects at the nanoscale to tune the functional properties in freestanding membranes.
Materials Science (cond-mat.mtrl-sci)
22 pages, 14 figures, including Supporting Information
Design of altermagnetic models from spin clusters
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2025-04-15 20:00 EDT
Xingchuan Zhu, Xingmin Huo, Shiping Feng, Song-Bo Zhang, Shengyuan A. Yang, Huaiming Guo
Altermagnetism, a new class of collinear compensated magnetic phase, has garnered tremendous interest because of its rich physics and promising applications. Physical models and verified material candidates for altermagnetism remain limited. Here, we propose a general scheme to construct altermagnetic models, which explicitly exhibits the blend of ferromagnetic and antiferromagnetic correlations in real space via the design of spin clusters, echoing the observation that properties of altermagnets resemble a mixture of ferromagnets and antiferromagnets. We show that in some of our models, the desired altermagnetic order can be spontaneously realized by electron-electron interaction in a broad range of the phase diagram. This development facilitates the study of fascinating physics of altermagnetism and sheds light on the discovery of new altermagnetic materials.
Strongly Correlated Electrons (cond-mat.str-el)
6 pages, 4 figures, to appear in PRL
Vortices in Tunable Dipolar Bose-Einstein condensates with Attractive Interactions
New Submission | Quantum Gases (cond-mat.quant-gas) | 2025-04-15 20:00 EDT
S. Sabari, R. Sasireka, R. Radha, A. Uthayakumar, L. Tomio
We investigate the formation of vortices in quasi-two-dimensional dipolar Bose-Einstein Condensates (BECs) through the interplay between two-body contact and long-ranged dipole-dipole interactions (DDIs), as both interactions can be tuned from repulsive to attractive. By solving the associated Gross-Pitaevskii equation for a rotating system, our initial approach concentrates on stabilizing a collapsing condensate with attractive s-wave two-body interactions by employing sufficiently large repulsive DDIs. Subsequently, the same procedure was applied after reversing the signs of both interactions to evaluate the sensitivity of vortex formation to such an interchange of interactions. As a reference to guide our investigation, valid for generic dipolar atomic species, we have assumed a condensate with the strong dipolar dysprosium isotope, 164Dy. The correlation of the results with other dipolar BEC systems was exemplified by considering rotating BECs with two other isotopes, namely 168Er and 52Cr. For a purely dipolar condensate (with zero contact interactions) under fixed rotation, we demonstrate how the number of visible vortices increases as the DDI becomes more repulsive, accomplished by tuning the orientation of the dipoles through a characteristic angle parameter.
Quantum Gases (cond-mat.quant-gas)
10 pages, 8 figures
Directional driving of vortex lines with oscillating magnetic field
New Submission | Superconductivity (cond-mat.supr-con) | 2025-04-15 20:00 EDT
The possibility of driving vortex lines with an oscillating magnetic field could be useful in many applications. For example, it can be used for the removal of undesired trapped flux from contactless elements of superconducting devices. We investigate the dynamics of vortex lines in a superconducting film with a ratchet thickness profile driven by an oscillating magnetic field applied parallel to the film. We numerically simulate the dynamics of a single flux line modeled as an elastic string with a variable length. We explore the behavior for different frequencies and amplitudes of the oscillating magnetic field and find several dynamic regimes. For moderate frequencies, the average velocity is finite only within specific amplitude ranges. A notable feature is the presence of extended velocity plateaus, which correspond to regimes when the line moves by integer multiples of the spatial period $ w$ during integer multiples of the time period $ T$ . The transitions to these plateau states are rather steep, especially at low frequencies. The plateau at velocity $ w/T$ dominates at intermediate frequencies but vanishes at high frequencies. The onset field amplitude of finite velocity nonmonotonically depends on the frequency and passes through a minimum at a certain frequency value. At low frequencies, the velocity exceeds $ w/T$ and progressively increases with the amplitude. These findings provide valuable insights into the dynamic behavior of vortex lines driven by oscillating magnetic field in patterned superconducting films, offering potential pathways for controlling the magnetic flux in superconducting devices.
Superconductivity (cond-mat.supr-con)
9 pages, 7 figures, submitted to Phys. Rev. Applied
Multi-band fractional Thouless pumps
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2025-04-15 20:00 EDT
Marius Jürgensen, Jacob Steiner, Gil Refael, Mikael C. Rechtsman
Quantization of particle transport lies at the heart of topological physics. In Thouless pumps - dimensionally reduced versions of the integer quantum Hall effect - quantization is dictated by the integer winding of single-band Wannier states. Here, we show that repulsive interactions can drive a transition from an integer- to a fractional-quantized Thouless pump (at fixed integer filling) by stabilizing a crystal of multi-band Wannier states, each with fractional winding. We numerically illustrate the concept in few-particle systems, and show that a dynamical Hartree-Fock ansatz can quantitatively reproduce the pumping phase diagram.
Strongly Correlated Electrons (cond-mat.str-el), Other Condensed Matter (cond-mat.other)
6 pages
Two-dimensional Indium Oxide at the Epitaxial Graphene/SiC Interface: Synthesis, Structure, Properties, and Devices
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-04-15 20:00 EDT
Furkan Turker, Bohan Xu, Chengye Dong, Michael Labella III, Nadire Nayir, Natalya Sheremetyeva, Zachary J. Trdinich, Duanchen Zhang, Gokay Adabasi, Bita Pourbahari, Wesley E. Auker, Ke Wang, Mehmet Z. Baykara, Vincent Meunier, Nabil Bassim, Adri C.T. van Duin, Vincent H. Crespi, Joshua A. Robinson
High-quality two-dimensional (2D) dielectrics are crucial for fabricating 2D/3D hybrid vertical electronic devices such as metal-oxide-semiconductor (MOS) based Schottky diodes and hot electron transistors, the production of which is constrained by the scarcity of bulk layered wide bandgap semiconductors. In this research, we present the synthesis of a new 2D dielectric, monolayer InO2, which differs in stoichiometry from its bulk form, over a large area (>300 um2) by intercalating at the epitaxial graphene (EG)/SiC interface. By adjusting the lateral size of graphene through optical lithography prior to the intercalation, we tune the thickness of InO2 where predominantly (~85%) monolayer InO2 is formed. The preference for monolayer formation of InO2 is explained using ReaxFF reactive molecular dynamics and density functional theory (DFT) calculations. Additionally, the band gap of InO2 is calculated to be 4.1 eV, differing from its bulk form (2.7 eV). Furthermore, MOS-based Schottky diode measurements on InO2 intercalated EG/n-SiC demonstrate that the EG/n-SiC junction transforms from ohmic to a Schottky junction upon intercalation, with a barrier height of 0.87 eV and a rectification ratio of ~10^5. These findings introduce a new addition to the 2D dielectric family, showing significant potential for monolayer InO2 to be used as a barrier in vertical electronic devices.
Materials Science (cond-mat.mtrl-sci)
Stability diagram of layer-polarized quantum Hall states in twisted trilayer graphene
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2025-04-15 20:00 EDT
Konstantin Davydov, Daochen Long, Jack Alexander Tavakley, Kenji Watanabe, Takashi Taniguchi, Ke Wang
In the twisted trilayer graphene (tTLG) platform, the rich beating patterns between the three graphene layers give rise to a plethora of new length scales and reconstructed electronic bands arising from the emergent moiré and moiré-of-moiré superlattices. The co-existing lattices and superlattices interact and compete with each other to determine the overall transport properties of tTLG, the hierarchy of which can be electrostatically controlled by tuning the out-of-plane charge distribution or layer polarization. In this work, we measure the stability diagram of layer-polarized quantum Hall states in tTLG by systematically mapping out layer-specific Chern numbers in each layer, and intra- and interlayer Chern transitions as a function of displacement field D and total carrier density n. In contrast to twisted bilayer systems, the rich interplay between the three atomic layers gives rise to a complex layer-polarized stability diagram with unconventional transport features that evolve rapidly with electric and magnetic fields. The stability diagram quantitatively characterizes the interlayer screening and charge distribution in tTLG with implication of strong inter-atomic-layer Coulomb coupling. Our work provides comprehensive guidance and insights into predicting and controlling layer-polarization and interlayer transitions in tTLG, and for tuning the individual role and interactions of each participating constituent towards novel material properties.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Materials Science (cond-mat.mtrl-sci)
Magnetic Interactions between Nanoscale Domains in Correlated Liquids
New Submission | Soft Condensed Matter (cond-mat.soft) | 2025-04-15 20:00 EDT
Mohammadhasan Dinpajooh, Giovanna Ricchiuti, Andrew J. Ritchhart, Tao E. Li, Elias Nakouzi, Sebastian T. Mergelsberg, Venkateshkumar Prabhakaran, Jaehun Chun, Maria L. Sushko
The formation of nanoscale domains (NDs) in correlated liquids and the emerging collective magnetic properties have been suggested as key mechanisms governing ion transport under external magnetic fields (eMFs). However, the molecular-level understanding of these magnetic field-driven phenomena and the interaction between these domains remain elusive. To this end, we introduce a simplified model of a solvated nanoparticle (NP) that consists of localized magnetic domains at their surfaces to represent groups of paramagnetic ions, forming NDs, whose effective magnetic dipole moments are at least one order of magnitude greater than the individual ions. We use classical density functional theory (cDFT) to estimate the effective interactions between these localized magnetic NPs (LMNPs). Our findings indicate that, unlike individual ions, magnetic dipole interactions of NDs in the LMNP model can indeed compete with the electrostatic, van der Waals, and hydration interactions. Depending on the direction of eMF, the cDFT effective interactions between two LMNPs turn out to become more attractive or repulsive, which may play a critical role in ion separation and nucleation processes. This indicates that the cDFT interaction barrier heights can be significantly affected by the magnetic dipole interactions and the barrier heights tend to increase as the size of LMNPs increases.
Soft Condensed Matter (cond-mat.soft)
16 pages, 6 figures in the main text, 6 figures in the appendix
Probing Spin Defects via Single Spin Relaxometry
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-04-15 20:00 EDT
Alex L. Melendez, Peter Groszkowski, Yueh-Chun Wu, Steven Randolph, Sujoy Ghosh, Liangbo Liang, Stephen Jesse, An-Ping Li, Joshua T. Damron, Yan Wang, Benjamin J. Lawrie, Ivan V. Vlassiouk, Huan Zhao
Spin defects in solids offer promising platforms for quantum sensing and memory due to their long coherence times and compatibility with quantum networks. Here, we integrate a single nitrogen-vacancy (NV) center in diamond with scanning probe microscopy to discover, read out, and spatially map arbitrary spin-based quantum sensors at the nanoscale. Using the boron vacancy (V$ _B^-$ ) center in hexagonal boron nitride$ \unicode{x2013}$ an emerging two-dimensional spin system$ \unicode{x2013}$ as a model, we detect its electron spin resonance through changes in the spin relaxation time ($ T_1$ ) of a nearby NV center, without requiring direct optical excitation or readout of the V$ _B^-$ fluorescence. Cross-relaxation between the NV and V$ _B^-$ ensembles results in a pronounced NV $ T_1$ reduction, enabling nanoscale mapping of spin defect distributions beyond the optical diffraction limit. This approach highlights NV centers as versatile quantum probes for characterizing spin systems, including those emitting at wavelengths beyond the range of silicon-based detectors. Our results open a pathway to hybrid quantum architectures where sensing and readout qubits are decoupled, facilitating the discovery of otherwise inaccessible quantum defects for advanced sensing and quantum networking.
Materials Science (cond-mat.mtrl-sci), Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
Strong altermagnetism and topological features in a two-dimensional van der Waals heterostructure via broken time reversal symmetry
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-04-15 20:00 EDT
The advent of altermagnetism, a new phase of magnetism, has garnered significant interest due to its extraordinary spin-polarized electronic bands despite zero net magnetization. Such spin-symmetry-guided robust non-relativistic alternating spin splitting in a compensated collinear magnet presents a novel platform for magnetotransport and nontrivial topology. Predominantly, altermagnetic behavior is observed in bulk magnetic materials upon incorporating external perturbations. However, van der Waals heterostructures can offer exceptional flexibility in tailoring their various emerging properties without the need for external perturbations in the two-dimensional regime. Here, an unconventional time reversal symmetry breaking with sizeable spin splitting via broken space-spin symmetry (\textit{P$ \mathcal{T}$ }) has been demonstrated in an antiferromagnet/nonmagnet vdW heterostructure. The lifted Kramer’s degeneracy alongwith spin-orbit interactions result in non-zero Berry curvature, contributing to the outstanding magnetotransport with a large value of anomalous Hall conductivity ($ \sim 732.9\ {\mathit{\Omega}}^{-1}{cm}^{-1}$ ). The presence of relativistic spin-orbit interactions in addition to predominant non-relativistic effects governed spin-momentum locking with a weak out-of-plane Dzyaloshinskii-Moriya interaction, which induces small spin canting. Further, the lowest magnetic anisotropy energy confirms collinear antiferromagnetic ground state. In particular, a nontrivial topology is observed along the surface [001], which is confirmed by the non-zero Chern number. This study provides a novel approach to realize strong altermagnetism in broken space-spin symmetry systems and fosters emergent transport behaviors.
