CMP Journal 2025-05-20
Statistics
Nature: 1
Nature Materials: 3
Nature Physics: 1
Physical Review Letters: 5
Physical Review X: 2
arXiv: 85
Nature
One-carbon homologation of alkenes
Original Paper | Synthetic chemistry methodology | 2025-05-19 20:00 EDT
Marcus C. Grocott, Matthew J. Gaunt
One-carbon homologs are structurally-related and functionally-identical organic molecules, whose chain-lengths differ by a single methylene (-CH2-) unit1. Across many classes of molecule-including pharmaceutical agents, natural products, agrochemicals, fragrances and petroleum products-the physicochemical characteristics displayed by members of a homologous series subtly differ from one compound to another, which can impart remarkable differences to their function2. The efficient generation of homologs is, therefore, an important strategy in molecular discovery programs3,4. Despite the availability of homologation strategies for several functional groups5,6, direct and general methods for one-carbon chain extension in alkenes remain an unmet synthetic need7,8. We report a catalytic one-carbon homologation process that is effective for many classes of alkene in simple and complex molecules. By leveraging the intrinsic reactivity of a novel multifaceted allyl-sulfone reagent, a streamlined one-pot process, involving cross-metathesis and a fragmentation/retro-ene cascade, formally inserts a single methylene unit to the alkene chain. Amongst applications of this process to several structurally and functionally complex molecules, we demonstrate how this practical transformation generates previously unexplored homologs of Cyclosporine-A9. These homologs show modulated pharmacological and biological properties and could provide promising leads as cyclophilin inhibitors, a target that has great potential in many disease areas10.
Synthetic chemistry methodology, Natural product synthesis
Nature Materials
Suppressing argyrodite oxidation by tuning the host structure for high-areal-capacity all-solid-state lithium-sulfur batteries
Original Paper | Batteries | 2025-05-19 20:00 EDT
Zhuo Yu, Baltej Singh, Yue Yu, Linda F. Nazar
Argyrodite (Li6PS5Cl) is a promising electrolyte for high-performance solid-state lithium-sulfur batteries (SSSBs), which operate on the reversible conversion of S↔Li2S. However, argyrodite is electrochemically decomposed above 2.5 V versus Li+/Li on charge, because free S2- ions in the lattice are oxidized to sulfur at a similar potential as Li2S. Here we demonstrate that creating a strong interaction between the Li ions in argyrodite and the sulfur host synergistically suppresses the oxidation of argyrodite by inhibiting the extraction of Li+ in the initial step. A carbon nitride/N-doped graphene host serves as a proof of concept to demonstrate this effect. Additionally, its moderate electron transport enables SSSB operation and constrains electron mobility at the argyrodite interface. Consequently, SSSBs utilizing this host deliver excellent rate capability and stable long-term cycling compared with non-polar carbon materials. An areal capacity of 2 mAh cm-2 was achieved over 230 cycles at room temperature, whereas a high capacity of 11.3 mAh cm-2 was obtained with 90% retention at 60 °C. The descriptors presented here could enrich the understanding of solid electrolyte redox activities and guide interface and materials design in SSSBs.
Batteries
Vortices and antivortices in antiferroelectric PbZrO3
Original Paper | Ferroelectrics and multiferroics | 2025-05-19 20:00 EDT
Ying Liu, Huazhang Zhang, Konstantin Shapovalov, Ranming Niu, Julie M. Cairney, Xiaozhou Liao, Krystian Roleder, Andrzej Majchrowski, Jordi Arbiol, Philippe Ghosez, Gustau Catalan
Ferroelectric materials are characterized by a parallel arrangement of electric dipoles, but at the nanoscale they can present vortices and other non-trivial topological structures1,2,3,4,5,6,7,8,9 that combine small size and topological protection, rendering them functionally attractive10,11,12,13. The driving force for the appearance of vortices in ferroelectrics is the need to minimize the depolarizing fields at interfaces3,4,5,14; by making the polarization rotate, depolarization fields vanish4,5,8,9. Antiferroelectrics, by contrast, are defined by an antiparallel arrangement of electric dipoles15. A priori, therefore, they lack the depolarization fields that drive the appearance of non-trivial topologies in ferroelectrics. At the atomic scale of the dipoles, however, we find that polar discontinuities can still happen, driving the appearance of topological singularities at ferroelastic domain walls.
Ferroelectrics and multiferroics, Topological defects
Sub-unit-cell-segmented ferroelectricity in brownmillerite oxides by phonon decoupling
Original Paper | Ceramics | 2025-05-19 20:00 EDT
Jinhyuk Jang, Yeongrok Jin, Yeon-Seo Nam, Heung-Sik Park, Jaegyu Kim, Kyeong Tae Kang, Yerin So, Jiwoung Choi, Youngchang Choi, Jaechan Shim, Panithan Sriboriboon, Dong Kyu Lee, Kyoung-June Go, Gi-Yeop Kim, Seungbum Hong, Jun Hee Lee, Daesu Lee, Myung-Geun Han, Junwoo Son, Yunseok Kim, Hiroki Taniguchi, Seokhyeong Kang, Jang-Sik Lee, He Tian, Chan-Ho Yang, Yimei Zhu, Sang-Wook Cheong, Woo Seok Choi, Jaekwang Lee, Si-Young Choi
The ultimate scaling limit in ferroelectric switching has been attracting broad attention in the fields of materials science and nanoelectronics. Despite immense efforts to scale down ferroelectric features, however, only few materials have been shown to exhibit ferroelectricity at the unit-cell level. Here we report a controllable unit-cell-scale domain in brownmillerite oxides consisting of alternating octahedral/tetrahedral layers. By combining atomic-scale imaging and in situ transmission electron microscopy, we directly probed sub-unit-cell-segmented ferroelectricity and investigated their switching characteristics. First-principles calculations confirm that the phonon modes related to oxygen octahedra are decoupled from those of the oxygen tetrahedra in brownmillerite oxides, and such localized oxygen tetrahedral phonons stabilize the sub-unit-cell-segmented ferroelectric domain. The unit-cell-wide ferroelectricity observed in our study could provide opportunities to design high-density memory devices using phonon decoupling.
Ceramics, Ferroelectrics and multiferroics
Nature Physics
Strain-stiffening universality in composite hydrogels and soft tissues
Original Paper | Biological physics | 2025-05-19 20:00 EDT
Jake Song, Elad Deiss-Yehiely, Serra Yesilata, Gareth H. McKinley
Soft biological tissues exhibit mechanical properties that reflect their composite structure of cells embedded within a biopolymer matrix. However, the microscopic mechanisms underlying their unique nonlinear mechanical response–characterized by strain stiffening in compression, but strain softening in shear or tension–remain poorly understood. Here we show that strain softening in composite systems can arise due to plastic dissipation, which is mediated by filler-polymer interactions. We characterize the nonlinear elasticity of composite hydrogels and soft tissues in isolation from these plastic effects, and show that their nonlinear elastic strain stiffening is driven by the stretching of the underlying biopolymer matrix. We thus show that strain stiffening in composite hydrogels and tissues is mediated by strain amplification factors that are universal in compression and shear. In doing so, we demonstrate the importance of fundamental composite properties such as filler concentration and filler-polymer interaction strength in mediating strain stiffening in composite systems. These findings highlight key structure-property relationships that underlie the nonlinear mechanics of biologically relevant soft solids such as composite gels and tissues.
Biological physics, Biopolymers in vivo, Gels and hydrogels
Physical Review Letters
Optimally Generating $\mathfrak{su}({2}^{N})$ Using Pauli Strings
Research article | Measurement-based quantum computing | 2025-05-19 06:00 EDT
Isaac D. Smith, Maxime Cautrès, David T. Stephen, and Hendrik Poulsen Nautrup
Any quantum computation consists of a sequence of unitary evolutions described by a finite set of Hamiltonians. When this set is taken to consist of only products of Pauli operators, we show that the minimal such set generating $\mathfrak{su}({2}^{N})$ contains $2N+1$ elements. We provide a number of examples of such generating sets and furthermore provide an algorithm for producing a sequence of rotations corresponding to any given Pauli rotation, which is shown to have optimal complexity. We also observe that certain sets generate $\mathfrak{su}({2}^{N})$ at a faster rate than others, and we show how this rate can be optimized by tuning the fraction of anticommuting pairs of generators. Finally, we briefly comment on implications for measurement-based and trapped ion quantum computation as well as the construction of fault-tolerant gate sets.
Phys. Rev. Lett. 134, 200601 (2025)
Measurement-based quantum computing, Quantum circuits, Quantum computation, Quantum control, Quantum information architectures & platforms, Quantum information with trapped ions
Optimality Condition for the Petz Map
Research article | Open quantum systems & decoherence | 2025-05-19 06:00 EDT
Bikun Li, Zhaoyou Wang, Guo Zheng, Yat Wong, and Liang Jiang
In quantum error correction, the Petz map serves as a perfect recovery map when the Knill-Laflamme conditions are satisfied. Notably, while perfect recovery is generally infeasible for most quantum channels of finite dimension, the Petz map remains a versatile tool with near-optimal performance in recovering quantum states. This work introduces and proves, for the first time, the necessary and sufficient conditions for the optimality of the Petz map in terms of entanglement fidelity. In some special cases, the violation of this condition can be easily characterized by a simple commutator that can be efficiently computed. We provide multiple examples that substantiate our new findings.
Phys. Rev. Lett. 134, 200602 (2025)
Open quantum systems & decoherence, Quantum channels, Quantum error correction, Quantum information processing
Long-Distance Window of the Hadronic Vacuum Polarization for the Muon $g- 2$
Research article | Lattice QCD | 2025-05-19 06:00 EDT
T. Blum, P. A. Boyle, M. Bruno, B. Chakraborty, F. Erben, V. Gülpers, A. Hackl, N. Hermansson-Truedsson, R. C. Hill, T. Izubuchi, L. Jin, C. Jung, C. Lehner, J. McKeon, A. S. Meyer, M. Tomii, J. T. Tsang, and X.-Y. Tuo (RBC and UKQCD Collaborations)
Using an isospin symmetric setup, a precise lattice QCD computation finds that the long-distance window contribution to the muon g-2 deviates significantly from that of the data-driven approach.
Phys. Rev. Lett. 134, 201901 (2025)
Lattice QCD, Muons, Magnetic moment
$^{16}\mathrm{O}$ Electroweak Response Functions from First Principles
Research article | Electromagnetic transitions | 2025-05-19 06:00 EDT
Bijaya Acharya, Joanna E. Sobczyk, Sonia Bacca, Gaute Hagen, and Weiguang Jiang
We present calculations of various electroweak response functions for the $^{16}\mathrm{O}$ nucleus obtained using coupled-cluster theory in conjunction with the Lorentz integral transform method. We employ nuclear forces derived at next-to-leading order and next-to-next-to-leading order in chiral effective field theory and perform a Bayesian analysis to assess uncertainties. Our results are in good agreement with available electron-scattering data at $|\mathbf{q}|\approx 326\text{ }\text{ }\mathrm{MeV}/\mathrm{c}$. Additionally, we provide several predictions for the weak response functions in the quasielastic peak region at $|\mathbf{q}|=300$ and $400\text{ }\text{ }\mathrm{MeV}/\mathrm{c}$, which are critical for long-baseline neutrino experiments.
Phys. Rev. Lett. 134, 202501 (2025)
Electromagnetic transitions, Electroweak interactions in nuclear physics, Nucleus-neutrino interactions
Observation of Extreme Anisotropic Sensitivity at Topological Bound States in the Continuum
Research article | Acoustic metamaterials | 2025-05-19 06:00 EDT
Ruizhi Dong, Yihuan Zhu, Dongxing Mao, Xu Wang, and Yong Li
Bound states in the continuum (BICs) are exceptional resonances with extremely high sensitivity and thus inherently fragile. Introducing topological concepts can fortify BICs against perturbations; however, existing topological BICs (TBICs) often rely on intricate strategies. Here, we explore the universality of TBICs governed by symmetry. Different symmetries naturally segregate wave states into uncoupled Hilbert subspaces, enabling independent topological band structure engineering in each subspace. This results in rich topological features, including TBICs, topological Fano resonance, and even exotic TBICs (eTBICs). Intriguingly, eTBICs inherit core attributes from both topological states and BICs, thereby exhibiting counterintuitive behavior—both strong immunity and high sensitivity. We conceptually and experimentally demonstrate this using an acoustic monolayer topological waveguide, uncovering exotic behavior in the transmission spectrum where the bulk is ‘’muted’’ and the eTBIC is identified with extreme anisotropic sensitivity. Our findings may enrich the research implications of both topological physics and BICs.
Phys. Rev. Lett. 134, 206601 (2025)
Acoustic metamaterials, Bound states in the continuum, Topological effects in acoustic systems
Physical Review X
Thermodynamic Theory of Proximity Ferroelectricity
Research article | Electric polarization | 2025-05-19 06:00 EDT
Eugene A. Eliseev, Anna N. Morozovska, Jon-Paul Maria, Long-Qing Chen, and Venkatraman Gopalan
Materials like AlN and ZnO, once thought unswitchable, can switch polarization when layered with ferroelectrics. A proposed theory explains this phenomenon via internal fields that reshape energy barriers and enable switching.
Phys. Rev. X 15, 021058 (2025)
Electric polarization, Ferroelectricity, Proximity effect, Ferroelectrics, Multilayer thin films
Measurement-Induced Entanglement and Complexity in Random Constant-Depth 2D Quantum Circuits
Research article | Quantum computation | 2025-05-19 06:00 EDT
Max McGinley, Wen Wei Ho, and Daniel Malz
Even shallow 2D quantum circuits can generate long-range entanglement during measurement, making them classically hard to simulate–not due to depth, but due to hidden complexity from measurements.
Phys. Rev. X 15, 021059 (2025)
Quantum computation, Quantum information theory, Quantum measurements, Quantum phase transitions, Quantum many-body systems
arXiv
Van der Waals-Driven Network Restructuring Explains Time-Dependent Piezoresistivity in Soft Nanocomposites
New Submission | Soft Condensed Matter (cond-mat.soft) | 2025-05-20 20:00 EDT
Logan Ritchie, Elke Pahl, Iain Anderson
Carbon-elastomer composites exhibit complex piezoresistive behaviour that cannot be fully explained by existing macroscopic or microstructural models. In this work, we introduce a network-based modelling methodology to explore the hypothesis that van der Waals interactions between carbon particles contribute to the formation of a conductivity-promoting network structure prior to curing. We combine a discrete aggregate-based representation of filler with a mesh-free, quasi-static viscoelastic model adapted from bond-based peridynamics, resolving equilibrium states through energy minimization. The resulting particle networks are analysed using graph-theoretic measures of connectivity and conductivity. Our simulations reproduce several unexplained experimental phenomena, including long-timescale resistivity decay, non-monotonic secondary peaks upon strain release, and the increasing prominence of these features with higher filler density. Crucially, these behaviours emerge from the interplay between viscoelastic stresses and van der Waals interactions. We show that the resistance response of the network operates over different characteristic timescales to the viscoelastic stress response. The approach has potential for understanding and predicting emergent behaviour in composite materials more broadly, where material characteristics often depend on percolating network structure.
