CMP Journal 2026-03-10
Statistics
Nature: 2
Nature Materials: 2
Physical Review Letters: 12
Physical Review X: 2
arXiv: 119
Nature
Maximizing carrier extraction in hybrid back-contact silicon solar cells
Original Paper | Solar cells | 2026-03-09 20:00 EDT
Zilong Zheng, Xiqi Yang, Jiaxing Wang, Qinghua Zeng, Chaohua Zhang, Hong Zhang, Jiarong Huang, Yuhua Wang, Zeguo Tang, Rongkun Zhou, Hongbo Cai, Xiaofei Xu, Shenghou Zhou, Wanyu Lu, Qian Kang, Xiaoqing Chen, Kun Zheng, Yongzhe Zhang, Zhiyong Wang, Yusheng Yang, Jinyan Zhang, Hui Yan
Hybrid back-contact (BC) silicon solar cells 1-3 combine the strengths of TOPCon-derived 4-7 n-type contacts, SHJ-derived 8-12 p-type contacts, and interdigitated BC (IBC)13,14 device structures. Though high performance in the form of 27.8% efficiency has been demonstrated,1 the understanding of the fundamental advantages of the hybrid BC architecture over conventional BC cells (e.g. eliminating front-surface metallization shading 3) remains unexplored. Here we take advantage of the design flexibility of the hybrid BC architecture to use a multifunctional front layer for both light trapping and passivation. Meanwhile, we improved carrier collection and process compatibility of the rear carrier-selective contacts. We also show the optimal c-Si absorber thickness is increased to 160-μm, leading to a certified efficiency of 27.62% for industrially compatible c-Si solar cells.
Solar cells
Alcohol group migration by proximity-enhanced H atom abstraction
Original Paper | Synthetic chemistry methodology | 2026-03-09 20:00 EDT
Qian Xu, Yichen Nie, Jacob-Jan Haaksma, Ronghua Zhang, Natalie Holmberg-Douglas, Farid van der Mei, Paul M. Scola, Chloe Williams, Jeremiah A. Johnson, Alison E. Wendlandt
Subtle changes in molecular structure can lead to profound changes in molecular function. However, even minor structural refinements can require the complete re-synthesis of a target molecule, adding time and cost to molecular design campaigns1. Recently, editing methods have emerged targeting subtle molecular perturbations, including atomic substitution, stereocenter inversion and functional group repositioning2. These precision tools hold the potential to streamline the optimization of molecular function by fine-tuning molecular structure. Here we report an editing method that enables the migration of common alcohol functional groups to proximal sites with predictable stereo- and regiochemical outcomes. The reaction proceeds through a 1,2-acyloxy radical migration step under reversible H atom transfer catalysis conditions promoted by excited state decatungstate polyanion. Proximity effects arising from non-covalent interactions between substrate and reagent enable efficient radical formation at polarity-mismatched positions. Application of this tool at a late synthetic stage allows for the precise re-positioning of alcohol functional groups, while integration with common alcohol group installation methods provides new synthetic strategies to access challenging oxygenation patterns.
Synthetic chemistry methodology, Photocatalysis
Nature Materials
Stress-relaxing granular bioprinting materials enable complex and uniform organoid self-organization
Original Paper | Biomedical engineering | 2026-03-09 20:00 EDT
Austin J. Graham, Michelle W. L. Khoo, Vasudha Srivastava, Sara Viragova, Honesty Kim, Kavita Parekh, Kelsey M. Hennick, Malia Bird, Nadine Goldhammer, Jie Zeng Yu, Grace Hu, Natasha T. Brinkley, Lucas Pardo, Jasmine S. Amaya, Cameron D. Morley, Nishant Chadha, Paul Lebel, Sanjay Kumar, Jennifer M. Rosenbluth, Tomasz J. Nowakowski, Ovijit Chaudhuri, Ophir Klein, Rafael Gómez-Sjöberg, Zev J. Gartner
Complex and robust tissue self-organization requires defined initial conditions and dynamic boundaries–neighbouring tissues and extracellular matrix that actively evolve to guide morphogenesis. A major challenge in tissue engineering is identifying material properties that are compatible with controlling initial culture conditions while mimicking dynamic tissue boundaries. Here we describe a highly tunable granular biomaterial, MAGIC matrix, that supports both long-term bioprinting and gold-standard tissue self-organization. We identify that significant stress relaxation at the long timescales and large deformation magnitudes relevant to self-organization is required for optimal morphogenesis. We apply optimized MAGIC matrices toward precise extrusion bioprinting of saturated cell suspensions directly into three-dimensional culture. Carefully controlling initial conditions for tissue growth yields dramatic increases in organoid reproducibility and complexity across multiple tissue types, enabling high-throughput generation of organoid arrays and perfusable three-dimensional microphysiological systems. Our results identify key biomaterial parameters for optimal organoid morphogenesis and lay the foundation for fabricating more complex and reproducible self-organized tissues.