Materials Science (cond-mat.mtrl-sci)
Photocurrent Nanoscopy of Quantum Hall Bulk
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2025-04-15 20:00 EDT
Ran Jing, Boyi Zhou, Jiacheng Sun, Shoujing Chen, Wenjun Zheng, Zijian Zhou, Heng Wang, Lukas Wehmeier, Bing Cheng, Michael Dapolito, Yinan Dong, Zengyi Du, G. L. Carr, Xu Du, D. N. Basov, Qiang Li, Mengkun Liu
Understanding nanoscale electronic and thermal transport of two-dimensional (2D) electron systems in the quantum Hall regime, particularly in the bulk insulating state, poses considerable challenges. One of the primary difficulties arises from the presence of chiral edge channels, whose transport behavior obscures the investigation of the insulating bulk. Using near-field (NF) optical and photocurrent (PC) nanoscopy, we probe real-space variations of the optical and thermal dynamics of graphene in the quantum Hall regime without relying on complex sample or electrode geometries. Near the charge neutrality point (CNP), we detect strong optical and photothermal signals from resonant inter-Landau level (LL) magnetoexciton excitations between the 0th and +-1st LLs, which gradually weaken with increasing doping due to Pauli blocking. Interestingly, at higher doping levels and full integer LL fillings, photothermal signals reappear across the entire sample over a ~10-micrometer scale, indicating unexpectedly long cooling lengths and nonlocal photothermal heating through the insulating bulk. This observation suggests thermal conductivity persists for the localized states even as electronic transport is suppressed - a clear violation of the Wiedemann-Franz (WF) law. Our experiments provide novel insights into nanoscale thermal and electronic transport in incompressible 2D gases, highlighting the roles of magnetoexcitons and chiral edge states in the thermo-optoelectric dynamics of Dirac quantum Hall state.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
18 pages, 4 figures
Luttinger compensated magnetic material LaMn2SbO6
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-04-15 20:00 EDT
Xiao-Yao Hou, Ze-Feng Gao, Huan-Cheng Yang, Peng-Jie Guo, Zhong-Yi Lu
Unconventional magnetism including altermagnetism and Luttinger compensated magnetism,
characterized by its duality of real-space antiferromagnetic alignment and momentum-space spin
splitting, has garnered widespread attention. While altermagnetism has been extensively studied,
research on Luttinger compensated magnetism remains very rare. In particular, Luttinger com pensated magnetic materials are only theoretically predicted and have not yet been synthesized
experimentally. In this study, based on symmetry analysis and the first-principles electronic struc ture calculations, we predict that LaMn2SbO6 is a Luttinger compensated magnetic semiconductor.
Given that the Mn ions at opposite spin lattice cannot be connected by any symmetry, the spin
splitting in LaMn2SbO6 is isotropic. More importantly, LaMn2SbO6 has already been synthesized
experimentally, and its magnetic structure has been confirmed by neutron scattering experiments.
Therefore, LaMn2SbO6 serves as an excellent material platform for investigating the novel physical
properties of Luttinger compensated magnetic materials.
Materials Science (cond-mat.mtrl-sci), Computational Physics (physics.comp-ph)
Inverse ac Josephson effect in Josephson diode
New Submission | Superconductivity (cond-mat.supr-con) | 2025-04-15 20:00 EDT
We study the Josephson junction where nonreciprocal critical current was induced by the interplay of the $ 4\pi$ -periodic and $ 2\pi$ -periodic current-phase relation of the junction. We take the model of a topological junction which serves as a Josephson diode with nonreciprocal critical currents. For this Josephson diode, we demonstrate an inverse ac Josephson effect where an effective dc voltage is induced by a pure ac driving current. We show that this inverse ac Josephson effect originates from the voltage rectification by the nonreciprocal critical current of the system. We explore the dependence of the induced dc voltage on the amplitude and frequency of the ac driving current and reveal the optimized condition for the inverse ac Josephson effect.
Superconductivity (cond-mat.supr-con)
7 pages, 6 figures
Micro Heat Engines With Hydrodynamic Flow
New Submission | Statistical Mechanics (cond-mat.stat-mech) | 2025-04-15 20:00 EDT
P. S. Pal, Sourabh Lahiri, Arnab Saha
Hydrodynamic flows are often generated in colloidal suspensions. Since colloidal particles are frequently used to construct stochastic heat engines, we study how the hydrodynamic flows influence the output parameters of the engine. We study a single colloidal particle confined in a harmonic trap with time-periodic stiffness that provides the engine protocol, in presence of a steady linear shear flow. The nature of the flow (circular, elliptic or hyperbolic) is externally tunable. At long times, the work done by the flow field is shown to dominate over the thermodynamic (Jarzynski) work done by the trap, if there is an appreciable deviation from the circular flow. The work by the time dependent trap is the sole contributor only for a perfectly circular flow. We also study an extended model, where a microscopic spinning particle (spinor) is tethered close to the colloidal particle, i.e. the working substance of the engine, such that the flow generated by the spinor influences the dynamics of the colloidal particle. We simulate the system and explore the influence of such a flow on the thermodynamics of the engine. We further find that for larger spinning frequencies, the work done by the flow dominates and the system cannot produce thermodynamic work.
Statistical Mechanics (cond-mat.stat-mech)
17 pages, 4 figures
Tri-component-pairing chiral superconductivity on the honeycomb lattice with mixed s- and d-wave symmetries
New Submission | Superconductivity (cond-mat.supr-con) | 2025-04-15 20:00 EDT
Yu-Hang Li, Jiarui Jiao, Xiao-Xiao Zhang, Congjun Wu, Wang Yang
In this work, we investigate chiral topological superconductors on a two-dimensional honeycomb lattice with coexisting d_1- (i.e., x^2-y^2), d_2- (i.e., xy), and s-wave pairing symmetries. Using a Ginzburg-Landau free energy analysis, the pairing gap function is shown to exhibit a tri-component form s + d_1 exp(i phi_1) + d_2 exp(i phi_2), where phi_1 and phi_2 are phase differences between the d- and s-wave pairing components, which spontaneously breaks both time reversal and C_6 rotational symmetries. Chern numbers of the energy bands are calculated to be nonzero, demonstrating the topologically nontrivial nature of the system. The anomalous AC Hall conductivity is also computed, which is not invariant under C_6 rotations, reflecting the anisotropic nature of the pairing gap function.
Superconductivity (cond-mat.supr-con)
Asymmetric real topology of conduction and valence bands
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2025-04-15 20:00 EDT
J. X. Dai, Chen Zhang, Y. X. Zhao
Previously, it was believed that conduction and valence bands exhibit a symmetry: they possess opposite topological invariants (e.g., the Chern numbers of conduction and valence bands for the Chern insulator are $ \pm C$ ). However, we present a counterexample: The second Stiefel-Whitney numbers for conduction and valence bands over the Klein bottle may be asymmetric, with one being nontrivial while the other trivial. Here, the Stiefel-Whitney classes are the characteristic classes for real Bloch functions under $ PT$ symmetry with $ (PT)^2=1$ , and the Klein bottle is the momentum-space unit under the projective anti-commutation relation of the mirror reflection reversing $ x$ and the translation along the $ y$ -direction. The asymmetry originates from the algebraic difference of real cohomology classes over Klein bottle and torus. This discovery is rooted in the fundation of topological band theory, and has the potential to fundamentally refresh our current understanding of topological phases.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
Effects resulting from magnetic interactions in low-dimensional systems
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2025-04-15 20:00 EDT
This research delves into the critical effects of magnetic interactions in low-dimensional systems, offering invaluable insights that deepen our comprehension of magnetic behavior at the nanoscale. By implementing this innovative approach, one can unequivocally identify two distinct magnetic states: demagnetizing and magnetizing. The resulting measurements significantly enhance our grasp of the magnetic dynamics within these nanostructures, paving the way for spin-wave excitations. To validate the effectiveness of this methodology, it was conducted rigorous numerical simulations on a diverse array of nanostructures, including one-dimensional nanowires and three-dimensional hexagonal arrays of nanowires. Each nanowire is precisely modeled as a chain of interacting ellipsoidal grains, illustrating the intricate nature of these magnetic interactions.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Applied Physics (physics.app-ph)
Reentrant localization transition induced by a composite potential
New Submission | Disordered Systems and Neural Networks (cond-mat.dis-nn) | 2025-04-15 20:00 EDT
We numerically investigate the localization transition in a one-dimensional system subjected to a composite potential consisting of periodic and quasi-periodic components. For the rational wave vector $ \alpha=1/2$ , the periodic component reduces to a staggered potential, which has been reported to induce the reentrant localization transition. In addition to $ \alpha=1/2$ , we find that other rational wave vectors can also lead to the reentrant phenomenon. To investigate the underlying mechanisms of the reentrant localization transition, we vary the parameters of the composite potential and find that the reentrant localization transition is sensitive to the phase factor of the periodic component. By further studying the structure of the periodic component, we confirm that this sensitivity arises from the periodic phase factor modulating the mirror symmetry. Finally, we map out a global phase diagram and reveal that the reentrant localization transition originates from a paradoxical effect: increasing the amplitude of the periodic component enhances localization but simultaneously strengthens the mirror symmetry, which favors the formation of extended states. Our numerical analysis suggests that the interplay between these competing factors drives the reentrant localization transition.
Disordered Systems and Neural Networks (cond-mat.dis-nn)
10 pages, 12 figures, To be published in Physical Review B
Electron Transport in Compacted Powders of VO2 Nanoparticles: Variable Range Hopping vs Percolation Behavior
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2025-04-15 20:00 EDT
E. Yu. Beliayev, Yogendra Kumar Mishra, Horst-Gunter Rubahn, I. A. Chichibaba, I. G. Mirzoiev, V. A. Horielyi, A. V. Terekhov
Electron transport properties in compacted VO2 nanopowders were studied. While VO2 usually exhibits a first-order metal-insulator transition (MIT) at ~340K, in our compressed nanopowder samples the MIT was significantly broadened due to structural disorder, interparticle barriers, and phase coexistence. Resistivity measurements in the temperature range of 78 - 682 K initially suggested a variable range hopping (VRH) transport mechanism, but further analysis indicates that the observed temperature dependence is governed by percolative conductivity, modified by activation-assisted tunneling effects. Suppression of the expected resistance jump at the MIT is attributed to dynamic intergranular barrier restructuring, residual localized states, and percolative electron transport. These findings highlight the necessity of considering percolation effects when analyzing transport mechanisms in granular VO2-based systems.
Strongly Correlated Electrons (cond-mat.str-el)
14 pages, 7 figures. Submission intended for Fizika Nizkikh Temperatur (Low Temperature Physics)
Q-ball mechanism of electron transport properties of high-T$_c$ superconductors
New Submission | Superconductivity (cond-mat.supr-con) | 2025-04-15 20:00 EDT
Proposed recently by the author Q-ball mechanism of the pseudogap state and high-Tc superconductivity in cuprates (2022) was supported by micro X-ray diffraction data in HgBa$ _2$ CuO$ _{4+y}$ (2023). In the present paper it is demonstrated that T-linear temperature dependence of electrical resistivity arises naturally in the Q-ball gas phase, that may explain corresponding experimental data in the “strange metal” phase of high-T$ _c$ cuprates, as reviewed by Barisic et al. (2013). In the present theory it arises due to scattering of electrons on the Q-balls gas of condensed charge/spin fluctuations. Close to the lowest temperature boundary of the “strange metal” phase, at which Q-ball radius diverges, electrical resistivity caused by a slide of the Q-balls as a whole is calculated using fluctuation paraconductivity calculation method by Alex Abrikosov (1987). The diamagnetic response of Q-balls gas is calculated as well and shows good accord with experimental data by this http URL et al. (2010) in the “strange metal” phase. In total, obtained results demonstrate different properties of the correlated electrons systems that arise due to formation of Q-balls possessing internal bosonic frequency $ \Omega=2\pi nT$ in Matsubara time and, thus, forming the quantum thermodynamic time polycrystals. Presented theory may give a clue concerning a possible mechanism of the experimentally measured properties of high-T$ _c$ cuprates in the “strange metal” phase of their phase diagram. We believe , these results provide support to the quantum thermodynamic time crystal model of the Euclidean Q-balls considered in the present paper.