Soft Condensed Matter (cond-mat.soft), Materials Science (cond-mat.mtrl-sci)
14 pages, 7 figures
A Robust Synthesis of Fluorosurfactants with Tunable Functions via a Two-Step Reaction
New Submission | Soft Condensed Matter (cond-mat.soft) | 2025-05-20 20:00 EDT
Jiyuan Yao, Shijian Huang, Shuting Xie, Zhenping Liu, Yueming Deng, Luca Carnevale, Mingliang Jin, Loes I. Segerink, Da Wang, Lingling Shui, Sergii Pud
Fluorosurfactant-stabilized microdroplets hold significant promise for a wide range of applications, owing to their biological and chemical inertness. However, conventional synthetic routes for fluorosurfactants typically require multiple reaction steps and stringent conditions, such as high temperatures and anaerobic environments. This complexity poses a significant limitation to the development of fluorosurfactant synthesis and their subsequent applications in droplet-based systems. In this work, we present a robust two-step synthesis of fluorosurfactants with tunable functionalities. Microdroplets stabilized by these fluorosurfactants exhibit enhanced stability and biocompatibility. Notably, these fluorosurfactants facilitate the formation of nanodroplets that efficiently transport and concentrate fluorophores with high selectivity. Furthermore, we demonstrate that colloidal self-assemblies with tunable morphologies can be engineered by modulating interactions between the fluorosurfactants and colloidal particles. Our synthetic approach provides a strategy for the rapid production of functional fluorosurfactants under mild conditions, enabling droplet-based microfluidic techniques with applications in biology and material science.
Soft Condensed Matter (cond-mat.soft), Materials Science (cond-mat.mtrl-sci)
Aharonov-Bohm caging of an electron in a quantum fractal
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2025-05-20 20:00 EDT
Fractal geometries exhibit complex structures with scale invariance self-similar pattern over various length scales. An artificially designed quantum fractal geometry embedded in a uniform magnetic flux has been explored in this study. It has been found that due to quantum mechanical effect, such quantum fractal display an exotic electronic property which is reflected in its transport characteristics. Owing to this uniform magnetic flux piercing through each closed-loop building block of the fractal structure, an electron traversing through such a fractal geometry will pick up a nontrivial Aharonov-Bohm phase factor, which will influence its transport through the system. It is shown that, one can completely block the transmission of an electron in this fractal geometry by setting the value of the uniform magnetic flux to half flux quantum. This phenomenon of Aharonov-Bohm caging of an electron in this quantum fractal geometry has been supported by the computation of the energy spectrum, two-terminal transport and persistent current in its various generations. This result is very robust against disorder and could be useful in designing efficient quantum algorithms using a quantum fractal network.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Materials Science (cond-mat.mtrl-sci), Other Condensed Matter (cond-mat.other)
8 pages, 6 figures; Accepted for publication in Physica Status Solidi - Rapid Research Letters (pss RRL)
The role of confined water in the emergence of electrostatic strong coupling as revealed by nanoseparated charged lipid layers
New Submission | Soft Condensed Matter (cond-mat.soft) | 2025-05-20 20:00 EDT
Swen Helstroffer, Ludovic Gardré, Giovanna Fragneto, Arnaud Hemmerle, Léo Henry, Laurent Joly, Fabrice Thalmann, Claire Loison, Pierre Muller, Thierry Charitat
This study investigates the interplay between Strong Coupling (SC) attraction and hydration repulsion in nanoconfined water between like-charged phospholipid layers. It challenges the assumption that SC attraction requires multivalent counterions by showing that hydration water can enhance electrostatic interactions. We combine reflectivities with numerical simulations to analyze supported phospholipid layers under different relative humidity and surface charge densities. X-ray fluorescence demonstrates that we can control the valence of the associated counterions. Experimental measurement of the water thickness, combined with precise determination of charged surface positions by numerical simulations, enable us to compare our experiments with a theoretical model. It shows that charge-screening by hydration water induces SC attraction, even at moderate surface charge densities with monovalent counterions. Furthermore, hydration repulsion is stronger for DPPS compared to DPPC. These findings offer insights into the forces that control interactions between phospholipid layers and have important implications for biological and colloidal systems.
Soft Condensed Matter (cond-mat.soft), Chemical Physics (physics.chem-ph)
23 pages, 4 figures, Supplementary informations 74 pages, 22 figures
Electronic origin of the reorganization energy in interfacial electron transfer
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-05-20 20:00 EDT
Sonal Maroo, Leonardo Coello Escalante, Yizhe Wang, Matthew P. Erodici, Jonathon N. Nessralla, Ayana Tabo, Takashi Taniguchi, Kenji Watanabe, Ke Xu, David T. Limmer, D. Kwabena Bediako
The activation free energy of electron transfer (ET) reactions is governed by a crucial parameter: the reorganization energy. In heterogeneous ET at electrified solid-liquid interfaces, it is presumed that only factors in the electrolyte phase are responsible for determining the reorganization energy. Here, we demonstrate the contribution of the electronic density of states (DOS) of the electrode to the reorganization energy. Using van der Waals assembly of two-dimensional crystals, we tune the DOS of graphene and measure its impact on outer-sphere ET. We find the ensuing variation in ET rate arises from modulation in a reorganization energy associated with image potential localization in the electrode, which is dependent on the DOS. This work establishes a fundamental role of the electrode electronic structure in interfacial charge transfer.
Materials Science (cond-mat.mtrl-sci)
Revisiting vestigial order in nematic superconductors: gauge-field mechanisms and model constraints
New Submission | Superconductivity (cond-mat.supr-con) | 2025-05-20 20:00 EDT
Ilaria Maccari, Egor Babaev, Johan Carlström
The possibility that nematicity induced by electron pairing could persist above the superconducting transition temperature represents a form of composite order, sometimes referred to as a vestigial nematic phase. However, it remains debated whether–and under what conditions–such a phase can emerge in realistic models of nematic superconductors. Recent analytical work [1] concluded that vestigial nematic phases and related mechanisms do not arise in commonly used models proposed, for example, for Bi2Se3-based candidates. To address this question, we perform large-scale Monte Carlo simulations of a three-dimensional Ginzburg-Landau model of a nematic superconductor. Consistent with the findings of Ref.[1], our numerical results confirm that the commonly considered models do not exhibit vestigial nematic phases or nematic-fluctuation-induced charge-4e superconductivity. In the second part of the study, we investigate a different class of models and show that, under restrictive conditions, vestigial nematic order can be stabilized by an alternative mechanism: intercomponent coupling mediated by a gauge field or the effects of strong correlations.
Superconductivity (cond-mat.supr-con), Statistical Mechanics (cond-mat.stat-mech), Strongly Correlated Electrons (cond-mat.str-el)
10 pages, 9 figures
Magnetic Interactions and Cluster Formation: Boosting Surface Thermopower in Topological Insulators
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2025-05-20 20:00 EDT
M. Tirgar, H. Barati Abgarmi, J. Abouie
This study theoretically investigates the thermoelectric properties of magnetic topological insulators (TIs), with a focus on the effects of magnetic atom exchange interactions on the thermopower of their surfaces. Our findings demonstrate that interactions among magnetic atoms significantly enhance the Seebeck coefficient. The formation of magnetic clusters through exchange interactions increases the scattering of Dirac electrons, thereby improving the thermoelectric power factor. We conducted extensive Monte Carlo simulations across various configurations, including ferromagnetic and antiferromagnetic bulk materials, comparing magnetic clustering in Ising and Heisenberg models. Special attention was given to cluster definitions related to surface critical temperatures. Our analysis indicates that the size and number of magnetic clusters influence relaxation times, as well as electrical and thermal resistivities, ultimately affecting the thermopower. Optimized interlayer and intralayer interactions can elevate the surface thermopower of TIs to values comparable to those observed in antiferromagnetic $ {\rm MnTe}$ , renowned for its unique spin-based thermoelectric properties. This work highlights the potential of magnetic TIs for thermoelectric applications and sets the stage for future research.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Materials Science (cond-mat.mtrl-sci)
16 pages, 14 Figures
Pull-off force prediction in viscoelastic adhesive Hertzian contact by physics augmented machine learning
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-05-20 20:00 EDT
Ali Maghami, Merten Stender, Antonio Papangelo
Understanding and predicting the adhesive properties of viscoelastic Hertzian contacts is crucial for diverse engineering applications, including robotics, biomechanics, and advanced material design. The maximum adherence force of a Hertzian indenter unloaded from a viscoelastic substrate has been studied with analytical and numerical models. Analytical models are valid within their assumptions, numerical methods offer precision but can be computationally expensive, necessitating alternative solutions. This study introduces a novel physics-augmented machine learning (PA-ML) framework as a hybrid approach, bridging the gap between analytical models and data-driven solutions, which is capable of rapidly predicting the pull-off force in an Hertzian profile unloaded from a broad band viscoelastic material, with varying Tabor parameter, preload and retraction rate. Compared to previous models, the PA-ML approach provides fast yet accurate predictions in a wide range of conditions, properly predicting the effective surface energy and the work-to-pull-off. The integration of the analytical model provides critical guidance to the PA-ML framework, supporting physically consistent predictions. We demonstrate that physics augmentation enhances predictive accuracy, reducing mean squared error (MSE) while increasing model efficiency and interpretability. We provide data-driven and PA-ML models for real-time predictions of the adherence force in soft materials like silicons and elastomers opening to the possibility to integrate PA-ML into materials and interface design. The models are openly available on Zenodo and GitHub.
Materials Science (cond-mat.mtrl-sci), Computational Physics (physics.comp-ph)
Explainable Machine Learning for Oxygen Diffusion in Perovskites and Pyrochlores
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-05-20 20:00 EDT
Grace M. Lu, Dallas R. Trinkle (Department of Materials Science and Engineering, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA)
Explainable machine learning can help to discover new physical relationships for material properties. To understand the material properties that govern the activation energy for oxygen diffusion in perovskites and pyrochlores, we build a database of experimental activation energies and apply a grouping algorithm to the material property features. These features are then used to fit seven different machine learning models. An ensemble consensus determines that the most important features for predicting the activation energy are the ionicity of the A-site bond and the partial pressure of oxygen for perovskites. For pyrochlores, the two most important features are the A-site $ s$ valence electron count and the B-site electronegativity. The most important features are all constructed using the weighted averages of elemental metal properties, despite weighted averages of the constituent binary oxides being included in our feature set. This is surprising because the material properties of the constituent oxides are more similar to the experimentally measured properties of perovskites and pyrochlores than the features of the metals that are chosen. The easy-to-measure features identified in this work enable rapid screening for new materials with fast oxide-ion diffusivity.
Materials Science (cond-mat.mtrl-sci), Machine Learning (cs.LG)
32 pages, 11 figures
Pseudogap in electron-doped cuprates: thermal precursor to magnetism
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2025-05-20 20:00 EDT
Emmanouil K. Kokkinis, Andrey V. Chubukov
We study pseudogap behavior in a metal near an antiferromagnetic instability and apply the results to electron-doped cuprates. We associate pseudogap behavior with thermal magnetic fluctuations and compute the fermionic self-energy along the Fermi surface beyond Eliashberg approximation. We analyze the spectral function as a function of frequency (energy distribution curves, EDC) and momentum (momentum distribution curves, MDC). We show that the EDC display pseudogap behavior with peaks at a finite frequency at all momenta. On the other hand, MDC peaks disperse within the pseudogap, ending at a gossamer Fermi surface. We analyze magnetically-mediated superconductivity and show that thermal fluctuations almost cancel out in the gap equation, even when the self-energy is obtained beyond the Eliashberg approximation. We favorably compare our results with recent ARPES study [K-J Xu et al, Nat. Phys. 19, 1834-1840 (2023)].
Strongly Correlated Electrons (cond-mat.str-el)
29 pages + 10 figures
Nitrogen-Vacancy Magnetometry of Edge Magnetism in WS2 Flakes
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2025-05-20 20:00 EDT
Ilja Fescenko, Raman Kumar, Thitinun Gas-Osoth, Yifei Wang, Suvechhya Lamichhane, Tianlin Li, Adam Erickson, Nina Raghavan, Tom Delord, Cory D. Cress, Nicholas Proscia, Samuel W. LaGasse, Sy-Hwang Liou, Xia Hong, Jose J. Fonesca, Toshu An, Carlos A. Meriles, Abdelghani Laraoui
Two-dimensional (2D) magnets are of significant interest both as a platform for exploring novel fundamental physics and for their potential applications in spintronic and optoelectronic devices. Recent magnetic bulk measurements have indicated a weak ferromagnetic response in WS2 and theoretical predictions suggest that the edges of such flakes exhibit magnetization when at least one edge of a flake is partially hydrogenated. Here, we use room-temperature wide-field quantum diamond magnetometry to image pristine and Fe-implanted WS2 thin flakes of variable thickness, exfoliated from a bulk crystal and transferred to nitrogen-vacancy (NV)-doped diamond substrates. We provide the first direct evidence of edge-localized stray fields, growing linearly with the applied magnetic field and reaching up to 4.7 uT. Magnetic simulations using alternative models favor the presence of edge magnetization aligned along an axis slightly tilted from the normal to the WS2 flake plane. Our observations open intriguing opportunities on the use of WS2 for spintronics applications.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
Role of Nematic Fluctuations on Superconductivity in FeSe${0.47}$Te${0.53}$ Revealed by NMR under Pressure
New Submission | Superconductivity (cond-mat.supr-con) | 2025-05-20 20:00 EDT
Qing-Ping Ding, Juan Schmidt, Jose A. Moreno, Sergey L. Bud’ko, Paul C. Canfield, Yuji Furukawa
The relationship between antiferromagnetic (AFM) spin fluctuations (SF), nematic fluctuations, and superconductivity (SC) has been central to understanding the pairing mechanism in iron-based superconductors (IBSCs). Iron chalcogenides, which hold the simplest crystal structure in IBSCs, provide a good platform to investigate the relationship. Here, we report $ ^{77}$ Se and $ ^{125}$ Te nuclear magnetic resonance studies of FeSe$ _{0.47}$ Te$ _{0.53}$ , which is located close to a nematic quantum critical point (QCP), under pressures up to 1.35 GPa. Both the superconducting critical temperature and AFMSF were found to be enhanced under pressure, which suggests a correlation between SC and AFMSF in FeSe$ _{0.47}$ Te$ _{0.53}$ . However, the contribution of AFMSF to SC in FeSe$ _{0.47}$ Te$ _{0.53}$ was found to be much less compared to that in FeSe$ _{1-x}$ S$ _{x}$ , suggesting that nematic fluctuations play a dominant role in the SC in FeSe$ _{1-x}$ Te$ _{x}$ around the nematic QCP.
Superconductivity (cond-mat.supr-con), Strongly Correlated Electrons (cond-mat.str-el)
8 pages, 3 figures, accepted for publication in Phys. Rev. Lett
Semiconductor quantum well magnetic memory using confinement from proximity exchange fields for high magnetoresistances in a field-effect transistor
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2025-05-20 20:00 EDT
William S. Rogers, Jean Anne C. Incorvia
There is a growing demand for highly-performant memories and memristive technologies for use in in-memory computing. Magnetic tunnel junctions (MTJs) have thus far addressed this need in the field of spintronics. Despite their low write power and high speeds, MTJs are limited by their modest on/off ratio at room temperature, which motivates a search for beyond-MTJ spintronic devices. In this work, we propose a device that uses two layers of ferromagnetic insulator (FMI) cladding a semiconductor QW, which is able to modulate the QW bandgap via electronic confinement resulting from proximity magnetization at the interfaces of the quantum well depending on the relative magnetization of the FMI layers. We predict that this device has the potential for very high magnetoresistances (MRs) possibly exceeding 10,000% at room temperature. We also predict that this device will operate with maximal MR in charge neutrality, and that electrostatic gating may promote the device to act as a magnetic memtransistor. This motivates the search for candidate materials and ultimately experimental demonstration of magnetic QW memories or memtransistors, which may have the potential to advance the state of the art in logic, memory, or neuromorphic circuits.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Materials Science (cond-mat.mtrl-sci)
7 pages, 3 figures
Mid infrared imaging of mass transport in polymer electrolyte membranes of an operating microfluidic water electrolyzer
New Submission | Soft Condensed Matter (cond-mat.soft) | 2025-05-20 20:00 EDT
Stéphane Chevalier, Meguya Ryu, Jean-Christophe Batsale, Junko Morikawa
This study investigates water transport in a polymer electrolyte membrane (PEM) electrolyzer using operando infrared spectroscopic imaging. By testing different H2SO4 anolyte concentrations, it examines electrochemical performance, water diffusion, and membrane hydration. Higher anolyte concentrations increased standard deviations in current densities and led to water diffusion gradients revealed by infrared imaging and confirming localized water transport variations. The study highlights the need for improved water management and optimized electrolyzer design for stable and efficient PEM electrolysis in industrial applications.
