CMP Journal 2025-07-01
Statistics
Nature: 1
Nature Nanotechnology: 1
Physical Review Letters: 10
arXiv: 89
Nature
Architecture, dynamics and biogenesis of GluA3 AMPA glutamate receptors
Original Paper | Cryoelectron microscopy | 2025-06-30 20:00 EDT
Aditya Pokharna, Imogen Stockwell, Josip Ivica, Bishal Singh, Johannes Schwab, Carlos Vega-Gutiérrez, Beatriz Herguedas, Ondrej Cais, James M. Krieger, Ingo H. Greger
AMPA-type glutamate receptors (AMPARs) mediate the majority of excitatory neurotransmission in the brain1. Assembled from combinations of four core subunits, GluA1-4, and ~20 auxiliary subunits, their molecular diversity tunes information transfer and storage in a brain circuit-specific manner. GluA3, a subtype strongly associated with disease2, functions as both a fast transmitting Ca2+-permeable (CP) AMPAR at sensory synapses3, and as a Ca2+-impermeable (CI) receptor at cortical synapses4,5. Here, we present cryo-EM structures of the CP GluA3 homomer, which substantially diverge from other AMPARs. The GluA3 extracellular domain tiers (NTD and LBD) are closely coupled throughout gating states, creating previously unseen interfaces that impact signalling and harbour human disease mutations. Central to this architecture is a stacking interaction between two arginine residues (Arg163) in the NTD dimer interface, trapping a unique NTD dimer conformation that enables close contacts with the LBD. Rupture of the Arg163 stack not only alters the structure and dynamics of the GluA3 extracellular region, but also increases receptor trafficking, and the expression of GluA3 heteromers at the synapse. We further show that a mammalian-specific GluA3 trafficking checkpoint determines conformational stability of the LBD tier. Hence, specific design features define communication and biogenesis of GluA3, offering a framework to interrogate this disease-prone glutamate receptor.
Cryoelectron microscopy, Ion channels in the nervous system
Nature Nanotechnology
Observation of chiral emission enabled by collective guided resonances
Original Paper | Photonic crystals | 2025-06-30 20:00 EDT
Ye Chen, Mingjin Wang, Jiahao Si, Zixuan Zhang, Xuefan Yin, Jingxuan Chen, Nianyuan Lv, Chenyan Tang, Wanhua Zheng, Yuri Kivshar, Chao Peng
A simple yet insightful question is whether it is possible to arrange optical resonances in such a way that their collective response differs from that of the individual constituents. Here, inspired by the collective oscillation of spatially localized modes and Fourier duality between real and momentum spaces, we demonstrate a chiral emission of collective guided modes by leveraging the omnidirectional hybridization of individual guided resonances within a photonic crystal slab. Specifically, we encircle a uniform photonic crystal with isotropic boundaries and hybridize discrete bulk guided resonances into a series of collective modes owing to the scatterings of the boundaries. This results in a chiral spiral vortex emission in real space. By using asymmetric pumping to lift the chiral symmetry, we then achieve stable single-mode lasing oscillation of the spiral collective mode and confirm the nature of vortex emission through polarization-resolved imaging and self-interference patterns, thus demonstrating a vivid example of collective oscillations in the momentum space.
Photonic crystals, Semiconductor lasers
Physical Review Letters
Sum of Entanglement and Subsystem Coherence Is Invariant under Quantum Reference Frame Transformations
Research article | Nonlocality | 2025-06-30 06:00 EDT
Carlo Cepollaro, Ali Akil, Paweł Cieśliński, Anne-Catherine de la Hamette, and Časlav Brukner
Recent work on quantum reference frames (QRFs) has demonstrated that superposition and entanglement are properties that change under QRF transformations. Given their utility in quantum information processing, it is important to understand how a mere change of perspective can produce or reduce these resources. Here we prove the existence of a QRF invariant which can be decomposed such that it captures the trade-off between entanglement and subsystem coherence: we demonstrate the invariance of the sum of entanglement and subsystem coherence for two pairs of resource quantifiers. Moreover, we find a weaker trade-off that holds for any possible pair of measures. Finally, we discuss the implications of this interplay for violations of Bell’s inequalities, clarifying that for any choice of QRF, there is a quantum resource responsible for the violation. These findings contribute to a better understanding of the quantum information theoretic aspects of QRFs, offering a foundation for future exploration in both quantum theory and quantum gravity.
Phys. Rev. Lett. 135, 010201 (2025)
Nonlocality, Quantum coherence & coherence measures, Quantum entanglement, Quantum foundations
Overcoming Quantum Metrology Singularity through Sequential Measurements
Research article | Quantum parameter estimation | 2025-06-30 06:00 EDT
Yaoling Yang, Victor Montenegro, and Abolfazl Bayat
The simultaneous estimation of multiple unknown parameters is the most general scenario in quantum sensing. Quantum multiparameter estimation theory provides fundamental bounds on the achievable precision of simultaneous estimation. However, these bounds can become singular (no finite bound exists) in multiparameter sensing due to parameter interdependencies, limited probe accessibility, and insufficient measurement outcomes. Here, we address the singularity issue in quantum sensing through a simple mechanism based on a sequential measurement strategy. This sensing scheme overcomes the singularity constraint and enables the simultaneous estimation of multiple parameters with a local and fixed measurement throughout the sensing protocol. This is because sequential measurements, involving consecutive steps of local measurements followed by probe evolution, inherently produce correlated measurement data that grows exponentially with the number of sequential measurements. Finally, through two different examples, namely a strongly correlated probe and a light-matter system, we demonstrate how such singularities are reflected when inferring the unknown parameters through Bayesian estimation.
Phys. Rev. Lett. 135, 010401 (2025)
Quantum parameter estimation, Quantum sensing, Strongly correlated systems, Bayesian methods
Robust Singularity Theorem
Research article | Entanglement entropy | 2025-06-30 06:00 EDT
Raphael Bousso
We prove the Penrose-Wall singularity theorem in the full semiclassical gravity regime, significantly expanding its range of validity. To accomplish this, we modify the definition of quantum-trapped surfaces without affecting their genericity. Our theorem excludes controlled ‘’bounces’’ in the interior of a black hole and in a large class of cosmologies.
Phys. Rev. Lett. 135, 011501 (2025)
Entanglement entropy, Quantum aspects of black holes, Quantum cosmology
Spatial String Tension and Its Effects on Screening Correlators in a Thermal QCD Plasma
Research article | Color confinement | 2025-06-30 06:00 EDT
Dibyendu Bala, Olaf Kaczmarek, Peter Petreczky, Sayantan Sharma, and Swagatam Tah
We calculate the spatial Wilson line correlator for $2+1$ flavor QCD using highly improved staggered quark discretization for fermions and in quenched QCD for a wide range of temperatures, from the chiral crossover temperature ${T}{\mathrm{pc}}\simeq 156\text{ }\text{ }\mathrm{MeV}$ or the deconfinement temperature $\simeq 300\text{ }\text{ }\mathrm{MeV}$, respectively, up to 2 GeV. Extracting the spatial string tension for different lattice cutoffs and by performing a continuum extrapolation of this observable, we show that the soft (magnetic) gluons interact nonperturbatively even at temperatures $\gtrsim 1\text{ }\text{ }\mathrm{GeV}$. We provide incriminating evidences to demonstrate that dimensionally reduced effective theories can describe these soft quark and gluon quasi-particles for both quenched and $2+1$ flavor QCD, at temperatures $T\gtrsim 5{T}{\mathrm{pc}}$. We also show for the first time the imprints of the nonperturbative pseudopotential in the properties of mesonic screening masses for temperatures ranging from 0.8 to 164 GeV in the quark-gluon plasma.
Phys. Rev. Lett. 135, 012301 (2025)
Color confinement, Effective field theory, Lattice QCD, Nonrelativistic QCD, Quantum chromodynamics, Quark-gluon plasma
Topological Nature of Edge States for One-Dimensional Systems without Symmetry Protection
Research article | Edge states | 2025-06-30 06:00 EDT
Janet Zhong, Heming Wang, Alexander N. Poddubny, and Shanhui Fan
We numerically verify and analytically prove a winding number invariant that correctly predicts the number of edge states in one-dimensional, nearest-neighbor (between unit cells), two-band models with any complex couplings and open boundaries. Our winding number uses analytical continuation of the wave-vector into the complex plane and involves two special points on the full Riemann surface band structure that correspond to bulk eigenvector degeneracies. Our winding number is invariant under unitary or similarity transforms. We emphasize that the topological criteria we propose here differ from what is traditionally defined as a topological or trivial phase in symmetry-protected classification studies. It is a broader invariant for our model that supports non-zero energy edge states and its transition does not coincide with the gap closing condition. When the relevant symmetries are applied, our invariant reduces to well-known Hermitian and non-Hermitian symmetry-protected topological invariants.
Phys. Rev. Lett. 135, 016601 (2025)
Edge states, Geometric & topological phases, 1-dimensional systems, Non-Hermitian systems
Electrical Switching of Altermagnetism
Research article | Magnetic order | 2025-06-30 06:00 EDT
Yiyuan Chen, Xiaoxiong Liu, Hai-Zhou Lu, and X. C. Xie
Switching magnetism using only electricity is of great significance for industrial applications but remains challenging. We find that altermagnetism, as a newly discovered unconventional magnetism, may open an avenue along this effort. Specifically, to have deterministic switching, i.e., reversing current direction must reverse magnetic structure, parity symmetry has to be broken. We discover that, due to their symmetry, which depends on chemical environments, altermagnet devices may naturally carry the parity symmetry breaking required for deterministic electrical switching of magnetism. More importantly, we identify MnTe bilayers (Te-Mn-Te-Mn-Te) as candidate devices, with the help of symmetry analysis, first-principles calculations, and magnetic dynamics simulations. This scheme will inspire further explorations on unconventional magnetism.
Phys. Rev. Lett. 135, 016701 (2025)
Magnetic order, Spintronics, Altermagnets, Density functional theory, Symmetries, Wannier function methods
Monolayer Control of Spin-Charge Conversion in van der Waals Heterostructures
Research article | Growth | 2025-06-30 06:00 EDT
Khasan Abdukayumov et al.
*et al.*Spin-charge conversion in van der Waals heterostructures of Pt/Gr can be controlled by the insertion of monolayer MoSe2, which fundamentally changes the physical origin of the Rashba effect responsible for the emission.
Phys. Rev. Lett. 135, 016702 (2025)
Growth, Spin-orbit coupling, Spintronics, 2-dimensional systems, Density functional theory, Electron microscopy, Epitaxy, Terahertz spectroscopy
Observation of Strong Nonreciprocal Thermal Emission
Research article | Heat radiation | 2025-06-30 06:00 EDT
Zhenong Zhang, Alireza Kalantari Dehaghi, Pramit Ghosh, and Linxiao Zhu
A newly designed structure exhibits the largest-recorded emissivity-absorptivity difference, a property that could prove useful in energy-harvesting and cloaking devices.
Phys. Rev. Lett. 135, 016901 (2025)
Heat radiation, Magneto-optics, Metamaterials, Nanophotonics, Infrared spectroscopy
Entropic Origin of Polymer Nucleation at Amorphous Solid Interfaces
Research article | Liquid-solid interfaces | 2025-06-30 06:00 EDT
Ming Wang, Zijian Song, Guoming Liu, and Dujin Wang
Interfaces play a pivotal role in various physical, chemical, and biological processes. In polymer crystallization, nucleation often occurs at solid interfaces due to the reduced barrier for heterogeneous nucleation, with the chain conformations and dynamics deviating significantly from their undisturbed (bulk) state. In this Letter, we employed a nanopore-confined system to differentiate between two nucleation scenarios: surface nucleation and homogeneous nucleation, through comprehensive crystal orientation analysis. Experimental findings reveal that surface-induced nucleation in polymers is predominantly driven by an entropic effect, arising from the loss of conformational entropy as polymer chains flatten at weakly interacting solid interfaces. Homogeneous nucleation is, instead, predominant in cases of strong interfacial interactions.
Phys. Rev. Lett. 135, 018101 (2025)
Liquid-solid interfaces, Semicrystalline polymers
Anomalous Hard-Wall Repulsion between Polymers in Solvent Mixtures and Its Implication for Biomolecular Condensates
Research article | Aggregation | 2025-06-30 06:00 EDT
Luofu Liu and Rui Wang
The system of polymers dissolved in a mixture of different solvents is a widely used coarse-grained model to represent biomolecular condensates in intracellular environments. Here, we apply a variational theory to simultaneously control the center of mass of two polymers and perform the first quantification of their interactions in a mixture of solvent and cosolvent. While the polymer can completely dissolve in both solvents, strong polymer-cosolvent affinity induces the occurrence of polymer-assisted cosolvent condensation. Even though all the molecular interactions are soft, the potential of mean force between two polymer-cosolvent condensates exhibits an anomalous feature of hard-wall repulsion upon contact, which cannot be categorized into any existing types of interchain interactions. This repulsion is enhanced as either the affinity or the bulk cosolvent fraction increases. The underlying mechanism is cosolvent regulation manifested as a discontinuous local condensation of cosolvent as two condensates approach. The hard-wall repulsion provides a kinetic barrier to prevent coalescence of condensates and hence highlights the intrinsic role of proteins as a cosolvent in stabilizing biomolecular condensates.
Phys. Rev. Lett. 135, 018201 (2025)
Aggregation, Interface & surface thermodynamics, Phase separation driven self-assembly, Polymer conformation changes, Polymer solutions, Self-consistent field theory
arXiv
Electron Transport in One-Dimensional Disordered Lattice
New Submission | Disordered Systems and Neural Networks (cond-mat.dis-nn) | 2025-07-01 20:00 EDT
V. Slavin, Y. Savin, M. Klimov, M. Kiyashko
We have studied the peculiarities of electron transport in one-dimensional (1D) disordered chain at the presence of correlations between on-site interaction and tunneling integrals. In the considered models the disorder in host-lattice sites positions is caused by presence of defects, impurities, existence of electron-phonon interaction, e.t.c. It is shown, that for certain combination of parameters the localization of electron state, inherited by a various of 1D disordered systems, disappear and electron transport becomes possible. The parameters of this transport are established.
Disordered Systems and Neural Networks (cond-mat.dis-nn), Quantum Physics (quant-ph)
An anomalous particle-exchange mechanism for two isolated Bose gases merged into one
New Submission | Statistical Mechanics (cond-mat.stat-mech) | 2025-07-01 20:00 EDT
In an isolated ideal Bose system with a fixed energy, the number of microstates depends solely on the configurations of bosons in excited states, implying zero entropy for particles in the ground state. When two such systems merge, the resulting entropy is less than the sum of the individual entropies. This entropy decrease is numerically shown to arise from an effectively but anomalous exchange of particles in excited states, where $ \overline{N}!/(\overline{N}{1}!\overline{N}{2}!)<1$ . Here, $ \overline{N}$ , $ \overline{N}{1}$ , and $ \overline{N}{2}$ are real decimals representing, respectively, the mean number of particles in excited states in the merged system and the two individual systems before merging, with $ \overline{N}<\overline{N}{1}+\overline{N}{2}$ .
Statistical Mechanics (cond-mat.stat-mech), Quantum Gases (cond-mat.quant-gas), Mathematical Physics (math-ph)
8 pages, no figure
Scalable Bayesian Optimization for High-Dimensional Coarse-Grained Model Parameterization
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-07-01 20:00 EDT
Carlos A. Martins Junior, Daniela A. Damasceno, Keat Yung Hue, Caetano R. Miranda, Erich A. Müller, Rodrigo A. Vargas-Hernández
Coarse-grained (CG) force field models are extensively utilised in material simulations due to their scalability. Traditionally, these models are parameterized using hybrid strategies that integrate top-down and bottom-up approaches; however, this combination restricts the capacity to jointly optimize all parameters. While Bayesian Optimization (BO) has been explored as an alternative search strategy for identifying optimal parameters, its application has traditionally been limited to low-dimensional problems. This has contributed to the perception that BO is unsuitable for more realistic CG models, which often involve a large number of parameters. In this study, we challenge this assumption by successfully extending BO to optimize a high-dimensional CG model. Specifically, we show that a 41-parameter CG model of Pebax-1657, a copolymer composed of alternating polyamide and polyether segments, can be effectively parameterized using BO, resulting in a model that accurately reproduces key physical properties of its atomistic counterpart. Our optimization framework simultaneously targets density, radius of gyration, and glass transition temperature. It achieves convergence in fewer than 600 iterations, resulting in a CG model that shows consistent improvements across all three properties.