Superconductivity (cond-mat.supr-con), Quantum Physics (quant-ph)
Evolution of a single spin in ideal Bose gas at finite temperatures
New Submission | Quantum Gases (cond-mat.quant-gas) | 2025-04-15 20:00 EDT
O. Hryhorchak, G. Panochko, V. Pastukhov
We study the finite-temperature dynamics of non-interacting bosons with a single static spinful impurity immersed. A non-zero contact boson-impurity pairwise interaction is assumed only for the spin-up impurity state. By tracing out bosonic degrees of freedom, the exact time evolution of the impurity spin is calculated for pure and mixed initial ensembles of states. The time-dependent momentum distribution of bosons initially created in the Bose condensed state and driven by the interaction with spin is analyzed.
Quantum Gases (cond-mat.quant-gas), Quantum Physics (quant-ph)
6 pages, 4 figures; comments and relevant references are welcome
Organic-Inorganic Polaritonics: Linking Frenkel and Wannier-Mott Excitons
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2025-04-15 20:00 EDT
V. G. M. Duarte, A. J. Chaves, N. M. R. Peres
In recent years, organic materials have emerged as promising candidates for a variety of light-harvesting applications ranging from the infrared to the visible regions of the electromagnetic spectrum. Their enhanced excitonic binding energies and large transition dipole moments enable strong coupling with light, with some systems already reaching the ultrastrong coupling regime. In contrast, a wide range of two-dimensional (2D) materials has been extensively explored in the literature, exhibiting high exciton stability and strong electron-hole coupling due to reduced screening effects. In this Letter, we present a microscopic model describing the interaction of 2D materials and organic molecular aggregates in an optical cavity. We predict the formation of a hybrid Wannier-Mott-Frenkel exciton-polariton with an enhanced Rabi splitting, exceeding that of the pure organic cavity by several tens of meV. To elucidate this phenomenon, we examine a cavity with 2D tungsten sulfide and a cyanine dye, where this enhancement corresponds to a $ 5%$ increase relative to the organic cavity. The complementary characteristics of Wannier-Mott and Frenkel excitons enable the formation of tunable polariton states that merge into a single hybrid state as a function of detuning, allowing for dual Rabi splitting mechanisms. This provides a promising platform for exploring quantum optical phenomena in both the strong and ultrastrong coupling regimes.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
6 pages, 3 figures
Multiphysics analysis of acoustically actuated nanospherical antennas embedded in polymer/metal medium with magneto-electro-elastic surface/interface effects
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-04-15 20:00 EDT
Mohsen Farsiani, Hossein M. Shodja
A precise analytical treatment for predicting the behavior of nano-sized magneto-electro-elastic (MEE) antennas and resonators under incident acoustic waves requires consideration of multiphysics surface/interface effects, including magnetization, polarization, and elasticity. No analytical solutions to date have incorporated all three phenomena simultaneously. This work presents a rigorous mathematical analysis of a nano-sized spherically isotropic embedded MEE spherical shell subjected to acoustic waves. The study distinguishes between the coupled spectral constitutive relations for the bulk of the MEE shell and those for its free inner surface and matrix-shell interface. The surrounding matrix may be isotropic dielectric or metallic. Conventional electrodynamics theories do not address MEE effects at the surface or interface. To overcome this, the equivalent impedance matrix (EIM) method combined with surface/interface elasticity is used to model the MEE behaviors. For metallic matrices, a plasmonics-based framework with optical properties described by the plasma model captures metallic behavior. The spectral EIM method, along with vector and tensor spherical harmonics, solves the coupled elastodynamics and Maxwell’s equations. This approach enables the exploration of surface/interface characteristic lengths, revealing size-dependent effects on electromagnetic radiated power and resonance frequency. The findings provide insights into the behavior of acoustically actuated nanospherical antennas, sensors, and resonators, with implications for the design of nanoscale devices in advanced technological applications.
Materials Science (cond-mat.mtrl-sci)
53 pages, 12 figures
Impact of network assortativity on disease lifetime in the SIS model of epidemics
New Submission | Statistical Mechanics (cond-mat.stat-mech) | 2025-04-15 20:00 EDT
To accurately represent disease spread, epidemiological models must account for the complex network topology and contact heterogeneity. Traditionally, most studies have used random heterogeneous networks, which ignore correlations between the nodes’ degrees. Yet, many real-world networks exhibit degree assortativity - the tendency for nodes with similar degrees to connect. Here we explore the effect degree assortativity (or disassortativity) has on long-term dynamics and disease extinction in the realm of the susceptible-infected-susceptible model on heterogeneous networks. We derive analytical results for the mean time to extinction (MTE) in assortative networks with weak heterogeneity, and show that increased assortativity reduces the MTE and that assortativity and degree heterogeneity are interchangeable with regard to their impact on the MTE. Our analytical results are verified using the weighted ensemble numerical method, on both synthetic and real-world networks. Notably, this method allows us to go beyond the capabilities of traditional numerical tools, enabling us to study rare events in large assortative networks, which were previously inaccessible.
Statistical Mechanics (cond-mat.stat-mech), Computational Physics (physics.comp-ph), Populations and Evolution (q-bio.PE)
10 pages, 6 figures
Harnessing Machine Learning for Quantum-Accurate Predictions of Non-Equilibrium Behavior in 2D Materials
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-04-15 20:00 EDT
Yue Zhang, Robert J. Appleton, Kui Lin, Megan J. McCarthy, Jeffrey T. Paci, Subramanian K.R.S. Sankaranarayanan, Alejandro Strachan, Horacio D. Espinosa
Accurately predicting the non-equilibrium mechanical properties of two-dimensional (2D) materials is essential for understanding their deformation, thermo-mechanical properties, and failure mechanisms. In this study, we parameterize and evaluate two machine learning (ML) interatomic potentials, SNAP and Allegro, for modeling the non-equilibrium behavior of monolayer MoSe2. Using a density functional theory (DFT) derived dataset, we systematically compare their accuracy and transferability against the physics-based Tersoff force field. Our results show that SNAP and Allegro significantly outperform Tersoff, achieving near-DFT accuracy while maintaining computational efficiency. Allegro surpasses SNAP in both accuracy and efficiency due to its advanced neural network architecture. Both ML potentials demonstrate strong transferability, accurately predicting out-of-sample properties such as surface stability, inversion domain formation, and fracture toughness. Unlike Tersoff, SNAP and Allegro reliably model temperature-dependent edge stabilities and phase transformation pathways, aligning closely with DFT benchmarks. Notably, their fracture toughness predictions closely match experimental measurements, reinforcing their suitability for large-scale simulations of mechanical failure in 2D materials. This study establishes ML-based force fields as a powerful alternative to traditional potentials for modeling non-equilibrium mechanical properties in 2D materials.
Materials Science (cond-mat.mtrl-sci)
23 pages, 5 figures, Supplementary Information (5 figures and two tables)
Activity drives self-assembly of passive soft inclusions in active nematics
New Submission | Soft Condensed Matter (cond-mat.soft) | 2025-04-15 20:00 EDT
Ahmet Umut Akduman, Yusuf Sariyar, Giuseppe Negro, Livio Nicola Carenza
Active nematics are out-of-equilibrium systems in which energy injection at the microscale drives emergent collective behaviors, from spontaneous flows to active turbulence. While the dynamics of these systems have been extensively studied, their potential for controlling the organization of embedded soft particles remains largely unexplored. Here, we investigate how passive droplets suspended in an active nematic fluid self-organize under varying activity levels and packing fractions. Through numerical simulations, we uncover a rich phase diagram featuring dynamic clustering, activity-induced gelation, and a novel inverse motility-induced phase separation regime where activity stabilizes dense droplet assemblies. Crucially, we demonstrate that temporal modulation of activity enables precise control over structural morphological transitions. Our results suggest new routes to design adaptive smart materials with tunable microstructure and dynamics, bridging active nematics with applications in programmable colloidal assembly and bio-inspired material design.
Soft Condensed Matter (cond-mat.soft)
Interface-Induced Stability of Nontrivial Topological Spin Textures: Unveiling Room-Temperature Hopfions and Skyrmions
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2025-04-15 20:00 EDT
F. Katmis, V. Lauter, R. Yagan, L.S. Brandt, A.M. Cheghabouri, H. Zhou, J.W. Freeland, C.I.L. de Araujo, M.E. Jamer, D. Heiman, M.C. Onbasli, J. S. Moodera
Topological spin configurations, such as soliton-like spin texture and Dirac electron assemblies, have emerged in recent years in both fundamental science and technological applications. Achieving stable topological spin textures at room-temperature is crucial for enabling these structures as long-range information carriers. However, their creation and manipulation processes have encountered difficulties due to multi-step field training techniques and competitive interactions. Thus, a spontaneous ground state for multi-dimensional topological spin textures is desirable, as skyrmions form swirling, hedgehog-like spin structures in two dimensions, while hopfions emerge as their twisted three-dimensional counterparts. Here, we report the first observation of robust and reproducible topological spin textures of hopfions and skyrmions observed at room temperature and in zero magnetic field, which are stabilized by geometric confinement and protected by interfacial magnetism in a ferromagnet/topological insulator/ferromagnet trilayer heterostructure. These skyrmion-hopfion configurations are directly observed at room temperature with Lorenz transmission electron microscopy. Using micromagnetic modelling, the experimental observations of hopfion-skyrmion assemblies are reproduced. Our model reveals a complete picture of how spontaneously organized skyrmion lattices encircled by hopfion rings are controlled by surface electrons, uniaxial anisotropy and Dzyaloshinskii-Moriya interaction, all at ambient temperature. Our study provides evidence that topological chiral spin textures can facilitate the development of magnetically defined information carriers. These stable structures hold promise for ultralow-power and high-density information processing, paving the way for the next generation of topologically defined devices.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
Resistive switching and charge accumulation in Hf0.5Zr0.5O2 nanoparticles
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-04-15 20:00 EDT
Oleksandr S. Pylypchuk, Ihor V. Fesych, Victor V. Vainberg, Yuri O. Zagorodniy, Victor I. Styopkin, Irina V. Kondakova, Lesya P. Yurchenko, Valentin V. Laguta, Anna O. Diachenko, Mykhailo M. Koptiev, Mikhail D. Volnyanskii, Juliya M. Gudenko, Eugene A. Eliseev, Mikhail P. Trubitsyn, Anna N. Morozovska
We revealed the resistive switching and charge accumulation effect in Hf0.5Zr0.5O2 nanopowders sintered by the auto-combustion sol-gel method. To explain the experimental results, we analyze phase composition of the nanopowder samples annealed at temperatures from 500°C to 800°C, determined by the X-ray diffraction analysis, and relate it with the peculiarities of their electronic paramagnetic resonance spectra. The analysis allows us to relate the resistive switching and charge accumulation observed in Hf0.5Zr0.5O2 nanopowders with the appearance of the ferroelectric-like polar regions in the orthorhombic Hf0.5Zr0.5O2 nanoparticles, which agrees with the calculations performed in the framework of Landau-Ginzburg-Devonshire approach and density functional theory.
Materials Science (cond-mat.mtrl-sci), Applied Physics (physics.app-ph)
32 pages, 11 figures, 4 Appendixes
Optical spatial dispersion via Wannier interpolation
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-04-15 20:00 EDT
Andrea Urru, Ivo Souza, Óscar Pozo Ocaña, Stepan S. Tsirkin, David Vanderbilt
We present a numerical implementation, based on Wannier interpolation, of a Kubo-Greenwood formalism for computing the spatially dispersive optical conductivity in crystals at first order in the wave vector of light. This approach is more efficient than direct $ \textit{ab initio}$ methods because, with less computational cost, it allows for a much finer sampling of reciprocal space, resulting in better resolved spectra. Moreover, Wannier interpolation avoids errors arising from truncation of the sums over conduction bands when evaluating the spatially dispersive optical matrix elements. We validate our method by computing the optical activity spectrum of selected crystals, both polar (GaN) and chiral (trigonal Te, trigonal Se, and $ \alpha$ -quartz), and comparing with existing literature.