Soft Condensed Matter (cond-mat.soft), Chemical Physics (physics.chem-ph)
HTSJ International Heat Transfer Symposium, Okinawa, 2025
Domain formation and correlation effects in quenched uniaxial ferroelectrics: A stochastic model perspective
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-05-20 20:00 EDT
Olga Yu. Mazur, Yuri A. Genenko, Leonid I. Stefanovich
The stochastic analysis of the polarization domain structures, emerging after quenching from a paraelectric to a ferroelectric state, in terms of the polarization correlation functions and their Fourier transforms is a fast and effective tool of the materials structure characterization. In spite of a significant volume of experimental data accumulated over the last three decades for the model uniaxial ferroelectric triglycine sulfate, there were no theoretical tools to comprehend these data until now. This work summarizes the recent progress in understanding of the experiments by means of the original stochastic model of polarization structure formation based on the Landau-Ginzburg-Devonshire theory and the Gauss random field concept assuming the predominance of the quenched polarization disorder over the thermal fluctuations. The system of integrodifferential equations for correlation functions of random polarization and electric field turns out to be analytically solvable. The model provides explanations to a range of experimental results on the polarization formation kinetics including the time-dependent correlation lengths and correlation functions on the macroscopic spatial and time scales. Notably, it predicts the dependence of the ferroelectric coercive field on the initial disordered state characteristics, which can be controlled by quenching parameters like the initial temperature and the cooling rate, thus paving the way for tailoring the functional properties of the material.
Materials Science (cond-mat.mtrl-sci)
Link to the access to the paper: this https URL
Physica B: Condensd Matter. Volume 713, 15 September 2025, 417360
Robust superzone gap opening in incommensurate antiferromagnetic semimetal EuAg$_4$Sb$_2$ under in-plane magnetic field
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2025-05-20 20:00 EDT
J. Green, Arpit Arora, Madalynn Marshall, Wanfei Shan, Péter Udvarhelyi, Zachary Morgan, Prineha Narang, Huibo Cao, Ni Ni
The interplay between magnetism and charge transport in semimetals has emerged as a fertile ground for discovering novel electronic phenomena. A notable example is the recent discovery of electronic commensuration arising from a spin moiré superlattice (SMS), realized as double-q spin modulation in the antiferromagnetic semimetal EuAg$ _4$ Sb$ _2$ . Here, we investigate the in-plane magnetic-field tunability of the SMS using neutron scattering, magnetic and transport measurements. We reveal an incommensurate noncollinear cycloidal magnetic ground state. Temperature-field phase diagrams constructed with field tilting uncover multiple spin-reoriented phases, suggesting the critical role of in-plane field components in driving magnetic transitions. Despite substantial spin reorientation of the double-q phase, we observe a persistent gap opening, evidenced by strong suppression in both Hall and longitudinal conductivities. Model calculations attribute this robustness to the stability of SMS under tilting fields. Our results establish EuAg$ _4$ Sb$ _2$ as a tunable platform for exploring spin-texture-driven superzone gap opening in electronic states.
Strongly Correlated Electrons (cond-mat.str-el)
7 pages, 4 figures
Qubit based on 0-$π$ Josephson junctions
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2025-05-20 20:00 EDT
We investigate the static properties of 0-$ \pi$ Josephson junctions, with particular emphasis on their application in superconducting quantum circuits. Using a theoretical framework based on the sine-Gordon equation, we analyze the phase evolution for 0-$ \pi$ junctions under various boundary and excitation conditions. These junctions, characterized by spatially varying phase shifts, offer promising configurations for qubit implementations due to their intrinsic symmetry and potential robustness against decoherence. We explore the energy landscape, quantized levels, and switching dynamics relevant for qubit state manipulation. Additionally, we present models for phase, flux, and charge qubit designs, emphasizing their operational principles and readout mechanisms. This work provides insights into the engineering of Josephson-based qubits and supports their continued development as scalable components for quantum information processing.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
12 pages, 8 figures
Can experimentally-accessible measures of entanglement distinguish quantum spin liquids from disorder-driven “random singlet” phases ?
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2025-05-20 20:00 EDT
Tokuro Shimokawa, Snigdh Sabharwal, Nic Shannon
At the theoretical level, quantum spin liquids are distinguished from other phases of matter by their entanglement properties. However, since the usual measure of entanglement, entanglement entropy, cannot accessed in experiment, indentifying quantum spin liquids in candidate materials remains an acute problem. Here we show other, experimentally-accessible, measures of entanglement can be used to distinguish a quantum spin liquid from a competing disorder-driven “random singlet” phase, in a model of a disordered antiferromagnet on a triangular lattice. The application of these results to the triangular-lattice systems YbZnGaO$ _4$ , YbZn$ _2$ GaO$ _5$ and KYbSe$ _2$ is discussed.
Strongly Correlated Electrons (cond-mat.str-el)
7+5 pages, 5+4 figures
A Universal Matrix Ensemble that Unifies Eigenspectrum Laws via Neural Network Models
New Submission | Disordered Systems and Neural Networks (cond-mat.dis-nn) | 2025-05-20 20:00 EDT
Arata Tomoto, Jun-nosuke Teramae
Random matrix theory, which characterizes the spectrum distribution of infinitely large matrices, plays a central role in theories across diverse fields, including high-dimensional data analysis, ecology, neuroscience, and machine learning. Among its celebrated achievements, the Marchenko–Pastur law and the elliptic law have served as key results for numerous applications. However, the relationship between these two laws remains elusive, and the existence of a universal framework unifying them is unclear. Inspired by a neural network model, we establish a universal matrix ensemble that unifies these laws as special cases. Through an analysis based on the saddle-node equation, we derive an explicit expression for the spectrum distribution of the ensemble. As a direct application, we reveal how the universal law clarifies the stability of a class of associative memory neural networks. By uncovering a fundamental law of random matrix theory, our results deepen the understanding of high-dimensional systems and advance the integration of theories across multiple disciplines.
Disordered Systems and Neural Networks (cond-mat.dis-nn), Data Analysis, Statistics and Probability (physics.data-an)
Main text, 6 pages, 4 figures. Supplementary Materials, 7 pages
Accelerating the Search for Superconductors Using Machine Learning
New Submission | Superconductivity (cond-mat.supr-con) | 2025-05-20 20:00 EDT
Suhas Adiga, Umesh V. Waghmare
Prediction of critical temperature $ (T_c)$ of a superconductor remains a significant challenge in condensed matter physics. While the BCS theory explains superconductivity in conventional superconductors, there is no framework to predict $ T_c$ of unconventional, higher $ T_{c}$ superconductors. Quantum Structure Diagrams (QSD) were successful in establishing structure-property relationship for superconductors, quasicrystals, and ferroelectric materials starting from chemical composition. Building on the QSD ideas, we demonstrate that the principal component analysis of superconductivity data uncovers the clustering of various classes of superconductors. We use machine learning analysis and cleaned databases of superconductors to develop predictive models of $ T_c$ of a superconductor using its chemical composition. Earlier studies relied on datasets with inconsistencies, leading to suboptimal predictions. To address this, we introduce a data-cleaning workflow to enhance the statistical quality of superconducting databases by eliminating redundancies and resolving inconsistencies. With this improvised database, we apply a supervised machine learning framework and develop a Random Forest model to predict superconductivity and $ T_c$ as a function of descriptors motivated from Quantum Structure Diagrams. We demonstrate that this model generalizes effectively in reasonably accurate prediction of $ T_{c}$ of compounds outside the database. We further employ our model to systematically screen materials across materials databases as well as various chemically plausible combinations of elements and predict $ \mathrm{Tl}{5}\mathrm{Ba}{6}\mathrm{Ca}{6}\mathrm{Cu}{9}\mathrm{O}{29}$ to exhibit superconductivity with a $ T{c}$ $ \sim$ 105 K. Being based on the descriptors used in QSD’s, our model bypasses structural information and predicts $ T_{c}$ merely from the chemical composition.
Superconductivity (cond-mat.supr-con), Materials Science (cond-mat.mtrl-sci)
Unlocking Photon Magnon Interplay via Saturation Magnetization
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-05-20 20:00 EDT
Sachin Verma, Jiten Mahalik, Abhishek Maurya, Rajeev Singh, Biswanath Bhoi
Photon magnon hybrid systems present a promising platform for the development of next generation devices in quantum information processing and quantum sensing technologies. In this study, we investigate the control of photon magnon coupling (PMC) strength through systematic variation of the saturation magnetization in a planar hexagonal ring resonator (HRR) integrated with a yttrium iron garnet (YIG) thin film configuration. Using full wave numerical simulations in CST Microwave Studio, we demonstrate that tuning the Ms of the YIG film from 1750 Oe to 900 Oe enables systematic control over the coupling strength across the 127 to 51 MHz range at room temperature. To explain the observed PMC dynamics, we develop a semiclassical analytical model based on electromagnetic theory that accurately reproduces the observed coupling behavior, revealing the key role of spin density in mediating the light matter interaction. The model is further extended to include the effects of variable magnon damping across different Ms values, enabling broader frequency control. These findings establish Ms as a key tuning parameter for tailoring PMC, with direct implications for the design of tunable hybrid systems for reconfigurable quantum devices.
Materials Science (cond-mat.mtrl-sci), Quantum Physics (quant-ph)
10 Pages, 8 Figures
Unveiling the thermal transport properties of Biphenylene nanotubes: A molecular dynamics study
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-05-20 20:00 EDT
Jhionathan de Lima, Cristiano F. Woellner
Biphenylene nanotubes (BPNNTs) represent a novel class of carbon-based nanomaterials, constructed by rolling a biphenylene network (BPN) monolayer into a one-dimensional tubular structure. In this study, the thermal transport properties of BPNNTs are investigated using reverse non-equilibrium molecular dynamics simulations. At room temperature, the lattice thermal conductivity of armchair and zigzag BPNNTs is found to be approximately 100 W/m.K and 90 W/m.K, respectively. These values are at least one order of magnitude lower than those of single-walled carbon nanotubes (SWCNTs). This significant reduction is attributed to the unique atomic arrangement of BPNNTs, which promotes enhanced phonon scattering and significantly lower phonon group velocity. Furthermore, the effects of nanotube length, diameter, and temperature on thermal transport are systematically analyzed. To elucidate the mechanisms underlying the geometry- and temperature-dependent thermal behavior, a comprehensive analysis of phonon dispersion relations, vibrational density of states, and phonon group velocities is conducted. This study offers valuable insight into the thermal transport properties of BPNNTs, with implications for thermal management and energy-related applications.
Materials Science (cond-mat.mtrl-sci)
Symmetry-broken magneto-toroidal artificial spin ices: magnetization states and dynamics
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2025-05-20 20:00 EDT
G. Alatteili, L. A. Scafuri, E. Iacocca
Magneto-toroidal artificial spin ices (MT-ASIs) are arrangements of nanomagnets that exhibit spontaneous toroidization. A ferrotoroidic order could have implications on the propagation of spin waves through this artificial spin ice, including the development of topological edge modes. Here, we numerically investigate the magnetization dynamics of an MT-ASI with and without spatial symmetry breaking. Through micromagnetic simulations, we compute the energies and ferromagnetic resonance spectra of the four lowest-order states, which exhibit ferrotoroidicity, antiferrotoroidicity, and no toroidicity. As expected, we find that the resonant modes split when spatial symmetry is broken. To determine whether our system exhibits topologically protected edge modes, we perform semi-analytical calculations to first estimate the ferromagnetic resonance and then compute the band structure. Our results show that symmetry-broken MT-ASIs are reconfigurable by magnetic field protocols, and that their band structures depend on magnetization state. Calculation of the Chern number indicates that the bands are topologically trivial in all cases, suggesting that the dynamic magnetic coupling is weak. The absence of a non-zero Chern number is proof of the weak dynamic coupling in ASIs, which must be addressed to unlock their full potential in magnonics applications.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
Measuring the mechanical properties of asymmetric membranes in computer simulations – new methods and insights
New Submission | Soft Condensed Matter (cond-mat.soft) | 2025-05-20 20:00 EDT
We present Monte Carlo simulations of an ultra coarse-grained lipid bilayer with different number of lipids on both leaflets. In the simulations, we employ a new method for measuring the elastic parameters of the membrane, including the area per lipid, area elasticity modulus, and bending rigidity. The method also allows to measure the spontaneous curvature and non-local bending modulus, which are not accessible by standard computer simulations with periodic boundary conditions. For membranes with lipid densities much smaller than the liquid to gel transition density, $ \rho_g$ , we find a very good agreement between the simulation results and the theory expressing the bilayer elastic free energy as the sum of quadratic free energies in the strains associated with the area density and the local curvature of the monolayers. The theory fails when the lipid area density (in the symmetric reference case) is only slightly smaller than $ \rho_g$ . Increasing the degree of asymmetry and changing the density of the condensed leaflet to a value larger than $ \rho_g$ , causes the layer to phase separate between regions with distinct densities which, in turn, may also induce density variations in the dilated liquid layer. Moreover, the phase separation may also trigger local curvature variations along the membrane, which can be attributed to the disparity between the values of the elastic parameters of the coexisting bilayer segments that are mechanically coupled. This mechanism leading to density-curvature variations and instabilities may play a role in cellular processes occurring in liquid-ordered raft domains that are surrounded by the disordered liquid matrix of the cell.
Soft Condensed Matter (cond-mat.soft), Statistical Mechanics (cond-mat.stat-mech), Biological Physics (physics.bio-ph)
To appear in a Faraday Discussions issue on Structural and functional asymmetry of plasma membranes
Integrability and exact large deviations of the weakly-asymmetric exclusion process
New Submission | Statistical Mechanics (cond-mat.stat-mech) | 2025-05-20 20:00 EDT
Alexandre Krajenbrink, Pierre Le Doussal
The weakly asymmetric exclusion process (WASEP) in one dimension is a paradigmatic system of interacting particles described by the macroscopic fluctuation theory (MFT) in the presence of driving. We consider an initial condition with densities $ \rho_1,\rho_2$ on either side of the origin, so that for $ \rho_1=\rho_2$ the gas is stationary. Starting from the microscopic description, we obtain exact formulae for the cumulant generating functions, and large deviation rate functions of the time-integrated current and the position of a tracer. As the asymmetry/driving is increased, these describe the crossover between the symmetric exclusion process (SSEP) and the weak noise regime of the Kardar-Parisi-Zhang (KPZ) equation: we recover the two limits and describe the crossover from the WASEP cubic tail to the $ 5/2$ and $ 3/2$ KPZ tail exponents. Finally, we show that the MFT of the WASEP is classically integrable, by exhibiting the explicit Lax pairs, which are obtained through a novel mapping between the MFT of the WASEP and a complex extension of the classical anisotropic Landau-Lifshitz spin chain. This shows integrability of all MFTs of asymmetric models with quadratic mobility as well as their dual versions.