Materials Science (cond-mat.mtrl-sci), Computational Physics (physics.comp-ph)
22 pages, 8 figures, (SI 9 pages, 2 figures, 8 tables)
Wafer-scale Synthesis of Mithrene and its Application in 2D Heterostructure UV Photodetectors
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-07-01 20:00 EDT
Maryam Mohammadi, Stefanie L. Stoll, Analía F. Herrero, Sana Khan, Federico Fabrizi, Christian Gollwitzer, Zhenxing Wang, Surendra B. Anantharaman, Max C. Lemme
Silver phenylselenide (AgSePh), known as mithrene, is a two-dimensional (2D) organic-inorganic chalcogenide (MOC) semiconductor with a wide direct band gap, narrow blue emission and in-plane anisotropy. However, its application in next-generation optoelectronics is limited by crystal size and orientation, as well as challenges in large-area growth. Here, we introduce a controlled tarnishing step on the silver surface prior to the solid-vapor-phase chemical transformation into AgSePh thin films. Mithrene thin films were prepared through thermally assisted conversion (TAC) at 100°C, incorporating a pre-tarnishing water (H$ {_2}$ O) vapor pulse and propylamine (PrNH$ {_2}$ ) as a coordinating ligand to modulate Ag$ {^+}$ ion reactivity and facilitate the conversion of Ph$ {_2}$ Se$ {_2}$ into an active intermediate. The AgSePh thin films were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), and grazing incidence wide-angle X-ray scattering (GIWAXS). The pre-tarnishing process, combined with organic ligands, resulted in large crystals exceeding 1 $ {\mu}$ m and improved homogeneous in-plane orientation, while also enabling the selective, wafer-scale synthesis of mithrene on 100 mm wafers. Furthermore, the films were integrated on planar graphene field-effect phototransistors (GFETs) and demonstrated photoresponsivity beyond 100 A/W at 450 nm, highlighting mithrene’s potential for blue light-detection applications.
Materials Science (cond-mat.mtrl-sci), Applied Physics (physics.app-ph)
26 pages
Conformal scalar field theory from Ising tricriticality on the fuzzy sphere
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2025-07-01 20:00 EDT
Joseph Taylor, Cristian Voinea, Zlatko Papić, Ruihua Fan
Free theories are landmarks in the landscape of quantum field theories: their exact solvability serves as a pillar for perturbative constructions of interacting theories. Fuzzy sphere regularization, which combines quantum Hall physics with state-operator correspondence, has recently been proposed as a promising framework for simulating three-dimensional conformal field theories (CFTs), but so far it has not provided access to free theories. We overcome this limitation by designing a bilayer quantum Hall system that hosts an Ising tricritical point – a nontrivial fixed point where first-order and second-order transitions meet – which flows to the conformally coupled scalar theory in the infrared. The critical energy spectrum and operator structure match those at the Gaussian fixed point, providing nonperturbative evidence for the emergence of a free scalar CFT. Our results expand the landscape of CFTs realizable on the fuzzy sphere and demonstrate that even free bosonic theories – previously inaccessible – can emerge from interacting electrons in this framework.
Strongly Correlated Electrons (cond-mat.str-el), Statistical Mechanics (cond-mat.stat-mech), High Energy Physics - Theory (hep-th)
18 pages, 15 figures
An Algebraic Theory of Gapped Domain Wall Partons
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2025-07-01 20:00 EDT
Matthew Buican, Roman Geiko, Milo Moses, Bowen Shi
The entanglement bootstrap program has generated new quantum numbers associated with degrees of freedom living on gapped domain walls between topological phases in two dimensions. Most fundamental among these are the so-called “parton” quantum numbers, which give rise to a zoo of composite sectors. In this note, we propose a categorical description of partons. Along the way, we make contact with ideas from generalized symmetries and SymTFT.
Strongly Correlated Electrons (cond-mat.str-el), High Energy Physics - Theory (hep-th), Mathematical Physics (math-ph), Quantum Algebra (math.QA), Quantum Physics (quant-ph)
9+7 pages, 13 figures
Characterization of WSe$_2$ films using reflection Kikuchi diffraction in the scanning electron microscope and multivariate statistical analyses
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-07-01 20:00 EDT
Tianbi Zhang, Jakub Holzer, Tomáš Vystavěl, Miroslav Kolíbal, Estácio Paiva de Araújo, Chris Stephens, T. Ben Britton
The study of thin films and 2D materials, including transition metal dichalcogenides such as WSe$ _2$ offers opportunities to leverage their properties in advanced sensors, quantum technologies, and device to optimize functional performance. In this work, we characterize thin WSe$ _2$ samples with variable thicknesses using scanning electron microscope (SEM)-based techniques focused on analysis of backscattered electron signal and Kikuchi diffraction patterns. These data were collected via a pixelated electron-counting direct electron detector positioned below the pole piece primarily configured for reflection Kikuchi diffraction (RKD), and a similar detector placed in the more conventional electron backscatter diffraction geometry. In addition to conventional pattern analysis for orientation microscopy, multivariate statistical methods (MSA) based on principal component analysis were applied to analyze diffraction patterns and differentiate thickness variations and crystal orientations within the thin films through data clustering. These results were compared with atomic force microscopy to validate thickness measurements. Our findings indicate that RKD combined with MSA is highly effective for characterizing 2D materials, enabling simultaneous assessment of thickness and crystallographic orientation. Systematic acceleration voltage variations in RKD experiments and comparisons with EBSD data suggest that the thickness dependency arises from inelastic scattering of diffracted electrons, which affects pattern contrast in the thin film regime. Collection and analysis of patterns obtained from monolayer, bilayer and tri-layer of WSe$ _2$ are also demonstrated. This work reinforces the utility of SEM-based techniques, such as RKD, as valuable tools for the materials characterization toolkit, particularly for thin films and 2D materials.
Materials Science (cond-mat.mtrl-sci)
Magnetic dilution in the triangular lattice antiferromagnet NaYb${1-x}$Lu${x}$O$_2$
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2025-07-01 20:00 EDT
Steven J. Gomez Alvarado, Brenden R. Ortiz, Soren Bear, Benito A. Gonzalez, Andrea N. Capa Salinas, Adam Berlie, Michael J. Graf, Stephen D. Wilson
The delafossite-like compound NaYbO$ _2$ hosts a triangular lattice of Yb$ ^{3+}$ moments and is a promising candidate for realizing a quantum spin liquid state. Here we leverage the substitution of nonmagnetic Lu$ ^{3+}$ onto the Yb$ ^{3+}$ sites to track the evolution of the quantum disordered ground state with increasing magnetic disorder in NaYb$ _{1-x}$ Lu$ _x$ O$ _2$ . Low temperature $ \mu$ SR measurements preclude conventional spin freezing and magnetic inhomogeneity, and instead resolve resilient, correlated magnetic fluctuations that persist to at least 15$ %$ dilution. Heat capacity and magnetic susceptibility measurements resolve a rapid suppression of the field-induced ``up-up-down” phase upon introducing magnetic disorder and a crossover in the power-law behavior of the low-temperature magnetic excitations associated with the zero-field quantum disordered ground state. Our combined results place constraints on theories modeling the emergence of the quantum spin liquid-like behavior in NaYbO$ _2$ .
Strongly Correlated Electrons (cond-mat.str-el)
8 pages, 4 figures
Accelerated discovery and design of Fe-Co-Zr magnets with tunable magnetic anisotropy through machine learning and parallel computing
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-07-01 20:00 EDT
Weiyi Xia, Maxim Moraru, Ying Wai Li, Timothy Liao, James R. Chelikowsky, Cai-Zhuang Wang
Rare earth (RE)-free permanent magnets, as alternative substitutes for RE-containing magnets for sustainable energy technologies and modern electronics, have attracted considerable interest. We performed a comprehensive search for new hard magnetic materials in the ternary Fe-Co-Zr space by leveraging a scalable, machine learning-assisted materials discovery framework running on GPU-enabled exascale computing resources. This framework integrates crystal graph convolutional neural network (CGCNN) machine learning (ML) method with first-principles calculations to efficiently navigate the vast composition-structure space. The efficiency and accuracy of the ML approach enable us to reveal 9 new thermodynamically stable ternary Fe-Co-Zr compounds and 81 promising low-energy metastable phases with their formation energies within 0.1 eV/atom above the convex hull. The predicted compounds span a wide range of crystal symmetries and magnetic behaviors, providing a rich platform for tuning functional properties. Based on the analysis of site-specific magnetic properties, we show that the Fe6Co17Zr6 compound obtained from our ML discovery can be further optimized by chemical doping. Chemical substitutions lead to a ternary Fe5Co18Zr6 phase with a strong anisotropy of K1 = 1.1 MJ/m3, and a stable quaternary magnetic Fe5Co16Zr6Mn4 compound.
Materials Science (cond-mat.mtrl-sci), Computational Physics (physics.comp-ph)
Susceptibility for extremely low external fluctuations and critical behaviour of Greenberg-Hastings neuronal model
New Submission | Disordered Systems and Neural Networks (cond-mat.dis-nn) | 2025-07-01 20:00 EDT
Joaquin Almeira, Daniel A. Martin, Dante R. Chialvo, Sergio A. Cannas
We consider the scaling behaviour of the fluctuation susceptibility associated with the average activation in the Greenberg-Hastings neural network model and its relation to microscopic spontaneous activation. We found that, as the spontaneous activation probability tends to zero, a clear finite size scaling behaviour in the susceptibility emerges, characterized by critical exponents which follow already known scaling laws. This shows that the spontaneous activation probability plays the role of an external field conjugated to the order parameter of the dynamical activation transition. The roles of different kinds of activation mechanisms around the different dynamical phase transitions exhibited by the model are characterized numerically and using a mean field approximation.
Disordered Systems and Neural Networks (cond-mat.dis-nn), Statistical Mechanics (cond-mat.stat-mech), Cellular Automata and Lattice Gases (nlin.CG)
12 pages, 8 figures
Hyperuniformity in ternary fluid mixtures: the role of wetting and hydrodynamics
New Submission | Soft Condensed Matter (cond-mat.soft) | 2025-07-01 20:00 EDT
Nadia Bihari Padhan, Axel Voigt
Phase separation in multicomponent fluids is central to understanding the organization of complex materials and biological structures. The Cahn-Hilliard-Navier-Stokes (CHNS) equations offer a robust framework for modeling such systems, capturing both diffusive dynamics and hydrodynamic interactions. In this work, we investigate hyperuniformity, characterized by suppressed large-scale density fluctuations, in ternary fluid mixtures governed by the ternary CHNS equations. Using large-scale direct numerical simulations, we systematically explore the influence of wetting conditions and hydrodynamic effects on emergent hyperuniformity. Similar to binary systems we observe that the presence of hydrodynamics weakens the hyperuniform characteristics. However, also the wetting properties have an effect. We find that in partial wetting regimes, all three components exhibit comparable degrees of hyperuniformity. In contrast, for complete wetting scenarios, where one component preferentially wets the other two, the wetting component displays a significant reduction in hyperuniformity relative to the others. These findings suggest that wetting asymmetry can act as a control parameter for spatial order in multicomponent fluids.
Soft Condensed Matter (cond-mat.soft), Statistical Mechanics (cond-mat.stat-mech), Fluid Dynamics (physics.flu-dyn)
13 pages, 9 figures
Brightening interlayer excitons by electric-field-driven hole transfer in bilayer WSe2
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2025-07-01 20:00 EDT
Tianyi Ouyang, Erfu Liu, Soonyoung Cha, Raj Kumar Paudel, Yiyang Sun, Zhaoran Xu, Takashi Taniguchi, Kenji Watanabe, Nathaniel M. Gabor, Yia-Chung Chang, Chun Hung Lui
We observe the interlayer A1s^I, A2s^I, and B1s^I excitons in bilayer WSe2 under applied electric fields using reflectance contrast spectroscopy. Remarkably, these interlayer excitons remain optically bright despite being well separated from symmetry-matched intralayer excitons-a regime where conventional two-level coupling models fail unless unphysically large coupling strengths are assumed. To uncover the origin of this brightening, we perform density functional theory (DFT) calculations and find that the applied electric field distorts the valence-band Bloch states, driving the hole wavefunction from one layer to the other. This field-driven interlayer hole transfer imparts intralayer character to the interlayer excitons, thereby enhancing their oscillator strength without requiring hybridization with bright intralayer states. Simulations confirm that this mechanism accounts for the major contribution to the observed brightness, with excitonic hybridization playing only a minor role. Our results identify interlayer hole transfer as a robust and general mechanism for brightening interlayer excitons in bilayer transition metal dichalcogenides (TMDs), especially when inter- and intralayer excitons are energetically well separated.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Optics (physics.optics)
10 pages, 4 figures
Alter-Piezoresponse in Two-Dimensional Lieb-Lattice Altermagnets
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-07-01 20:00 EDT
Altermagnetism, featuring alternating spin structures in reciprocal space, has sparked growing interest. Here, we predict novel real-space alternative piezomagnetic and piezoelectric responses in an emerging altermagnetic family of Lieb lattices, specifically transition-metal chalcogenides M2WS4 (M = Mn, Fe, Co). The unique S4T crystal-spin symmetry leads to distinct magnetic and electric responses depending on the direction of applied stress. When subjected to axial stress, they exhibit a giant piezomagnetic response, which is about one to two orders of magnitude larger than that of most piezomagnetic materials, while the residual C2 symmetry suppresses the piezoelectric effect. In contrast, diagonal stress induces an imbalance of oppositely aligned electric dipole moments and a significant piezoelectric response, while in-plane mirror symmetry inhibits the piezomagnetic effect. This alternative piezoresponse offers an unprecedented opportunity to precisely control electric and magnetic properties independently, opening new avenues for altermagnetic materials in high-fidelity multifunctional memory and sensor applications.
Materials Science (cond-mat.mtrl-sci), Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
4 figures and 1 table
Determining Exciton Binding Energy and Reduced Effective Mass in Metal Tri-Halide Perovskites from Optical and Impedance Spectroscopy Measurements
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-07-01 20:00 EDT
K. Lizárraga, J. A. Guerra, L. A. Enrique-Moran, E. Serquen, E. Ventura, Cesar E. P. Villegas, A. R. Rocha, P. Venezuela
Accurate determination of the exciton binding energy and reduced effective mass in halide perovskites is of utmost importance for the selective design of optoelectronic devices. Although these properties are currently determined by several spectroscopic techniques, complementary theoretical models are often required to bridge macroscopic and microscopic properties. Here, we present a novel method to determine these quantities while fully accounting for polarization effects due to carrier interactions with longitudinal optical phonons. Our approach estimates the exciton-polaron binding energy from optical absorption measurements using a recently developed Elliott based Band Fluctuations model. The reduced effective mass is obtained via the Pollmann-Buttner exciton-polaron model, which is based on the Frohlich polaron framework, where the strength of the electron-phonon interaction arises from changes in the dielectric properties. The procedure is applied to the family of perovskites ABX3 (A = MA, FA, Cs; B = Pb; X = I, Br, Cl), showing excellent agreement with high field magnetoabsorption and other optical-resolved techniques. The results suggest that the Pollmann-Buttner model offers a robust and novel approach for determining the reduced effective mass in metal tri-halide perovskites and other polar materials exhibiting free exciton bands.
Materials Science (cond-mat.mtrl-sci)
submitted to Physical Review Materials
Low-temperature “Depletion” of Superfluid Density
New Submission | Quantum Gases (cond-mat.quant-gas) | 2025-07-01 20:00 EDT
Viktor Berger, Nikolay Prokof’ev, Boris Svistunov
Landau theory of superfluidity associates low-temperature flow of the normal component with the phonon wind. This picture does not apply to superfluids in which Galilean invariance is broken either by disorder, or porous media, or lattice potential, and the phonon wind is no longer responsible for depletion of the superfluid component. Based on Popov’s hydrodynamic action with aharmonic terms, we present a general theory for temperature dependence of the superfluid stiffness at low $ T$ , which reproduces Landau result as a special case when several parameters of the hydrodynamic action are fixed by the Galilean invariance. At the technical level, the theory of low-temperature depletion in a $ d$ -dimensional quantum superfluid maps onto the problem of finite-size corrections in a $ (d+1)$ -dimensional anisotropic (pseudo-)classical-field system with U(1)-symmetric complex-valued action. We validate our theory with numeric simulations of interacting lattice bosons and the J-current model. In a broader context, our approach reveals universal low-temperature thermodynamics of superfluids.