Biomedical engineering, Gels and hydrogels, Rheology, Tissue engineering, Tissues
Two-dimensional crystalline hard masks for high-aspect-ratio nanofabrication
Original Paper | Surface patterning | 2026-03-09 20:00 EDT
Pranavram Venkatram, Ziheng Chen, Krishnendu Mukhopadhyay, Bob Hengstebeck, Lei Ding, Vlastimil Mazanek, Yang Yang, Zdenek Sofer, Saptarshi Das
Hard masks with high etch selectivity are essential for fabricating high-aspect-ratio nanostructures via deep and anisotropic plasma etching. While most two-dimensional materials are susceptible to plasma damage, we report that van der Waals metal oxyhalides, specifically CrOCl and FeOCl, exhibit extraordinary resistance to aggressive SF6/O2 plasma, far surpassing conventional hard mask materials. CrOCl achieves etch rates as low as ~2.4 nm min-1 and an etch selectivity >200:1 relative to silicon, representing improvements of ~30× over Si3N4, ~2.3× over Al2O3 and ~20× over TiN under identical conditions. CrOCl maintains subnanometre surface roughness after etching, even exhibiting plasma-induced surface smoothening. Beyond its inherent etch resistance, CrOCl can be chemically patterned using Cl2 plasma and mechanically transferred onto a broad range of substrates, including perovskite oxides, polymers, glasses and monolayer two-dimensional semiconductors, enabling patterning on materials that are typically incompatible with conventional hard masks. Using CrOCl masks, we demonstrate deep silicon etching with aspect ratios exceeding 39:1 and minimal feature distortion. These findings establish van der Waals metal oxyhalides as a versatile and scalable platform for next-generation nanofabrication, combining extreme plasma robustness, high-resolution patternability and broad substrate compatibility in one material system.
Surface patterning, Two-dimensional materials
Physical Review Letters
Symmetry Fragmentation
Article | Quantum Information, Science, and Technology | 2026-03-09 06:00 EDT
Thomas Iadecola
In quantum many-body systems with kinetically constrained dynamics, the Hilbert space can split into exponentially many disconnected subsectors, a phenomenon known as Hilbert-space fragmentation. These subsectors can be viewed as protecting classical information about the initial state. We show that…
Phys. Rev. Lett. 136, 100401 (2026)
Quantum Information, Science, and Technology
Nonperturbative Switching Rates in Bistable Open Quantum Systems: From Driven Kerr Oscillators to Dissipative Cat Qubits
Article | Quantum Information, Science, and Technology | 2026-03-09 06:00 EDT
Léon Carde, Ronan Gautier, Nicolas Didier, Alexandru Petrescu, Joachim Cohen, and Alexander McDonald
In this Letter, we use path integral techniques to predict the switching rate in a single-mode bistable open quantum system. While analytical expressions are well-known to be accessible for systems subject to Gaussian noise obeying classical detailed balance, we extend this approach to a class of op…
Phys. Rev. Lett. 136, 100402 (2026)
Quantum Information, Science, and Technology
Long-Distance Free-Space Quantum Key Distribution with Continuous Variables
Article | Quantum Information, Science, and Technology | 2026-03-09 06:00 EDT
Tianxiang Zhan, Huasheng Li, Peng Huang, Haoze Chen, Jiaqi Han, Zijing Wu, Hao Fang, Hanwen Yin, Zehao Zhou, Huiting Fu, Feiyu Ji, Piao Tan, Yingming Zhou, Xueqin Jiang, Tao Wang, Jincai Wu, Cheng Ye, Yajun Miao, Wei Qi, and Guihua Zeng