Statistical Mechanics (cond-mat.stat-mech), Disordered Systems and Neural Networks (cond-mat.dis-nn), Mathematical Physics (math-ph), Probability (math.PR), Exactly Solvable and Integrable Systems (nlin.SI)
73 pages
Dislocation Glides in Monolayered Granular Media: Effect of Lattice Constant
New Submission | Soft Condensed Matter (cond-mat.soft) | 2025-05-20 20:00 EDT
Fumiaki Nakai, Takashi Uneyama, Yuto Sasaki, Kiwamu Yoshii, Hiroaki Katsuragi
A recent study demonstrated that granular crystals containing a single dislocation exhibit dislocation glide analogous to that observed in atomic-scale crystals, resulting in plastic deformation at yield stresses several orders of magnitude lower than those of dislocation-free crystals. The yielding behavior strongly depends on the interparticle friction coefficient $ \mu$ : dislocation glide occurs for friction coefficients below a critical value $ \mu_c$ , while crystalline order deteriorates above $ \mu_c$ . In this work, we use discrete element method simulations to systematically investigate how the lattice constant, which determines the interparticle spacing and is a fundamental parameter in microscopic crystalline solids, and the friction coefficient $ \mu$ influence the yielding behavior in monolayered granular crystals with dislocation. By decreasing the lattice constant, we find an increase in the critical friction coefficient $ \mu_c$ , allowing dislocation glide to persist at higher friction values. Furthermore, we observe a linear scaling of yield stress with normal stress, except at extremely low friction coefficients.
Soft Condensed Matter (cond-mat.soft), Statistical Mechanics (cond-mat.stat-mech)
5 pages, 4 figures, This paper is scheduled to be published in “EPJ Web of Conferences’’ (Powders & Grains 2025, 8-12 December, Goa, India)
Soft superconductivity in covalent bismuth dihydride BiH2 under extreme conditions
New Submission | Superconductivity (cond-mat.supr-con) | 2025-05-20 20:00 EDT
Jianning Guo, Dmitrii V. Semenok, Ivan A. Troyan, Di Zhou, Yulong Wang, Yuzhi Chen, Su Chen, Kexin Zhang, Xinyue Wu, Sven Luther, Toni Helm, Andrey V Sadakov, Alexey S. Usoltsev, Leonid A Morgun, Vladimir M Pudalov, Viktor V Struzhkin, Xiaoli Huang
Strong magnetic fields provide a unique environment for investigating the fundamental properties of superconducting materials especially for hydride superconductors with large upper critical fields. Following this idea, we have investigated the effect of pulsed magnetic fields on covalent bismuth dihydride, successfully synthesized under pressure up to 211 GPa. The electrical resistance measurements indicate that the superconducting phase P21m BiH2 exhibits the highest superconducting critical temperature (Tc) of 70 K among MH2type hydrides apart from H2S. The electrical transport experiments under both pulsed (up to 50 T) and steady magnetic fields (up to 16 T) for P21m and C2m BiH2 indicate that the upper critical fields miu0Hc2(0) is 12 to 16 T are unusually low, much lower than that of clathrate-like metal polyhydrides with similar Tc. This is due to the unexpectedly high Fermi velocity in BiH2, about 1.1 106 m s, which allows to classify BiH2 as a soft molecular superconducting hydride with relatively weak vortex pinning. Measurements of the current voltage characteristics in the pulsed mode make it possible to experimentally establish the temperature dependence of the critical current density (the maximum Jc(0) is 10 kA mm2), which indicates the presence of two s wave superconducting gaps in BiH2 at 172 to 176 GPa: deltaL(0) is 6.9 1.2 meV and deltaS(0) is 1.5 meV.
Superconductivity (cond-mat.supr-con), Classical Physics (physics.class-ph)
16 pages, 4 figures
Preventing clustering of active particles in microchannels
New Submission | Soft Condensed Matter (cond-mat.soft) | 2025-05-20 20:00 EDT
Juan Pablo Carrillo-Mora, Moniellen Pires Monteiro, V.I. Marconi, Maria Luisa Cordero, Ricardo Brito, Rodrigo Soto
The trajectories of microswimmers moving in narrow channels of widths comparable to their sizes are significantly altered when they encounter another microswimmer moving in the opposite direction. The consequence of these encounters is a delay in the progress of both swimmers, which can be conceptualized as an instantaneous effective backward displacement. Similarly, the modeling of tumble events in bacteria, which occur over a finite time, can be represented as an instantaneous effective displacement in addition to a change in direction. Such effective displacements can be incorporated directly into a kinetic theory for the partial densities of swimmers moving in the channel. The linear analysis of the resulting equation yields the critical density at which clusters emerge. The methodology is then applied to the case of soil bacteria moving in long channels of cross-section 1.8$ {\mu}$ m $ \times$ 1.8$ {\mu}$ m. The tracking of the swimmers permits the straightforward acquisition of the effective displacements, which in turn allows the critical density ($ {\rho}_{\text{crit}}\simeq$ 0.10 bact/$ {\mu}$ m) to be predicted prior to cluster formation. The advantage of this proposed approach is that it does not necessitate the determination of an effective density-dependent speed, which is a requisite of the standard motility-induced phase separation theory.
Soft Condensed Matter (cond-mat.soft)
Data Mining and Computational Screening of Rashba-Dresselhaus Splitting and Optoelectronic Properties in Two-Dimensional Perovskite Materials
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-05-20 20:00 EDT
Robert Stanton, Wanyi Nie, Sergei Tretiak, Dhara J. Trivedi
Recent developments highlighting the promise of two-dimensional perovskites have vastly increased the compositional search space in the perovskite family. This presents a great opportunity for the realization of highly performant devices, and practical challenges associated with the identification of candidate materials. High-fidelity computational screening offers great value in this regard. In this study, we carry out a multiscale computational workflow, generating a dataset of two-dimensional perovskites in the Dion-Jacobson and Ruddlesden-Popper phases. Our dataset comprises ten B-site cations, four halogens, and over 20 organic cations across over 2,000 materials. We compute electronic properties, thermoelectric performance, and numerous geometric characteristics. Furthermore, we introduce a framework for the high-throughput computation of Rashba-Dresselhaus splitting. Finally, we use this dataset to train machine learning models for the accurate prediction of band gaps, candidate Rashba-Dresselhaus materials, and partial charges. The work presented herein can aid future investigations of two-dimensional perovskites with targeted applications in mind.
Materials Science (cond-mat.mtrl-sci), Chemical Physics (physics.chem-ph), Computational Physics (physics.comp-ph)
Main Manuscript: 34 pages, 7 figures. Supplementary Material: 19 pages, 11 figures
Strange metallicity encompasses high magnetic field-induced superconductivity in UTe2
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2025-05-20 20:00 EDT
T.I. Weinberger, H. Chen, Z. Wu, M. Long, A. Cabala, Y. Skourski, J. Sourd, T. Haidamak, V. Sechovsky, M. Valiska, F.M. Grosche, A.G. Eaton
The heavy fermion material UTe$ _2$ hosts a suite of exotic superconducting phases, the most extreme of which resides in a narrow angular window of intense magnetic fields $ >$ 40 T. Here we report that in the angular and field regime in which field-induced superconductivity is most robust, the normal-state resistivity exhibits a linear temperature dependence characteristic of strange metallicity, sharply contrasting with the Fermi-liquid behavior observed at low fields and away from this angular window. Through angle-dependent magnetotransport measurements in high magnetic fields, we find that the strange metal state is confined to a narrow angular range where field-induced superconductivity is also maximized, suggesting a shared underlying mechanism. These findings reveal a novel setting for strange metallicity - proximate to spin-triplet, field-induced superconductivity - and point to the presence of quantum critical fluctuations, likely of a magnetic origin. The coexistence of strange metallicity and putatively spin-triplet pairing challenges prevailing paradigms of non-Fermi-liquid phenomenology, and highlights UTe$ _2$ as a unique platform for exploring the interplay between unconventional superconductivity and quantum criticality.
Strongly Correlated Electrons (cond-mat.str-el)
Efficient and Accurate Machine Learning Interatomic Potential for Graphene: Capturing Stress-Strain and Vibrational Properties
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-05-20 20:00 EDT
Felipe Hawthorne, Paulo R. E. Raulino, Ronaldo Rodrigues Pelá, Cristiano F. Woellner
Machine learning interatomic potentials (MLIPs) offer an efficient and accurate framework for large-scale molecular dynamics (MD) simulations, effectively bridging the gap between classical force fields and \textit{ab initio} methods. In this work, we present a reactive MLIP for graphene, trained on an extensive dataset generated via \textit{ab initio} molecular dynamics (AIMD) simulations. The model accurately reproduces key mechanical and vibrational properties, including stress-strain behavior, elastic constants, phonon dispersion, and vibrational density of states. Notably, it captures temperature-dependent fracture mechanisms and the emergence of linear acetylenic carbon chains upon tearing. The phonon analysis also reveals the expected quadratic ZA mode and excellent agreement with experimental and DFT benchmarks. Our MLIP scales linearly with system size, enabling simulations of large graphene sheets with \textit{ab initio}-level precision. This work delivers a robust and transferable MLIP, alongside an accessible training workflow that can be extended to other materials.
Materials Science (cond-mat.mtrl-sci), Computational Physics (physics.comp-ph)
15 pages, 7 figures
Superconductivity in La1.85Sr0.15CuO4 Ceramic Samples
New Submission | Superconductivity (cond-mat.supr-con) | 2025-05-20 20:00 EDT
N. V. Dalakova, B. I. Belevtsev, E. Yu. Beliayev, Yu. A. Savina, O. I. Yuzephovich, S. V. Bengus, N. P. Bobrysheva
Effects related to the granularity of a La1.85Sr0.15CuO4 ceramic sample, synthesized by the solidstate reaction method, are presented. The superconducting transition exhibits a step-like behavior. Lowtemperature features of magnetoresistance hysteresis loops associated with the granular structure of the sample have been observed.
Superconductivity (cond-mat.supr-con)
5 pages, 4 figures. Author-prepared English version of a 2014 article (Izvestiya RAN, Seriya Fizicheskaya). Text revised and expanded
Polymer (imperfect) single-file diffusion: A phase diagram
New Submission | Soft Condensed Matter (cond-mat.soft) | 2025-05-20 20:00 EDT
We use Langevin dynamics (LD) simulations to investigate single-file diffusion (SFD) in a dilute solution of flexible linear polymers inside a narrow tube with periodic boundary conditions (a torus). The transition from SFD, where the time (t) dependence of the mean-square displacement scales like $ \langle x^2\rangle \sim t^{1/2}$ , to normal diffusion with $ \langle x^2 \rangle \sim t$ , is studied as a function of the system parameters, such as the size and concentration of the polymer chains and the width of the tube. We propose a phase diagram describing different diffusion regimes. In particular, we highlight the fact that there are two different pathways to normal long-time diffusion. We also map this problem onto a one-dimensional Lattice Monte Carlo model where the diffusing object represents the polymer center of mass. Possible extensions of this work to polydisperse polymer solutions, one-dimensional electrophoresis and DNA mapping are discussed.
Soft Condensed Matter (cond-mat.soft), Biological Physics (physics.bio-ph)
11 pages, 12 figures
Shubnikov-de Haas quantum oscillations with large spin splitting in highmobility Al0.8Ga0.2Sb/InAs/ Al0.8Ga0.2Sb quantum-well heterostructures
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2025-05-20 20:00 EDT
Zhenghang Zhi, Hanzhi Ruan, Jiuming Liu, Xinpeng Li, Yong Zhang, Qi Yao, Chenjia Tang, Yujie Xiao, Xufeng Kou
We report the epitaxial growth of high-quality Al0.8Ga0.2Sb-InAs-Al0.8Ga0.2Sb quantum well films featured by high carrier mobility and strong spin-orbit coupling. By appropriately optimizing the Al-to-Ga ratio in the AlGaSb barrier layer, the quantum confinement of the heterostructure is significantlyenhanced, which results in both an ultra-high electron mobility of 924000 cm2/Vs and a giant magnetoresistance ratio of 365000 at low temperatures. Meanwhile, pronounced Shubnikov-deHaas quantum oscillations persist up to 30 K, and their single-frequency feature indicates a well defined Fermi surface without subband mixing in the two-dimensional electron gas channel. Moreover, the large effective g-factor of 12.93 leads to the observation of Zeeman splitting at large magnetic fields. Our results validate the AlGaSb/InAs quantum well heterostructures as a suitable candidate for constructing energy-efficient topological spintronic devices.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Materials Science (cond-mat.mtrl-sci)
Inhomogeneity-driven multiform Spontaneous Hall Effect in conventional and unconventional superconductors
New Submission | Superconductivity (cond-mat.supr-con) | 2025-05-20 20:00 EDT
Nadia Stegani (1, 2), Ilaria Pallecchi (2), Nicola Manca (2), Martina Meinero (1,2), Michela Iebole (1,2), Matteo Cialone (1,2), Valeria Braccini (2), Vadim Grinenko (3), Marina Putti (1,2), Federico Caglieris (2) ((1) University of Genoa, Via Dodecaneso 33, 16146, Genoa, Italy, (2) Consiglio Nazionale delle Ricerche (CNR)-SPIN, Corso Perrone 24, 16152, Genoa, Italy, (3) Tsung-Dao Lee Institute, No.520 Shengrong Road, Shanghai, 201210)
The spontaneous Hall effect (SHE), a finite voltage occurring transversal to the electrical current in zero-magnetic field, has been observed in both conventional and unconventional superconductors, appearing as a peak near the superconducting transition temperature. The origin of SHE is strongly debated, with proposed explanations ranging from intrinsic and extrinsic mechanisms such as spontaneous symmetry breaking and time-reversal symmetry breaking (BTRS), Abrikosov vortex motion, or extrinsic factors like material inhomogeneities, such as non-uniform critical temperature (Tc) distributions or structural asymmetries. This work is an experimental study of the SHE in various superconducting materials. We focused on conventional, low-Tc, sharp transition Nb and unconventional, intermediate-Tc, smeared transition Fe(Se,Te). Our findings show distinct SHE peaks around the superconducting transition, with variations in height, sign and shape, indicating a possible common mechanism independent of the specific material. We propose that spatial inhomogeneities in the critical temperature, caused by local chemical composition variations, disorder, or other forms of electronic spatial inhomogeneities could explain the appearing of the SHE. This hypothesis is supported by comprehensive finite elements simulations of randomly distributed Tc by varying Tc-distribution, spatial scale of disorder and amplitude of the superconducting transition. The comparison between experimental results and simulations suggest a unified origin for the SHE in different superconductors, whereas different phenomenology can be explained in terms of amplitude of the transition temperature in respect to Tc-distribution.
Superconductivity (cond-mat.supr-con)
Antipolar and short and long-range magnetic ordering in quasi-two-dimensional AgCrP2S6
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2025-05-20 20:00 EDT
Chaitanya B. Auti, Atul G. Chakkar, Shantanu Semwal, Sebastian Selter, Yuliia Shemerliuk, Bernd Büchner, Saicharan Aswartham, Koushik Pal, Pradeep Kumar
Within the Landau theoretical framework, the decreased entropy with decreasing the temperature is accompanied by the symmetry breaking and hence a corresponding phase transition. The broken symmetries leave its imprint on the underlying excitations and the same may be gauged using renormalization of these excitations. AgCrP2S6 provides a versatile playground to probe dynamics of the quasiparticle excitations as well as multiple phase transitions with lowering temperature linked with the polar, lattice and spin degrees of freedom. Here, we report an in-depth temperature- and polarization-dependent Raman scattering measurements on single crystals of quasi 2D zigzag antiferromagnet AgCrP2S6 along with the first principle based phonon calculations. We observed multiple phase transitions triggered by the short and long-range ordering of spins at ~ 90 K and 20 K, respectively; within the Cr sublattice where spins are arranged in a 1D chain, evident by the distinct anomalies in the phonon modes self-energy parameters as well as intensity. Contrary to the conventional belief, we uncovered potential quasi-antipolar ordering at ~ 200 K and with further lowering in temperature an antipolar ordering at ~ 140 K attributed to the Ag ions, which is conjectured to be forbidden owing to the heaviness of Ag ions. The quasi-antipolar and antipolar ordering is gauged via the distinct renormalization of the phonon parameters, which survives at all the temperatures. Additionally, large number of modes appears with decreasing the temperature, in the window of ~ 200-140 K, where antipolar ordering starts settling in. The emergence of large number of phonon modes below ~ 200 K, nearly double of those at room temperature, suggests the lowering of symmetry from high temperature C2h to the low temperature C2 or Cs and as a result doubling of the unit cell.