Quantum Gases (cond-mat.quant-gas), Statistical Mechanics (cond-mat.stat-mech)
17 pages, 11 figures
Unconventional superlattice ordering in intercalated transition metal dichalcogenide V$_{1/3}$NbS$_2$
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-07-01 20:00 EDT
Shannon S. Fender, Noah Schnitzer, Wuzhang Fang, Lopa Bhatt, Dingbin Huang, Amani Malik, Oscar Gonzalez, Veronika Sunko, Lilia S. Xie, David A. Muller, Joseph Orenstein, Yuan Ping, Berit H. Goodge, D. Kwabena Bediako
The interplay between symmetry and topology in magnetic materials makes it possible to engineer exotic phases and technologically useful properties. A key requirement for these pursuits is achieving control over local crystallographic and magnetic structure, usually through sample morphology (such as synthesis of bulk crystals versus thin-films) and application of magnetic or electric fields. Here we show that V$ _{1/3}$ NbS$ _2$ can be crystallized in two ordered superlattices, distinguished by the periodicity of out-of-plane magnetic intercalants. Whereas one of these structures is metallic and displays the hallmarks of altermagnetism, the other superlattice, which has not been isolated before in this family of intercalation compounds, is a semimetallic noncollinear antiferromagnet that may enable access to topologically nontrivial properties. This observation of an unconventional superlattice structure establishes a powerful route for tailoring the tremendous array of magnetic and electronic behaviors hosted in related materials.
Materials Science (cond-mat.mtrl-sci)
7 pages, 4 figures
Protein Drift-Diffusion in Membranes with Non-equilibrium Fluctuations arising from Gradients in Concentration or Temperature
New Submission | Soft Condensed Matter (cond-mat.soft) | 2025-07-01 20:00 EDT
We investigate proteins within heterogeneous cell membranes where non-equilibrium phenomena arises from spatial variations in concentration and temperature. We develop simulation methods building on non-equilibrium statistical mechanics to obtain stochastic hybrid continuum-discrete descriptions which track individual protein dynamics, spatially varying concentration fluctuations, and thermal exchanges. We investigate biological mechanisms for protein positioning and patterning within membranes and factors in thermal gradient sensing. We also study the kinetics of Brownian motion of particles with temperature variations within energy landscapes arising from heterogeneous microstructures within membranes. The introduced approaches provide self-consistent models for studying biophysical mechanisms involving the drift-diffusion dynamics of individual proteins and energy exchanges and fluctuations between the thermal and mechanical parts of the system. The methods also can be used for studying related non-equilibrium effects in other biological systems and soft materials.
Soft Condensed Matter (cond-mat.soft), Adaptation and Self-Organizing Systems (nlin.AO), Biological Physics (physics.bio-ph), Computational Physics (physics.comp-ph), Subcellular Processes (q-bio.SC)
Observation of Dual Spin Reorientation Transitions in Polycrystalline CeCr$x$Fe${1-x}$O$_3$(x=0.33 and 0.67)
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-07-01 20:00 EDT
We investigate the magnetic behavior of polycrystalline CeCr$ _x$ Fe$ _{1-x}$ O$ _3$ (x = 0, 0.33, 0.67, and 1) synthesized via solid state reaction. Rare earth orthoferrite and orthochromite materials are well known for exhibiting spin reorientation transitions. Cr$ ^{3+}$ doping in CeFeO$ _3$ results in the unusual occurrence of two spin reorientation transitions, $ {\Gamma}_4$ (G$ _x$ , A$ _y$ , F$ _z$ ) $ \rightarrow$ $ {\Gamma}_1$ (A$ _x$ , G$ _y$ , C$ _z$ ) near 230 K and $ {\Gamma}_4$ (G$ _x$ , A$ _y$ , F$ _z$ ) $ \rightarrow$ $ {\Gamma}_2$ (F$ _x$ , C$ _y$ , G$ _z$ ) near 100 K. In addition, two Néel transitions are identified. The results indicate that CeCr$ _x$ Fe$ _{1-x}$ O$ _3$ offers a rich collection of magnetic behaviors with application potential for spintronic devices.
Materials Science (cond-mat.mtrl-sci)
13 pages, 5 figures
Tunable Competing Electronic Orders in Double Quantum Spin Hall Superlattices
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2025-07-01 20:00 EDT
Yi-Chun Hung, Chen-Hsuan Hsu, Arun Bansil
Competing superconducting (SC) and density-wave orders are of key importance in generating unconventional superconductivity and emergent electronic responses. Quasi-one-dimensional models provide insight into these competing orders and suggest higher-dimensional realizations through coupled-wire constructions, but analysis of such systems remains limited. Recent studies suggest that double helical edge states (DHESs) in double quantum spin Hall insulators (DQSHIs) form a two-channel Luttinger liquid that exhibits SC and spin density wave (SDW) phases and their $ \pi$ -junction analogs. Here, we analyze weakly coupled DHESs from the surface of a periodically stacked layered structure consisting of DQSHIs and dielectrics, where inter-edge interactions approximately develop a tunable helical sliding Luttinger liquid (HSLL) order. Using a renormalization-group analysis, we construct phase diagrams and identify a regime of HSLL parameters that favor competing two-dimensional $ \pi$ -SC and $ \pi$ -SDW orders. We identify parameter regimes where the competing orders could be realized experimentally in nanoscale devices. Our study suggests a promising materials platform for exploring tunable $ \pi$ -SC and $ \pi$ -SDW orders in double quantum spin Hall superlattices.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
11 pages, 6 figures
Anisotropic nonlinear transport in two-dimensional ferroelectrics
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2025-07-01 20:00 EDT
Qin Zhang, Xu Chen, Mingbo Dou, M. Ye. Zhuravlev, A. V. Nikolaev, Xianjie Wang, L. L. Tao
The longitudinal nonlinear response plays a crucial role in the nonreciprocal charge transport and may provide a simple electrical means to probe the spin-orbit coupling, magnetic order and polarization states, etc. Here, we report on a study on the polarization and magnetic field control of longitudinal nonlinear transport in two-dimensional (2D) ferroelectrics with in-plane polarization. Based on the Boltzmann transport theory, we first study that using a general Hamiltonian model and show that the nonlinear conductivity can be significantly tuned by the polarization and magnetic field. In addition, the nonlinear conductivity reveals a strong spatial anisotropy. We further derive the analytical formulas for the anisotropic nonlinear conductivity in exact accordance with numerical results. Then, we exemplify those phenomena in the 2D ferroelectric SnTe monolayer in the presence of an external magnetic field based on the density functional theory calculations. It is also revealed that the polarity of nonlinear conductivity is locked to the direction of the polarization, thus pointing to the possibility of the nonlinear detection of polarization states. Our work uncovers intriguing features of the longitudinal nonlinear transport in 2D ferroelectrics and provides guidelines for designing the polarization control of rectifying devices.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
Non-Bloch Band Theory for 2D Geometry-Dependent Non-Hermitian Skin Effect
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2025-07-01 20:00 EDT
Chenyang Wang, Jinghui Pi, Qinxin Liu, Yaohua Li, Yong-Chun Liu
The non-Hermitian skin effect (NHSE), characterized by boundary-localized eigenstates under open boundary conditions, represents the key feature of the non-Hermitian lattice systems. Although the non-Bloch band theory has achieved success in depicting the NHSE in one-dimensional (1D) systems, its extension to higher dimensions encounters a fundamental hurdle in the form of the geometry-dependent skin effect (GDSE), where the energy spectra and the boundary localization of the eigenstates rely on the lattice geometry. In this work, we establish the non-Bloch band theory for two-dimensional (2D) GDSE, by introducing a strip generalized Brillouin zone (SGBZ) framework. Through taking two sequential 1D thermodynamic limits, first along a major axis and then along a minor axis, we construct geometry-dependent non-Bloch bands, unraveling that the GDSE originates from the competition between incompatible SGBZs. Based on our theory, we derive for the first time a crucial sufficient condition for the GDSE: the non-Bloch dynamical degeneracy splitting of SGBZ eigenstates, where a continuous set of degenerate complex momenta breaks down into a discrete set. Moreover, our SGBZ formulation reveals that the Amoeba spectrum contains the union of all possible SGBZ spectra, which bridges the gap between the GDSE and the Amoeba theory. The proposed SGBZ framework offers a universal roadmap for exploring non-Hermitian effects in 2D lattice systems, opening up new avenues for the design of novel non-Hermitian materials and devices with tailored boundary behaviors.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Quantum Gases (cond-mat.quant-gas), Mathematical Physics (math-ph), Optics (physics.optics), Quantum Physics (quant-ph)
36 pages, 13 figures in main text and 4 figures in Supplementary Materials
Detecting secondary-phase in bainite microstructure through deep-learning based single-shot approach
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-07-01 20:00 EDT
Vinod Kumar, Sharukh Hussain, Vishwas Subramanian, P G Kubendran Amos
Relating properties and processing conditions to multiphase microstructures begins with identifying the constituent phases. In bainite, distinguishing the secondary phases is an arduous task, owing to their intricate morphology. In this work, deep-learning techniques deployed as object-detection algorithms are extended to realise martensite-austenite (MA) islands in bainite microstructures, which noticeably affect their mechanical properties. Having explored different techniques, an extensively trained regression-based algorithm is developed to identify the MA islands. This approach effectively detects the secondary phases in a single-shot framework without altering the micrograph dimensions. The identified technique enables scalable, automated detection of secondary phase in bainitic steels. This extension of the detection algorithm is suitably prefaced by an analysis exposing the inadequacy of conventional classification approaches in relating the processing conditions and composition to the bainite microstructures with secondary phases.
Materials Science (cond-mat.mtrl-sci)
Strain-Induced Non-alter Compensated Magnet and Its Application to Magnetic Tunnel Junction Device Design
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-07-01 20:00 EDT
Fangqi Liu, Yanrong Song, Zhenhua Zhang, Yong Liu, Sicong Zhu, Zhihong Lu, Rui Xiong
The recent proposal of altermagnetism has drawn widespread attention to antiferromagnet (AFM) exhibiting spin splitting, extending beyond the realm of sign-alternating spin splitting in momentum space protected solely by rotational symmetry. Herrin, we propose a shear-strain strategy that enables significant modulation of d-wave altermagnets into an non-alter compensated magnets. A comprehensive analysis combining the magnetic moment compensation characteristics of opposite spin sublattices with the distribution of spin-resolved conduction channels in momentum space under the [001] crystal orientation reveals that shear strain breaks the rotational symmetry of alternatmagnets. To explore the application potential of non-alter compensated magnets, we designe RuO2/TiO2/RuO2 magnetic tunnel junctions (MTJ) with three crystallographic orientations ((001), (110), (100)) and investigated their transport properties under shear strain. This non-alter electronic structure not only enhances the tunneling magnetoresistance (TMR) in spin-split paths of intrinsic RuO2 (226% to 431%) but also enables substantial TMR in spin-degenerate paths (from 0-88%)). Our work provides guidelines for broadening magnetic materials and device platforms.
Materials Science (cond-mat.mtrl-sci), Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
The mechanics of disclination emergence in 3D active nematics
New Submission | Soft Condensed Matter (cond-mat.soft) | 2025-07-01 20:00 EDT
Yingyou Ma, Christopher Amey, Aparna Baskaran, Michael F. Hagan
The spontaneous creation of disclinations is a defining characteristic of active nematics, which is rarely observed in equilibrium systems or other active matter systems. Thus, understanding the mechanics of disclinations is crucial for developing reliable continuum theories and practical applications. In this work, we explore this intrinsic mechanics by performing large-scale 3D simulations of a particle-based model of active semiflexible filaments. We investigate the effects of filament stiffness and activity on the collective behavior of active nematics. Analysis of the steady state and the topological properties of initial disclination loops reveals that the system is governed by a single parameter, an activity-dependent effective stiffness. Then, we develop a method to visualize director field orientations in a physically transparent manner during the formation of disclination loops. Based on this, we establish a unified theory for the mechanics of disclination emergence, across the range of bend and twist. This disclination analysis framework can also be applied to diverse other 3D liquid crystal systems.
Soft Condensed Matter (cond-mat.soft)
Dislocation Engineering: A New Key to Enhancing Ceramic Performances
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-07-01 20:00 EDT
Haoxuan Wang, Yifan Wang, Xu Liang, Wenshan Yu, Xufei Fang, Shengping Shen
Dislocations are line defects in crystalline solids and often exert a significant influence on the mechanical properties of metals. Recently, there has been a growing interest in using dislocations in ceramics to enhance materials performance. However, dislocation engineering has frequently been deemed uncommon in ceramics owing to the brittle nature of ceramics. Contradicting this conventional view, various approaches have been used to introduce dislocations into ceramic materials without crack formation, thereby paving the way for controlled ceramics performance. However, the influence of dislocations on functional properties is equally complicated owing to the intricate structure of ceramic materials. Furthermore, despite numerous experiments and simulations investigating dislocation-controlled properties in ceramics, comprehensive reviews summarizing the effects of dislocations on ceramics are still lacking. This review focuses on some representative dislocation-controlled properties of ceramic materials, including mechanical and some key functional properties, such as transport, ferroelectricity, thermal conductivity, and superconducting properties. A brief integration of dislocations in ceramic is anticipated to offer new insights for the advancement of dislocation engineering across various disciplines.
Materials Science (cond-mat.mtrl-sci), Applied Physics (physics.app-ph)
This timely review redefines dislocation engineering in ceramics, challenging traditional brittleness limitations. The authors systematically analyze recent breakthroughs in fracture-free dislocation introduction, offering new pathways to tailor both mechanical and functional ceramic properties
Size-Dependent Tensile Behavior of Nanocrystalline HfNbTaTiZr High-Entropy Alloy: Roles of Solid-Solution and Short-Range Order
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-07-01 20:00 EDT
Yihan Wu, Gaosheng Yan, Pengfei Yu, Yaohong Suo, Wenshan Yu, Shengping Shen
This study investigates the size-dependent mechanical behavior of the HfNbTaTiZr refractory high-entropy alloy (RHEA) under uniaxial tension, with a focus on the effects of random solid-solution (RSS) and chemical short-range order (CSRO). A machine learning framework is developed to accelerate the parameterization of interatomic force fields (FFs), enabling molecular dynamics simulations of three nanocrystalline models: (i) a meta-atom (MA) mode representing the RHEA as a hypothetical sing-element system with averaged properties, (ii) a quinary RSS model with randomly distributed constituent atoms, and (iii) a Monte Carlo (MC) model with internal CSRO. The results reveal that RSS enhances strength, while CSRO reduces flow stress level but improves strain hardening and failure resistance. A transition from Hall-Petch (HP) strengthening to inverse Hall-Petch (IHP) softening is observed, with CSRO suppressing this transition. The underlying plastic mechanisms (i.e., dislocation slip, deformation twinning, phase transformation and grain boundary movements) are analyzed from both nanostructural and energetic perspectives. Theoretical models are established to describe the size-dependent yield strength and predict the critical grain size. Additionally, the contributions of different plastic mechanisms to the overall stress response are separately quantified. These findings provide new insights into the design and performance optimization of RHEAs through nanostructural engineering.
Materials Science (cond-mat.mtrl-sci)
35 pages, 15 figures
Actively induced supercoiling can slow down plasmid solutions by trapping the threading entanglements
New Submission | Soft Condensed Matter (cond-mat.soft) | 2025-07-01 20:00 EDT
Roman Staňo, Renáta Rusková, Dušan Račko, Jan Smrek
Harnessing the topology of ring polymers as a design motif in functional nanomaterials is becoming a promising direction in the field of soft matter. For example, the ring topology of DNA plasmids prevents the relaxation of excess twist introduced to the polymer, instead resulting in helical supercoiled structures. In equilibrium semi-dilute solutions, tightly supercoiled rings relax faster than their torsionally relaxed counterparts, since the looser conformations of the latter allow for rings to thread through each other and entrain via entanglements. Here we use molecular simulations to explore a non-equilibrium scenario, in which a supercoiling agent, akin to gyrase enzymes, rapidly induces supercoiling in the suspensions of relaxed plasmids. The activity of the agent not only alters the conformational topology from open to branched, but also locks-in threaded rings into supramolecular clusters, which relax very slowly. Ultimately, our work shows how the polymer topology under non-equilibrium conditions can be leveraged to tune dynamic behavior of macromolecular systems, suggesting a pathway to novel class of driven materials glassified by activity.