Materials Science (cond-mat.mtrl-sci)
25 pages, 12 figures, 3 tables
Stiffness, strength, energy dissipation and reusability in heterogeneous architected polycrystals
New Submission | Soft Condensed Matter (cond-mat.soft) | 2025-04-15 20:00 EDT
We design, fabricate and test heterogeneous architected polycrystals, composed of hard plastomers and soft elastomers, which thus show outstanding mechanical resilience and energy dissipation simultaneously. Grain boundaries that separate randomly oriented single crystalline grains is carefully designed, first enabling coherent connectivity and strength in the grain boundary regions throughout the polycrystalline network. By combining experiments and numerical simulations on 3D-printed prototypes, we show that the interplay between grain interiors and grain boundaries is responsible for the grain-size effects emerging in these architected materials, analogous to those in their atomic or metallic counterparts. Furthermore, direct visualization of inter- and intra-grain deformation and failure mechanisms at the macroscopic scale reveals that crystallographic texture throughout the polycrystalline aggregates plays a fundamental role in the key mechanical features in our new heterogeneous polycrystals. Our results show that the engineered grain boundary and crystallographic texture not only modify the highly resilient yet dissipative global responses but also critically influence reusability in this new class of architected materials.
Soft Condensed Matter (cond-mat.soft), Materials Science (cond-mat.mtrl-sci)
Many-body localization properties of one-dimensional anisotropic spin-1/2 chains
New Submission | Disordered Systems and Neural Networks (cond-mat.dis-nn) | 2025-04-15 20:00 EDT
Taotao Hu, Yuting Li, Jiameng Hong, Xiaodan Li, Dongyan Guo, Kangning Chen
In this paper, we theoretically investigate the many-body localization (MBL) properties of one-dimensional anisotropic spin-1/2 chains by using the exact matrix diagonalization method. Starting from the Ising spin-1/2 chain, we introduce different forms of external fields and spin coupling interactions, and construct three distinct anisotropic spin-1/2 chain models. The influence of these interactions on the MBL phase transition is systematically explored. We first analyze the eigenstate properties by computing the excited-state fidelity. The results show that MBL phase transitions occur in all three models, and that both the anisotropy parameter and the finite system size significantly affect the critical disorder strength of the transition. Moreover, we calculated the bipartite entanglement entropy of the system, and the critical points determined by the intersection of curves for different system sizes are basically consistent with those obtained from the excited-state fidelity. Then, the dynamical characteristics of the systems are studied through the time evolution of diagonal entropy (DE), local magnetization, and fidelity. These observations further confirm the occurrence of the MBL phase transition and allow for a clear distinction between the ergodic (thermal) phase and the many-body localized phase. Finally, to examine the effect of additional interactions on the transition, we incorporate Dzyaloshinskii-Moriya (DM) interactions into the three models. The results demonstrate that the MBL phase transition still occurs in the presence of DM interactions. However, the anisotropy parameter and finite system size significantly affect the critical disorder strength. Moreover, the critical behavior is somewhat suppressed, indicating that DM interactions tend to inhibit the onset of localization.
Disordered Systems and Neural Networks (cond-mat.dis-nn)
Symphony of Symmetry Selective Resonances in Fe-MgO-ZnO-MgO-Fe
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2025-04-15 20:00 EDT
Sabarna Chakraborti, Arti Kashyap, Abhishek Sharma
We propose the perspective of symmetry-selective resonance of the $ \Delta_1$ states in the Fe/MgO/ZnO/MgO/Fe heterostructures, offering a broad landscape to design magnetic tunnel junctions (MTJs) that yield a towering tunnel magnetoresistance (TMR) up to $ 3.5\times10^4%$ with the resistance area (RA) product dipping down to a minimum of $ 0.05\Omega\cdot\mu \text{m}^2$ , while maintaining a nearly perfect (99%) spin polarization. Our predictions are based on the self-consistent coupling of the non-equilibrium Green’s function with density functional theory. We also present the charge current, spin current, and TMR with applied voltage of the Fe/MgO(3-layer)/ZnO(3-layer)/MgO(3-layer)/Fe MTJ, which offers a superior performance triad of TMR ($ 1.3\times10^4%$ ), RA ($ 0.45\Omega\cdot\mu \text{m}^2$ ), and spin polarization (99%) over a regular Fe/MgO(6-layer)/Fe based MTJ (TMR $ \approx 3.4\times10^3%$ , RA $ \approx 22~\Omega\cdot\mu \text{m}^2$ ). We provide a comprehensive insight integrating the transmission eigenchannel, spectral density, and the band structure of the Fe contacts to establish the role of symmetry-selective resonance in the Fe/MgO/ZnO/MgO/Fe MTJ.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
$\mathbb{Z}_N$ generalizations of three-dimensional stabilizer codes
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2025-04-15 20:00 EDT
Chanbeen Lee, Yaozong Hu, Gil Young Cho, Haruki Watanabe
In this work, we generalize several three-dimensional Z2 stabilizer models–including the X-cube model, the three-dimensional toric code, and Haah’s code–to their ZN counterparts. Under periodic boundary conditions, we analyze their ground state degeneracies and topological excitations, and uncover behaviors that strongly depend on system size. For the X-cube model, we identify excitations with mobility restricted under local operations but relaxed under nonlocal ones derived from global topology. These excitations, previously confined to open boundaries in the Z2 model, now appear even under periodic boundaries. In the toric code, we observe nontrivial braiding between string and point excitations despite the absence of ground state degeneracy, indicating long-range entanglement independent of topological degeneracy. Again, this effect extends from open to periodic boundaries in the generalized models. For Haah’s code, we find new excitations–fracton tripoles and monopoles–that remain globally constrained, along with a relaxation of immobility giving rise to lineons and planons. These results reveal new forms of topological order and suggest a broader framework for understanding fracton phases beyond the conventional Z2 setting.
Strongly Correlated Electrons (cond-mat.str-el)
36 pages, 25 figures
Evaporative Refrigeration Effect in Evaporation and Condensation between Two Parallel Plates
New Submission | Statistical Mechanics (cond-mat.stat-mech) | 2025-04-15 20:00 EDT
It is well-known that evaporation can lead to cooling. However, little is known that evaporation can actually create a refrigeration effect, i.e., the vapor phase temperature can drop below the temperature of the liquid-vapor interface. This possibility was recently pointed out via modeling based on a quasi-continuum approach. Experimental evidence for this effect has been scarce so far. Here, we examine evaporation and condensation between two parallel plates, including the liquid films on both sides, by coupling the solution of the Boltzmann transport equation in the vapor phase with the continuum treatments in both liquid films. Our solution shows that the vapor phase temperature at the evaporating side can be much lower than the coldest wall temperature at the condensing surface, i.e., the evaporative refrigeration effect. Our work not only re-affirms the refrigeration effect, but clarifies that this effect is caused by two mechanisms. At the interface, the asymmetry in the distribution between the outgoing and the incoming molecules creates a cooling effect, which is the dominant mechanism. Additional cooling occurs within the Knudsen layer due to the sudden expansion similar to the Joule-Thomson effect, although with subtle differences in that the interfacial expansion is not an isenthalpic process. Our work will motivate future experiments to further confirm this prediction and explore its potential applications in air-conditioning and refrigeration.
Statistical Mechanics (cond-mat.stat-mech), Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Soft Condensed Matter (cond-mat.soft), Applied Physics (physics.app-ph), Fluid Dynamics (physics.flu-dyn)
28 pages, 4 figures
The Universal Gap-to-Critical Temperature Ratio in Superconductors: a Statistical Mechanical Perspective
New Submission | Superconductivity (cond-mat.supr-con) | 2025-04-15 20:00 EDT
We propose a statistical mechanical framework to unify the observed relationship between the superconducting energy gap $ \Delta$ , the pseudogap $ \Delta^\ast$ , and the critical temperature $ T_\mathrm{c}$ . In this model, fermions couple as a composite boson and condense to occupy a single bound state as the temperature drops. We derive a concise formula for $ T_\mathrm{c}$ in terms of $ \Delta$ and $ \Delta^\ast$ , namely: $ \frac{\Delta}{k_\mathrm{B} T_\mathrm{c}} = 1.4+4\log(\Delta^\ast/\Delta).$ This expression reproduces the standard BCS gap-to-$ T_\mathrm{c}$ ratio in the absence of a pseudogap, while naturally explaining its enhancement in unconventional superconductors. The model is supported by comparisons with experimental data from several cuprates and iron-based superconductors, which highlight its generality. This formulation also offers a theoretical explanation for the observed persistence of the pseudogap phase into the overdoped regime.
Superconductivity (cond-mat.supr-con)
Probing the Quantum Capacitance of Rydberg Transitions of Surface Electrons on Liquid Helium via Microwave Frequency Modulation
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2025-04-15 20:00 EDT
Asher Jennings, Ivan Grytsenko, Yiran Tian, Oleksiy Rybalko, Jun Wang, Josef Barabash, Erika Kawakami
We present a method for probing the quantum capacitance associated with the Rydberg transition of surface electrons on liquid helium using RF reflectometry. Excitation to Rydberg states induces a redistribution of image charges on capacitively coupled electrodes, giving rise to a quantum capacitance. By applying frequency-modulated resonant microwaves to drive the Rydberg transition, we systematically measured a capacitance sensitivity of 0.38~aF/$ \sqrt{\mathrm{Hz}}$ . This level of sensitivity is sufficient to resolve the Rydberg transition of a single electron, providing a scalable pathway toward the implementation of qubit readout schemes based on surface electrons on helium.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Quantum Physics (quant-ph)
A mechanical approach to facilitate the formation of dodecagonal quasicrystals and their approximants
New Submission | Soft Condensed Matter (cond-mat.soft) | 2025-04-15 20:00 EDT
Zhehua Jiang, Jianhua Zhang, Mengyuan Zhan, Jiaqi Si, Junchao Huang, Hua Tong, Ning Xu
The conditions for forming quasicrystals and their approximants are stringent, normally requiring multiple length scales to stabilize the quasicrystalline order. Here we report an unexpected finding that the approximants and motifs of dodecagonal quasicrystals can be spontaneously formed in the simplest system of identical hard disks, utilizing the unstable feature of the initial square packing subject to mechanical perturbations. Because there is only one length scale involved, this finding challenges existing theories of quasicrystals and their approximants. By applying the same approach to a system known to form a dodecagonal quasicrystal, we develop decent quasicrystalline order in a purely mechanical manner. With the aid of thermal treatment, we achieve a significantly better quasicrystalline order than that from the direct self-assembly of the liquid state within the same period of time. In sufficiently low temperatures where the self-assembly of a liquid is significantly hindered, our approach still promotes the formation of quasicrystals. Our study thus opens a venue for high-efficiency search and formation of quasicrystals, and may have broader implications for the design and synthesis of quasicrystalline materials.
Soft Condensed Matter (cond-mat.soft)
Berry curvature-induced intrinsic spin Hall effect in light-element-based CrN system for magnetization switching
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-04-15 20:00 EDT
Gaurav K. Shukla, Prabhat Kumar, Shinji Isogami
The current-induced spin-orbit torque-based devices for magnetization switching are commonly relied on the 4d and 5d heavy metals owing to their strong spin-orbit coupling (SOC) to produce large spin current via spin Hall effect (SHE). Here we present the sizable SHE in CrN, a light element-based system and demonstrate the current-induced magnetization switching in the adjacent ferromagnetic layer [Co(0.35nm)/Pt(0.3nm)]3, which exhibits perpendicular magnetic anisotropy. We found the switching current density of 2.6 MA/cm2. The first principles calculation gives the spin Hall conductivity (SHC) to be 120 (hcross/e) S/cm due to intrinsic Berry curvature arising from SOC induced band splitting near Fermi-energy. The theoretically calculated intrinsic SHC is close to the experimental SHC extracted from second harmonic Hall measurement. We estimated spin Hall angle to be 0.09, demonstrating efficient charge-to-spin conversion in CrN system.