Strongly Correlated Electrons (cond-mat.str-el)
Enhancement of d-wave Pairing in Strongly Correlated Altermagnet
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2025-05-20 20:00 EDT
Jianyu Li, Ji Liu, Xiaosen Yang, Ho-Kin Tang
Altermagnetism, featuring momentum-dependent spin splitting without net magnetization, has attracted a growing interest for spintronics. We study a Fermi Hubbard model with altermagnetic order arising from the spin-anisotropic hopping near half-filling using constrained-path quantum Monte Carlo. Spin-dependent hopping breaks SU(2) symmetry and disrupts Fermi surface nesting, giving rise to an altermagnetic state with momentum-space spin splitting but no net magnetization. We find that increasing anisotropy suppresses long-range antiferromagnetic order and significantly enhances effective $ d$ -wave pairing correlations. Our results demonstrate a doping-free route to unconventional superconductivity mediated by short-range spin fluctuations in an altermagnetic background.
Strongly Correlated Electrons (cond-mat.str-el), Superconductivity (cond-mat.supr-con)
Conservative Join with memory in token-based Brownian circuits and its thermodynamic cost
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2025-05-20 20:00 EDT
The token-based Brownian circuit harnesses the Brownian motion of particles for computation. The conservative join (CJoin) is a circuit element that synchronizes two Brownian particles, and its realization using repelling particles, such as magnetic skyrmions or electrons, is key to building the Brownian circuit. Here, a theoretical implementation of the CJoin using a simple quantum dot circuit is proposed, incorporating an internal state-a double quantum dot that functions as a one-bit memory, storing the direction of two-particle transfer. A periodic reset protocol is introduced, allowing the CJoin to emit particles in a specific direction. The stochastic thermodynamics under periodic resets identifies the thermodynamic cost as the work done for resets minus the entropy reduction due to resets, with its lower bound remaining within a few multiples of $ k_{\rm B} T$ at temperature $ T$ . Applying the speed limit relation to a subsystem in bipartite dynamics, the number of emitted particles is shown to be relatively tightly bounded from above by an expression involving the subsystem’s irreversible entropy production rate and dynamical activity rate.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Statistical Mechanics (cond-mat.stat-mech)
16 pages, 11 figures, 2 tables
Intrinsic layer polarization and multi-flatband transport in non-centrosymmetric mixed-stacked multilayer graphene
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2025-05-20 20:00 EDT
Kai Liu, Yating Sha, Bo Yin, Shuhan Liu, Yulu Ren, Zhongxun Guo, Jingjing Gao, Ming Tian, Neng Wan, Kenji Watanabe, Takashi Taniguchi, Bingbing Tong, Guangtong Liu, Li Lu, Yuanbo Zhang, Weidong Luo, Zhiwen Shi, Quansheng Wu, Guorui Chen
Graphene multilayers exhibit electronic spectra that depend sensitively on both the number of layers and their stacking order. Beyond trilayer graphene, mixed stacking sequences (alternating Bernal and rhombohedral layers) give rise to multiple coexisting low-energy bands. Here we investigate ABCBC-stacked pentalayer graphene, a less-studied non-centrosymmetric mixed sequence. This stacking can be regarded as an ABC (rhombohedral) trilayer on top of an AB (Bernal) bilayer, so its low-energy band structure contains both a cubic band and a parabolic band that hybridize. In transport measurements, we observe an intrinsic band gap at charge neutrality whose magnitude changes asymmetrically under an applied perpendicular displacement field. This behavior reflects the spontaneous layer polarization inherent to the broken inversion symmetry and mirror symmetry. By tuning the displacement field and carrier density, we drive multiple Lifshitz transitions in the Fermi surface topology and realize Landau levels with different degeneracies arising from the multi-flatband system. Remarkably, a v = -6 quantum Hall state emerges at an exceptionally low magnetic field (~20 mT), indicating the interplay between spontaneous symmetry breaking and Berry curvatures. Our results establish mixed-stacked multilayer graphene as a tunable platform with various broken symmetries and multiple flatbands, suitable for exploring emergent correlated electronic states.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
Thermal and thermoelectric transport in monolayer h-NbN: Roles of four-phonon scattering and tensile strain
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-05-20 20:00 EDT
Himanshu Murari, Subhradip Ghosh, Mukul Kabir, Ashis Kundu
Unlocking the thermal and thermoelectric potential of 2D materials, we explore the h-NbN monolayer, which lacks mirror symmetry and features a large acoustic-optical phonon gap and quadratic flexural mode. First-principles calculations and the Boltzmann transport formalism reveal a complex interplay of multi-phonon scattering processes, where flexural phonons and four-phonon interactions play a significant role in heat transport, primarily dominated by acoustic phonons. Notably, the four-phonon interactions are predominantly confined to acoustic phonons. Tensile strain preserves the underlying scattering mechanisms while reducing anharmonicity, consequently, the scattering rates, enhancing thermal conduction. Simultaneously, competing modifications in thermal and electrical transport shape the strain-dependent thermoelectric response, achieving a figure of merit approaching 1 at elevated temperatures, a testament to its thermoelectric promise. Our findings underscore the critical role of microscopic transport modeling in accurately capturing thermal and thermoelectric properties, paving the way for advanced applications of 2D materials.
Materials Science (cond-mat.mtrl-sci), Applied Physics (physics.app-ph)
11 pages, 6 figures
Voltage-tuned anomalous-metal to metal transition in hybrid Josephson junction arrays
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2025-05-20 20:00 EDT
S. Sasmal, M. Efthymiou-Tsironi, G. Nagda, E. Fugl, L. L. Olsen, F. Krizek, C. M. Marcus, S. Vaitiekėnas
We report voltage-tuned phase transitions in arrays of hybrid semiconductor-superconductor islands arranged in a square lattice. A double-layer electrostatic gate geometry enables independent tuning of inter-island coupling and proximity-induced superconductivity. This design enables access to the superconductor-insulator, superconductor-metal, and metal-insulator transitions in a single device, revealing critical points and emergent intermediate phases. We find that the superconductor-insulator transition is interrupted by an anomalous metallic phase with saturating low-temperature resistivity. Across gate voltages, this regime extends over three orders of magnitude in resistivity and can be continuously tuned into the conventional metallic phase. The signature of the anomalous metallic phase is suppressed by magnetic frustration.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Superconductivity (cond-mat.supr-con)
8 pages, 5+6 figures
Microscopic theory of electron quadrupling condensates
New Submission | Superconductivity (cond-mat.supr-con) | 2025-05-20 20:00 EDT
Albert Samoilenka, Egor Babaev
A plethora of materials exhibit electron pairing, leading to the phenomenon of superconductivity. Recently, experiments found evidence consistent with the formation of more complex states characterized by order in four-electron composite objects, termed electron quadrupling or composite order. In the first part of the paper, we provide a general microscopic framework to describe these and the other four-fermion composite states. In the second part of the paper, we derive and solve a specific fermionic model in two and three dimensions that hosts time-reversal symmetry-breaking electron quadrupling order. The fermionic microscopic theory is used to estimate the specific heat and electron density of states.
Superconductivity (cond-mat.supr-con)
13 pages, 6 figures
Reentrant Rigidity Transition in Planar Epithelia with Volume- and Area Elasticity
New Submission | Soft Condensed Matter (cond-mat.soft) | 2025-05-20 20:00 EDT
We recover a rigidity transition in 3D epithelial monolayers, described by cell Volume- and Area Elasticity (VAE). An in-plane isotropic strain drives a reentrant columnar-to-sqamous rigidity transition, with a critical point near the unit cell aspect ratio. In addition to the vanishing shear modulus, the phase diagram also features floppy states with zero in-plane bulk modulus and a discontinuous columnar-squamous transition, controlled by the lateral tension. Our results provide a 3D context to the rigidity transition of the well-studied 2D Area- and Perimeter-Elasticity (APE) model of epithelia, offering a resolution to a counterintuitive compression-induced tissue softening predicted by the 2D model.
Soft Condensed Matter (cond-mat.soft)
Vortex Mass in Superfluid Fermi Gases along the BEC–BCS Crossover
New Submission | Quantum Gases (cond-mat.quant-gas) | 2025-05-20 20:00 EDT
Lucas Levrouw, Hiromitsu Takeuchi, Jacques Tempere
Vortex mass is a key concept in the study of superfluid dynamics, referring to the inertia of vortices in a superfluid, which affects their motion and behavior. Despite being an important quantity, the vortex mass has never been observed experimentally, and remains an unresolved issue in this field. As of now, a large body of research assumes that the vortex mass is a local parameter. In contrast, we present a calculation that suggests a logarithmic dependence on the system size, agreeing with some earlier predictions in the context of Bose gases. We analyze the problem using an effective field theory that describes ultracold atomic Fermi gases over the BEC–BCS crossover at both zero and nonzero temperatures. Our study reveals a strong dependence of the vortex mass on the scattering length; in particular, the vortex mass grows rapidly when moving towards the BCS side. Furthermore, we find that the system-size dependence of the vortex mass results in values an order of magnitude larger than those predicted by other models for realistic system sizes. This implies that the vortex mass could be observable in a wider parameter range than was previously expected. This is particularly relevant considering recent advances in experimental techniques that place the observation of vortex mass in superfluid Fermi gases within reach.
Quantum Gases (cond-mat.quant-gas)
Driven Critical Dynamics in Tricitical Point
New Submission | Statistical Mechanics (cond-mat.stat-mech) | 2025-05-20 20:00 EDT
Ting-Long Wang, Yi-Fan Jiang, Shuai Yin
The conventional Kibble-Zurek (KZ) mechanism, describing driven dynamics across critical points based on the adiabatic-impulse scenario (AIS), have attracted broad attentions. However, the driven dynamics in tricritical point with two independent relevant directions has not been adequately studied. Here, we employ time dependent variational principle to study the driven critical dynamics at a one-dimensional supersymmetric Ising tricritical point. For the relevant direction along the Ising critical line, the AIS apparently breaks down. Nevertheless, we find that the critical dynamics can still be described by the KZ scaling in which the driving rate has the dimension of $ r=z+1/\nu_\mu$ with $ z$ and $ \nu_\mu$ being the dynamic exponent and correlation length exponent in this direction, respectively. For driven dynamics along other direction, the driving rate has the dimension $ r=z+1/\nu_p$ with $ \nu_p$ being the other correlation length exponent. Our work brings new fundamental perspective into the nonequilibrium critical dynamics near the tricritical point, which could be realized in programmable quantum processors in Rydberg atomic systems.
Statistical Mechanics (cond-mat.stat-mech), Quantum Gases (cond-mat.quant-gas), Strongly Correlated Electrons (cond-mat.str-el), Quantum Physics (quant-ph)
6+2 pages, 6+2 figures
Superconductivity and phase diagram in Sr-doped La${3-x}$Sr${x}$Ni$_2$O$_7$ thin films
New Submission | Superconductivity (cond-mat.supr-con) | 2025-05-20 20:00 EDT
Bo Hao, Maosen Wang, Wenjie Sun, Yang Yang, Zhangwen Mao, Shengjun Yan, Haoying Sun, Hongyi Zhang, Lu Han, Zhengbin Gu, Jian Zhou, Dianxiang Ji, Yuefeng Nie
Recent studies have demonstrated ambient pressure superconductivity in compressively strained La$ {3}$ Ni$ {2}$ O$ {7}$ thin films, yet the phase diagram of heterovalent doping$ -$ critical for advancing the field$ -$ remains unexplored. Here, we report superconductivity in Sr$ ^{2+}$ -doped La$ {3-x}$ Sr$ {x}$ Ni$ 2$ O$ 7$ films synthesized via molecular beam epitaxy with ozone-assisted post-annealing. The superconducting transition temperature ($ T{\mathrm{c}}$ ) follows an asymmetric dome-like profile, persisting across a wide doping range ($ 0 \leq x \leq 0.21$ ) before diminishing at $ x \approx 0.38$ . Optimally doped films ($ x = 0.09$ ) achieve $ T{\mathrm{c}}$ of $ \sim$ 42 K, with high critical current ($ J{\mathrm{c}} > 1.4$ $ \mathrm{kA/cm^{2}}$ at 2 K) and upper critical fields ($ \mu{0}H{\mathrm{c,\parallel}}(0)= 83.7$ $ \mathrm{T}$ , $ \mu{0}H{\mathrm{c,\perp}}(0)= 110.3$ $ \mathrm{T}$ ), comparable to reported La$ _{3-x}$ Pr$ _{x}$ Ni$ _2$ O$ 7$ films. Scanning transmission electron microscopy reveals oxygen vacancies predominantly occupy at planar NiO$ {2}$ sites$ -$ unlike apical-site vacancies in bulk samples$ -$ due to Coulomb repulsion destabilizing planar oxygen under compressive strain. Additionally, the elongated out-of-plane Ni-O bonds, exceeding those in pressurized bulk samples by $ 4%$ , likely weaken the interlayer $ d{z^2}$ coupling, thus contributing to the reduced $ T{\mathrm{c}}$ in strained films. This work establishes heterovalent Sr$ ^{2+}$ doping as a robust tuning parameter for nickelate superconductivity, unveiling a unique phase diagram topology.
Superconductivity (cond-mat.supr-con), Materials Science (cond-mat.mtrl-sci), Strongly Correlated Electrons (cond-mat.str-el)
31 pages, 12 figures
Unconventional band splitting of CeSb in the devil’s staircase transition
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2025-05-20 20:00 EDT
Tongrui Li, Zhanfeng Liu, Peng Li, Yuzhe Wang, Zhisheng Zhao, Shiwu Su, Zhicheng Jiang, Yuhao Hong, Hui Tian, Xin Zheng, Yi Liu, Yilin Wang, Zhengtai Liu, Dawei Shen, Zhe Sun, Yang Liu, Juan Jiang, Donglai Feng
The interplay between magnetism and electronic band structure is a central theme in condensed matter physics. CeSb, with its complex devil’s staircase antiferromagnetic transition, offers a unique opportunity to explore this interplay. Using angle-resolved photoemission spectroscopy (ARPES), we investigate the electronic structure evolution across the devil’s staircase transition. Upon entering the antiferromagnetic phase, we observe an intriguing band splitting of the electron pocket around the X point. The energy separation between the split bands changes abruptly with temperature, consistent with the characteristics of the first-order phase transition. However, their respective spectral weights behave gradually with temperature. Combined with our density functional theory (DFT) calculations, we suggest that this atypical behavior deviates from conventional magnetically induced band splitting and potentially arises from the intricate modulation of paramagnetic and antiferromagnetic layers within the devil’s staircase transition. Our results provide insights into the complex relationship between electronic structure and magnetism in correlated electron systems.
Strongly Correlated Electrons (cond-mat.str-el)
13 pages, 4 figures
Communications Materials volume 6, Article number: 97 (2025)
Emergence of the electronic states by quantum charge fluctuations in electron-doped high-$T_c$ cuprates superconductors
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2025-05-20 20:00 EDT
Hiroshi Yamaguchi, Yudai Miyai, Yuki. Tsubota, Masashi Atira, Hitoshi Sato, Dongjoon Song, Kiyoshia Tanakae, Kenya Shimada, Shin-ichiro Ideta
The origin of electron-boson interactions is a key to understanding the mechanism of high-$ T_c$ superconductivity in cuprates. While interactions with phonons and magnetic fluctuations are widely considered to mediate electron pairing in cuprates, the role of charge fluctuations, which is one of the fundamental degrees of freedom, remains unclear. Here, we performed angle-resolved photoemission spectroscopy (ARPES) and angle-resolved inverse photoemission spectroscopy (AR-IPES) to investigate the electronic structure of the occupied and unoccupied states, respectively, in the electron-doped high-$ T_c$ cuprate superconductor Nd$ _{2-x}$ Ce$ _x$ CuO$ _4$ . We found emergent spectral features in both the occupied (ARPES) and unoccupied states (AR-IPES), which are likely induced by charge fluctuations. The present study paves the way for a deeper understanding of the relationship between quantum charge fluctuations and superconductivity.