Soft Condensed Matter (cond-mat.soft), Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Statistical Mechanics (cond-mat.stat-mech), Biological Physics (physics.bio-ph), Biomolecules (q-bio.BM)
Symmetry, microscopy and spectroscopy signatures of altermagnetism
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-07-01 20:00 EDT
Tomas Jungwirth, Jairo Sinova, Rafael M. Fernandes, Qihang Liu, Hikaru Watanabe, Shuichi Murakami, Satoru Nakatsuji, Libor Smejkal
Altermagnetism is a collinear compensated magnetically-ordered phase with a d, g or i-wave anisotropy and alternating spin polarization of the electronic structure in the position and momentum space. Its recent discovery was in part motivated by the research of compensated magnets towards highly scalable spintronic technologies. Simultaneously, altermagnetism shares the anisotropic higher-partial-wave nature of ordering with unconventional superfluid phases which have been at the forefront of research for the past several decades. These examples illustrate the interest in altermagnetism from a broad range of science and technology perspectives. After summarizing the diverse research context, we turn the focus of this review to the symmetry, microscopy and spectroscopy signatures of altermagnetism. We start from the description of spontaneously broken and retained symmetries which delineate the compensated altermagnetic ordering as a distinct magnetic phase. Next we focus on microscopic signatures and ordering mechanism of the altermagnetic phase. We highlight crystal-structure realizations of a characteristic ferroic order of anisotropic higher-partial-wave components of atomic-scale spin densities in altermagnets, ranging from weakly-interacting metals to strongly correlated insulators. The symmetry and microscopy signatures of altermagnetism are directly reflected in spin-dependent electronic spectra and responses. We review salient band-structure features originating from the altermagnetic ordering, and from its interplay with spin-orbit coupling and topological phenomena. Throughout the review we compare altermagnetism to traditional ferromagnetism and Neel antiferromagntism, and to the currently intensely explored magnetic phases with non-collinear symmetry-protected compensated spin orders. We accompany the theoretical discussions by references to relevant experiments.
Materials Science (cond-mat.mtrl-sci)
22 pages, 7 figures
Ising spin-1/2 XXZ chain’s quantum problems beyond the spinon paradigm
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2025-07-01 20:00 EDT
J. M. P. Carmelo, P. D. Sacramento
Spin chains are correlated quantum models of great interest in quantum systems and materials exhibiting quasi-one-dimensional magnetic properties. Here we review results on quantum problems associated with spin chains that are beyond the usual spinon paradigm. In this review we consider two quantum problems that are beyond the spinon representation: (a) Spin Bethe strings of length n that have no spinon representation, contribute to the dynamical properties of the spin-1/2 XXZ chain with anisotropy larger than 1 and for n=1,2,3 were experimentally identified and realized in the zigzag materials SrCo2V2O8 and BaCo2V2O8; (b) The spin stiffness associated with ballistic spin transport at arbitrary finite temperature, which involves a huge number of energy eigenstates, many of which are generated in the thermodynamic limit from ground states by an infinite number of elementary processes.
Strongly Correlated Electrons (cond-mat.str-el)
28 pages, 11 figures
Chaos 34, 072101 (2024)
Gigantic Harmonic Generation in Néel-Torque Antiferromagnetic Resonance
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2025-07-01 20:00 EDT
We theoretically investigate the resonant and higher-harmonic magnetic responses of a collinear antiferromagnet induced by Néel spin-orbit torques (NSOTs). By deriving the dynamical susceptibilities up to the third harmonic, we find remarkable NSOT-induced amplifications of the linear and nonlinear magnetic dynamics by orders of magnitude compared to conventional spin-orbit torques, enabling highly-efficient frequency conversion in the sub-terahertz frequency range. We then propose a multilayer antiferromagnetic nano-device leveraging the gigantic harmonic generation to achieve unprecedented frequency amplifiers and converters. Our work uncovers a previously overlooked role of the NSOTs in nonlinear dynamics.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Materials Science (cond-mat.mtrl-sci), Other Condensed Matter (cond-mat.other)
First-Principles Nanocapacitor Simulations of the Optical Dielectric Constant in Water Ice
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2025-07-01 20:00 EDT
Anthony Mannino, Graciele M. Arvelos, Kedarsh Kaushik, Emilio Artacho, Pablo Ordejon, Alexandre R. Rocha, Luana S. Pedroza, Marivi Fernández-Serra
We introduce a combined density functional theory (DFT) and non-equilibrium Green’s function (NEGF) framework to compute the capacitance of nanocapacitors and directly extract the dielectric response of a sub-nanometer dielectric under bias. We identify that at the nanoscale conventional capacitance evaluations based on stored charge per unit voltage suffer from an ill-posed partitioning of electrode and dielectric charge. This partitioning directly impacts the geometric definition of capacitance through the capacitor width, which in turn makes the evaluation of dielectric response uncertain. This ambiguous separation further induces spurious interfacial polarizability when analyzed via maximally localized Wannier functions. Focusing on crystalline ice, we develop a robust charge-separation protocol that yields unique capacitance-derived polarizability and dielectric constants, unequivocally demonstrating that confinement neither alters ice’s intrinsic electronic response nor its insensitivity to proton order. Our results lay the groundwork for rigorous interpretation of capacitor measurements in low-dimensional dielectric materials.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
Energetic variational modeling of active nematics: coupling the Toner-Tu model with ATP hydrolysis
New Submission | Soft Condensed Matter (cond-mat.soft) | 2025-07-01 20:00 EDT
We present a thermodynamically consistent energetic variational model for active nematics driven by ATP hydrolysis, with a focus on the coupling between chemical reactions and mechanical dynamics. Extending the classical Toner-Tu framework, we introduce a chemo-mechanical coupling mechanism in which the self-advection and polarization dynamics are modulated by the ATP hydrolysis rate. The model is derived using an energetic variational approach that integrates both chemical free energy and mechanical energy into a unified energy-dissipation law. The reaction rate equation explicitly incorporates mechanical feedback, revealing how active transport and alignment interactions influence chemical fluxes and vice versa. This formulation not only preserves consistency with nonequilibrium thermodynamics but also provides a transparent pathway for modeling energy transduction in active systems. We also present numerical simulations demonstrating how ATP consumption drives the merging of topological defects and enables the system to escape a quasi-equilibrium, a phenomenon not observed in passive nematic systems. This framework offers new insights into energy transduction and regulation mechanisms in biologically related active systems.
Soft Condensed Matter (cond-mat.soft)
15 pages, 2 figures
Superconducting exchange coupling driven bistable and absolute switching
New Submission | Superconductivity (cond-mat.supr-con) | 2025-07-01 20:00 EDT
As per de Gennes predictions, a superconducting layer placed between two ferromagnetic insulators can drive an antiferromagnetic exchange coupling between them. Using two ferromagneticinsulating GdN layers having dissimilar switching fields sandwiching a superconducting Vanadium thin film, we demonstrate evidence of such exchange coupling. We demonstrate that such an exchange coupling promotes switching between zero and finite resistance states of Vanadium. Our devices hold either a finite resistance or a zero-resistance state at zero magnetic field, dependent on their magnetic field history. Moreover, we demonstrate the absolute switching effect, thus making such devices suitable for application at the lowest temperatures as non-volatile cryogenic memory useful for futuristic quantum circuits and for several other superconducting spintronic applications.
Superconductivity (cond-mat.supr-con)
Band-Gap Tunability in Anharmonic Perovskite-like Semiconductors Driven by Polar Electron-Phonon Coupling
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-07-01 20:00 EDT
Pol Benítez, Ruoshi Jiang, Siyu Chen, Cibrán López, Josep-Lluís Tamarit, Edgardo Saucedo, Bartomeu Monserrat, Claudio Cazorla
The ability to finely tune optoelectronic properties in semiconductors is crucial for the development of advanced technologies, ranging from photodetectors to photovoltaics. In this work, we propose a novel strategy to achieve such tunability by utilizing electric fields to excite low-energy polar optical phonon modes, which strongly couple to electronic states in anharmonic semiconductors. We conducted a high-throughput screening of over $ 10,000$ materials, focusing on centrosymmetric compounds with imaginary polar phonon modes and suitable band gaps, and identified $ 310$ promising candidates with potential for enhanced optoelectronic tunability. From this set, three perovskite-like compounds –Ag$ _3$ SBr, BaTiO$ _3$ , and PbHfO$ _3$ – were selected for in-depth investigation based on their contrasting band-gap behavior with temperature. Using first-principles calculations, \textit{ab initio} molecular dynamics simulations, tight-binding models, and anharmonic Fröhlich theory, we analyzed the underlying physical mechanisms. Our results show that polar phonon distortions can induce substantial band-gap modulations at ambient conditions, including reductions of up to $ 70%$ in Ag$ _3$ SBr and increases of nearly $ 23%$ in BaTiO$ _3$ , relative to values calculated at zero temperature, while PbHfO$ _3$ exhibits minimal change. These contrasting responses arise from distinct electron-phonon coupling mechanisms and orbital hybridization at the band edges. This work establishes key design principles for harnessing polar lattice dynamics to engineer tunable optoelectronic properties, paving the way for adaptive technologies such as wavelength-selective optical devices and solar absorbers.
Materials Science (cond-mat.mtrl-sci)
16 pages, 5 figures
Thermodynamic properties of CrMnFeCoNi high entropy alloy at elevated electronic temperatures
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-07-01 20:00 EDT
The Cantor alloy (equiatomic CrMnFeCoNi) is a high-entropy alloy with unique physical properties and radiation resistance. To model its response to intense laser pulses, the parameters of the electronic ensemble are required. In this work, the electronic heat capacity, thermal conductivity, and electron-phonon coupling strength at elevated electronic temperatures are evaluated using a combined approach that incorporates tight-binding molecular dynamics and the Boltzmann equation. The damage threshold fluence is estimated for a wide range of photon energies, from XUV to hard X-rays. It is found that at the electronic temperatures ~24,000 K (absorbed dose ~6 eV/atom), the Cantor alloy experiences nonthermal melting due to modification of the interatomic potential induced by electronic excitation, even without the increase of the atomic temperature. This effect must be included in reliable models of CrMnFeCoNi ablation under ultrafast laser irradiation.
Materials Science (cond-mat.mtrl-sci)
Josephson diode effect: a phenomenological perspective
New Submission | Superconductivity (cond-mat.supr-con) | 2025-07-01 20:00 EDT
Da Wang, Qiang-Hua Wang, Congjun Wu
As a novel quantum phenomenon with nonreciprocal supercurrent, the Josephson diode effect was intensively studied in recent years. Here, we construct a generalized resistively capacitance shunted junction (RCSJ) model as a low-energy effective/phenomenological theory for a general Josephson junction. For the ideal diode effect defined by unequal critical currents $ |I_{c+}|\ne|I_{c-}|$ , both inversion $ \mathcal{I}$ and time-reversal $ \mathcal{T}$ symmetries are required to be broken. It can be further divided into two classes: intrinsic ($ \mathcal{T}$ -breaking for the junction itself) and extrinsic ($ \mathcal{T}$ -breaking under external current reversion). In addition, a pseudo diode effect ($ \mathcal{T}$ -breaking not necessary) can be defined by $ |I_{c+}|=|I_{c-}|$ but unequal retrapping currents $ |I_{r+}|\ne|I_{r-}|$ , for which noise current is further shown to produce the diode feature effectively. Finally, when radio-frequency AC external current exists, the Shapiro steps appear and can be used to distinguish the above three types of the diode effect. Our work provides a unified framework for studying the Josephson diode effect and can be applied to design workable superconducting circuits incorporating the Josephson diode as a fundamental circuit element.
Superconductivity (cond-mat.supr-con)
5 pages, 3 figures, 1 table
Quantitative electron beam-single atom interactions enabled by sub-20-pm precision targeting
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2025-07-01 20:00 EDT
Kevin M. Roccapriore, Frances M. Ross, Julian Klein
The ability to probe and control matter at the picometer scale is essential for advancing quantum and energy technologies. Scanning transmission electron microscopy offers powerful capabilities for materials analysis and modification, but sample damage, drift, and scan distortions hinder single atom analysis and deterministic manipulation. Materials analysis and modification via electron-solid interactions could be transformed by precise electron delivery to a specified atomic location, maintaining the beam position despite drift, and minimizing collateral dose. Here we develop a fast, low-dose, sub-20-pm precision electron beam positioning technique, atomic lock-on, (ALO), which offers the ability to position the beam on a specific atomic column without previously irradiating that column. We use this technique to lock onto the same selected atomic location to repeatedly measure its weak electron energy loss signal despite sample drift. Moreover, we quantitatively measure electron beam matter interactions of single atomic events with microsecond time resolution. This enables us to observe single atom dynamics such as atomic bistability in the electron microscope, revealing partially bonded atomic configurations and recapture phenomena. We discuss the prospects for high-precision measurements and deterministic control of matter for quantum technologies using electron microscopy.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Materials Science (cond-mat.mtrl-sci), Other Condensed Matter (cond-mat.other)
main: 11 pages, 5 figures; SI: 14 pages, 9 figures, table 1
Adv. Sci. e02551 (2025)
Spontaneous symmetry breaking in an antiferromagnetic Heisenberg chain
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2025-07-01 20:00 EDT
Jingya Wang, Zenan Liu, Bin-Bin Mao, Zijian Xiong, Zhe Wang, Zheng Yan
It is generally believed that spontaneous breaking of continuous symmetry is restricted by Hohenberg-Mermin-Wagner theorem. A special case is that the 1D ferromagnetic Heisenberg chain holds long-range order because the order parameter commutes with the Hamiltonian. The other one is that the recently found frustration-free Hamiltonians can bypass this theorem, but the observed symmetry breaking is fragile under generic perturbations. In this work, we have discovered a new example that goes beyond the above two examples – a 1D antiferromagnetic Heisenberg model – that can achieve spontaneous breaking of continuous symmetry. Importantly, it is not a frustration-free model and its order parameter does not commute with the Hamiltonian. Moreover, the long-range order is robust under symmetry-preserving perturbations. Combining numerical simulation and theoretical analysis, we have further confirmed and understood this nontrivial phenomenon.
Strongly Correlated Electrons (cond-mat.str-el)
Exact treatment of rotation-induced modifications in two-dimensional quantum rings
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2025-07-01 20:00 EDT
Carlos Magno O. Pereira, Frankbelson dos S. Azevedo, Edilberto O. Silva
We investigate the influence of rotation on the Fermi energy, magnetization, and persistent current in two-dimensional quantum rings. Using the Tan-Inkson confinement potential and incorporating rotational effects through a non-inertial coupling, we derive analytical expressions for the energy levels and examine the modifications induced by rotation. We then numerically explore how variations in angular velocity affect the Fermi energy, magnetization, and persistent current. Our results show that rotation has a significant impact on these physical properties, underscoring the importance of considering rotational effects in quantum ring systems. This suggests that rotation could serve as a control parameter in the development of new mesoscopic devices, without the need for additional fields or geometric modifications.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Quantum Physics (quant-ph)
10 pages, 12 figures
Spiral dislocation as a tunable geometric parameter for optical responses in quantum rings
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2025-07-01 20:00 EDT
Hassan Hassanabadi, Kangxian Guo, Liangliang Lu, Edilberto O. Silva
We investigate the optical and quantum mechanical properties of a charged spinless particle confined in a two-dimensional quantum ring under the simultaneous influence of a spiral dislocation and an external magnetic field. The dislocation is modeled by a torsion-induced metric that alters the spatial geometry without introducing curvature. Using the minimal coupling procedure in curved space, we derive a modified Schrödinger equation incorporating both topological and electromagnetic effects. The geometric deformation leads to an energy-dependent effective potential, enabling a tunable control over the bound-state spectrum. We analyze how the spiral dislocation modifies the absorption coefficient, refractive index variation, and photoionization cross-section. The results demonstrate that the dislocation not only shifts the resonance peaks but also enhances or suppresses specific optical transitions depending on the angular momentum. These findings open up possibilities for geometrically tuning light-matter interactions in topological quantum devices.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Quantum Physics (quant-ph)
9 pages, 6 figures, 1 Table
Tunable Field-Linked $s$-wave Interactions in Dipolar Fermi Mixtures
New Submission | Quantum Gases (cond-mat.quant-gas) | 2025-07-01 20:00 EDT
Jing-Lun Li, Georgios M. Koutentakis, Mateja Hrast, Mikhail Lemeshko, Andreas Schindewolf, Ragheed Alhyder
Spin mixtures of degenerate fermions are a cornerstone of quantum many-body physics, enabling superfluidity, polarons, and rich spin dynamics through $ s$ -wave scattering resonances. Combining them with strong, long-range dipolar interactions provides highly flexible control schemes promising even more exotic quantum phases. Recently, microwave shielding gave access to spin-polarized degenerate samples of dipolar fermionic molecules, where tunable $ p$ -wave interactions were enabled by field-linked resonances available only by compromising the shielding. Here, we study the scattering properties of a fermionic dipolar spin mixture and show that a universal $ s$ -wave resonance is readily accessible without compromising the shielding. We develop a universal description of the tunable $ s$ -wave interaction and weakly bound tetratomic states based on the microwave-field parameters. The $ s$ -wave resonance paves the way to stable, controllable and strongly-interacting dipolar spin mixtures of deeply degenerate fermions and supports favorable conditions to reach this regime via evaporative cooling.