Continuous-variable quantum key distribution (CVQKD) enables remote users to share high-rate and unconditionally secure secret keys while maintaining compatibility with classical optical communication networks and effective resistance against background noise. However, CVQKD experiments have been de…
Phys. Rev. Lett. 136, 100801 (2026)
Quantum Information, Science, and Technology
Guiding Fast Ion Beam by Suppressing Secondary Ions
Article | Atomic, Molecular, and Optical Physics | 2026-03-09 06:00 EDT
Yingli Xue, Junliang Liu, Mingwu Zhang, Daniel Fischer, Guoxing Xia, Nikolaus Stolterfoht, Reinhold Schuch, Yehong Wu, Bian Yang, Xiaoxiao Li, Caojie Shao, Wei Wang, Zhangyong Song, Xing Fang, Cheng Qian, Liangting Sun, Hongwei Zhao, Guoqing Xiao, Xiaohong Cai, and Deyang Yu
We demonstrate that secondary ions sputtered from a macrocapillary's inner surface by the primary beam induce premature saturation of the guiding field, hindering fast ion guiding. By suppressing secondary ion sputtering with grooved surfaces, we achieve a guiding-field potential difference exceedin…
Phys. Rev. Lett. 136, 103001 (2026)
Atomic, Molecular, and Optical Physics
Probing Coherences and Itinerant Magnetism in a Dipolar Lattice Gas
Article | Atomic, Molecular, and Optical Physics | 2026-03-09 06:00 EDT
Thomas Lauprêtre, Jose Daniel Bernal, Youcef Baamara, Ana Maria Rey, Laurent Vernac, and Bruno Laburthe-Tolra
We report on the study of itinerant magnetism of lattice-trapped magnetic atoms, driven by magnetic dipole-dipole interactions, in the low-entropy and close-to-unit filling regime. We have used advanced dynamical decoupling techniques to efficiently suppress the sensitivity to magnetic field fluctua…
Phys. Rev. Lett. 136, 103401 (2026)
Atomic, Molecular, and Optical Physics
Photonic Cyclic Orbit Bound to a Single Weyl Point
Article | Atomic, Molecular, and Optical Physics | 2026-03-09 06:00 EDT
Zhongfu Li, Qingyang Mo, Oubo You, Qingdong Yang, Shaojie Ma, Xinhua Wen, Yuanjiang Xiang, and Shuang Zhang
Weyl orbits are topologically protected cyclotron trajectories that connect Weyl nodes of opposite chiralities in momentum space, coupling bulk chiral Landau levels and surface Fermi arcs to produce quantum oscillations under static magnetic fields. While well-studied in condensed matter systems, th…
Phys. Rev. Lett. 136, 103801 (2026)
Atomic, Molecular, and Optical Physics
Elastic Turbulence in Highly Entangled Polymers and Wormlike Micelles
Article | Physics of Fluids, Earth & Planetary Science, and Climate | 2026-03-09 06:00 EDT
Theo A. Lewy, Suzanne M. Fielding, Peter D. Olmsted, and Rich R. Kerswell
We show theoretically that an initially homogeneous planar Couette flow of a concentrated polymeric fluid is linearly unstable to the growth of two-dimensional (2D) perturbations, within two widely used constitutive models: the Johnson-Segalman model and the Rolie-Poly model. We perform 2D direct no…
Phys. Rev. Lett. 136, 104001 (2026)
Physics of Fluids, Earth & Planetary Science, and Climate
Practical Kinetic Models for Dense Fluids
Article | Physics of Fluids, Earth & Planetary Science, and Climate | 2026-03-09 06:00 EDT
Ilya Karlin and Seyed Ali Hosseini
A novel approach to constructing kinetic models is proposed on the basis of the separation of local and nonlocal contributions to particle interaction. The method results in a generic kinetic equation for complex fluid systems, amenable to efficient numerical realization. The main obstruction to cau…
Phys. Rev. Lett. 136, 104002 (2026)
Physics of Fluids, Earth & Planetary Science, and Climate