Strongly Correlated Electrons (cond-mat.str-el)
4 figures
Thermodynamic analysis of diverse percolation transitions
New Submission | Statistical Mechanics (cond-mat.stat-mech) | 2025-05-20 20:00 EDT
Seonghyeon Moon, Young Sul Cho
This work extends the thermodynamic analysis of random bond percolation to explosive and hybrid percolation models. We show that this thermodynamic analysis is well applicable to both explosive and hybrid percolation models by using the critical exponents $ \alpha$ and $ \delta$ obtained from scaling relations with previously measured values of $ \beta$ and $ \gamma$ within the error range. As a result, Rushbrooke inequality holds as an equality, $ \alpha + 2\beta + \gamma = 2$ , in both explosive and hybrid percolation models, where $ \alpha > 0$ leads to the divergence of specific heats at the critical points. Remarkably, entropy clearly reveals a continuous decrease even in a finite-sized explosive percolation model, unlike the order parameter. In contrast, entropy decreases discontinuously during a discontinuous transition in a hybrid percolation model, resembling the heat outflow during discontinuous transitions in thermal systems.
Statistical Mechanics (cond-mat.stat-mech)
25 pages, 7 figures
Chaos, Solitons & Fractals 198, 116491 (2025)
Correlated Dirac semimetal states in nonsymmorphic MIrO$_3$ (M=Sr, Ba and Ca)
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2025-05-20 20:00 EDT
Nonsymmorphic symmetries can give rise to Dirac semimetal (DSM) states. However, few studies have been conducted on DSMs in interacting systems. Here, we induce interacting DSM states in nonsymmorphic iridium oxides SrIrO$ _3$ , BaIrO$ 3$ and CaIrO$ 3$ , and contend that the interaction of electron-electron correlations, strong spin-orbital coupling, and symmetry protection can drive robust and exotic DSM states. Based on the density functional theory combined with dynamical mean-field theory (DFT + DMFT), with the Coulomb interaction parameters computed through doubly screened Coulomb correction approach, we discover that the Dirac fermions are constituted by the strongly spin-orbital coupled $ J{\mathrm{eff}} = 1/2$ states resulting from $ t{2g}$ orbits of Ir, with significant mass enhancement. Moreover, the nonsymmorphic symmetries induce topological surface bands and Fermi arcs on the (001) surface, which are well separated from bulk states. Our findings establish nonsymmorphic iridium oxides as correlated DSMs under strong electron-electron and spin-orbital interactions.
Strongly Correlated Electrons (cond-mat.str-el)
6 pages, 4 figures
A Deep Learning Potential for Accurate Shock Response Simulations in Tin
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-05-20 20:00 EDT
Yixin Chen, Xiaoyang Wang, Wanghui Li, Mohan Chen, Han Wang
Tin (Sn) plays a crucial role in studying the dynamic mechanical responses of ductile metals under shock loading. Atomistic simulations serves to unveil the nano-scale mechanisms for critical behaviors of dynamic responses. However, existing empirical potentials for Sn often lack sufficient accuracy when applied in such simulation. Particularly, the solid-solid phase transition behavior of Sn poses significant challenges to the accuracy of interatomic potentials. To address these challenges, this study introduces a machine-learning potential model for Sn, specifically optimized for shock-response simulations. The model is trained using a dataset constructed through a concurrent learning framework and is designed for molecular simulations across thermodynamic conditions ranging from 0 to 100 GPa and 0 to 5000 K, encompassing both solid and liquid phases as well as structures with free surfaces. It accurately reproduces density functional theory (DFT)-derived basic properties, experimental melting curves, solid-solid phase boundaries, and shock Hugoniot results. This demonstrates the model’s potential to bridge ab initio precision with large-scale dynamic simulations of Sn.
Materials Science (cond-mat.mtrl-sci)
33 pages, 6 figures, 2 tables
Itinerant ferromagnetism in an SU(3) Fermi-Hubbard model at finite temperature: A DMFT study
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2025-05-20 20:00 EDT
Juntaro Fujii, Kazuki Yamamoto, Akihisa Koga
We investigate an SU(3) Fermi-Hubbard model on a hypercubic lattice at finite temperatures, combining dynamical mean-field theory with continuous-time quantum Monte Carlo simulations. Taking strong correlations into account carefully, we find a ferromagnetically ordered state, in which one of the three components becomes dominant, when holes are doped away from one-third filling. Furthermore, we demonstrate that this ferromagnetically ordered phase undergoes a first-order transition to a paramagnetic state. We clarify the stability of the ferromagnetically ordered state against interaction strength, hole doping, and temperatures. The relevance of generalized Nagaoka ferromagnetism is also addressed, by comparing the results on the Bethe lattice.
Strongly Correlated Electrons (cond-mat.str-el), Quantum Gases (cond-mat.quant-gas)
10 pages, 10 figures
Characterization of phospholipid-cholesterol bilayers as self-assembled amphiphile block polymers that contain headgroups
New Submission | Soft Condensed Matter (cond-mat.soft) | 2025-05-20 20:00 EDT
Xiaoyuan Wang, Fredric S. Cohen, Shixin Xu, Yongqiang Cai
Cholesterol is known to modulate the structure and function of biological membranes. In this study, we use self-consistent field theory (SCFT) to investigate phospholipid/cholesterol bilayer membranes modeled with two types of diblock copolymers. These copolymer-based bilayers serve as biomimetic platforms with applications in areas such as drug delivery. Our simulations identify a minimum free energy configuration characterized by phospholipid tails tilted relative to the membrane normal. The model quantitatively captures the well-known area condensation effect as cholesterol concentration increases, along with membrane thickening and reduced tilt angle. Thermodynamically, we observe a linear dependence between cholesterol’s chemical potential and its concentration within the 37-50% range, consistent with experimental results. Additionally, we analyze the effects of block copolymer length and headgroup interactions on bilayer structure. Interactions between phospholipid headgroups and the solvent emerge as the most influential. This work provides a theoretical framework for understanding cholesterol’s regulatory role in membrane structure and mechanics.
Soft Condensed Matter (cond-mat.soft), Biological Physics (physics.bio-ph)
Unifying Strain-driven and Pressure-driven Superconductivity in La${3}$Ni${2}$O$_{7}$: Suppressed charge/spin density waves and enhanced interlayer coupling
New Submission | Superconductivity (cond-mat.supr-con) | 2025-05-20 20:00 EDT
Xin-Wei Yi, Wei Li, Jing-Yang You, Bo Gu, Gang Su
Recent strain-stabilized superconductivity at ambient pressure in La$ _3$ Ni$ 2$ O$ {7}$ films opens new avenues for nickelates research, in parallel with its pressure-induced counterpart. Using density functional theory calculations, we elucidate the critical factors bridging strain- and pressure-driven superconductivity in La$ 3$ Ni$ 2$ O$ {7}$ by comprehensively analyzing structural, electronic, magnetic, and density wave characteristics. Consistent with recent scanning transmission electron microscopy observations, we find an $ I4/mmm$ structural transition at $ -0.9%$ strain, preceding superconductivity onset. Electronic analysis shows compressive strain lowers Ni-$ d{z^2}$ orbital energy levels, while interfacial Sr diffusion effectively reconstructs the $ d{z^2}$ pockets, quantitatively matching angle-resolved photoemission spectroscopy experiments. The interlayer antiferromagnetic coupling $ J\perp$ under pressure or strain closely tracks experimental superconducting $ T_c$ variation. The dome-shaped pressure dependence and monotonic strain dependence of $ J\perp$ mainly arise from modulations in the apical oxygen $ p_z$ energy levels. Moreover, compressive strain suppresses both charge density waves (CDW) and spin density waves (SDW) instabilities analogous to pressure effects, with SDW vanishing concurrently with the structural transition and CDW disappearing at $ \sim-3.3%$ strain. Our results indicate that suppressed density waves and enhanced $ J\perp$ are crucial for both strain- and pressure-driven superconductivity. Accordingly, we propose several candidate substrates capable of achieving greater compressive strain, thereby potentially increasing $ T_c$ .
Superconductivity (cond-mat.supr-con)
9 pages, 4 figures
Resolving self-cavity effects in two-dimensional quantum materials
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2025-05-20 20:00 EDT
Marios H. Michael, Gunda Kipp, Alexander M. Potts, Matthew W. Day, Toru Matsuyama, Guido Meier, Hope M. Bretscher, James W. McIver
Two-dimensional materials and van der Waals (vdW) heterostructures host many strongly correlated and topological quantum phases on the $ \sim$ meV energy scale. Direct electrodynamical signatures of such states are thus expected to appear in the terahertz (THz) frequency range (1 THz $ \sim$ 4 meV). Because the typical size of vdW heterostructures ($ \sim$ 10 $ \mu m$ ) is much smaller than the diffraction limit of THz light, probing THz optical conductivities necessitates the use of near-field optical probes. However, interpreting the response of such near-field probes is complicated by finite-size effects, the presence of electrostatic gates, and the influence of the probe itself on material dynamics – all of which conspire to form polaritonic self-cavities, in which interactions between THz electromagnetic fields and material excitations form discretized standing waves. In this paper, we demonstrate the relevance of self-cavity effects in 2D materials and derive an analytical framework to resolve these effects using the emerging experimental technique of time-domain on-chip THz spectroscopy. We show that by pairing experiments with the analytical theory, it is possible to extract the THz conductivity and resolve collective mode dynamics far outside the light cone, with $ \sim \mu m$ in-plane and $ \sim nm$ out-of-plane resolution. This study lays the groundwork for studying quantum phases and cavity effects in vdW heterostructures and 2D quantum materials.
Strongly Correlated Electrons (cond-mat.str-el), Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
9 pages, 5 figures
Theory of charge-to-spin conversion under quantum confinement
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2025-05-20 20:00 EDT
Alfonso Maiellaro, Francesco Romeo, Mattia Trama, Irene Gaiardoni, Jacopo Settino, Claudio Guarcello, Nicolas Bergeal, Manuel Bibes, Roberta Citro
The interplay between spin and charge degrees of freedom in low-dimensional systems is a cornerstone of modern spintronics, where achieving all-electrical control of spin currents is a major goal. Spin-orbit interactions provide a promising mechanism for such control, yet understanding how spin and charge transport emerge from microscopic principles remains a fundamental challenge. Here we develop a spin-dependent scattering matrix approach to describe spin and charge transport in a multiterminal system in the presence of Rashba spin-orbit interaction. Our framework generalizes the Büttiker formalism by offering explicit real-space expressions for spin and charge current densities, along with the corresponding linear response function. It simultaneously captures the effects of quantum confinement, the orbital response to external magnetic fields, and the intrinsic (geometric) properties of the electronic bands, offering a comprehensive description of the spin-charge interconversion mechanisms at play in a Hall bar, in agreement with experiments.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Materials Science (cond-mat.mtrl-sci)
12 pages, 10 figures
Numerical Investigation on the Compressive Behavior of Hierarchical Granular Piles
New Submission | Soft Condensed Matter (cond-mat.soft) | 2025-05-20 20:00 EDT
Sota Arakawa, Mikito Furuichi, Daisuke Nishiura
Hierarchical granular piles composed of aggregates are key structural features in both geoscience and planetary science, from fault gouge in seismic zones to the internal structures of comets. Although experimental studies have suggested a multi-step evolution in their packing structure, this hypothesis has lacked numerical validation. In this study, we performed large-scale numerical simulations using the discrete element method to investigate the compressive behavior of hierarchical granular piles. We successfully reproduced and confirmed a three-stage evolution process: (i) rearrangement of the aggregate packing structure, (ii) plastic deformation of small aggregates, and (iii) elastic deformation of constituent particles. Additionally, we developed a semi-analytical model for the compression curve, offering insights into the compressive stages and structural dynamics. Our findings have applications in modeling the internal density profiles of comets and in understanding the early thermal evolution of small icy bodies.
Soft Condensed Matter (cond-mat.soft), Earth and Planetary Astrophysics (astro-ph.EP), Geophysics (physics.geo-ph)
Accepted for publication in Earth, Planets and Space
Breaking Sensitivity Barriers in Luminescence Thermometry: Synergy Between Structural Phase Transition and Luminescence Thermal Quenching
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-05-20 20:00 EDT
M. Tahir Abbas, M. Szymczak, M. Drozd, D. Szymanski, A. Owczarek, A.Musialek, L. Marciniak
One of the key parameters determining the performance of a luminescent thermometer is its relative sensitivity. In ratiometric luminescence thermometry, high relative sensitivity to temperature variations is typically achieved when the two monitored emission bands exhibit opposite thermal monotonicity. However, realizing a thermal enhancement in the luminescence intensity of one of the emission bands remains a significant challenge. In this study, we present a novel approach that leverages the synergistic effect of two phenomena: (1) the high thermal sensitivity of Mn4+ ion luminescence, and (2) a thermally induced structural phase transition in LaGaO3, which facilitates the enhancement of the luminescence signal from Tb3+ ions in the high-temperature phase of the host material. This dual effect not only led to an increased maximum relative sensitivity but also extended the temperature range over which the sensitivity exceeded 1% K-1. The highest recorded sensitivity was 4.5 K-1 at 400 K. Additionally, to the best of our knowledge, the luminescence of Mn4+ ions in the high-temperature phase of LaGaO3:Mn4+ was observed and reported here for the first time. The thermally induced modifications in the emission profile of LaGaO3:Mn4+,Tb3+ enabled the development of a quadruple ratiometric luminescence thermometer, with complementary operating ranges, offering enhanced versatility and accuracy across a broad temperature span.
Materials Science (cond-mat.mtrl-sci)
Mechanistic Insights into the Early Stages of Oxidation at Copper Terrace: The Role of O-O Repulsion and Substrate-mediated Effects
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-05-20 20:00 EDT
E V Charan Reddy, Abhijit Chatterjee
Copper-based catalysts play a crucial role in industrial oxidation reactions. Although many theoretical studies consider copper to be metallic, it is well established that copper readily oxides at ambient conditions, forming a passivating oxide layer. Experimental investigations spanning two decades have shown that in addition to the anticipated step-oxide formation, oxide can directly form at the Cu(111) terrace. The atomistically-resolved mechanism for direct oxidation at flat terraces remains unknown. Using density functional theory (DFT) calculations, we demonstrate that the formation of subsurface oxide occurs through a coordinated mechanism that takes place in the presence of specific clusters of adsorbed oxygen atoms. Certain oxygen atoms in the cluster function like pincers to extract a copper atom from the surface layer and induce localized surface restructuring. This process creates open channels that allow an oxygen atom to diffuse into the subsurface layer. The subsurface oxide formation is barrierless. This implies that the Cu oxide surface is highly dynamic. At low O coverages, subsurface oxidation is unlikely via step oxide growth nor direct terrace oxidation as the subsurface oxygen is unstable. Substrate mediated O-Cu-O adsorbate interactions govern the oxide stability. These insights provide a foundation for developing a more accurate dynamic models for copper catalysis.