Quantum Gases (cond-mat.quant-gas), Atomic and Molecular Clusters (physics.atm-clus)
Tension-Induced Soft Stress and Viscoelastic Bending in Liquid Crystal Elastomers for Enhanced Energy Dissipation
New Submission | Soft Condensed Matter (cond-mat.soft) | 2025-07-01 20:00 EDT
Beijun Shen, Yuefeng Jiang, Christopher M. Yakacki, Sung Hoon Kang, Thao D. Nguyen
Architected materials that harness elastic snap-through buckling can trap energy reversibly. Liquid crystal elastomers (LCEs) exhibit excellent dissipation capabilities due to polymer network viscoelasticity and rate-dependent soft stress behavior associated with mesogen rotation. Incorporating LCEs into buckling lattice structures enhances energy absorption; however, conventional design cannot take advantage of the dissipation mechanism associated with mesogen rotation because buckling occurs at strains below the threshold of the soft stress response. In this study, we investigate tension-induced mesogen rotation as an additional dissipation mechanism in horizontal members of structures composed of tilted LCE beams under compression. Viscoelastic properties of LCEs with two crosslinking densities were characterized experimentally, and a nonlinear viscoelastic user-defined element was implemented in Abaqus/Standard to capture finite-strain behavior, including soft stress effects. Simulations and experiments revealed a non-monotonic dependence of energy dissipation on the thickness ratio between horizontal and tilted LCE members. Optimized structures with stretchable horizontal bars dissipated 2-3 times more energy than rigid-bar counterparts by balancing tension-driven soft stress with viscoelastic beam bending. Energy contributions from mesogen rotation and polymer network viscoelasticity were quantified. These findings inform the design strategies for LCE-based architected materials to enhance dissipation.
Soft Condensed Matter (cond-mat.soft), Applied Physics (physics.app-ph)
in total 38 pages, 10 figures in main text, and 11 figures in appendix
The effect of droplet configurations within the Functional Renormalization Group of low-dimensional Ising models
New Submission | Statistical Mechanics (cond-mat.stat-mech) | 2025-07-01 20:00 EDT
Ivan Balog, Lucija Nora Farkaš, Maroje Marohnić, Gilles Tarjus
We explore the application of the nonperturbative functional renormalization group (NPFRG) within its most common approximation scheme based on truncations of the derivative expansion to the $ Z_2$ -symmetric scalar $ \varphi^4$ theory as the lower critical dimension $ d_{\rm lc}$ is approached. We aim to assess whether the NPFRG - a broad, nonspecialized method which is accurate in $ d\geq 2$ - can capture the effect of the localized (droplet) excitations that drive the disappearance of the phase transition in $ d_{\rm lc}$ and control the critical behavior as $ d\to d_{\rm lc}$ . We extend a prior analysis to the next (second) order of the derivative expansion, which turns out to be much more involved. Through extensive numerical and analytical work we provide evidence that the convergence to $ d_{\rm lc}$ is nonuniform in the field dependence and is characterized by the emergence of a boundary layer near the minima of the fixed-point effective potential. This is the mathematical mechanism through which the NPFRG within the truncated derivative expansion reproduces nontrivial features predicted by the droplet theory of Bruce and Wallace [1,2], namely, the existence of two distinct small parameters as $ d\to d_{\rm lc}$ that control different aspects of the critical behavior and that are nonperturbatively related.
[1] A. D. Bruce and D. J. Wallace, Phys. Rev. Lett. 47, 1743 (1981), [2] A. D. Bruce and D. J. Wallace, Journal of Physics A: Mathematical and General 16, 1721 (1983).
Statistical Mechanics (cond-mat.stat-mech)
23 pages, 25 figures
Topotactic phase transformation in correlated vanadium dioxide through oxygen vacancy ordering
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-07-01 20:00 EDT
Xuanchi Zhou, Xiaohui Yao, Xiaomei Qiao, Jiahui Ji, Guowei Zhou, Huihui Ji, Xiaohong Xu
Controlling the insulator-metal transition (IMT) in correlated oxide system through oxygen vacancy ordering opens up a new paradigm for exploring exotic structural transformation and physical functionality. Oxygen vacancy serves as a powerful tuning knob for adjusting the IMT property in VO2, though driving topochemical reduction to V2O3 remains challenging due to structural incompatibility and competing phase instability. Here we unveil consecutive oxygen-vacancy-driven VO2-VO2-x-V2O3 topotactic phase transformation route with enticing facet-dependent anisotropy, engendering tunable IMT properties over an extended temperature range. Remarkably, topochemically reduced V2O3 inherits the crystallographic characteristics from parent VO2, enabling emergent lattice framework and IMT behavior inaccessible via direct epitaxial growth. Analogous electron doping arising from hydrogenation and oxygen vacancy contributes cooperatively to drive the Mott phase transition in VO2 through band-filling control. Our work not only unveils sequential topotactic phase transformations in VO2 through oxygen vacancy ordering but also provides fundamentally new insights for defect-mediated Mott transitions.
Materials Science (cond-mat.mtrl-sci), Strongly Correlated Electrons (cond-mat.str-el)
Multiple Photon Field-induced Topological States in Bulk HgTe
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-07-01 20:00 EDT
Dongbin Shin, I-Te Lu, Benshu Fan, Emil Vinas Bostrom, Hang Liu, Mark Kamper Svendsen, Simone Latini, Peizhe Tang, Angel Rubio
Strong light-matter interactions can be exploited to modify properties of quantum materials both in and out of thermal equilibrium. Recent studies suggest electromagnetic fields in photonic structures can hybridize with condensed matter systems, resulting in photon field-dressed collective quantum states such as charge density waves, superconductivity, and ferroelectricity. Here, we show that photon fields in photonic structures, including optical cavities and waveguides, induce emergent topological phases in solids through polarization-mediated symmetry-breaking mechanisms. Using state-of-the-art quantum electrodynamic density functional theory (QEDFT) calculations, we demonstrate that strong light-matter coupling can reconfigure both the electronic and ionic structures of HgTe, driving the system into Weyl, nodal-line, or topological insulator phases. These phases depend on the relative orientation of the sample in the photonic structures, as well as the coupling strength. Unlike previously reported laser-driven phenomena with ultrashort lifetimes, the photon field-induced symmetry breaking arises from steady-state photon-matter hybridization, enabling multiple robust topological states to emerge. Our study demonstrates that vacuum fluctuations in photonic structures can be used to engineer material properties and realize rich topological phenomena in quantum materials on demand.
Materials Science (cond-mat.mtrl-sci)
4 figures
Seeding neural network quantum states with tensor network states
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2025-07-01 20:00 EDT
We find an efficient approach to approximately convert matrix product states (MPSs) into restricted Boltzmann machine wave functions consisting of a multinomial hidden unit through a canonical polyadic (CP) decomposition of the MPSs. This method allows us to generate well-behaved initial neural network quantum states for quantum many-body ground-state calculations in polynomial time of the number of variational parameters and systematically shorten the distance between the initial states and the ground states with increasing the rank of the CP decomposition. We demonstrate the efficiency of our method by taking the transverse-field Ising model as an example and discuss possible applications of our method to more general quantum many-body systems in which the ground-state wave functions possess complex nodal structures.
Strongly Correlated Electrons (cond-mat.str-el), Machine Learning (cs.LG), Numerical Analysis (math.NA), Quantum Physics (quant-ph)
13 pages, 13 figures
First-Principles Insights into Excitonic and Electron-Phonon Effects in van der Waals Heterostructures
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-07-01 20:00 EDT
Mohammad Ali Mohebpour, Carmine Autieri, Meysam Bagheri Tagani
Motivated by the successful synthesis of isolated ZrS2 and HfS2 transition metal dichalcogenide (TMD) monolayers and inspired by their nearly identical lattice constants, we construct and investigate a vertical ZrS2/HfS2 van der Waals (vdW) heterostructure. Using first-principles calculations based on density functional theory (DFT) and many-body perturbation theory (MBPT), we explore its electronic, optical, and excitonic properties, with particular emphasis on excitonic effects and their temperature dependence. Based on the GW method, the ZrS2/HfS2 vdW heterostructure exhibits an indirect band gap of 2.60 eV with a Type-I band alignment. The optical gap of the heterostructure is found to be 2.64 eV, with an exciton binding energy of 0.71 eV, both reduced compared to those in the isolated monolayers. Moreover, we investigate the temperature-dependent optoelectronic behavior of the heterostructure, considering electron-phonon coupling. A zero-point renormalization of 0.04 eV in the direct band gap is observed. While the direct band gap decreases monotonically with temperature from 0 K to 400 K, the indirect band gap displays a non-monotonic trend. As a result, the absorption spectrum undergoes a meaningful redshift with increasing temperature. At room temperature, the optical gap of the heterostructure is reduced to 2.51 eV and the exciton binding energy to 0.63 eV. Our findings highlight the important role of electron-phonon interaction in the optoelectronic response of ZrS2/HfS2 vdW heterostructure, supporting its use in high-performance optoelectronic devices.
Materials Science (cond-mat.mtrl-sci), Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
22 pages, 6 figures
Soft Coulomb Gap Limits the Performance of Organic Thermoelectrics
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-07-01 20:00 EDT
Yuqian Liu, Xiaoran Wei, Dorothea Scheunemann, Maojie Zhang, Wanlu Zhang, Martijn Kemerink, Guangzheng Zuo
Although consensus exists that the thermoelectric properties of doped organic semiconductors result from a complex interplay between a large number of mutually dependent factors, there is no consensus on which of these are dominant, or even on how to best describe the charge and energy transport. This holds particularly in the intermediate doping regime where the optimal performance is typically observed at the roll-off in the Seebeck coefficient - conductivity (S-{\sigma} correlation, fundamentally limiting the rational advancement of organic thermoelectric materials. Here, we combine experiments on a board set of conjugated polymers with kinetic Monte Carlo simulations across varying doping levels to uncover a general transport framework. We demonstrate that the optimal thermoelectric power factor (PF_max) consistently occurs at the transition between conventional variable-range hopping (VRH) and VRH in a density of states in which a soft Coulomb gap forms at the Fermi level, as described by Efros and Shklovskii (ES-VRH). This suggests the use of high dielectric constant materials or the promotion of charge delocalization as an avenue to shift the roll-off of the S-{\sigma}} curve, which constrains PF_max, to higher doping levels and accordingly higher PF.
Materials Science (cond-mat.mtrl-sci)
Topological Electronic and phononic chiral edge states in SiTc Crystal
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-07-01 20:00 EDT
Shivendra Kumar Gupta, Saurabh Kumar Sen, Nagarjuna Patra, Ajit Singh Jhala, Poorva Singh
Topological materials hosting multifold fermions and bosons have emerged as a rich platform for exploring unconventional quasiparticles and transport phenomena. In this work, we investigate the chiral crystal SiTc using first-principles density functional theory and symmetry-based analysis to explore its topological electronic and phononic properties. Our study identifies multiple high-fold degeneracies and topological nodes in both the electronic band structure and phonon dispersion. We have analyzed the impact of spin-orbit coupling on the evolution of band crossing and identified Weyl points and their associated chiralities. Surface electronic states, Fermi arcs, Berry curvature distributions, and intrinsic spin Hall conductivity are computed to probe the topological response. On the phononic side, we uncover topologically nontrivial bosonic modes and corresponding longest possible Fermi arc features. These results establish SiTc as a promising candidate that simultaneously hosts topological fermionic and bosonic excitations, offering new opportunities for investigating the interplay between electronic and phononic topology.
Materials Science (cond-mat.mtrl-sci)
8 pages, 7 figures
A Rigorous Foundation for Stochastic Thermodynamics via the Microcanonical Ensemble
New Submission | Statistical Mechanics (cond-mat.stat-mech) | 2025-07-01 20:00 EDT
We consider a small Hamiltonian system strongly interacting with a much larger Hamiltonian system (the bath), while being driven by both a time-dependent control parameter and non-conservative forces. The joint system is assumed to be thermally isolated. Under the assumption of time-scale separation (TSS)–where the bath equilibrates much faster than the system and the external driving–the bath remains in instantaneous equilibrium, described by the microcanonical ensemble conditioned on the system state and the control parameter. We identify a decomposition of the total Hamiltonian that renders the bath energy an adiabatic invariant under slow evolution. This same decomposition defines the system Hamiltonian as the Hamiltonian of mean force, and ensures that neither the system nor the control parameter does reactive work on the bath. Using time-reversal symmetry and TSS, and without invoking any model details, we rigorously prove that the reduced dynamics of the system is Markovian and satisfies a form of local detailed balance (LDB) which involves transition probabilities but not path probabilities. By working entirely within the microcanonical framework and adopting a precise decomposition of the total energy, we provide rigorous definitions of bath entropy as the Boltzmann entropy, and of heat as the negative change of the bath energy. Our approach bypasses the ambiguities associated with conventional definitions of thermodynamic variables and path probabilities, and establishes a rigorous and thermodynamically consistent foundation for stochastic thermodynamics, valid even under strong system-bath coupling.
Statistical Mechanics (cond-mat.stat-mech), Soft Condensed Matter (cond-mat.soft)
Establishment of global phase coherence in a highly disordered fractal MgO/MgB2 nanocomposite: Roles of interface, morphology and defect
New Submission | Superconductivity (cond-mat.supr-con) | 2025-07-01 20:00 EDT
Iku Nakaaki, Aoi Hashimoto, Shun Kondo, Yuichi Ikuhara, Shuuichi Ooi, Minoru Tachiki, Shunichi Arisawa, Akiko Nakamura, Taku Moronaga, Jun Chen, Hiroyo Segawa, Takahiro Sakurai, Hitoshi Ohta, Takashi Uchino
Recently, we have reported that a highly disordered fractal MgO/MgB2 nanocomposite exhibits bulk-like superconducting properties with isotropic pinning, showing an excellent phase-coherent capability irrespective of the low volume fraction (~30 vol. %) of MgB2 [Uchino et al., Phys. Rev. B 101, 035146 (2020); Teramachi et al,, Phys. Rev. B 108, 155146 (2023)]. Hence, this nanocomposite provides a useful experimental system to investigate the relationship between the structural disorder and the establishment of the superconducting phase coherence. In this work, we show from 3D focused ion beam scanning electron microscopy (FIB-SEM) data that in the nanocomposite, a complex MgO/MgB2 microstructure spreads isotropically throughout the sample with a constant fractal dimension of ~1.67. Atomic-resolution scanning transmission electron microscopy (STEM) has revealed that the MgO/MgB2 interfaces are atomically clean and free from amorphous grain boundaries, even leading to atomically coherent interfaces. Detailed ac susceptibility measurements have demonstrated a smooth crossover from an intragranular to an intergranular superconducting regime, giving evidence of the establishment of the critical state due to strong intergranular coupling just below the superconducting transition temperature. Also, spatially-resolved cathodoluminescence measurements have demonstrated that oxygen vacancies in the MgO-rich phase tend to aggregate near the MgO/MgB2 boundary regions, forming long channels of oxygen vacancies through the nanocomposite. These channels of oxygen vacancies will contribute to the long-range carrier transfer and the related Andreev reflection via coherent tunneling of charge carriers among the oxygen vacancy sites.
Superconductivity (cond-mat.supr-con), Disordered Systems and Neural Networks (cond-mat.dis-nn)
16 pages, 17 figures
Kerr microscopy study of magnetic domains and their dynamics in bulk Ni-Mn-Ga austenite
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-07-01 20:00 EDT
A. Perevertov, I. Soldatov, R. Schaefer, R.H. Colman, O. Heczko
The observation of magnetic domains on austenite Ni-Mn-Ga bulk samples has been a big challenge for many years. Using advanced Kerr microscopy, with automatic compensation of the sample motion and monochromatic LED light we were able to observe magnetic domains and follow their evolution with magnetic field on the 100 faces of an austenite bulk single crystal. After mechanical polishing variable fine stress-induced domains patterns were observed at different locations. The surface coercivity visualized by the Kerr loop was two orders higher than the bulk coercivity from magnetometry measurement. After additional electropolishing, wide 180 domains were observed with a width of about 50 micrometers and the Kerr loop coercivity decreased to the level determined from the magnetometry. Surprisingly, the magnetic domains were observed only along one of two 100 cubic axes lying in the surface plane.