Observation of Quasisteady Dark Excitons and Gapped State in a Doped Semiconductor
Article | Condensed Matter and Materials | 2026-03-09 06:00 EDT
Shangkun Mo, Yunfei Bai, Chunlong Wu, Xingxia Cui, Guangqiang Mei, Qiang Wan, Renzhe Li, Cao Peng, Keming Zhao, Dingkun Qin, Shuming Yu, Hao Zhong, Xingzhe Wang, Enting Li, Yiwei Li, Limin Cao, Min Feng, Sheng Meng, and Nan Xu
Excitons underpin optical phenomena and can intertwine with correlated electronic states. Unlike bright excitons, dark excitons evade conventional optical detection, and their impact on quasiequilibrium electronic structures remains largely unexplored. Here, using angle-resolved photoemission spectr…
Phys. Rev. Lett. 136, 106401 (2026)
Condensed Matter and Materials
Disentangling Electronic and Ionic Nonlinear Polarization Effects in Bulk THz Kerr Response
Article | Condensed Matter and Materials | 2026-03-09 06:00 EDT
Chao Shen, Maximilian Frenzel, Sebastian F. Maehrlein, and Zhanybek Alpichshev
Terahertz (THz) spectroscopy is a powerful probe of low-energy excitations in complex materials. Extending it into the nonlinear regime broadens its scope and can provide valuable insight into interactions among these modes. However, interpreting nonlinear spectra is challenging because resonant fea…
Phys. Rev. Lett. 136, 106901 (2026)
Condensed Matter and Materials
Giant Helicity-Dependent Second Harmonic Generation in Type-2 Weyl Semimetal
Article | Condensed Matter and Materials | 2026-03-09 06:00 EDT
Aindrila Sinha, K. P. Mithun, D. V. S. Muthu, and A. K. Sood
Second harmonic generation (SHG) has emerged as a powerful probe of fundamental geometric and topological attributes of the band structure of the Weyl semimetals (WSMs) through the photocurrent generation (shift, injection, and anomalous currents). Notably, circular photocurrents, such as injection …
Phys. Rev. Lett. 136, 106902 (2026)
Condensed Matter and Materials
Cooperative Native Contact Formation Facilitates Free Energy Barrier Crossing in Protein Folding
Article | Polymers, Chemical Physics, Soft Matter, and Biological Physics | 2026-03-09 06:00 EDT
Chi-Jui Feng, Ulrich Baxa, John M. Louis, and Hoi Sung Chung
High-temporal-resolution fluorescence measurements reveal how quickly proteins cross energy barriers separating unfolded and folded states.
Phys. Rev. Lett. 136, 108401 (2026)
Polymers, Chemical Physics, Soft Matter, and Biological Physics
Physical Review X
Unraveling Real-Time Chemical Shifts in the Ultrafast Regime
Article | 2026-03-09 06:00 EDT
Daniel E. Rivas, Lorenzo Paoloni, Rebecca Boll, Alberto De Fanis, Ana Martínez Gutiérrez, Tommaso Mazza, Solène Oberli, Oliver Alexander, André Al-Haddad, Thomas M. Baumann, Christoph Bostedt, Simon Dold, Gianluca Geloni, Markus Ilchen, Dooshaye Moonshiram, Daniel Rolles, Artem Rudenko, Philipp Schmidt, Svitozar Serkez, Sergey Usenko, Ángel Martín Pendás, Michael Meyer, Jesús González-Vázquez, and Antonio Picón
Combining ultrafast x-ray measurements with a theoretical model allows for tracking bond breaking, molecular motion, and chemical reactions.
Phys. Rev. X 16, 011051 (2026)
Ultracold High-Spin $\mathrm{Σ}$-State Polar Molecules for New Physics Searches
Article | 2026-03-09 06:00 EDT
Alessio Ciamei, Adam Koza, Marcin Gronowski, and Michał Tomza
Ultracold YbCr molecules, featuring large internal electric fields and an ideal rotational structure controllable with modest laboratory fields, are proposed as a sensitive platform for probing physics beyond the standard model.