Materials Science (cond-mat.mtrl-sci)
Strain Engineering of Magnetoresistance and Magnetic Anisotropy in CrSBr
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-04-15 20:00 EDT
Eudomar Henríquez-Guerra, Alberto M. Ruiz, Marta Galbiati, Alvaro Cortes-Flores, Daniel Brown, Esteban Zamora-Amo, Lisa Almonte, Andrei Shumilin, Juan Salvador-Sánchez, Ana Pérez-Rodríguez, Iñaki Orue, Andrés Cantarero, Andres Castellanos-Gomez, Federico Mompeán, Mar Garcia-Hernandez, Efrén Navarro-Moratalla, Enrique Díez, Mario Amado, José J. Baldoví, M. Reyes Calvo
Tailoring magnetoresistance and magnetic anisotropy in van der Waals magnetic materials is essential for advancing their integration into technological applications. In this regard, strain engineering has emerged as a powerful and versatile strategy to control magnetism at the two-dimensional (2D) limit. Here, we demonstrate that compressive biaxial strain significantly enhances the magnetoresistance and magnetic anisotropy of few-layer CrSBr flakes. Strain is efficiently transferred to the flakes from the thermal compression of a polymeric substrate upon cooling, as confirmed by temperature-dependent Raman spectroscopy. This strain induces a remarkable increase in the magnetoresistance ratio and in the saturation fields required to align the magnetization of CrSBr along each of its three crystalographic directions, reaching a twofold enhancement along the magnetic easy axis. This enhancement is accompanied by a subtle reduction of the Néel temperature by ~10K. Our experimental results are fully supported by first-principles calculations, which link the observed effects to a strain-driven modification in interlayer exchange coupling and magnetic anisotropy energy. These findings establish strain engineering as a key tool for fine-tuning magnetotransport properties in 2D magnetic semiconductors, paving the way for implementation in spintronics and information storage devices.
Materials Science (cond-mat.mtrl-sci), Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Applied Physics (physics.app-ph)
Enhancement and Suppression of Active Particle Movement Due to Membrane Deformations
New Submission | Soft Condensed Matter (cond-mat.soft) | 2025-04-15 20:00 EDT
Adam Hitin Bialus, Bhargav Rallabandi, Naomi Oppenheimer
Microswimmers and active colloids often move in confined systems, including those involving interfaces. Such interfaces, especially at the microscale, may deform in response to the stresses of the flow created by the active particle. We develop a theoretical framework to analyze the effect of a nearby membrane due to the motion of an active particle whose flow fields are generated by force-free singularities. We demonstrate our result on a particle represented by a combination of a force dipole and a source dipole, while the membrane resists deformation due to tension and bending rigidity. We find that the deformation either enhances or suppresses the motion of the active particle, depending on its orientation and the relative strengths between the fundamental singularities that describe its flow. Furthermore, the deformation can generate motion in new directions.
Soft Condensed Matter (cond-mat.soft), Fluid Dynamics (physics.flu-dyn)
Probing Temperature at Nanoscale through Thermal Vibration Characterization using Scanning Precession Electron Diffraction
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-04-15 20:00 EDT
Kun Yang, Chao Zhang, Chengwei Wu, Qian Du, Bingzhi Li, Zhen Fang, Liang Li, Jianbo Wu, Tianru Wu, Hui Wang, Tao Deng, Wenpei Gao
Accurate, non-contact temperature measurement with high spatial resolution is essential for understanding thermal behavior in integrated nanoscale devices and heterogeneous interfaces. However, existing techniques are often limited by the need for physical contact or insufficient spatial resolution for the measurement of local temperature and mapping its distribution. Here, we showcase the direct temperature measurement of graphene with nanometer spatial resolution in transmission electron microscopy. In experiments, combining a scanning nanobeam with precession electron diffraction offers the collection of kinemetic diffraction from a local area at the nanometer scale. In analysis, we use a pre-calculated, sample-specific structure-factor-based correction method to enable the linear fitting of the diffraction intensities, allowing the determination of the Debye-Waller factor as a function of temperature at the precision of 10-4Å2/°C. With the high spatial resolution and measurement precision, the temperature and thermal vibration mapping further reveal the influence of graphene lattice parameters and thickness on the Debye-Waller factor, providing valuable insights into the vibrational properties impacted by temperature, lattice structure, and graphene layer thickness.
Materials Science (cond-mat.mtrl-sci)
9 pages, 4 figures
Static Magnetic Properties of Cryogel$^{\tiny{\circledR}}$ and Pyrogel$^{\tiny{\circledR}}$ at Low Temperatures and in High Magnetic Fields
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-04-15 20:00 EDT
Caeli L. Benyacko, Garrett T. Hauser, Raven J. Rawson, Alan J. Sherman, Quinton L. Wiebe, Krittin Poottafai, Daniel R. Talham, Mark W. Meisel
The static magnetic properties of the silica-based aergoels of Cryogel$ ^{\tiny{\circledR}}$ and Pyrogel$ ^{\tiny{\circledR}}$ , manufactured by Aspen Aerogels$ ^{\tiny{\circledR}}$ , were measured over a range of temperatures (2 K $ \leq$ T $ \leq$ 400 K) and in magnetic fields up to 70 kG. These data and a model of the responses are reported so these properties are familiar to others who may benefit from knowing them before the materials are employed in potential applications.
Materials Science (cond-mat.mtrl-sci)
10 pages, 4 figures, 2 tables
Learning rate matrix and information-thermodynamic trade-off relation
New Submission | Statistical Mechanics (cond-mat.stat-mech) | 2025-04-15 20:00 EDT
Kenshin Matsumoto, Shin-ichi Sasa, Andreas Dechant
Non-equilibrium systems exchange information in addition to energy. In information thermodynamics, the information flow is characterized by the learning rate, which is not invariant under coordinate transformations. To formalize the property of the learning rate under variable transformations, we introduce a learning rate matrix. This matrix has the learning rates as its diagonal elements and characterizes the changes in the learning rates under linear coordinate transformations. The maximal eigenvalue of the symmetric part of the learning rate matrix gives the maximal information flow under orthogonal transformations. Furthermore, we derive a new trade-off relation between the learning rate and the heat dissipation of a subsystem. Finally, we illustrate the results using analytically solvable yet experimentally feasible models.
Statistical Mechanics (cond-mat.stat-mech)
21 pages, 4 figures
Nonlinear transport of Wigner solid phase surrounding the two-flux composite fermion liquid
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2025-04-15 20:00 EDT
Yu-jiang Dong, Xinghao Wang, Jianmin Zheng, Weiliang Qiao, Rui-Rui Du, Loren N. Pfeiffer, Kenneth W. West, Kirk W. Baldwin
We have investigated the low temperature (T) transport properties of fractional quantum Hall (FQH) states in a high-mobility two-dimensional hole gas. According to the composite fermion (CF) model, FQH states stemming from a half-filled Landau level, specifically at filling factors $ {\nu}=p/(2p+1) (p=\pm 1,\pm 2,\pm 3,…)$ , can be associated with two-flux-attached CFs at the corresponding Lambda filling factor p. The zero-resistance minima and Hall plateaus of these states exhibit unusual temperature dependencies, characterized by rapid increases in width below a threshold temperature around 100 mK. Differential conductivity measurements from Corbino samples reveal that the regimes surrounding the CF liquid display clear nonlinear transport characteristics. This nonlinearity implies that each CF liquid is surrounded by CF solid phase composed of dilute CF excitations. Quantitatively, the applied electric field E influences the motion of CF solid in a way analogous to T, which is dubbed the “E-T duality”. Our analysis indicates that this E-T duality is consistent with the Berezinskii-Kosterlitz-Thouless theory in two-dimensional phase transitions.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
Many-Body Colloidal Dynamics under Stochastic Resetting: Competing Effects of Particle Interactions on the Steady State Distribution
New Submission | Soft Condensed Matter (cond-mat.soft) | 2025-04-15 20:00 EDT
The random arrest of the diffusion of a single particle and its return to its origin has served as the paradigmatic example of a large variety of processes undergoing stochastic resetting. While the implications and applications of stochastic resetting for a single particle are well understood, less is known about resetting of many interacting particles. In this study, we experimentally and numerically investigate a system of six colloidal particles undergoing two types of stochastic resetting protocols: global resetting, where all particles are returned to their origin simultaneously, and local resetting, where particles are reset one at a time. Our particles interact mainly through hard-core repulsion and hydrodynamic flows. We find that the most substantial effect of interparticle interactions is observed for local resetting, specifically when particles are physically dragged to the origin. In this case, hard-core repulsion broadens the steady-state distribution, while hydrodynamic interactions significantly narrow the distribution. The combination results in a steady-state distribution that is wider compared to that of a single particle system both for global and local resetting protocols.
Soft Condensed Matter (cond-mat.soft), Statistical Mechanics (cond-mat.stat-mech)
6 pages 5 figures
Deconfined Quantum Critical Point: A Review of Progress
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2025-04-15 20:00 EDT
Deconfined quantum critical points (DQCPs) have been proposed as a class of continuous quantum phase transitions occurring between two ordered phases with distinct symmetry-breaking patterns, beyond the conventional framework of Landau-Ginzburg-Wilson (LGW) theory. At the DQCP, the system exhibits emergent gauge fields, fractionalized excitations, and enhanced symmetries. Here we review recent theoretical and experimental progress on exploring DQCPs in condensed matter systems. We first introduce theoretical advancements in the study of DQCPs over the past twenty years, particularly in magnetic models on square lattices, honeycomb lattices, kagome lattices, and one-dimensional spin chains. We then discuss recent progress on experimental realization of DQCP in quantum magnetic systems. Experimentally, the Shastry-Sutherland model, realized in SrCu$ _2$ (BO$ _3$ )$ _2$ , offers a particularly promising platform for realizing DQCPs. The magnetic frustration inherent to this model drives phase transitions between two distinct symmetry-breaking states: a valence bond solid (VBS) phase and a Néel antiferromagnetic phase. Remarkably, SrCu$ _2$ (BO$ _3$ )$ _2$ has provided the first experimental evidence of a proximate DQCP through a field-induced Bose-Einstein condensation, transitioning from the VBS state to the Néel state. Nevertheless, the direct experimental realization of a DQCP remains a significant challenge. Despite this, it offers a promising platform for exploring emergent phenomena through quantum phase transition in low-dimensional quantum systems.
Strongly Correlated Electrons (cond-mat.str-el)
Review article, to appear in Chinese Physics Letters
CMOS-compatible vanadium dioxide via Pulsed Laser and Atomic Layer deposition: towards ultra-thin film phase-change layers
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-04-15 20:00 EDT
Anna Varini, Cyrille Masserey, Vanessa Conti, Zahra Saadat Somaehsofla, Ehsan Ansari, Igor Stolichnov, Adrian M. Ionescu
Vanadium dioxide, a well-known Mott insulator, is a highly studied electronic material with promising applications in information processing and storage. While fully crystalline layers exhibit exceptional properties, such as a sharp and abrupt conductivity change at the metal-insulator transition, fabricating poly-crystalline films on silicon substrates often involves trade-offs in transport characteristics and switching performance, especially for ultra-thin layers required in advanced gate applications. In this study, we explore the growth of vanadium dioxide films on standard wet-oxidized silicon wafers using two established deposition techniques with pulsed laser deposition and atomic layer deposition. Thin films, ranging in thickness from 200 to 10 nano meters, were systematically characterized through structural and electrical analyses to optimize key growth parameters. Temperature and pressure were identified as the primary factors affecting film quality, and the optimal growth conditions across the entire thickness range are discussed in detail. We demonstrate that both pulsed laser deposition and atomic layer deposition methods can successfully produce ultra-thin vanadium dioxide layers down to 8 nano meters with functional properties suitable for practical applications. This work underscores the potential of vanadium dioxide for fully industry compatible phase-change switching devices and provides valuable insights into optimizing growth processes for poly-crystalline films.
Materials Science (cond-mat.mtrl-sci), Applied Physics (physics.app-ph)
28 pages, 10 figures
Long-range magnetic interactions in Nd$_2$PdSi$_3$ and the formation of skyrmion phases in centrosymmetric metals
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2025-04-15 20:00 EDT
Viviane Peçanha-Antonio, Zhaoyang Shan, Michael Smidman, Juba Bouaziz, Bachir Ouladdiaf, Iurii Kibalin, Marie Helene Lemee, Christian Balz, Jakob Lass, Daniel A. Mayoh, Geetha Balakrishnan, Julie B. Staunton, Davashibhai Adroja, Andrew T. Boothroyd
We present an extensive X-ray and neutron scattering study of the structure and magnetic excitations of Nd$ _2$ PdSi$ _3$ , a sister compound of Gd$ _2$ PdSi$ _3$ which was recently found to host a skyrmion lattice phase despite its centrosymmetric crystal structure. Dispersive magnetic excitations were measured throughout the Brillouin zone and modelled using mean-field random-phase approximation to determine the magnetic interactions between Nd ions. Our analysis reveals that the magnetic interactions in this system extend over large distances and are significantly affected by a crystallographic superstructure formed by ordering of the Pd and Si atoms. The results suggest that the mechanism for the skyrmion phase formation in this family of materials, e.g. Gd$ _2$ PdSi$ _3$ is through the long-range RKKY interactions rather than short-range triangular-lattice frustration.