Materials Science (cond-mat.mtrl-sci)
Submitted to Applied Physics Letters. 4 pages. 5 figures
Controlling the quantum phase transition in a double quantum dot Josephson junction via interactions
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2025-07-01 20:00 EDT
Cong Li, Yiyan Wang, Bing Dong
In this work, we employ a surrogate BCS model with discrete energy levels to investigate a hybrid system comprising two quantum dots (QD1 and QD2), where QD1 is tunnel-coupled to two superconducting leads. Through exact diagonalization of this system, we obtain numerically exact solutions that enable rigorous computation of key physical quantities. Our analysis reveals a rich phase diagram featuring multiple controllable phase transitions mediated by quantum dot interactions. Specifically, the system first undergoes an initial phase transition when tuning QD2’s interaction strength while maintaining QD1 in the non-interacting regime. Subsequent adjustment of QD1’s interaction induces a secondary phase transition, followed by a third transition arising from inter-dot coupling modulation. Furthermore, we demonstrate that parallel magnetic field application can drive reversible ferromagnetic-antiferromagnetic phase transitions under specific parameter conditions. Finally, we report the emergence of non-local magnetization phenomena when subjecting QD1 to weak magnetic fields. And our results demonstrate that the orientation of nonlocal magnetization can be precisely manipulated through systematic adjustment of the on-site interaction strength $ U_2$ in QD2.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Strongly Correlated Electrons (cond-mat.str-el)
12 pages, 9 figures
Precise quantum-geometric electronic properties from first principles
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-07-01 20:00 EDT
José Luís Martins, Carlos Loia Reis, Ivo Souza
The calculation of quantum-geometric properties of Bloch electrons – Berry curvature, quantum metric, orbital magnetic moment and effective mass – was implemented in a pseudopotential plane-wave code. The starting point was the first derivative of the periodic part of the wavefunction psi_k with respect to the wavevector k. This was evaluated with perturbation theory by solving a Sternheimer equation, with special care taken to deal with degenerate levels. Comparison of effective masses obtained from perturbation theory for silicon and gallium arsenide with carefully-converged numerical second derivatives of band energies confirms the high precision of the method. Calculations of quantum-geometric quantities for gapped graphene were performed by adding a bespoke symmetry-breaking potential to first-principles graphene. As the two bands near the opened gap are reasonably isolated, the results could be compared with those obtained from an analytical two-band model, allowing to assess the strengths and limitations of such widely-used models. The final application was trigonal tellurium, where quantum-geometric quantities flip sign with chirality.
Materials Science (cond-mat.mtrl-sci)
30 pages, 10 figures, 3 tables
High-mobility heavy quasiparticles in a van der Waals antiferromagnetic dense Kondo lattice CeTe$_3$
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2025-07-01 20:00 EDT
Hai Zeng, Yang Zhang, Bingke Ji, Jiaqiang Cai, Shuo Zou, Zhuo Wang, Chao Dong, Kangjian Luo, Yang Yuan, Kai Wang, Jinglei Zhang, Chuanyin Xi, Junfeng Wang, Yaomin Dai, Jing Li, Yongkang Luo
Two-dimensional van der Waals (vdW) materials exhibit high carrier mobility and tunability, making them suitable for low-power, high-performance electronic and spintronic applications. Incorporating narrow-band electronic correlation effects could further promote tunability, though mass renormalization may impact carrier mobility. It is therefore challenging to identify a vdW material with both high mobility and strong correlation. Herein, by a combination of optical spectroscopy and high-field quantum-oscillation measurements, we observe significant effective-mass enhancement in CeTe$ _3$ at low temperature, arising from not only the band-structure modulation by antiferromagnetic ordering but also the narrow-band correlation effect. Despite the mass enhancement, the quantum mobility surprisingly \textit{increases} and reaches $ \sim$ 2403 cm$ ^2$ /Vs, likely benefiting from topological protection. Remarkably, these unique properties are maintained in atomically thin nanoflakes with quantum mobility enhanced to $ \sim$ 3158 cm$ ^2$ /Vs. Thus, CeTe$ _3$ emerges as a promising vdW antiferromagnetic metal with high-mobility heavy quasiparticles, potentially unlocking new device concepts.
Strongly Correlated Electrons (cond-mat.str-el), Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Materials Science (cond-mat.mtrl-sci), Superconductivity (cond-mat.supr-con), Quantum Physics (quant-ph)
21+6 pages, 4+6 figures, 1 table
Reexamination of the charge-ordered dimer pattern in the spinel compound CuIr2S4 using single-crystal synchrotron x-ray diffraction
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2025-07-01 20:00 EDT
T. Ohashi, N. Katayama, K. Kojima, M. Emi, C. Koyama, T. Hara, K. Hashimoto, S. Kitani, H. Kawaji, H. S. Suzuki, S. Nagata, K. Sugimoto, K. Iida, H. Sawa
We have re-investigated the crystal structure of a spinel type CuIr2S4 at low temperatures using a single-crystal in a synchrotron radiation x-ray diffraction experiment. The crystal structure of the low-temperature phase of CuIr2S4 has been already studied by diffraction experiments using a powder sample, and it has been reported that the formation of dimer molecules accompanied by charge ordering of Ir has been achieved. The crystal structure of the low-temperature phase obtained in our reanalysis was the same as the previously reported structure in that it showed the formation of Ir dimers accompanied by charge ordering, but the charge ordering pattern and arrangement of the dimers in the unit cell were different. We will discuss the validity of the structure obtained in this study and provide the structural parameters revealed in the reanalysis. The results of this study should provide a basis for further studies of the physical properties of CuIr2S4, which are still being actively investigated.
Strongly Correlated Electrons (cond-mat.str-el)
13 pages, 4 figures, 7 tables
Physical Review B 111, 224114 (2025)
Dynamic modes of active Potts models with factorizable numbers of states
New Submission | Statistical Mechanics (cond-mat.stat-mech) | 2025-07-01 20:00 EDT
We studied the long-term nonequilibrium dynamics of q-state Potts models with q = 4, 5, 6, and 8 using Monte Carlo simulations on a two-dimensional square lattice. When the contact energies between the nearest neighbors for the standard Potts models are used, cyclic changes in the q homogeneous phases and q-state coexisting wave mode appear at low and high flipping energies, respectively, for all values of q. However, for a factorizable q value, dynamic modes with skipping states emerge, depending on the contact energies. For q = 6, a spiral wave mode with three domain types (one state dominant or two states mixed) and cyclic changes in three homogeneous phases are found. Although three states can coexist spatially under thermal equilibrium, the scaling exponents of the transitions to the wave modes are modified from the equilibrium values.
Statistical Mechanics (cond-mat.stat-mech), Pattern Formation and Solitons (nlin.PS)
14 pages, 21 figures
Development and validation of an electron temperature-dependent interaction potential for silicon and copper for the use in atomistic simulations of laser ablation
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-07-01 20:00 EDT
Laser pulses with a duration of the order of femtoseconds lead to a strong excitation, heating and potentially to ablation of the irradiated material. During the time of strong excitation, the interaction of the atoms and thus the material dynamics can be strongly altered. To take this effect into account, an ip was developed for copper that takes the excitation of the electrons into account up to an electron temperature of 1.2 eV. Furthermore, several ways to identify non-thermal effects in Density Functional Theory calculations and how to incorporate and validate them in molecular dynamics simulations are presented. Explicitly, the free energy curves, elastic constants and phonon spectra are compared. Additionally, it is shown that the change of the melting temperature with the degree of excitation is consistent with all of these properties. Moreover, the behaviour of copper upon excitation is compared to silicon by using a similar potential that was previously developed by a different author.
Materials Science (cond-mat.mtrl-sci)
Photonic obstructed atomic insulator
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-07-01 20:00 EDT
Topological quantum chemistry (TQC) classifies the topological phases by real-space invariant in which obstructed atomic insulators belong to the trivial case but sometimes show the feature of higher-order topological insulator. Here, for a two-dimensional magnetic photonic obstructed atomic insulator, we show that the emergence of corner states is associate with the Wyckoff positions. In such a square lattice with four +M elements and four -M elements, corner states appears when the superlattice exposes 2b Wyckoff positions. And the corner states will decrease when the number of exposed 2b Wyckoff positions decreases and disappear when 2b Wyckoff positions no longer stand at the edge. By arranging all magnetic rod into one magnetization direction, we find that time-reversal symmetry is not important for corner states. Our finding indicates that the real-space distribution of atoms determines the feature of higher-order topological insulators for obstructed atomic insulator in TQC.
Materials Science (cond-mat.mtrl-sci)
Reviewing Current-Driven Dynamics and Monte Carlo based Analysis of Thermodynamic Properties of a Magnetic Skyrmion Crystal
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2025-07-01 20:00 EDT
Magnetic skyrmions with its topologically protected, nano-sized spin textures have already earned immense fame as information carriers due to their stability and low-current mobility. While ferromagnetic skyrmions suffer from a transverse deflection (i.e., the skyrmion Hall effect), their anti-ferromagnetic counterparts promise straight-line motion and ultrafast dynamics. Here we present a numerical study of the dynamics of lattice-based antiferromagnetic skyrmions driven by spin-transfer torque for which the Landau-Lifshitz-Gilbert-Slonczewski (LLGS) equation is solved using a fourth-order Range-Kutta integration. Then we conduct a detailed Monte Carlo study of the two-dimensional classical XY model to quantify how spatial anisotropy and Dzyaloshinskii-Moriya (DM) coupling reshape its thermal response across multiple lattice sizes. By tuning the ratio Jy/Jx, we document a systematic evolution of the specific-heat anomaly. For example, in the quasi-one-dimensional limit, CV exhibits a broad, low-temperature hump, whereas stronger anisotropy yields sharper peaks that migrate to higher inverse temperature. Finite-size scaling confirms the crossover from quasi-1D fluctuations to a two-dimensional Kosterlitz-Thouless transition. Incorporating a DM interaction further enriches this landscape. At D/J = 0.1, the main peak shifts modestly upward and is slightly suppressed; raising D/J elevates the peak magnitudes and creates a pronounced low-temperature plateau. This residual CV signals enduring chiral excitations and complex spin-twist textures beyond simple vortex unbinding. Our findings chart how directional and chiral couplings can be harnessed to tune pseudo-critical temperatures and thermodynamic signatures in two-dimensional magnets, providing a practical blueprint for engineering topological spin systems.
Strongly Correlated Electrons (cond-mat.str-el)
Preliminary review
Two-Dimensional Materials-Based Josephson Junctions
New Submission | Superconductivity (cond-mat.supr-con) | 2025-07-01 20:00 EDT
We consider a two-dimensional monolayer MoS2-based Josephson junction which is composed by an intermediate semiconductor flake and the semi-infinite topological and non-topological superconductor leads and study its quantum transport properties by using the tight-binding non-equilibrium Green function method. By introducing a simple tight-binding model, it is shown that, when the absolute value of chemical potential is much smaller than the superconductor paring potential, the Majorana zero modes, whose Chern number is two, are formed in the topological leads. Also, we show that, in Josephson junction with ordinary superconductor leads, the Josephson current has sinusoidal behavior (due to forming the Andreev bound states (ABS)), when the absolute value of energy of carriers (and the chemical potential) is much smaller (greater) than the superconductor pairing potential. Of course, for Josephson junction with topological superconductor leads, it is shown that the ABS are not formed and in consequence the related Josephson current is zero. Therefore, one can consider the two-dimensional monolayer MoS2-based Josephson junction as a two-state switch which is in open-state (due to ABS) when the chemical potential is greater than 0.8 eV and is in close-state (due to Majorana) when the chemical potential is less than < 0.8 or is equal to zero, i.e., ABS cannot mimic the Majorana state, as zero-bias conductance.
Superconductivity (cond-mat.supr-con)
EuPdSn2; magnetic structures in view of resonant x-ray Bragg diffraction
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2025-07-01 20:00 EDT
The magnetic properties of materials hosting Eu2+(J = 7/2, 4f7) ions have attracted much attention in the science of strongly correlated electrons. In part because crystal electric field effects are impoverished for an s-state ion, as with Gd3+ intermetallics, and Eu2+ substitution in biological and optically active materials is resourceful. The magnetic structure of EuPdSn2 is not wholly resolved. Ferromagnetic and antiferromagnetic structures coexist in powder neutron diffraction patterns, and compete in the ground state. Moreover, the specific heat as a function of temperature is enigmatic and indicative of J = 5/2. We present symmetry-informed analytic magnetic structure factors for single crystal resonant x-ray Bragg diffraction using Eu atomic resonances that reveal significant potential for the technique. Europium ions use acentric Wyckoff positions in magnetic space groups inferred from neutron diffraction. In consequence, axial and polar Eu multipoles are compulsory components of both magnetic neutron and resonant x-ray Bragg diffraction patterns. The proposed antiferromagnetic phase of EuPdSn2 supports anapoles (magnetic polar dipoles) already observed in magnetic neutron diffraction patterns presented by Gd doped SmAl2, and several resonant x-ray diffraction patterns.
Strongly Correlated Electrons (cond-mat.str-el)
The Effects of Cobalt Doping on the Skyrmion Hosting Material Cu$_2$OSeO$_3$
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-07-01 20:00 EDT
M. Vás, A. J. Ferguson, H. E. Maynard-Casely, C. Ulrich, E. P. Gilbert, S. Yick, T. Söhnel
Cu$ _2$ OSeO$ _3$ has fascinating magnetic phases that can be easily manipulated through chemical doping. In this work, we report on the synthesis and characterization of Co-doped Cu$ _2$ OSeO$ _3$ and its influence on both the atomic and magnetic structure. Polycrystalline (Cu$ {1-x}$ Co$ _x$ )$ _2$ OSeO$ _3$ samples with 0 < x < 0.1 were synthesized and the presence of Co was confirmed via elemental analysis. Using synchrotron powder X-ray diffraction, and high-resolution neutron powder diffraction, the incorporation of Co$ ^{2+}$ into the Cu2 sites was confirmed. Co-doping led to an expansion to the unit cell but shows no apparent changes in bond lengths and angles in the crystal structure. Magnetization measurements showed that the incorporation of Co$ ^{2+}$ into the Cu2 site led to significant changes to the magnetic ordering of the material. Including an increase to the critical fields, the lowering of the critical temperature of the helimagnetic phase, and both a lowering and expansion of the skyrmion pocket temperatures. Lastly, small-angle neutron scattering was used to probe the magnetic structures hosted by the material. It was found that upon doping, the skyrmion lattice nucleates at lower temperatures as well as stabilized over a large temperature range. The observed results highlight the effects of incorporating a magnetic ion into the crystal structure and how it affects the internal magnetic structures.
Materials Science (cond-mat.mtrl-sci), Strongly Correlated Electrons (cond-mat.str-el)
The main text consists of 23 pages, 7 figures and 1 table while the supplementary information file consists of 19 pages, 11 figures and 7 tables
First observation of quantum oscillations by transport measurements in semi-destructive pulsed magnetic fields up to 125 T
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2025-07-01 20:00 EDT
M. Massoudzadegan, S. Badoux, N. Bruyant, I. Gilmutdinov, I. Haik-Dunn, G. de Oliveira Rodrigues, N. Lourenco Prata, A. Zitouni, M. Nardone, O. Drashenko, O. Portugall, S. Wiedmann, B. Fauqué, D. Vignolles, B. Reulet, C. Proust
High magnetic fields have proven instrumental in exploring the physical properties of condensed matter, leading to groundbreaking discoveries such as the quantum Hall effect in 2D heterostructures and quantum oscillations in cuprate superconductors. The ability to conduct precise measurements at progressively higher magnetic fields continues to push the frontiers of knowledge and enable new discoveries. In this work, we present the development of a microwave technique for performing two-point transport measurements in semi-destructive pulsed magnetic fields (up to 125 T) and at low temperatures (down to 1.5 K) with unprecedented sensitivity. This new setup was tested on a variety of samples. We present results on the metal-insulator transition in InAs and we report notably the first observation of Shubnikov-de-Haas oscillations in WTe$ _{2}$ at magnetic fields beyond 100 T.
Strongly Correlated Electrons (cond-mat.str-el), Instrumentation and Detectors (physics.ins-det)
6 pages, 4 figures
Quantum polaritons go hyperbolic
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2025-07-01 20:00 EDT
Kateryna Domina, Tetiana Slipchenko, D.-H.-Minh Nguyen, Alexey B. Kuzmenko, Luis Martin-Moreno, Dario Bercioux, Alexey Y. Nikitin
Magnetized charge-neutral graphene supports collective hybrid electronic excitations - polaritons - which have quantum origin. In contrast to polaritons in doped graphene, which arise from intraband electronic transitions, those in charge-neutral graphene originate from interband transitions between Landau levels, enabled by the applied magnetic field. Control of such quantum polaritons and shaping their wavefronts remains totally unexplored. Here we design an artificial two-dimensional quantum material formed by charge-neutral graphene nanoribbons exposed to an external magnetic field. In such metasurface, quantum polaritons acquire a hyperbolic dispersion. We find that the topology of the isofrequency curves of quantum hyperbolic magnetoexciton polaritons excited in this quantum material can change, so that the shape of isofrequency curves transforms from a closed to open one by tuning the external magnetic field strength. At the topological transition, we observe canalization phenomena, consisting of the propagation of all the polaritonic plane waves in the continuum along the same direction when excited by a point source. From a general perspective, our fundamental findings introduce a novel type of actively-tunable quantum polaritons with hyperbolic dispersion and can be further generalized to other types of quantum materials and polaritons in them. In practice, quantum hyperbolic polaritons can be used for applications related to quantum sensing and computing.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Materials Science (cond-mat.mtrl-sci)
20 Pages with 3 figures
Superconducting Ring Resonators: Modelling, Simulation, and Experimental Characterisation
New Submission | Superconductivity (cond-mat.supr-con) | 2025-07-01 20:00 EDT
Zhenyuan Sun, Stafford Withington, Christopher Thomas, Songyuan Zhao
We present a theoretical and experimental study of superconducting ring resonators as an initial step towards their application to superconducting electronics and quantum technologies. These devices have the potentially valuable property of supporting two orthogonal electromagnetic modes that couple to a common Cooper pair, quasiparticle, and phonon system. We present here a comprehensive theoretical and experimental analysis of the superconducting ring resonator system. We have developed superconducting ring resonator models that describe the key features of microwave behaviour to first order, providing insights into how transmission line inhomogeneities give rise to frequency splitting and mode rotation. Furthermore, we constructed signal flow graphs for a four-port ring resonator to numerically validate the behaviour predicted by our theoretical analysis. Superconducting ring resonators were fabricated in both coplanar waveguide and microstrip geometries using Al and Nb thin films. Microwave characterisation of these devices demonstrates close agreement with theoretical predictions. Our study reveals that frequency splitting and mode rotation are prevalent in ring systems with coupled degenerate modes, and these phenomena become distinctly resolved in high quality factor superconducting ring resonators.