Materials Science (cond-mat.mtrl-sci)
31 pages, 10 figures
Anomalous persistent current in a 1D dimerized ring with aperiodic site potential: Non-interacting and interacting cases
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2025-05-20 20:00 EDT
Souvik Roy, Santanu K. Maiti, David Laroze
In this work, we investigate the magnetic response by examining flux-driven circular currents in a Su-Schrieffer-Heeger (SSH) tight-binding (TB) ring threaded by an Aharonov-Bohm (AB) flux, $ \phi$ . We consider both non-interacting and interacting electrons, where site energies are modulated by a slowly varying cosine form. Repulsive electron-electron interaction is incorporated through an on-site Hubbard term, and we analyze the system using the Hartree-Fock (HF) mean-field (MF) approximation. We discuss the characteristics of flux-driven circular currents to aperiodic potentials, dimerized hopping integrals, and Hubbard interactions. For the chosen aperiodic potential, both the strength and configuration play a crucial role, and we explore these aspects in depth. Interestingly, we observe a counterintuitive delocalizing effect as the aperiodic potential increases, unlike in conventional disordered rings. The effects of system size, filling factor, the presence of circular spin current, and the accuracy of MF results are also discussed. Finally, we provide a brief description of possible experimental realizations of our chosen quantum system. This investigation can be extended to explore additional properties in various loop substructures, promising further insights.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Disordered Systems and Neural Networks (cond-mat.dis-nn), Strongly Correlated Electrons (cond-mat.str-el)
15 pages, 15 figures (Accepted for publication in Chinese Journal of Physics)
Hydrogen Bond Topology Reveals Layering of LDL-like and HDL-like Water at its Liquid/Vapor Interface
New Submission | Soft Condensed Matter (cond-mat.soft) | 2025-05-20 20:00 EDT
Pal Jedlovszky, Christoph Dellago, Marcello Sega
The discovery of high-density liquid (HDL) and low-density liquid (LDL) water has been a major success of molecular simulations, yet extending this analysis to interfacial water is challenging due to conventional order parameters assuming local homogeneity. This limitation previously prevented resolving the composition of the surface layer of the liquid/vapour interface. Here, we apply a recently introduced topological order parameter [R. Foffi and F. Sciortino, J. Phys. Chem. B 127, 378-386 (2022)] to analyze the composition of the water/vapor interface across a broad temperature range. Our results reveal that LDL-like water dominates the outermost region at all temperatures, while HDL-like water accumulates beneath it, presenting a clear layering roughly below the temperature of maximum density. This structured stratification, previously inaccessible, highlights the power of the topological order parameter in resolving interfacial molecular heterogeneity and provides new insights into the structural properties of water at interfaces.
Soft Condensed Matter (cond-mat.soft), Chemical Physics (physics.chem-ph)
submitted to J Chem Phys
Variability analysis in memristors based on electrodeposited prussian blue
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-05-20 20:00 EDT
L. B. Avila, A. Cantudo, M.A. Villena, D. Maldonado, F. Abreu Araujo, C. K. Müller, J. B. Roldán
This work presents a comprehensive analysis of the variability and reliability of the resistive switching (RS) behavior in Prussian Blue (a mixed-valence iron(III/II) hexacyanoferrate compound) thin films, used as the active layer. These films are fabricated through a simple and scalable electrochemical process, and exhibit robust bipolar resistive switching, making them suitable both for neuromorphic computing applications and hardware cryptography. A detailed statistical evaluation was conducted over 100 consecutive switching cycles using multiple parameter extraction techniques to assess cycle-to-cycle (C2C) variability in key RS parameters, including set/reset voltages and corresponding currents. One and two-dimensional coefficients of variation (1DCV and 2DCV) were calculated to quantify variability and identify application potential. Results demonstrate moderate variability compatible with neuromorphic computing and cryptographic functionalities, including physical unclonable functions and true random number generation. These findings position Prussian Blue-based memristors as promising candidates for low-cost, stable, and multifunctional memory.
Materials Science (cond-mat.mtrl-sci)
Thermal transport mapping in twisted double bilayer graphene
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2025-05-20 20:00 EDT
Jean Spièce, Roop Kumar Mech, Alessandra Canetta, Rebeca Ribeiro-Palau, Oleg Kolosov, Pascal Gehring
Two-dimensional (2D) materials have attracted significant interest due to their tunable physical properties when stacked into heterostructures. Twisting adjacent layers introduces moire patterns that strongly influence the material’s electronic and thermal behavior. In twisted graphene systems, the twist angle critically alters phonon transport, leading to reduced thermal conductivity compared to Bernal-stacked configurations. However, experimental investigations into thermal transport in twisted structures remain limited. Here, we study the local thermal properties of twisted double bilayer graphene (TDBG) using Scanning Thermal Microscopy (SThM). We find a reduction in thermal resistance of 0.3 +/- 0.1 x 10^6 K W^-1 compared to untwisted bilayers, attributed to changes in both intrinsic thermal conductivity and the tip-sample interface. These results, supported by analytical modeling, provide new insight into thermal transport mechanisms in twisted 2D systems and offer a pathway toward thermal engineering in twistronic devices.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
Nanoindentation simulations for copper and tungsten with adaptive-precision potentials
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-05-20 20:00 EDT
David Immel, Matous Mrovec, Ralf Drautz, Godehard Sutmann
We perform nanoindentation simulations for both the prototypical face-centered cubic metal copper and the body-centered cubic metal tungsten with a new adaptive-precision description of interaction potentials including different accuracy and computational costs: We combine both a computationally efficient embedded atom method (EAM) potential and a precise but computationally less efficient machine learning potential based on the atomic cluster expansion (ACE) into an adaptive-precision (AP) potential tailored for the nanoindentation. The numerically expensive ACE potential is employed selectively only in regions of the computational cell where large accuracy is required. The comparison with pure EAM and pure ACE simulations shows that for Cu, all potentials yield similar dislocation morphologies under the indenter with only small quantitative differences. In contrast, markedly different plasticity mechanisms are observed for W in simulations performed with the central-force EAM potential compared to results obtained using the ACE potential which is able to describe accurately the angular character of bonding in W due to its half-filled d-band. All ACE-specific mechanisms are reproduced in the AP nanoindentation simulations, however, with a significant speedup of 20-30 times compared to the pure ACE simulations. Hence, the AP potential overcomes the performance gap between the precise ACE and the fast EAM potential by combining the advantages of both potentials.
Materials Science (cond-mat.mtrl-sci), Computational Physics (physics.comp-ph)
16 pages, 16 figures
Tricritical Kibble-Zurek Scaling in Rydberg Atom Ladders
New Submission | Quantum Gases (cond-mat.quant-gas) | 2025-05-20 20:00 EDT
Hanteng Wang, Xingyu Li, Chengshu Li
The Kibble-Zurek (KZ) mechanism is being actively explored on quantum simulation platforms. In this work, we study the KZ scaling around tricritical phase transition points, with Rydberg atom ladders as a concrete incarnation. The criticality is of Ising and Potts type for two- and three-leg ladders, respectively. When slowly ramping across or near the tricritical point from the disordered phase to the ordered phase, we obtain universal power-law scaling in agreement with conventional KZ predictions. We study a “tangential” KZ ramping that both begins and ends in the disordered phase, a novel protocol enabled by the two-dimensional phase diagram. The tangential KZ directly reveals subleading critical exponents of the critical point. Finally, we explore the regime of intermediate-speed ramping and find a dynamical analog of the celebrated Zamolodchikov’s c-theorem. Practically, our work provides an immediately relevant protocol for current experiments to pinpoint the elusive tricritical points. More broadly, tangential and intermediate-speed rampings go beyond the conventional KZ paradigm and introduce new insights into critical quantum dynamics.
Quantum Gases (cond-mat.quant-gas), Statistical Mechanics (cond-mat.stat-mech), Strongly Correlated Electrons (cond-mat.str-el), Quantum Physics (quant-ph)
9 pages, 5 figures + Supplementary Materials 2 pages, 3 figures
Ultrafast Laser Induces Macroscopic Symmetry-Breaking of Diamond Color Centers
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-05-20 20:00 EDT
Yang Gao, Qi-Zheng Ji, Chao-Bo Liu, Qi Xiao, Chao Lian
We employ real-time time-dependent density functional theory (RT-TDDFT) to investigate the electron-phonon-spin correlated dynamics in negatively charged nitrogen-vacancy centers (NV$ ^{-}$ ) and construct a comprehensive dynamical picture. Laser excitation promotes minority-spin electrons within 100fs, establishing a three-fold rotation symmetry breaking (3RSB) charge ordering. Subsequently, ionic motion on the potential energy surface of the excited electrons generates two distinct dynamical modes: (1) symmetric oscillations of carbon-nitrogen bonds and (2) dynamic Jahn-Teller distortions (DJT) with 3RSB. These distortions induce nonlocal coherent phonons in the diamond lattice, which propagate with 3RSB at the sound velocity ($ \sim$ 2Å/fs). Furthermore, the NV$ ^{-}$ spin state remains preserved during photoexcitation but undergoes rapid reorientation within 100~fs via enhanced spin-orbit-phonon coupling. Our RT-TDDFT simulations provide direct time-resolved visualization of these processes, offering novel insights into the microscopic interplay of electrons, phonons, and spins in NV$ ^{-}$ centers. These results advance the fundamental understanding of dynamical mechanisms in solid-state quantum systems, with implications for optimizing NV$ ^{-}$ -based quantum sensing technologies.
Materials Science (cond-mat.mtrl-sci)
Competing Magnetic States in the Candidate Altermagnet GdAlGe
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-05-20 20:00 EDT
Oleg E. Parfenov, Dmitry V. Averyanov, Ivan S. Sokolov, Alexey N. Mihalyuk, Ivan A. Yakovlev, Oleg A. Kondratev, Alexander N. Taldenkov, Andrey M. Tokmachev, Vyacheslav G. Storchak
Altermagnetism, a newly discovered magnetic order, combines zero net magnetization with non-relativistic spin splitting of electronic bands. Its ability to utilize the advantages of both antiferromagnets and ferromagnets is highly promising for spintronic applications. Currently, the merge of altermagnetism and weak ferromagnetism in a single material excites significant interest as it provides additional control mechanisms over material properties. However, the role of dimensionality in this interplay is yet to be explored. Here, we study magnetism and electron transport in epitaxial films of the candidate altermagnet GdAlGe ranging from bulklike to a single monolayer. The films exhibit the anomalous Hall effect and negative magnetoresistance. In contrast to altermagnetic GdAlSi, the candidate altermagnet GdAlGe demonstrates an admixture of the ferromagnetic state which contribution increases as the system approaches the 2D limit. The coexistence of the magnetic states induces technologically important intrinsic exchange bias. The present work underpins future studies and applications of nanoscale altermagnets.
Materials Science (cond-mat.mtrl-sci)
34 pages, 24 figures
Phase transitions from linear to nonlinear information processing in neural networks
New Submission | Disordered Systems and Neural Networks (cond-mat.dis-nn) | 2025-05-20 20:00 EDT
We investigate a phase transition from linear to nonlinear information processing in echo state networks, a widely used framework in reservoir computing. The network consists of randomly connected recurrent nodes perturbed by a noise and the output is obtained through linear regression on the network states. By varying the standard deviation of the input weights, we systematically control the nonlinearity of the network. For small input standard deviations, the network operates in an approximately linear regime, resulting in limited information processing capacity. However, beyond a critical threshold, the capacity increases rapidly, and this increase becomes sharper as the network size grows. Our results indicate the presence of a discontinuous transition in the limit of infinitely many nodes. This transition is fundamentally different from the conventional order-to-chaos transition in neural networks, which typically leads to a loss of long-term predictability and a decline in the information processing capacity. Furthermore, we establish a scaling law relating the critical nonlinearity to the noise intensity, which implies that the critical nonlinearity vanishes in the absence of noise.
Disordered Systems and Neural Networks (cond-mat.dis-nn)
9 pages, 8figures
Energy Dissipation in Cyclic Strain of Amorphous Solids
New Submission | Soft Condensed Matter (cond-mat.soft) | 2025-05-20 20:00 EDT
Itamar Procaccia, Tuhin Samanta
The study of the response of amorphous materials to oscillatory strain is traditionally performed with many repeated cycles. We argue that it pays to consider carefully just one cycle (and may be a second), to reveal the rich physics that characterizes cyclic strain. The response can be conservative or dissipative, with a sharp transition between these options as a function of preparation parameters, accompanied by symmetry breaking and the onset of screening. We choose an example for which the mesoscopic theory can be solved exactly, and the microscopic physics can be revealed by numerical simulations. The mechanism of energy dissipation (when it exists) is explored in detail, shedding light on the reason why repeated cycles exhibit ever decreasing dissipation per cycle, which is often consistent with a universal law.
Soft Condensed Matter (cond-mat.soft), Statistical Mechanics (cond-mat.stat-mech)
5 pages, 8 Figures
Renormalization group analysis of a continuous model with self-organized criticality: Effects of randomly moving environment
New Submission | Statistical Mechanics (cond-mat.stat-mech) | 2025-05-20 20:00 EDT
N.V. Antonov, P.I. Kakin, N.M. Lebedev, A.Yu. Luchin
We study a strongly anisotropic self-organized critical system coupled to an isotropic random fluid environment. The former is described by a continuous (coarse-grained) model due to Hwa and Kardar. The latter is modeled by the Navier–Stokes equation with a random stirring force of a rather general form that includes, in particular, the overall shaking of the system and a non-local part with power-law spectrum $ \sim k^{4-d-y}$ that describes, in the limiting case $ y \to 4$ , a turbulent fluid. The full problem of the two coupled stochastic equations is represented as a field theoretic model which is shown to be multiplicatively renormalizable and logarithmic at $ d=4$ . Due to the interplay between isotropic and anisotropic interactions, the corresponding renormalization group (RG) equations reveal a rich pattern of possible infrared (large scales, long times) regimes of asymptotic behaviour of various Green’s functions. The attractors of the RG equations in the five-dimensional space of coupling parameters include a two-dimensional surface of Gaussian (free) fixed points, a single fixed point that corresponds to the plain advection by the turbulent fluid (the Hwa–Kardar self-interaction is irrelevant) and a one-dimensional curve of fixed points that corresponds to the case where the Hwa–Kardar nonlinearity and the uniform stirring are simultaneously relevant. The character of attractiveness is determined by the exponent $ y$ and the dimension of space $ d$ ; the most interesting case $ d=3$ and $ y \to 4$ is described by the single fixed point. The corresponding critical dimensions of the frequency and the basic fields are found exactly.
Statistical Mechanics (cond-mat.stat-mech)
Imaging the Acceptor Wave Function Anisotropy in Silicon
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2025-05-20 20:00 EDT
Manuel Siegl, Julian Zanon, Joseph Sink, Adonai Rodrigues da Cruz, Holly Hedgeland, Neil J. Curson, Michael E. Flatté, Steven R. Schofield
We present the first scanning tunneling microscopy (STM) images of hydrogenic acceptor wave functions in silicon. These acceptor states appear as square ring-like features in STM images and originate from near-surface defects introduced by high-energy bismuth implantation into a silicon (001) wafer. Scanning tunneling spectroscopy confirms the formation of a p-type surface. Effective-mass and tight-binding calculations provide an excellent description of the observed square ring-like features, confirming their acceptor character and attributing their symmetry to the light- and heavy-hole band degeneracy in silicon. Detailed understanding of the energetic and spatial properties of acceptor wave functions in silicon is essential for engineering large-scale acceptor-based quantum devices.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
19 pages, 3 figures
Disorder-Driven Exceptional Points and Concurrent Topological Phase Transitions in Non-Hermitian Lattice
New Submission | Disordered Systems and Neural Networks (cond-mat.dis-nn) | 2025-05-20 20:00 EDT
Xiaoyu Cheng, Tiantao Qu, Yaqing Yang, Lei Zhang, Jun Chen
Exceptional point (EP) and topological phase transition (TPT) in non-Hermitian systems have recently garnered significant attention owing to their fundamental importance and potential applications in sensing and topological devices. Beyond the EP induced by non-reciprocal hopping, we show that random disorder can also drive the valence and conduction bands across EPs, even twice in the non-Hermitian regime. Remarkably, a TPT can occur concurrently with an EP as disorder strength increases. These disorder-driven EPs and concurrent TPTs are well captured by effective medium theory. The analysis reveals that their emergence results from the interplay between disorder-induced energy level renormalization and non-reciprocal hopping-induced inter-level coupling, which fundamentally restructures the spectral properties of the system. The phase diagram in the parameter space of non-reciprocal hopping and disorder strength identifies robust EP lines. Interestingly, two EP lines can emerge from the TPT point in the Hermitian limit. As non-reciprocal hopping increases, these lines split, with one aligning the TPT, leading to distinct disorder-induced EPs. Our results uncover a robust, disorder-driven mechanism for generating EPs and concurrent TPTs, offering a new direction for exploring non-Hermitian topological matter.