Strongly Correlated Electrons (cond-mat.str-el), Other Condensed Matter (cond-mat.other)
7 pages main, 11 pages supplemental
Giant and anisotropic magnetostriction in $β$-O$_{2}$ at 110 T
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2025-04-15 20:00 EDT
Akihiko Ikeda, Yuya Kubota, Yuto Ishii, Xuguang Zhou, Shiyue Peng, Hiroaki Hayashi, Yasuhiro H. Matsuda, Kosuke Noda, Tomoya Tanaka, Kotomi Shimbori, Kenta Seki, Hideaki Kobayashi, Dilip Bhoi, Masaki Gen, Kamini Gautam, Mitsuru Akaki, Shiro Kawachi, Shusuke Kasamatsu, Toshihiro Nomura, Yuichi Inubushi, Makina Yabashi
Magnetostriction is a crystal’s deformation under magnetic fields, usually in the range of $ 10^{-6}$ - $ 10^{-3}$ , where the lattice change occurs with the change of spin and orbital state through spin-lattice couplings. In strong magnetic fields beyond 100 T, the significant Zeeman energy competes with the lattice interactions, where one can expect considerable magnetostriction. However, directly observing magnetostriction above 100 T is challenging, because generating magnetic fields beyond 100 T accompanies the destruction of the coil with a single-shot $ \mu$ -second pulse. Here, we observed the giant and anisotropic magnetostriction of $ \sim$ 1 % at 110 T in the spin-controlled crystal of $ \beta$ -O$ _{2}$ , by combining the single-shot diffraction of x-ray free-electron laser (XFEL) and the state-of-the-art portable 100 T generator. The magnetostriction of $ \sim$ 1 % is the largest class as a deformation of the unit cell. It is a response of the soft lattice of $ \beta$ -O$ _{2}$ originating, not only in the competing van der Waals force and exchange interaction, but also the soft state of spin and lattice frustrated on the triangular network. Meanwhile, the anisotropy originates from the strong two-dimensionality of the spin system. Giant magnetostriction in crystals should become more ubiquitous and diverse beyond 100 T, where our XFEL experiment above 100 T opens a novel pathway for their exploration, providing fundamental insights into the roles of spin in stabilizing crystal structures.
Strongly Correlated Electrons (cond-mat.str-el), Materials Science (cond-mat.mtrl-sci), Soft Condensed Matter (cond-mat.soft)
8 pages, 5 figures
Influence of packing protocol on fractal exponents in dense polydisperse packings
New Submission | Soft Condensed Matter (cond-mat.soft) | 2025-04-15 20:00 EDT
Artem A. Vladimirov, Alexander Yu. Cherny, Eugen M. Anitas, Vladimir A. Osipov
We study fractal properties of a system of densely and randomly packed disks, obeying a power-law distribution of radii, which is generated by using various protocols: Delaunay triangulation (DT) with both zero and periodic boundary conditions and the constant pressure protocol with periodic boundary conditions. The power-law exponents of the mass-radius relation and structure factor are obtained numerically for various values of the size ratio of the distribution, defined as the largest-to-smallest radius ratio. It is shown that the size ratio is an important control parameter responsible for the consistency of the fractal properties of the system: the greater the ratio, the less the finite size effects are pronounced and the better the agreement between the exponents. For the DT protocol, the exponents of the mass-radius relation, structure factor, and power-law distribution coincide even at moderate values of the size ratio. By contrast, for the constant-pressure protocol, all three exponents are found to be different for both moderate (around 300) and large (around 1500) size ratios, which might indicate a biased rather than random spatial distribution of the disks. Nevertheless, there is a tendency for the exponents to converge as the size ratio increases, suggesting that all the exponents become equal in the limit of infinite size ratio.
Soft Condensed Matter (cond-mat.soft), Statistical Mechanics (cond-mat.stat-mech)
7 pages, 5 figures
Performances in solving the Bethe-Salpeter equation with the Yambo code
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-04-15 20:00 EDT
Petru Milev, Blanca Mellado-Pinto, Muralidhar Nalabothula, Ali Esquembre Kucukalic, Fernando Alvarruiz, Enrique Ramos, Ludger Wirtz, Jose E. Roman, Davide Sangalli
In this work, we analyze the performances of two different strategies in solving the structured eigenvalue problem deriving from the Bethe-Salpeter equation (BSE) in condensed matter physics. The first strategy employs direct diagonalization, while the second is based on an iterative solver. The BSE matrix is constructed with the Yambo code, and the two strategies are implemented by interfacing Yambo with the ScaLAPACK and ELPA libraries for direct diagonalization, and with the SLEPc library for the iterative approach. We consider both the hermitian (Tamm-Dancoff approximation) and pseudo-hermitian forms, addressing dense matrices of three different sizes. A description of the implementation is also provided, with details for the pseudo-hermitian case. Timing and memory utilization are analyzed on both CPU and GPU clusters. The CPU simulations are performed on a local cluster in Rome, while the GPU simulations are performed on the Leonardo HPC cluster of CINECA. Our results demonstrate that it is now feasible to handle dense BSE matrices of the order 10$ ^5$ .
Materials Science (cond-mat.mtrl-sci), Distributed, Parallel, and Cluster Computing (cs.DC)
Submitted to Euro-Par 2025 conference
Preliminary experimental investigation on the interaction of a subaqueous dune like granular structure with a turbulent open channel flow
New Submission | Soft Condensed Matter (cond-mat.soft) | 2025-04-15 20:00 EDT
Durbar Roy, Ikbal Ahmed, Abdul Hakkim, Rama Govindarajan
We study the interaction of a subaqueous dune like granular structure with a turbulent open channel flow experimentally using optical diagnostics in the Reynolds and Froude parameter space ($ 7.7{\times}10^3<Re<3.8{\times}10^4$ , $ 0.1<Fr<0.4$ ). Interactions between the turbulent flow and the granular structure give rise to transient erosion-deposition dynamics leading to various types of particle transport. The subaqueous structures in the channel bed evolves due to shear-stress-induced erosion, gravity-driven deposition, and subsequent particle transport. We study the centroid motion and the granular structure shape evolution. At lower end of our $ Re-Fr$ parameter space, we observe no erosion and the structure remains at rest. At intermediate values of $ Re$ and $ Fr$ , we observe very slow erosion and the granular structure moves vere slowly as a rigid body without significant shape deformation. Higher values of $ Re$ and $ Fr$ causes vortex formation at the upstream of the dune resulting in stronger erosion, rapid shape deformation and relatively higher translation velocity of the centroid.
Soft Condensed Matter (cond-mat.soft), Fluid Dynamics (physics.flu-dyn)
$t$-$J$ model for strongly correlated two-orbital systems: Application to bilayer nickelate superconductors
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2025-04-15 20:00 EDT
Tatsuya Kaneko, Masataka Kakoi, Kazuhiko Kuroki
We derive a $ t$ -$ J$ model applicable to strongly correlated two-orbital systems including bilayer nickelate superconductors. Using the Schrieffer-Wolff transformation, we exclude the doubly occupied states raising the on-site Coulomb energy and derive resulting spin interactions from the two-orbital Hubbard model. We also introduce effective interactions attributed to the interorbital Coulomb interaction. To adapt the effective model to bilayer nickelates that exhibit high-temperature superconductivity, we quantitatively evaluate the strengths of the spin interactions based on the hopping parameters in La$ _3$ Ni$ _2$ O$ _7$ . Considering the evaluated effective interactions, we propose a simplified $ t$ -$ J$ model for bilayer nickelate superconductors.
Strongly Correlated Electrons (cond-mat.str-el), Superconductivity (cond-mat.supr-con)
20 pages, 8 figures
Design Optimization of Flip FET Standard Cells with Dual-sided Pins for Ultimate Scaling
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2025-04-15 20:00 EDT
Rui Gui, Haoran Lu, Jiacheng Sun, Xun Jiang, Lining Zhang, Ming Li, Yibo Lin, Runsheng Wang, Heng Wu, Ru Huang
Recently, we proposed a novel transistor architecture for 3D stacked FETs called Flip FET (FFET), featuring N/P transistors back-to-back stacked and dual-sided interconnects. With dual-sided power rails and signal tracks, FFET can achieve an aggressive 2.5T cell height. As a tradeoff, the complex structure and limited numbers of M0 tracks could limit the standard cell design. As a solution, multiple innovations were introduced and examined in this work. Based on an advanced node design rule, several unique building blocks in FFET such as drain merge (DM), gate merge (GM), field drain merge (FDM) and buried signal track (BST) were investigated. Other key design concepts of multi-row, split gate and dummy gate insertion (DG) were also carefully studied, delivering around 35.6% area reduction compared with 3T CFET. Furthermore, the symmetric design of FFET has unique superiority over CFET thanks to the separate N/P logic on two sides of the wafer and their connections using DM and GM. New routing scheme with dual-sided output pins on both wafer frontside (FS) and backside (BS) was proposed for the first time. Finally, we conducted a comprehensive evaluation on complex cell design, taking AOI22 as an example. New strategies were proposed and examined. The FDM design is identified as the best, outperforming the BST and dummy gate design by 1.93% and 5.13% for the transition delay.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
Accepted by IEEE Transactions on Electron Devices
Unravelling the Flow of Information in a Nonequilibrium Process
New Submission | Statistical Mechanics (cond-mat.stat-mech) | 2025-04-15 20:00 EDT
Biswajit Das, Sreekanth K Manikandan, Ayan Banerjee
Identifying the origin of nonequilibrium characteristics in a generic interacting system having multiple degrees of freedom is a challenging task. In this context, information theoretic measures such as mutual information and related polymorphs offer valuable insights. Here, we explore these measures in a minimal experimental model consisting of two hydrodynamically coupled colloidal particles, where a nonequilibrium drive is introduced via an exponentially correlated noise acting on one of the particles. We show that the information-theoretic tools considered enable a systematic, data-driven dissection of information flow within the system. These measures allow us to identify the driving node and reconstruct the directional dependencies between particles. Notably, they help explain a recently observed, counterintuitive trend in the dependence of irreversibility on interaction strength under coarse-graining (B. Das this http URL., arXiv:2405.00800 (2024)). Finally, our results demonstrate how directional information measures can uncover the hidden structure of nonequilibrium dynamics and provide a framework for studying similar effects in more complex systems.
Statistical Mechanics (cond-mat.stat-mech)
15 pages, 9 figures
Topological exciton bands and many-body exciton phases in transition metal dichalcogenide trilayer heterostructures
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2025-04-15 20:00 EDT
Ze-Hong Guo, Tao Yan, Jin-Zhu Zhao, Yuan-Jun Jin, Qizhong Zhu
Twisted multilayer transition metal dichalcogenides (TMDs) are a promising platform for realizing topological exciton phases. Here we propose that twisted TMD heterotrilayers WX$ _2$ /MX$ _2$ /WX$ _2$ with layer symmetry represents a realistic system for realizing topological exciton bands and interesting many-body excitonic phases, simply by tuning the twist angle. These symmetric heterotrilayers form a type-II band alignment, where the electrons are confined in the middle layer and holes are distributed among the outer two layers, for the lowest energy excitons. The outer two layers are then rotated at different centers by opposite angles, forming a helical structure. Interlayer excitons with opposite dipoles are hybridized by the coupling between outer two layers, resulting in topological moiré exciton bands. Furthermore, by constructing a three-orbital tight-binding model, we map the many-body phase diagram of interacting dipolar and quadrupolar excitons at different twist angles and exciton densities and reveal the existence of sublattice-dependent staggered superfluid and Mott insulator phases. The recent experimental observation of quadrupolar excitons in symmetric heterotrilayers brings the intriguing phases predicted in this study within immediate experimental reach.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
12 pages, 7 figures
Orbital orders under magnetic fields in cubic PrIr$2$Zn${20}$
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2025-04-15 20:00 EDT
Hitoko Okanoya, Kazumasa Hattori
We study orbital orders in quadrupolar heavy-fermion compound PrIr$ _2$ Zn$ _{20}$ under magnetic fields on the basis of the Landau theory. Assuming E$ _g$ orbital (electric quadrupolar) orders in the cubic symmetry with the ordering wavenumber at the L points in the face-centered cubic lattice Brillouin zone as observed experimentally, we construct the Landau free energy and analyze it. We find that the unidentified high-temperature ordered phase under the magnetic field H ||[001] reported earlier can be interpreted as the consequence of the internal rotation in the orbital moments of f electrons at the Pr site. We discuss the phase diagram for various magnetic-field directions and also possible double-q quadrupolar orders in this system.