Superconductivity (cond-mat.supr-con), Instrumentation and Methods for Astrophysics (astro-ph.IM)
Probing and tuning geometric frustration in an organic quantum magnet via elastocaloric measurements under strain
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2025-07-01 20:00 EDT
Francisco Lieberich, Yohei Saito, Yassine Agarmani, Takahiko Sasaki, Naoki Yoneyama, Stephen M. Winter, Michael Lang, Elena Gati
Geometric frustration is a key ingredient in the emergence of exotic states of matter, such as the quantum spin liquid in Mott insulators. While there has been intense interest in experimentally tuning frustration in candidate materials, achieving precise and continuous control has remained a major hurdle – particularly in accessing the properties of the ideally frustrated lattice. Here, we show that large, finely controlled anisotropic strains can effectively tune the degree of geometric frustration in the Mott insulating $ \kappa$ -(ET)$ _2$ Cu$ _2$ (CN)$ _3$ – a slightly anisotropic triangular-lattice quantum magnet. Using thermodynamic measurements of the elastocaloric effect, we experimentally map out a temperature-strain phase diagram that captures both the ground state of the isotropic lattice and the less frustrated parent state. Our results provide a new benchmark for calculations of the triangular-lattice Hubbard model as a function of frustration and highlight the power of lattice engineering as a route to realizing perfectly frustrated quantum materials.
Strongly Correlated Electrons (cond-mat.str-el)
main text (3 figures) + supplementary materials
Supersolid Phases in Ultracold Gases of Microwave Shielded Polar Molecules
New Submission | Quantum Gases (cond-mat.quant-gas) | 2025-07-01 20:00 EDT
Wei Zhang, Hongye Liu, Fulin Deng, Kun Chen, Su Yi, Tao Shi
We propose a novel scheme to realize the supersolid phase in ultracold gases of microwave-shielded polar molecules by engineering an additional anisotropy in inter-molecular dipolar interaction via an elliptically polarized microwave. It is shown through quantum Monte-Carlo calculations that the interplay of the anisotropies between the interaction and trapping potential gives rise to rich quantum phases. Particularly, it is found that the supersolid phase emerges in the parameter regime accessible to current experiments. Our study paves the way for exploring the properties of supersolid phases in ultracold gases of polar molecules.
Quantum Gases (cond-mat.quant-gas)
Pressure and doping effects on the electronic structure and magnetism of the single-layer nickelate La$_2$NiO$_4$
New Submission | Superconductivity (cond-mat.supr-con) | 2025-07-01 20:00 EDT
J. B. de Vaulx, F. Bernardini, V. Olevano, Q. N. Meier, A. Cano
La$ _2$ NiO$ _4$ is a prototypical member of the Ruddlesden-Popper nickelate series that offers a valuable reference point for elucidating the key ingredients behind the intriguing properties of these systems. However, the structural and electronic properties of La$ _2$ NiO$ _4$ under pressure and doping remain surprisingly underexplored. Here, we investigate these properties using density-functional-theory calculations. We find that its tetragonal $ I4/mmm$ structure can be stabilized, not only under comparatively low pressures of $ \sim$ 8 GPa, but also at ambient pressure via the partial substitution of La with Ba. Moreover, we show that the combined effects of Ba substitution and pressure leads to qualitative changes in the electronic structure towards the formal $ d^{7.5}$ configuration of the superconducting bilayer nickelates. Further, while La$ _2$ NiO$ _4$ can undergo a insulator-metal transition with pressure retaining G-type antiferromagnetic order, La$ _{1.5}$ Ba$ _{0.5}$ NiO$ _4$ exhibits metallic behavior with an enhanced competition between different magnetic states. Our results thus offer new insights into the interplay of structure, doping, and magnetism across the Ruddlesden-Popper nickelate series.
Superconductivity (cond-mat.supr-con), Materials Science (cond-mat.mtrl-sci), Strongly Correlated Electrons (cond-mat.str-el)
8 pages, 9 figures
Anomalous Scaling Laws of Dispersion Interactions in Anisotropic Nanostructures
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2025-07-01 20:00 EDT
Hui Pan, Yuhua Ren, Jian-Sheng Wang
The van der Waals (vdW) dispersion interaction between two finite neutral objects typically follows the standard nonretarded $ d^{-6}$ law. Here, we reveal an anomalous $ d^{-10}$ scaling law between nanostructures with strong geometric or electric anisotropy, driven intrinsically by symmetry-restricted plasmon interactions. At finite anisotropy ratios, a scaling crossover from $ d^{-10}$ to $ d^{-6}$ occurs due to plasmon mode competition, marked by a finite critical separation. Furthermore, we demonstrate tunability of interlayer vdW forces in two-dimensional materials with strong in-plane electronic anisotropy. By pushing the conventional lower bound of vdW scaling laws, these findings open new opportunities for tailoring nanoscale forces, with potential applications in low-stiction nanomechanical devices, vdW superstructure assembly, metamaterials, and molecular simulations.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Materials Science (cond-mat.mtrl-sci)
7 pages, 4 figures
Decoding Noise in Nanofluidic Systems: Adsorption versus Diffusion Signatures in Power Spectra
New Submission | Soft Condensed Matter (cond-mat.soft) | 2025-07-01 20:00 EDT
Anna Drummond Young, Alice L. Thorneywork, Sophie Marbach
Adsorption processes play a fundamental role in molecular transport through nanofluidic systems, but their signatures in measured signals are often hard to distinguish from other processes like diffusion. In this paper, we derive an expression for the power spectral density (PSD) of particle number fluctuations in a channel, accounting for diffusion and adsorption/desorption to a wall. Our model, validated by Brownian dynamics simulations, is set in a minimal yet adaptable geometry, allowing us to eliminate the effects of specific geometries. We identify distinct signatures in the PSD as a function of frequency $ f$ , including $ 1/f^{3/2}$ and $ 1/f^{1/2}$ scalings related to diffusive entrance and re-entrance effects, and a $ 1/f^2$ scaling associated with adsorption. These scalings appear in key predicted quantities – the total number of particles in the channel and the number of adsorbed or unadsorbed particles – and can dominate or combine in non-trivial ways depending on parameter values. Notably, when there is a separation of timescales between diffusion within the channel and adsorption/desorption times, the PSD can exhibit two distinct slopes in some of the predicted quantities. We provide a phase diagram to classify experimental systems based on predicted PSD shapes. These PSDs reflect measured properties in physical systems on the nano- and micro-scale, such as ion channels, nanopores, and electrochemical sensors, potentially offering insights into noisy experimental data.
Soft Condensed Matter (cond-mat.soft), Statistical Mechanics (cond-mat.stat-mech)
The following article has been submitted to the Journal of Chemical Physics
Superconducting gap and its Little-Parks like oscillations with high-order harmonics in lithium intercalated 1T-TiSe$_2$
New Submission | Superconductivity (cond-mat.supr-con) | 2025-07-01 20:00 EDT
Jia-Yi Ji, Zongzheng Cao, Yi Hu, Haoyang Wu, Heng Wang, Yuying Zhu, Haiwen Liu, Lexian Yang, Qi-Kun Xue, Ding Zhang
The superconducting phase of doped 1T-TiSe$ _2$ is a fruitful playground for exploring exotic quantum phenomena such as the anomalous metal state and spontaneously formed superconducting network. Here, we address these emergent states by studying the superconducting gap of lithium intercalated TiSe$ _2$ -a fundamental quantity that has remained unexplored so far. We fabricate a device that combines solid-state lateral lithium intercalation, resistance measurements and tunneling spectroscopy. We successfully probe the superconducting gap of TiSe$ _2$ and reveal that the gap closing temperature well exceeds the transition temperature ($ T_c$ ) expected from the Bardeen-Cooper-Schrieffer theory, indicating pronounced superconducting fluctuations even in a bulk-like system. Moreover, the symmetric gap persists even in the anomalous metal state, demonstrating the particle-hole symmetry of this exotic phase directly from the density of states. Finally, the superconducting gap shows magneto-oscillations with higher harmonics, attesting to a rather regular structure of the intrinsic superconducting network.
Superconductivity (cond-mat.supr-con)
25 pages,5 figures
Nano Letters 2025
Density functional theory study of effect of NO annealing on electronic structures and carrier scattering properties of 4H-SiC(0001)/SiO$_2$ interface
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-07-01 20:00 EDT
Nahoto Funaki, Kosei Sugiyama, Mitsuharu Uemoto, Tomoya Ono
The effect of the nitrided layer introduced by NO annealing on the electronic structure and carrier scattering property of the 4H-SiC(0001)/SiO$ _2$ interface is investigated by the density functional theory calculation using the interface models where the areal N atom density corresponds to that in practical devices. The areal N atom density is one third of the areal C atom density in practical devices. It is found that the nitrided layer screens the unfavorable Coulomb interaction of O atoms in the SiO$ _2$ . However, the electrons flowing under the nitrided layer are significantly scattered by the fluctuation of potential due to the low areal N atom density. These results imply that the areal N atom density should be increased so that the fluctuation of potential is suppressed.
Materials Science (cond-mat.mtrl-sci)
11 pages, 5 figures
Thermodynamics of Hard Sphere and Spherocylinder Mixtures – Scaled Particle Theory and Monte Carlo Simulations
New Submission | Soft Condensed Matter (cond-mat.soft) | 2025-07-01 20:00 EDT
Volodymyr Shmotolokha (1), Jonas Maier-Borst (2), Mark Vis (1), Anja Kuhnhold (2), Remco Tuinier (1) ((1) Eindhoven University of Technology, Eindhoven, Netherlands, (2) University of Freiburg, Freiburg, Germany)
We review the literature on scaled particle theory (SPT) and its extensions and discuss results applied to describe the thermodynamics of hard particle mixtures. After explaining the basic concepts of scaled particle theory to compute the free energy of immersing a particle into a mixture, examples are discussed for the simple case of a hard sphere dispersion and the free volume fraction of ghost spheres in a hard sphere dispersion. Next, the concept is applied to mixtures, and general expressions are shown that relate the free volume fraction in mixtures to the key thermodynamic properties, such as the chemical potential(s) and (osmotic) pressure. Subsequently, it is revealed how these concepts can be extended towards multi-component systems. It is shown that free volume fractions provide chemical potentials and total pressure of multi-component mixtures, and thereby yield the full equation of state. We present novel results for ternary particle dispersions composed of hard spherocylinders and two types of hard spheres differing in size. Throughout, we show the accuracy of SPT by comparing the results with those of Monte Carlo computer simulations.
Soft Condensed Matter (cond-mat.soft)
35 pages, 14 figures
Diffusion and heat dissipation in marginally stable linear time-delayed Langevin systems
New Submission | Statistical Mechanics (cond-mat.stat-mech) | 2025-07-01 20:00 EDT
We investigate the dynamics and heat dissipation in marginally stable linear time-delayed Langevin systems. We analytically characterize two distinct critical classes: (i) diffusive criticality, where the variance grows linearly with suppressed/enhanced diffusion due to time-delayed forces, and (ii) oscillatory criticality, exhibiting oscillations with diffusing amplitude. Crucially, we derive asymptotic heat dissipation rates, revealing fundamentally different thermodynamic signatures: a constant dissipation rate for diffusive criticality and linear divergence accompanied by oscillations for oscillatory criticality. These results highlight how spectral properties of dynamics govern nonequilibrium thermodynamics in time-delayed systems. Our work bridges dynamics and stochastic thermodynamics at stability boundaries for linear systems, providing foundational insights for extending thermodynamic frameworks to nonlinear time-delayed stochastic systems.
Statistical Mechanics (cond-mat.stat-mech)
8 pages, 4 figures
Topological two-body interaction obstructing trivial ground states: an indicator of fractional Chern insulators
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2025-07-01 20:00 EDT
Nobuyuki Okuma, Tomonari Mizoguchi
The search for candidate materials for fractional Chern insulators (FCIs) has mainly focused on the topological and geometrical structures of single-particle Chern bands. However, there are inherent limitations in approaches that neglect interaction effects, highlighting the need for complementary methods. In this work, we discuss how the Chern number defined for the effective interaction projected onto a Chern band is related to the stabilization of FCIs. Specifically, by formulating both the effective interaction and the two-particle problem using a common matrix, we establish a connection between the two-particle band structure and the effective interaction. This formulation allows us to characterize the effective interaction through the topology of the two-particle band. To investigate the relationship between topological effective interactions and FCIs, we perform numerical calculations primarily based on exact diagonalization. We find a notable correlation between the fact that the dominant two-particle bands carry a unit Chern number and the realization of a robust FCI at the filling fraction $ \nu = 1/3$ . This result is consistent with the presumed correspondence between pseudopotentials in the fractional quantum Hall effect and the two-particle band structure. From another perspective, our findings suggest that the topology inherent in the interaction itself can obstruct trivial ground states. We also discuss this in the context of scattering channels. Extending such topological two-body interactions could pave the way for realizing exotic states beyond FCIs.
Strongly Correlated Electrons (cond-mat.str-el), Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Materials Science (cond-mat.mtrl-sci), Superconductivity (cond-mat.supr-con), Quantum Physics (quant-ph)
14pages, 4 figures
High-Performance Ultra-Wide-Bandgap CaSnO3 Metal-Oxide-Semiconductor Field-Effect Transistors
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-07-01 20:00 EDT
Weideng Sun, Junghyun Koo, Donghwan Kim, Hongseung Lee, Rishi Raj, Chengyu Zhu, Kiyoung Lee, Andre Mkhoyan, Hagyoul Bae, Bharat Jalan, Gang Qiu
The increasing demand for high-voltage and high-power electronic applications has intensified the search for novel ultrawide bandgap (UWB) semiconductors. Alkaline earth stannates possess wide band gaps and exhibit the highest room-temperature electron mobilities among all perovskite oxides. Among this family, Calcium stannate (CaSnO3) has the largest band gap of ~4.7 eV, holding great promise for high-power applications. However, the demonstration of CaSnO3 power electronic devices is so far limited. In this work, high-performance metal-oxide-semiconductor field-effect transistor (MOSFET) devices based on La-doped CaSnO3 are demonstrated for the first time. The MOSFETs exhibit an on/off ratio exceeding 10^8, along with field-effect mobility of 8.4 cm2 V-1 s-1 and on-state current of 30 mA mm-1. The high performance of the CaSnO3 MOSFET devices can be ascribed to the excellent metal-to-semiconductor contact resistance of 0.73 k{\Omega}{\mu}m. The devices also show great potential for harsh environment operations, as high-temperature operations up to 400 K have been demonstrated. An off-state breakdown voltage of 1660 V is achieved, with a breakdown field of ~8.3 MV cm-1 among the highest reported for all UWB semiconductors. This work represents significant progress toward realizing the practical application of CaSnO3 in future high-voltage power electronic technologies.