Disordered Systems and Neural Networks (cond-mat.dis-nn)
6 pages, 4 figures
Anomalous Temperature Dependence of Quantum-Geometric Superfluid Weight
New Submission | Superconductivity (cond-mat.supr-con) | 2025-05-20 20:00 EDT
Yuma Hirobe, Taisei Kitamura, Youichi Yanase
The symmetry of Cooper pairs encodes key information about superconductivity and has been widely studied through the temperature dependence of the superfluid weight. However, in systems dominated by quantum geometry, conventional theories miss its essential properties. We study the temperature dependence of the quantum-geometric superfluid weight and classify the relationship to the superconducting symmetry and band structures. The obtained power laws are different from conventional behavior, and unconventional superconductivity in twisted multilayer graphene is discussed. Our findings provide insights into the superconducting symmetry and the pairing mechanism via quantum geometry.
Superconductivity (cond-mat.supr-con)
7 pages, 3 figures, 2 tables, and the Supplemental Materials
Electronic and optical and topological properties of defects in bismuthene
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-05-20 20:00 EDT
Gabriel Elyas Gama Araujo, Andreia Luisa da Rosa, Alexandre Cavalheiro Dias, Thomas Frauenheim
In this work we use first principles density-functional theory and Bethe-Salpeter equation together with tight-binding based maximally localized wannier functions (MLWF-TB) to investigate the electronic, optical and topological properties of two-dimensional bismuth (bismuthene) containing vacancy defects. We demonstrate that these properties depends on the shape and size of the nanopores. Furthermore, \textit{ab initio} molecular dynamics (AIMD) simulations shows that all pores are thermally stable at room temperature. Finally, adsorption of gas phase small molecules indicates that these pores can serve as sensors, opening the path for further applications in gas separation and sensing.
Materials Science (cond-mat.mtrl-sci)
Quantifying dissipation in flocking dynamics: When tracking internal states matter
New Submission | Statistical Mechanics (cond-mat.stat-mech) | 2025-05-20 20:00 EDT
Karel Proesmans, Gianmaria Falasco, Atul Tanaji Mohite, Massimiliano Esposito, Étienne Fodor
Aligning self-propelled particles undergo a nonequilibrium flocking transition from apolar to polar phases as their interactions become stronger. We propose a thermodynamically consistent lattice model, in which the internal state of the particles biases their diffusion, to capture such a transition. Changes of internal states and jumps between lattice sites obey local detailed balance with respect to the same interaction energy. We unveil a crossover between two regimes: for weak interactions, the dissipation is maximal, and partial inference (namely, based on discarding the dynamics of internal states) leads to a severe underestimation; for strong interactions, the dissipation is reduced, and partial inference captures most of the dissipation. Finally, we reveal that the macroscopic dissipation, evaluated at the hydrodynamic level, coincides with the microscopic dissipation upon coarse-graining. We argue that this correspondence stems from a generic mapping of active lattice models with local detailed balance into a specific class of non-ideal reaction-diffusion systems.
Statistical Mechanics (cond-mat.stat-mech)
11 pages, 4 figure
Entropy production rate in thermodynamically consistent flocks
New Submission | Statistical Mechanics (cond-mat.stat-mech) | 2025-05-20 20:00 EDT
Tal Agranov, Robert L. Jack, Michael E. Cates, Étienne Fodor
We study the entropy production rate (EPR) of aligning self-propelled particles which undergo a flocking transition towards a polarized collective motion. In our thermodynamically consistent lattice model, individual self-propulsion is the exclusive source of irreversibility. We derive the fluctuating hydrodynamics for large system sizes using a controlled coarse-graining: our procedure entails an exact correspondence between the EPR evaluated at the hydrodynamic and particle-based levels. We reveal that EPR is maximal when the system adopts a homogeneous configuration, either apolar or polar, and reduced in the non-homogeneous state where a polar band travels in a apolar background due to strong spatial EPR modulations. By analyzing the latter we also show that asymmetric energetic exchanges occur at the trailing and leading edges, which we map into a thermodynamic cycle in density-polarization space. Finally, we demonstrate that the regime of weak self-propulsion features a singular scaling of EPR, and a non-analyticity of the travelling band profiles.
Statistical Mechanics (cond-mat.stat-mech), Soft Condensed Matter (cond-mat.soft)
33 pages, 9 figures
Lattice thermal conductivity of 16 elemental metals from molecular dynamics simulations with a unified neuroevolution potential
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-05-20 20:00 EDT
Shuo Cao, Ao Wang, Zheyong Fan, Hua Bao, Ping Qian, Ye Su, Yu Yan
Metals play a crucial role in heat management in electronic devices, such as integrated circuits, making it vital to understand heat transport in elementary metals and alloys. In this work, we systematically study phonon thermal transport in 16 metals using the efficient homogeneous nonequilibrium molecular dynamics (HNEMD) method and the recently developed unified neuroevolution potential version 1 (UNEP-v1) for 16 metals and their alloys. We compare our results with existing ones based on the Boltzmann transport equation (BTE) approach and find that our HNEMD results align well with BTE results obtained by considering phonon-phonon scattering only. By contrast, HNEMD results based on the conventional embedded-atom method potential show less satisfactory agreement with BTE ones. Given the high accuracy of the UNEP-v1 model demonstrated in various metal alloys, we anticipate that the HNEMD method combined with the UNEP-v1 model will be a promising tool for exploring phonon thermal transport properties in complex systems such as high-entropy alloys.
Materials Science (cond-mat.mtrl-sci), Computational Physics (physics.comp-ph)
10 pages, 8 figures
Quantum Kinetic Uncertainty Relations in Mesoscopic Conductors at Strong Coupling
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2025-05-20 20:00 EDT
Gianmichele Blasi, Ricard Ravell Rodríguez, Mykhailo Moskalets, Rosa López, Géraldine Haack
Kinetic Uncertainty Relations (KURs) establish quantum transport precision limits by linking signal-to-noise ratio (SNR) to the system’s dynamical activity, valid in the weak-coupling regime where particle-like transport dominates. At strong coupling, quantum coherence challenges the validity of KURs and questions the meaning of the concept of activity itself. Here, we introduce a generalized dynamical activity valid at arbitrary coupling and derive a steady-state quantum KUR (QKUR) expressed in terms of this generalized activity. Explicit expressions are obtained within Green’s function and Landauer-Büttiker formalisms. This QKUR ensures that uncertainty relations are valid across all coupling strengths, offering a general framework for out-of-equilibrium quantum transport precision analysis. We illustrate these concepts for paradigmatic quantum-coherent mesoscopic devices: a single quantum channel pinched by a quantum point contact and open single- and double-quantum dot systems.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Statistical Mechanics (cond-mat.stat-mech), Quantum Physics (quant-ph)
Ab initio study of strain-driven vacancy clustering in aluminum
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-05-20 20:00 EDT
Sayan Bhowmik, Abhiraj Sharma, Andrew J. Medford, John E. Pask, Phanish Suryanarayana
We present a first principles investigation of vacancy clustering in aluminum. Specifically, we perform Kohn-Sham density functional theory calculations to study the influence of hydrostatic strains on clustering in tri-, quad-, and heptavacancies. We find that compressive strains are a key driving force for vacancy aggregation, particularly on the experimentally observed (111) plane. Notably, we find that the heptavacancy forms a prismatic dislocation loop on the (111) plane for hydrostatic compressive strains exceeding 5%, highlighting the critical role of such strains in prismatic dislocation loop nucleation in aluminum.
Materials Science (cond-mat.mtrl-sci), Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
7 pages, 4 figures, 1 table
A Family of Aperiodic Tilings with Tunable Quantum Geometric Tensor
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2025-05-20 20:00 EDT
Hector Roche Carrasco, Justin Schirmann, Aurelien Mordret, Adolfo G. Grushin
The strict geometric rules that define aperiodic tilings lead to the unique spectral and transport properties of quasicrystals, but also limit our ability to design them. In this work, we explore the first continuously tunable family of two-dimensional aperiodic tilings in which the underlying real-space geometry becomes a control knob of the wave-function’s quantum geometric tensor. The real-space geometry can be used to tune into topological phases occupying an expanded phase space compared to crystals, or into a disorder-driven topological Anderson insulator. The quantum metric can also be tuned continuously, opening new routes towards tunable single- and many-body physics in aperiodic solid-state and synthetic systems.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
14 pages, 7 figures and 1 video
Emergent High-Entropy Phases in Geometrically Frustrated Pyrochlore Magnets
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2025-05-20 20:00 EDT
Prakash Timsina, Andres Chappa, Deema Alyones, Igor Vasiliev, Ludi Miao
Frustrated magnets provide a platform for exploring exotic phases beyond conventional ordering, with potential relevance to functional materials and information technologies. In this work, we use Monte Carlo simulations to map the thermodynamic phase diagram of pyrochlore iridates R2Ir2O7 (R = Dy, Ho) with three stable magnetic ground-state stable phases: frustrated spin-ice 2 in 2 out (2I2O) phase, frustrated fragmented 3 in 1 out/1 in 3 out (3I1O/1I3O) phase, and antiferromagnetic all in all out (AIAO) phase without frustration. We discovered two additional emergent metastable phases at finite temperatures, located between the boundaries separating those stable phases. These metastable phases exhibit high magnetic susceptibility and high entropy without long-range order. Their stabilization arises from entropic minimization of the free energy, where the entropy dominates energetic competition near phase boundaries at finite temperatures. Our results demonstrate a platform to engineer highly susceptible and degenerated states through frustration and thermal activation, offering a foundation for entropy-based design of metastable phases in correlated systems.
Strongly Correlated Electrons (cond-mat.str-el), Materials Science (cond-mat.mtrl-sci)
9 pages, 5 figures
Heterogeneous diffusion in an harmonic potential: the role of the interpretation
New Submission | Statistical Mechanics (cond-mat.stat-mech) | 2025-05-20 20:00 EDT
Adrian Pacheco-Pozo, Igor M. Sokolov, Ralf Metzler, Diego Krapf
Diffusion in heterogeneous energy and diffusivity landscapes is widespread in biological systems. However, solving the Langevin equation in such environments introduces ambiguity due to the interpretation parameter $ \alpha$ , which depends on the underlying physics and can take values in the range $ 0<\alpha<1$ . The typical interpretations are Itô ($ \alpha=0$ ), Stratonovich ($ \alpha=1/2$ ), and Hänggi-Klimontovich ($ \alpha=1$ ). Here, we analyse the motion of a particle in an harmonic potential – modelled as an Ornstein-Uhlenbeck process – with diffusivity that varies in space. Our focus is on two-phase systems with a discontinuity in environmental properties at $ x=0$ . We derive the probability density of the particle position for the process, and consider two paradigmatic situations. In the first one, the damping coefficient remains constant, and fluctuation-dissipation relations are not satisfied. In the second one, these relations are enforced, leading to a position-dependent damping coefficient. In both cases, we provide solutions as a function of the interpretation parameter $ \alpha$ , with particular attention to the Itô, Stratonovich, and Hänggi-Klimontovich interpretations, revealing fundamentally different behaviours, in particular with respect to an interface located at the potential minimum.
Statistical Mechanics (cond-mat.stat-mech), Disordered Systems and Neural Networks (cond-mat.dis-nn), Mathematical Physics (math-ph)
19 pages, 5 figures, 4 appendices
Reflection phase shifts of bouncing Bogoliubov waves
New Submission | Quantum Gases (cond-mat.quant-gas) | 2025-05-20 20:00 EDT
The Bogoliubov-de Gennes equations are solved for an inhomogeneous condensate in the vicinity of a turning point, addressing the full continuous spectrum. A basis change in the space of the two Bogoliubov “particle” and “hole” amplitudes is introduced that decouples them approximately. We find a spatially extended mode that governs mainly excitations in the condensate phase, while another mode is localised to regions with density gradients. An analytical and numerical discussion of the phase shift is provided that incident matter waves suffer upon reflection at the turning point, forming standing waves. As an application, we compute eigenfrequencies in a gravitational trap, without recourse to the local density approximation. The non-condensate density at finite temperature and its quantum depletion are discussed in a companion paper.
Quantum Gases (cond-mat.quant-gas), Quantum Physics (quant-ph)
companion paper in preparation
Optical signatures of bulk g-wave altermagnetism in MnTe
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-05-20 20:00 EDT
Luca Haag, Marius Weber, Kai Leckron, Libor Šmejkal, Jairo Sinova, Hans Christian Schneider
In planar altermagnets, optical excitation by linearly polarized ultrashort pulses can induce spin polarizations in the electronic excited states in a controlled fashion, even though the material is magnetically compensated. Here, we theoretically analyze the response of the prototypical bulk g-wave altermagnet $ \alpha$ -MnTe to polarized ultrashort pulses. By calculating the excited electron distributions based on ab-initio band structure data, we show how this excited electronic spin response in $ \alpha$ -MnTe exhibits different symmetries which are determined by the nodal planes intrinsic to the bulk g-wave altermagnet. We present a simple procedure to obtain the symmetry of the electronic spin response from the two-dimensional cuts through the three-dimensional band structure.
Materials Science (cond-mat.mtrl-sci)
Emergence of cross-layer composite spins in La$_4$Ni$3$O${10}$ under pressure and possible routes to enhance its superconductivity
New Submission | Superconductivity (cond-mat.supr-con) | 2025-05-20 20:00 EDT
Jiang Ruoshi, Fan Zhiyu, Monserrat Bartomeu, Ku Wei
Trilayer La$ _4$ Ni$ _3$ O$ _{10}$ has been recently found to exhibit superconductivity in its high-pressure phase, similar to the previously discovered bilayer La$ _3$ Ni$ _2$ O$ _7$ , but with a notably lower transition temperature. To date the pressure effects on the electronic correlations beneficial for unconventional superconductivity remains unclear, as well as the potential similarities or differences compared to the bilayer La$ _3$ Ni$ _2$ O$ _7$ . We use a multi-energy-scale derivation of the inter-layer electron dynamics to identify the dominant emergent spin-charge correlations in trilayer La$ _4$ Ni$ _3$ O$ _{10}$ . Similar to the bilayer La$ _3$ Ni$ _2$ O$ _7$ , we find fractionalization of ionic spins in the high-pressure phase that results in cuprate-like spin-$ \frac{1}{2}$ ions correlated with itinerant carriers. This suggests a similar superconducting mechanism in other nickelate and cuprate superconductors. Interestingly, extra composite spins emerge as cross-layer trimers in the trilayer system, whose suppression of ionic spin fluctuations naturally explains the weaker superconductivity observed in La$ _4$ Ni$ _3$ O$ _{10}$ , and indicates that lowering layer symmetry is a viable strategy to improve superconductivity in this trilayer nickelate.
Superconductivity (cond-mat.supr-con), Strongly Correlated Electrons (cond-mat.str-el)
7 pages, 2 figures, 3 tables