Strongly Correlated Electrons (cond-mat.str-el)
12 pages, 9 figures
Cryogenic Ferroelectric Behavior of Wurtzite Ferroelectrics
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-04-15 20:00 EDT
Ruiqing Wang, Jiuren Zhou, Siying Zheng, Feng Zhu, Wenxin Sun, Haiwen Xu, Bochang Li, Yan Liu, Yue Hao, Genquan Han
This study presents the first experimental exploration into cryogenic ferroelectric behavior in wurtzite ferroelectrics. A breakdown field (EBD) to coercive field (EC) ratio of 1.8 is achieved even at 4 K, marking the lowest ferroelectric switching temperature reported for wurtzite ferroelectrics. Additionally, a significant evolution in fatigue behavior is captured, transitioning from hard breakdown to ferroelectricity loss at cryogenic temperatures. These findings unlock the feasibility for wurtzite ferroelectrics to advance wide temperature non-volatile memory.
Materials Science (cond-mat.mtrl-sci), Applied Physics (physics.app-ph)
4 pages,6 figures
Tailoring Neel orders in Layered Topological Antiferromagnets
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2025-04-15 20:00 EDT
Xiaotian Yang, Yongqian Wang, Yongchao Wang, Zichen Lian, Jinsong Zhang, Yayu Wang, Chang Liu, Wenbo Wang
In the two-dimensional limit, the interplay between Neel order and band topology in van der Waals topological antiferromagnets can give rise to novel quantum phenomena in the quantum anomalous Hall state, including the cascaded quantum phase transition and spin-modulation effect. However, due to the absence of net magnetization in antiferromagnets, probing the energetically degenerate Neel orders has long remained a significant challenge. Inspired by recent advances in realizing the quantum anomalous Hall effect in AlOx-capped layered topological antiferromagnet MnBi2Te4, we demonstrate deterministic control over the Neel order through surface anisotropy engineering enabled by the AlOx capping layer. By tuning the surface anisotropy, we uncover paritydependent symmetry breaking states that manifest as distinct odd-even boundary architectures, including 180 degree domain walls or continuous spin structures. Comparative studies between AlOx-capped and pristine odd-layer MnBi2Te4 flakes using domain-resolved magnetic force microscopy reveal pronounced differences in coercivity and magnetization-reversal dynamics. Notably, an unconventional giant exchange bias, which arises from perpendicular magnetic anisotropy rather than traditional interface pinning mechanisms, is observed for the first time. Our findings establish a pathway for manipulating Neel order through surface modification in A-type antiferromagnets, offering new opportunities for spintronic devices and quantum information technologies.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
Highly Hydrogenated Monolayer Graphene with Wide Band Gap Opening
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-04-15 20:00 EDT
Alice Apponi (1,2), Orlando Castellano (1,2), Daniele Paoloni (1,2), Domenica Convertino (3), Neeraj Mishra (3), Camilla Coletti (3,4), Carlo Mariani (5,6), Alessandro Ruocco (1,2) ((1) Dipartimento di Scienze, Universitá degli Studi di Roma Tre, (2) INFN Sezione di Roma Tre, (3) Center for Nanotechnology Innovation @NEST, (4) Graphene Labs, Istituto italiano di tecnologia, (5) Sapienza Universitá di Roma, (6) INFN Sezione di Roma)
A thorough spectroscopic characterisation of highly hydrogenated monolayer graphene trasferred on TEM grids is herein reported. The graphene hydrogenation has the effect to distort the $ sp^2$ arrangement of carbon atoms in the lattice toward a $ sp^3$ -like coordination, through the breaking of the $ \pi$ -bonds, as determined by X ray photoelectron spectroscopy of the C 1s core level. The hydrogen bonding was found to be favoured for a more distorted graphene lattice. Indeed, a 100$ %$ $ sp^3$ -saturation - the highest ever achieved - was observed after the hydrogenation of a sample with more pristine $ sp^3$ -like deformed bonds, while the flatter, more $ sp^2$ -arranged, sample reached a 59$ %$ $ sp^3$ -saturation. Electron energy loss spectroscopy confirmed the photoemission result showing the $ \pi$ -plasmon excitation quenching, in the totally hydrogenated sample, and significant reduction, for the other one. High loading levels of hydrogenation were also witnessed by the opening of a wide optical band gap (6.3 and 6.2 eV). The observation of the C-H stretching vibrational mode is also reported, as a direct footprint of graphene hydrogenation. Finally, valence band measurements of the 59$ %$ saturated sample suggest the coexistence of one-side and two-side hydrogenation morphologies.
Materials Science (cond-mat.mtrl-sci)
Elastic displacements in wedge-shaped geometries with a straight edge: Green’s functions for perpendicular forces
New Submission | Soft Condensed Matter (cond-mat.soft) | 2025-04-15 20:00 EDT
Abdallah Daddi-Moussa-Ider, Andreas M. Menzel
Edges are abundant when fluids are contained in vessels or elastic solids glide in guiding rails. We here address induced small-scale flows in viscous fluids or displacements in elastic solids in the vicinity of one such edge. For this purpose, we solve the underlying low-Reynolds-number flow equations for incompressible fluids and the elasticity equations for linearly elastic, possibly compressible solids. Technically speaking, we derive the associated Green’s functions under confinement by two planar boundaries that meet at a straight edge. The two boundaries both feature no-slip or free-slip conditions, or one of these two conditions per boundary. Previously, we solved the simpler case of the force being oriented parallel to the straight edge. Here, we complement this solution by the more challenging case of the force pointing into a direction perpendicular to the edge. Together, these two cases provide the general solution. Specific situations in which our analysis may find application in terms of quantitative theoretical descriptions are particle motion in confined colloidal suspensions, dynamics of active microswimmers near edges, or actuated distortions of elastic materials due to activated contained functionalized particles.
Soft Condensed Matter (cond-mat.soft), Fluid Dynamics (physics.flu-dyn)
11 pages, 3 figures
Universality, Robustness, and Limits of the Eigenstate Thermalization Hypothesis in Open Quantum Systems
New Submission | Statistical Mechanics (cond-mat.stat-mech) | 2025-04-15 20:00 EDT
Gabriel Almeida, Pedro Ribeiro, Masudul Haque, Lucas Sá
The eigenstate thermalization hypothesis (ETH) underpins much of our modern understanding of the thermalization of closed quantum many-body systems. Here, we investigate the statistical properties of observables in the eigenbasis of the Lindbladian operator of a Markovian open quantum system. We demonstrate the validity of a Lindbladian ETH ansatz through extensive numerical simulations of several physical models. To highlight the robustness of Lindbladian ETH, we consider what we dub the dilute-click regime of the model, in which one postselects only quantum trajectories with a finite fraction of quantum jumps. The average dynamics are generated by a non-trace-preserving Liouvillian, and we show that the Lindbladian ETH ansatz still holds in this case. On the other hand, the no-click limit is a singular point at which the Lindbladian reduces to a doubled non-Hermitian Hamiltonian and Lindbladian ETH breaks down.
Statistical Mechanics (cond-mat.stat-mech), Disordered Systems and Neural Networks (cond-mat.dis-nn), Chaotic Dynamics (nlin.CD), Quantum Physics (quant-ph)
7 pages, 5 figures
Large magnetoreflectance and optical anisotropy due to $4f$ flat bands in the frustrated kagome magnet HoAgGe
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2025-04-15 20:00 EDT
F. Schilberth, L. DeFreitas, K. Zhao, F. LeMardelé, I. Mohelsky, M. Orlita, P. Gegenwart, H. Chen, I. Kézsmárki, S. Bordács
We report peculiar optical properties of the frustrated itinerant magnet HoAgGe, which exhibits multiple magnetically ordered states obeying the kagome spin-ice rule. The optical conductivity is surprisingly higher for light polarization perpendicular to the kagome plane, both for the free carrier response and the interband transitions. The latter ones have strong contributions from Ho $ 4f$ flat bands located near the Fermi level, as revealed by our \textit{ab initio} calculations, explaining the unusual anisotropy of the optical properties and the pronounced temperature dependence of the interband transitions for out–of–plane light polarization. The key role of Ho $ 4f$ states is further supported by the large variation of the reflectivity upon the metamagnetic transitions, that follows the field dependence of the magnetization, in contrast to that of the dc magnetotransport data. Such heavy-electron bands near the Fermi level offer an efficient way to control transport and optical properties.
Strongly Correlated Electrons (cond-mat.str-el)
Zero-shot Autonomous Microscopy for Scalable and Intelligent Characterization of 2D Materials
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-04-15 20:00 EDT
Jingyun Yang, Ruoyan Avery Yin, Chi Jiang, Yuepeng Hu, Xiaokai Zhu, Xingjian Hu, Sutharsika Kumar, Xiao Wang, Xiaohua Zhai, Keran Rong, Yunyue Zhu, Tianyi Zhang, Zongyou Yin, Jing Kong, Neil Zhenqiang Gong, Zhichu Ren, Haozhe Wang
Characterization of atomic-scale materials traditionally requires human experts with months to years of specialized training. Even for trained human operators, accurate and reliable characterization remains challenging when examining newly discovered materials such as two-dimensional (2D) structures. This bottleneck drives demand for fully autonomous experimentation systems capable of comprehending research objectives without requiring large training datasets. In this work, we present ATOMIC (Autonomous Technology for Optical Microscopy & Intelligent Characterization), an end-to-end framework that integrates foundation models to enable fully autonomous, zero-shot characterization of 2D materials. Our system integrates the vision foundation model (i.e., Segment Anything Model), large language models (i.e., ChatGPT), unsupervised clustering, and topological analysis to automate microscope control, sample scanning, image segmentation, and intelligent analysis through prompt engineering, eliminating the need for additional training. When analyzing typical MoS2 samples, our approach achieves 99.7% segmentation accuracy for single layer identification, which is equivalent to that of human experts. In addition, the integrated model is able to detect grain boundary slits that are challenging to identify with human eyes. Furthermore, the system retains robust accuracy despite variable conditions including defocus, color temperature fluctuations, and exposure variations. It is applicable to a broad spectrum of common 2D materials-including graphene, MoS2, WSe2, SnSe-regardless of whether they were fabricated via chemical vapor deposition or mechanical exfoliation. This work represents the implementation of foundation models to achieve autonomous analysis, establishing a scalable and data-efficient characterization paradigm that fundamentally transforms the approach to nanoscale materials research.
Materials Science (cond-mat.mtrl-sci), Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Artificial Intelligence (cs.AI), Computer Vision and Pattern Recognition (cs.CV), Machine Learning (cs.LG)
13 pages, 4 figures
Electron-Phonon Coupling Mediated by Fröhlich Interaction in Rb2SnBr6 Perovskite
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-04-15 20:00 EDT
C. C. S. Soares, J. S. Rodríguez-Hernández, Bruno P. Silva, Mayra A. P. Gómez, V. S. Neto, A. P. Ayala, C.W.A. Paschoal
Due to their well-suited optoelectronic properties, metal halide perovskites are emerging semiconductor materials with potential applications in solar cells, detectors, and light-emitting diodes. Beyond the traditional 3D perovskites, low-dimensional counterparts have more attractive effects such as excitonic emissions and quantum confinements that are enhanced by the reduced dimensionality, which involve the Electron-Phonon Coupling (EPC). Such phenomenon, which comprehends the interaction between charge carriers and lattice vibrations, usually strongly impacts the photoluminescence (PL) response in low-dimensional frameworks. In this paper, we investigated the intrinsic EPC onto low-temperature PL of the zero-dimensional (0D) Rb2SnBr6 perovskite. Temperature-dependent PL measurements, complemented by various characterization techniques and theoretical calculations, revealed broadband emission with a significant Stokes shift attributed to self-trapped excitons (STEs). The Fröhlich mechanism, mediated by interactions between excitonic charge carriers and longitudinal optical (LO) phonons, primarily accounts for the emission broadening through phonon-assisted radiative recombination. The EPC strength was evaluated through the Huang-Rhys factor S=34, confirming strong correlations between electronic and vibrational properties and supporting the STE emission assumption. The possible mechanism of STE formation was evaluated by the Fröhlich parameter {\alpha} of 1.94 for electrons and 4.73 for holes, which points out a major contribution of the hole-polaron quasi-particle on exciton trapping. Our findings give insights regarding the influence of EPC in 0D perovskites and STE formation, which leads to the assessment of Rb2SnBr6 for light-harvesting applications.