Materials Science (cond-mat.mtrl-sci), Applied Physics (physics.app-ph)
Enhancement of hydrogen absorption and hypervalent metal hydride formation in lanthanum using cryogenic ball milling
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-07-01 20:00 EDT
Sakun Duwal, Vitalie Stavila, Catalin Spataru, Mohana Shivanna, Portia Allen, Timothy Elmslie, Christopher T. Seagle, Jason Jeffries, Nenad Velisavljevic, Jesse Smith, Paul Chow, Yuming Xiao, Maddury Somayazulu, Peter A. Sharma
Rare earth superhydrides exhibit high temperature superconductivity but are difficult to characterize and use in applications due to their high formation and stability pressures, which are typically in excess of 100 GPa. We studied how modification of the rare earth precursor improves hydrogen reactivity and hydrogen uptake for forming such metal hydrides at lower pressures. An elemental lanthanum precursor was milled at liquid nitrogen temperatures for different time intervals. After exposure to gaseous hydrogen at 380 C and 100 bar, we found a systematic enhancement of hydrogen absorption with increasing ball milling time for forming the LaHx, x=2-3 phase. Exposing the precursor to pressures up to 60 GPa with an ammonia borane (BNH6) hydrogen source resulted in a hypervalent LaH4 phase. This LaH4 phase is associated with the suppression of a rhombohedral distortion of the Fm3-m cubic structure after cryomilling the precursor.
Materials Science (cond-mat.mtrl-sci), Superconductivity (cond-mat.supr-con)
Half-metallicity and anomalous Slater-Pauling behaviour in half-Heusler CrMnSb
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-07-01 20:00 EDT
Himanshu Joshi, Shradhanjali Dewan, Lalrin Kima, Aldrin Lalremtluanga, Homnath Luitel, K. C. Bhamu, D.P. Rai
This study provides a first-principles insight into half-Heusler CrMnSb to understand its deviation from the conventional Slater-Pauling semiconducting behavior. CrMnSb, having a valence electron count of 18, has been proposed to exhibit compensated ferrimagnetic character instead of the expected nonmagnetic semiconducting ground state. As half-Heusler systems with a valence electron count of 18 are not known to exhibit magnetic ordering, we have investigated the electronic and magnetic properties of CrMnSb using a combination of density functional theory and Green’s function-based multiple-scattering theory. We show that, despite satisfying the 18 valence electron Slater-Pauling rule, CrMnSb does not exhibit ground-state nonmagnetic semiconducting behavior. Instead, it reveals a half-metallic, fully compensated ferrimagnetic ground state. This anomaly originates from the presence of localized sublattice moments, resulting from antiparallel alignment between Cr and Mn sublattices, which enforces half-metallic ferrimagnetism despite its ideal 18 valence electron count.
Materials Science (cond-mat.mtrl-sci), Computational Physics (physics.comp-ph)
12 pages, 6 figures, 1 table
Spatial QUBO: Convolutional Formulation of Large-Scale Binary Optimization with Dense Interactions
New Submission | Disordered Systems and Neural Networks (cond-mat.dis-nn) | 2025-07-01 20:00 EDT
Hiroshi Yamashita, Hideyuki Suzuki
The spatial photonic Ising machine (SPIM) is a promising optical hardware solver for large-scale combinatorial optimization problems with dense interactions. As the SPIM can represent Ising problems with rank-one coupling matrices, multiplexed versions have been proposed to enhance the applicability to higher-rank interactions. However, the multiplexing cost reduces the implementation efficiency, and even without multiplexing, the SPIM is known to represent coupling matrices beyond rank-one. In this paper, to clarify the intrinsic representation power of the original SPIM, we propose spatial QUBO (spQUBO), a formulation of Ising problems with spatially convolutional structures. We prove that any spQUBO reduces to a two-dimensional spQUBO, with the convolutional structure preserved, and that any two-dimensional spQUBO can be efficiently implemented on the SPIM without multiplexing. We further demonstrate its practical applicability to distance-based combinatorial optimization, such as placement problems and clustering problems. These results advance our understanding of the class of optimization problems where SPIMs exhibit superior efficiency and scalability. Furthermore, spQUBO’s efficiency is not limited to the SPIM architecture; we show that its convolutional structure allows efficient computation using Fast Fourier Transforms (FFT).
Disordered Systems and Neural Networks (cond-mat.dis-nn), Emerging Technologies (cs.ET), Applied Physics (physics.app-ph), Optics (physics.optics)
18 pages, 6 figures (including supplementary information, 7 pages, 1 figure)
Minimally dissipative multi-bit logical operations
New Submission | Statistical Mechanics (cond-mat.stat-mech) | 2025-07-01 20:00 EDT
Jérémie Klinger, Grant M. Rotskoff
Modern computing architectures are vastly more energy-dissipative than fundamental thermodynamic limits suggest, motivating the search for principled approaches to low-dissipation logical operations. We formulate multi-bit logical gates (bit erasure, NAND) as optimal transport problems, extending beyond classical one-dimensional bit erasure to scenarios where existing methods fail. Using entropically regularized unbalanced optimal transport, we derive tractable solutions and establish general energy-speed-accuracy trade-offs that demonstrate that faster, more accurate operations necessarily dissipate more energy. Furthermore, we demonstrate that the Landauer limits cannot be trivially overcome in higher dimensional geometries. We develop practical algorithms combining optimal transport with generative modeling techniques to construct dynamical controllers that follow Wasserstein geodesics. These protocols achieve near-optimal dissipation and can, in principle, be implemented in realistic experimentally set-ups. The framework bridges fundamental thermodynamic limits with scalable computational design for energy-efficient information processing.
Statistical Mechanics (cond-mat.stat-mech)
13 pages, 5 figures, 6 pages SM
Coercivity Panorama of Dynamic Hysteresis
New Submission | Statistical Mechanics (cond-mat.stat-mech) | 2025-07-01 20:00 EDT
Miao Chen, Xiu-Hua Zhao, Yu-Han Ma
We study the stochastic $ \phi^4$ model under periodic driving by an external field $ H$ at different scales of driving rate $ v_H$ , where the noise strength $ \sigma$ quantifies the deviation of the system size from the thermodynamic limit. For large systems with small $ \sigma$ , we find the coercivity $ H_c=H(\langle\phi\rangle=0)$ sequentially exhibits distinct behaviors with increasing $ v_H$ : $ v_H$ -scaling increase from zero, stable plateau ($ v_H^0$ ), $ v_H^{1/2}$ -scaling increase, and abrupt decline to disappearance. The $ H_c$ -plateau reflects the competition between thermodynamic and quasi-static limits, namely, $ \lim_{\sigma\to 0}\lim_{v_H\to 0}H_c = 0$ , and $ \lim_{v_H\to 0}\lim_{\sigma\to 0}H_c=H^\ast$ . Here, $ H^\ast$ is exactly the first-order phase transition (FOPT) point. In the post-plateau slow-driving regime, $ H_c-H^\ast$ scales with $ v_H^{2/3}$ . Moreover, we reveal a finite-size scaling for the coercivity plateau $ H_P$ as $ (H^\ast-H_P)\sim\sigma^{4/3}$ by utilizing renormalization-group theory. These predicted scaling relations are demonstrated in magnetic hysteresis obtained with the Curie-Weiss model. Our work provides a panoramic view of the finite-time evolution of the stochastic $ \phi^4$ model, bridges dynamics of FOPT and dynamic phase transition, and offers new insights into finite-time/finite-size effect interplay in non-equilibrium thermodynamics.
Statistical Mechanics (cond-mat.stat-mech)
comments are welcome!
Combine effect of site dilution and long-range interaction on magnetic and transport properties in the half-filled Hubbard model
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2025-07-01 20:00 EDT
Sudip Mandal, Sourav Chakraborty, Kalpataru Pradhan
We investigate the magnetotransport properties of a diluted half-filled one-band Hubbard model with second-nearest-neighbor hopping on a simple cubic lattice, aiming to explore the possibility of metallicity in diluted antiferromagnetic systems. Our semiclassical Monte Carlo (s-MC) calculations reveal an antiferromagnetic metallic regime in diluted correlated materials. This unexpected metallic regime naturally leads to a central question: how does the introduction of dilution into an antiferromagnetic material, especially with long-range magnetic interactions, induce metallicity – a feature not commonly associated with antiferromagnets? To address this question, we demonstrate that when the on-site repulsion strength ($ U$ ) is set to zero on a percentage of the sites (site dilution), the insulating state weakens due to percolative conduction among the diluted sites at low temperatures. Remarkably, this occurs without any significant alteration to the underlying long-range antiferromagnetic (AF) ordering in the system, thereby providing a pathway to realize antiferromagnetic metals. In addition, we show how the sublattice-dependent hopping can be exploited to engineer spin-polarized half-metallic antiferromagnets. Overall, our numerical results collectively provide a basis for understanding the combined effect of site dilution and competing interactions, which will assist in the design of new antiferromagnetic metals for future spintronic applications.
Strongly Correlated Electrons (cond-mat.str-el)
16 Pages, 11 Figs
Dynamical Heterogeneity in Supercooled Water and its Spectroscopic Fingerprints
New Submission | Soft Condensed Matter (cond-mat.soft) | 2025-07-01 20:00 EDT
Cesare Malosso, Edward Danquah Donkor, Stefano Baroni, Ali Hassanali
A growing body of theoretical and experimental evidence strongly supports the existence of a second liquid-liquid critical point (LLCP) in deeply supercooled water leading to the co-existence of two phases: a high-and low-density liquid (HDL and LDL). While the thermodynamics associated with this putative LLCP has been well characterised through numerical simulations, the dynamical properties of these two phases close to the critical point remain much less understood. In this work, we investigate their dynamical and spectroscopic features using machine-learning interatomic potentials (MLIPs). Dynamical analyses using the van-Hove correlation function, reveal that LDL exhibits very sluggish and heterogeneous molecular mobility, in contrast to the faster and more homogeneous dynamics of HDL. Infrared absorption (IR) spectra further show clear vibrational distinctions between LDL and HDL, in particular in the far IR region between 400 - 1000 cm-1. Together, these findings provide new dynamical fingerprints that clarify the microscopic behavior of supercooled water and offer valuable guidance for experimental efforts aimed at detecting the long-sought liquid-liquid transition.
Soft Condensed Matter (cond-mat.soft)
DNA Unzipping Transition
New Submission | Soft Condensed Matter (cond-mat.soft) | 2025-07-01 20:00 EDT
This review focuses on the force-induced unzipping transition of double-stranded DNA. It begins with a brief history of DNA melting, which emerged alongside the growth of the field of molecular biology, juxtaposed with the advancements in physics during the same post-World War II period. The earlier theories of melting of DNA were based on the Ising model and its modifications, but gradually moved towards polymer-based models. The idea of force-induced unzipping was first introduced in 1999 as a cooperative mechanism for breaking base pairs without the need for temperature changes. The paper discusses several subsequent developments addressing different aspects of the unzipping transition.
Soft Condensed Matter (cond-mat.soft), Statistical Mechanics (cond-mat.stat-mech)
18 pages
Dissipation Pathways in a Photosynthetic Complex
New Submission | Other Condensed Matter (cond-mat.other) | 2025-07-01 20:00 EDT
Ignacio Gustin, Chang Woo Kim, Ignacio Franco
Determining how energy flows within and between molecules is crucial for understanding chemical reactions, material properties, and even vital processes such as photosynthesis. While the general principles of energy transfer are well established, elucidating the specific molecular pathways by which energy is funneled remains challenging as it requires tracking energy flow in complex molecular environments. Here, we demonstrate how photon excitation energy is partially dissipated in the light-harvesting Fenna-Matthews-Olson (FMO) complex, mediating the excitation energy transfer from light-harvesting chlorosomes to the photosynthetic reaction center in green sulfur bacteria. Specifically, we isolate the contribution of the protein and specific vibrational modes of the pigment molecules to the energy dynamics. For this, we introduce an efficient computational implementation of a recently proposed theory of dissipation pathways for open quantum systems. Using it and a state-of-the-art FMO model with highly structured and chromophore-specific spectral densities, we demonstrate that energy dissipation is dominated by low-frequency modes ($ <$ 800 cm$ ^{-1}$ ) as their energy range is near-resonance with the energy gaps between electronic states of the pigments. We identify the most important mode for dissipation to be in-plane breathing modes ($ \sim$ 200 cm$ ^{-1}$ ) of the bacteriochlorophylls in the complex. Conversely, far-detuned intramolecular vibrations with higher frequencies ($ >$ 800 cm$ ^{-1}$ ) play no role in dissipation. Interestingly, the FMO complex first needs to borrow energy from the environment to release excess photonic energy, making the energy dissipation dynamics non-monotonic. Beyond their fundamental value, these insights can guide the development of artificial light-harvesting devices and, more broadly, engineer environments for chemical and quantum control tasks.
Other Condensed Matter (cond-mat.other)
Ruelle-Pollicott resonances of diffusive U(1)-invariant qubit circuits
New Submission | Statistical Mechanics (cond-mat.stat-mech) | 2025-07-01 20:00 EDT
We study Ruelle-Pollicott resonances of translationally invariant magnetization-conserving qubit circuits via the spectrum of the quasi-momentum-resolved truncated propagator of extensive observables. Diffusive transport of the conserved magnetization is reflected in the Gaussian quasi-momentum $ k$ dependence of the leading eigenvalue (Ruelle-Pollicott resonance) of the truncated propagator for small $ k$ . This, in particular, allows us to extract the diffusion constant. For large $ k$ , the leading Ruelle-Pollicott resonance is not related to transport and governs the exponential decay of correlation functions. Additionally, we conjecture the existence of a continuum of eigenvalues below the leading diffusive resonance, which governs non-exponential decay, for instance, power-law hydrodynamic tails. We expect our conclusions to hold for generic systems with exactly one U(1) conserved quantity.
Statistical Mechanics (cond-mat.stat-mech), Chaotic Dynamics (nlin.CD), Quantum Physics (quant-ph)
14 + 6 pages, 12 figures
Nonlinear Symmetry-Fragmentation of Nonabelian Anyons In Symmetry-Enriched Topological Phases: A String-Net Model Realization
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2025-07-01 20:00 EDT
Nianrui Fu, Siyuan Wang, Yu Zhao, Yidun Wan
Symmetry-enriched topological (SET) phases combine intrinsic topological order with global symmetries, giving rise to novel symmetry phenomena. While SET phases with Abelian anyons are relatively well understood, those involving non-Abelian anyons remain elusive. This obscurity stems from the multi-dimensional internal gauge spaces intrinsic to non-Abelian anyons – a feature first made explicit in [1,2] and further explored and formalized in our recent works [3-8]. These internal spaces can transform in highly nontrivial ways under global symmetries. In this work, we employ an exactly solvable model – the multifusion Hu-Geer-Wu string-net model introduced in a companion paper [9] – to reveal how the internal gauge spaces of non-Abelian anyons transform under symmetries. We uncover a universal mechanism, global symmetry fragmentation (GSF), whereby symmetry-invariant anyons exhibit internal Hilbert space decompositions into eigensubspaces labeled by generally fractional symmetry charges. Meanwhile, symmetry-permuted anyons hybridize and fragment their internal spaces in accordance with their symmetry behavior. These fragmented structures realize genuinely nonlinear symmetry representations – to be termed coherent representations – that transcend conventional linear and projective classifications, reflecting the categorical nature of symmetries in topological phases. Our results identify nonlinear fragmentation as a hallmark of non-Abelian SETs and suggest new routes for symmetry-enabled control in topological quantum computation.
Strongly Correlated Electrons (cond-mat.str-el), Statistical Mechanics (cond-mat.stat-mech), High Energy Physics - Theory (hep-th), Mathematical Physics (math-ph)
12+21 pages
Approximate half-integer quantization in anomalous planar transport in $d$-wave altermagnets
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2025-07-01 20:00 EDT
Srimayi Korrapati, Snehasish Nandy, Sumanta Tewari
We investigate anomalous planar transport phenomena in a recently identified class of collinear magnetic materials known as $ d$ -wave altermagnets. The anomalous planar effects manifest in a configuration when the applied electric field/temperature gradient, magnetic field, and the measured Hall voltage are all co-planar, but the planar magnetic field is instrumental in breaking $ \hat{C}_{4z}\hat{\mathcal{T}}$ symmetry of the $ d$ -wave altermagnet, where $ \hat{\mathcal{T}}$ is the time reversal operator, resulting in a Zeeman gap at a shifted Dirac node and a nonzero Berry curvature monopole. We demonstrate that these systems exhibit nearly half-quantized anomalous planar Hall and planar thermal Hall effects at low temperatures that persist over a range of magnetic fields. The angular dependence of the planar transport reveals a $ \cos2\phi$ dependence on the magnetic field direction, where $ \phi$ is the azimuthal angle made by the magnetic field. We also discuss the anomalous planar Nernst effect, or transverse thermopower, and demonstrate that the Nernst conductivity peaks when the chemical potential lies just outside the induced Zeeman gap and vanishes within the gap. We further explore the dependence of all three coefficients on the polar and the azimuthal angle of the magnetic field when it is rotated in the full $ 3D$ space. Our results reveal the presence of approximately half-quantized anomalous planar thermal Hall plateau for a range of in-plane magnetic fields without requiring topological superconductivity and conducting Majorana modes, and can be probed in experiments in $ d$ -wave altermagnets.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Other Condensed Matter (cond-mat.other)