Materials Science (cond-mat.mtrl-sci)
32 pages, 4 Figures
Existence of Nonequilibrium Glasses in the Degenerate Stealthy Hyperuniform Ground-State Manifold
New Submission | Disordered Systems and Neural Networks (cond-mat.dis-nn) | 2025-04-15 20:00 EDT
Stealthy interactions are an emerging class of nontrivial, bounded long-ranged oscillatory pair potentials with classical ground states that can be disordered, hyperuniform, and infinitely degenerate. Their hybrid crystal-liquid nature endows them with novel physical properties with advantages over their crystalline counterparts. Here, we show the existence of nonequilibrium hard-sphere glasses within this unusual ground-state manifold as the stealthiness parameter $ \chi$ tends to zero that are remarkably configurationally extremely close to hyperuniform 3D maximally random jammed (MRJ) sphere packings. The latter are prototypical glasses since they are maximally disordered, perfectly rigid, and perfectly nonergodic. Our optimization procedure, which leverages the maximum cardinality of the infinite ground-state set, not only guarantees that our packings are hyperuniform with the same structure-factor scaling exponent as the MRJ state, but they share other salient structural attributes, including a packing fraction of $ 0.638$ , a mean contact number per particle of 6, gap exponent of $ 0.44(1)$ , and pair correlation functions $ g_2(r)$ and structures factors $ S(k)$ that are virtually identical to one another for all $ r$ and $ k$ , respectively. Moreover, we demonstrate that stealthy hyperuniform packings can be created within the disordered regime ($ 0 < \chi <1/2$ ) with heretofore unattained maximal packing fractions. As $ \chi$ increases from zero, they always form interparticle contacts, albeit with sparser contact networks as $ \chi$ increases from zero, resulting in linear polymer-like chains of contacting particles with increasingly shorter chain lengths. The capacity to generate ultradense stealthy hyperuniform packings for all $ \chi$ opens up new materials applications in optics and acoustics.
Disordered Systems and Neural Networks (cond-mat.dis-nn), Statistical Mechanics (cond-mat.stat-mech), Computational Physics (physics.comp-ph)
10 pages, 7 figures
Performance of a Brownian information engine through potential profiling: Optimum output requisites, Heating-to-Refrigeration transition and their Re-entrance
New Submission | Soft Condensed Matter (cond-mat.soft) | 2025-04-15 20:00 EDT
Brownian Information engine (BIE) harnesses the energy from a fluctuating environment by utilizing the associated information change in the presence of a single heat bath. The engine operates in a space-dependent confining potential and requires an appropriate feedback control mechanism. In general, the feedback controller has three different steps: measurement, feedback, and relaxation. The feedback step is related to a sudden change in the potential energy that is essential for a nonzero work output. BIE utilises the amount of information (surprise) acquired during the measurement step for the energy output. However, due to the relaxation process, a certain amount of acquired information is lost or becomes unavailable. So, controlling information loss during relaxation is crucial for the overall efficiency of the engine. The net (available) information, therefore, can be monitored by tuning the feedback controller and the shape of the confining potential. In this paper, we explore the effect of the shape modulation of the confining potential, which may have multiple stable valleys and unstable hills, on the net available information and, hence, the performance of a BIE that operates under an asymmetric feedback protocol. We examine the optimal performance requirements of the BIE and the amount of maximum work output under different potential profiling. For monostable trapping, a concave shape in confining potential results in a higher work output than a convex one. We also find that hills and valleys in the confining potential may lead to multiple good operating conditions. An appropriate shape modulation can create a heater-refrigerator transition and their reentrance due to non-trivial changes in information loss during the relaxation process.
Soft Condensed Matter (cond-mat.soft)
11 Pages, 16 Figures
MIPS is a Maxwell fluid with an extended and non-monotonic crossover
New Submission | Soft Condensed Matter (cond-mat.soft) | 2025-04-15 20:00 EDT
José Martín-Roca, Chantal Valeriani, Kristian Thijssen, Tyler Shendruk, Angelo Cacciuto
Understanding the mechanical properties of active suspensions is crucial for their potential applications in materials engineering. Among the various phenomena in active matter that have no analogue in equilibrium systems, motility-induced phase separation (MIPS) in active colloidal suspensions is one of the most extensively studied. However, the mechanical properties of this fundamental active state of matter remain poorly understood. This study investigates the rheology of a suspension of active colloidal particles under constant and oscillatory shear. Systems consisting of pseudo-hard active Brownian particles exhibiting co-existence of dense and dilute phases behave as a viscoelastic Maxwell fluid at low and high frequencies, displaying exclusively shear thinning across a wide range of densities and activities. Remarkably, the cross-over point between the storage and loss moduli is non-monotonic, rising with activity before the MIPS transition but falling with activity after the transition, revealing the subtleties of how active forces and intrinsically out-of-equilibrium phases affect the mechanical properties of these systems.
Soft Condensed Matter (cond-mat.soft)
Improving diffusion modeling in all-solid-state lithium batteries: a novel approach for grain boundary effects
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-04-15 20:00 EDT
Lena Scholz, Yongliang Ou, Blazej Grabowski, Felix Fritzen
All-solid-state lithium-ion batteries offer promising advantages with respect to capacity, safety, and performance. The diffusion behavior of lithium ions in the contained polycrystalline solid-state electrolyte is crucial for battery function. While atomistic studies indicate that grain boundaries (GBs) and grain size significantly impact diffusivity, the corresponding effects are either neglected in simulations on larger scales or considered only under strong assumptions such as isotropy. Our approach considers the fully resolved crystalline structure with a parametrization aligned with the atomistic perspective to describe diffusion along and across GBs. The approach is embedded into a finite element simulation using a novel collapsed interface element based on an analytical description in thickness direction. Results are governed by different and potentially anisotropic diffusion coefficients in bulk and GB domains. The mesoscale response is derived using linear computational homogenization to capture large-scale effects. The novel collapsed interface description allows for a reconstruction of the 3D transport behavior within the GB domain without resolving it and is able to capture the relevant transport mechanisms such as channeling effects and concentration jumps. Grain size and GB volume fraction are expressed in terms of an affine parameter dependence and can be altered without any changes to geometry or mesh. Together with the observed dependence of the effective material response on the anisotropic GB parametrization, this leads to the identification of four distinct diffusion regimes, each with implications for the design of battery materials.
Materials Science (cond-mat.mtrl-sci)
Spin-Orbital Intertwined Topological Superconductivity in a Class of Correlated Noncentrosymmetric Materials
New Submission | Superconductivity (cond-mat.supr-con) | 2025-04-15 20:00 EDT
Lichuang Wang, Ran Wang, Xinliang Huang, Xianxin Wu, Ning Hao
In this study, we propose an alternative route to achieving topological superconductivity (TSC). Our approach applies to a new class of correlated noncentrosymmetric materials that host two spin-split Fermi surfaces with identical spin textures due to a spin-orbital intertwined effect. Incorporating multi-orbital repulsive Hubbard interactions, we calculate the superconducting pairings of a minimal two-orbital effective model within a spin-fluctuation-mediated superconductivity framework. We find that, depending on the effective Rashba spin-orbit coupling (RSOC) strength and filling level, the Hubbard interaction can drive the leading pairing symmetry into the $ A_1(S_{\pm})$ , $ B_1$ , $ B_2$ or $ B_2(d_{\pm})$ irreducible representations (IRs) of the $ C_{4v}$ point group. Notably, the $ A_1(S_{\pm})$ pairing gives rise to a fully gapped TSC characterized by a $ Z_2$ invariant, while the $ B_2(d_{\pm})$ pairing results in a nodal TSC. Our analysis reveals that the fully gapped TSC is predominated by spin-singlet regardless of the presence of the spin-triplet components. This distinguishes our model from noncentrosymmetric materials with conventional Rashba-split band structures, where TSC typically emerges near the van Hove singularity and is primarily driven by $ p$ -wave or $ f$ -wave spin-triplet pairing. These features enhances its experimental accessibility, and we discuss potential experimental systems for its realization.
Superconductivity (cond-mat.supr-con), Materials Science (cond-mat.mtrl-sci)
7 pages, 4 figures
Maximum entropy modeling of Optimal Transport: the sub-optimality regime and the transition from dense to sparse networks
New Submission | Statistical Mechanics (cond-mat.stat-mech) | 2025-04-15 20:00 EDT
Lorenzo Buffa, Dario Mazzilli, Riccardo Piombo, Fabio Saracco, Giulio Cimini, Aurelio Patelli
We present a bipartite network model that captures intermediate stages of optimization by blending the Maximum Entropy approach with Optimal Transport. In this framework, the network’s constraints define the total mass each node can supply or receive, while an external cost field favors a minimal set of links, driving the system toward a sparse, tree-like structure. By tuning the control parameter, one transitions from uniformly distributed weights to an optimal transport regime in which weights condense onto cost-favorable edges. We quantify this dense-to-sparse transition, showing with numerical analyses that the process does not hinge on specific assumptions about the node-strength or cost distributions. Finite-size analysis confirms that the results persist in the thermodynamic limit. Because the model offers explicit control over the degree of sub-optimality, this approach lends to practical applications in link prediction, network reconstruction, and statistical validation, particularly in systems where partial optimization coexists with other noise-like factors.
Statistical Mechanics (cond-mat.stat-mech)
32 pages, 7 figures, submitted to Communications Physics
Quantum geometry from the Moyal product: quantum kinetic equation and non-linear response
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2025-04-15 20:00 EDT
Takamori Park, Xiaoyang Huang, Lucile Savary, Leon Balents
We systematically derive the dissipationless quantum kinetic equation for a multi-band free fermionic system with U(1) symmetry. Using the Moyal product formalism, we fully band-diagonalize the dynamics. Expanding to the second order in gradients, which is beyond the semiclassical limit, we give a complete analysis of the band-resolved thermodynamics and transport properties, especially those arising from the quantum geometric tensor. We apply our framework to a Bloch band theory under electric fields near equilibrium and find the linear and nonlinear transport coefficients. We also obtain the dynamical density-density response functions in the metallic case, including quantum metric corrections. Our results and approach can be applied very generally to multi-band problems even in situations with spatially varying Hamiltonians and distributions.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Statistical Mechanics (cond-mat.stat-mech), Strongly Correlated Electrons (cond-mat.str-el)
AC Current-Driven Magnetization Switching and Nonlinear Hall Rectification in a Magnetic Topological Insulator
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2025-04-15 20:00 EDT
Yuto Kiyonaga, Masataka Mogi, Ryutaro Yoshimi, Yukako Fujishiro, Yuri Suzuki, Max T. Birch, Atsushi Tsukazaki, Minoru Kawamura, Masashi Kawasaki, Yoshinori Tokura
Spin-orbit torque arising from the spin-orbit-coupled surface states of topological insulators enables current-induced control of magnetization with high efficiency. Here, alternating-current (AC) driven magnetization reversal is demonstrated in a semi-magnetic topological insulator (Cr,Bi,Sb)2Te3/(Bi,Sb)2Te3, facilitated by a low threshold current density of 1.5x10^9 A/m^2. Time-domain Hall voltage measurements using an oscilloscope reveal a strongly nonlinear and nonreciprocal Hall response during the magnetization reversal process. Fourier analysis of the time-varying Hall voltage identifies higher-harmonic signals and a rectified direct-current (DC) component, highlighting the complex interplay among the applied current, external magnetic field, and magnetization dynamics. Furthermore, a hysteretic behavior in the current-voltage characteristics gives rise to frequency mixing under dual-frequency excitation. This effect, distinct from conventional polynomial-based nonlinearities, allows for selective extraction of specific frequency components. The results demonstrate that AC excitation can not only switch magnetization efficiently but also induce tunable nonlinear responses, offering a new pathway for multifunctional spintronic devices with potential applications in energy-efficient memory, signal processing, and frequency conversion.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Materials Science (cond-mat.mtrl-sci), Applied Physics (physics.app-ph)
29 pages, 10 figures