Phys. Rev. X 16, 011052 (2026)
arXiv
Phase field as a front propagation method for modeling grain growth in additive manufacturing
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-03-10 20:00 EDT
Murali Uddagiri, Pankaj Antala, Ingo Steinbach
A mesoscopic grain-envelope model applying a phase-field front-propagation method is developed to simulate grain growth under additive manufacturing process conditions. The envelope represents the outer surface of dendritic grains through a diffuse interface. While a modified heat-conduction model that incorporates moving heat sources and latent-heat release provides the evolution of local thermal field. Envelope propagation is determined from microscopic-solvability-based kinetic law. The model is validated through two- and three-dimensional simulations and subsequently applied to examine the influence of material and process parameters on microstructure evolution. The results demonstrate that the proposed mesoscopic model offers an efficient and predictive approach for modeling grain growth during multi-pass and multi-layer build-up in additive manufacturing.
Materials Science (cond-mat.mtrl-sci)
Collapse of Jahn-Teller Phonons in La${1-x}$Sr${x}$MnO$_3$ with Weak Magnetoresistance
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-03-10 20:00 EDT
Tyler C. Sterling, Andrei T. Savici, Ryoichi Kajimoto, Kazuhiko Ikeuchi, Nazir Khan, Frank Weber, Dmitry Reznik
Perovskite manganites are quantum materials exhibiting competing interactions inducing colossal magnetoresistance (CMR). The prevailing theory of CMR highlights the essential role of electron-phonon coupling (EPC), but mounting evidence suggests the underlying mechanism is more complicated. Here, we investigate phonons and spin-phonon coupling in ferromagnetic CMR manganites La$ _{1-x}$ Sr$ _x$ MnO$ _3$ ($ x$ =0.2,0.3) with relatively small CMR associated with melting of the magnetic order above room temperature. High-resolution neutron scattering experiments combined with density functional theory (DFT) show that the low-temperature ferromagnetic phase is conventional: neutron scattering from phonons agrees with DFT predictions and magnons follow sinusoidal dispersions. Fluctuating magnetic moments and low-energy phonons remain conventional in the high temperature paramagnetic phase, indicating the Mn and La/Sr sublattices are not strongly perturbed by melting of ferromagnetism. In contrast, the Jahn-Teller-active optical oxygen vibrations collapse entirely above the Curie temperature, despite low CMR in these compositions, with some of the lost spectral weight reappearing as quasielastic scattering. We attribute this highly anomalous behavior to giant EPC in the charge and/or orbital channel. It drives cooperative diffusive motion of quasistatic carrier-trapping oxygen sublattice distortions once ferromagnetism disappears. We hypothesize the magnitude of magnetoresistance correlates with the rate of diffusion rather than with the strength of Jahn-Teller EPC.
Materials Science (cond-mat.mtrl-sci), Strongly Correlated Electrons (cond-mat.str-el)
Effect of Exchange-Correlation Functionals on Schottky Barriers at Si/Metal Interfaces
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-03-10 20:00 EDT
Viviana Dovale-Farelo, Kamal Choudhary
Accurate prediction of Schottky barrier heights (SBHs) at metal-semiconductor (M-SC) interfaces is essential for understanding and optimizing charge injection in electronic and optoelectronic devices. However, first-principles calculations of SBHs remain challenging due to the combined difficulties of semiconductor bandgap underestimation, metal Fermi level placement, lattice-mismatch, relative geometric alignment and electrostatic potential alignment across heterogeneous interfaces. In this work, we present a systematic and physically grounded assessment of computational strategies for SBH prediction using Si(111)/Metal (Al, Cu, Ag, Au) interfaces as representative test cases. We evaluate multiple exchange-correlation (XC) treatments, in combination with three distinct bulk reference protocols: relaxed bulk, relaxed bulk with spin-orbit coupling, and strained bulk references consistent with the interface geometry. By benchmarking against experimental data, we demonstrate that structural and electrostatic consistency between interface and bulk reference calculations is the dominant factor governing SBH accuracy. We show that mixed hybrid-semilocal approaches combined with strained reference protocols yield uniformly positive and significantly improved SBHs, achieving near-experimental accuracy while maintaining a favorable balance between computational cost and predictive performance. Our results establish a clear and transferable methodology for reliable Schottky barrier prediction and provide practical guidance for large-scale screening and interface engineering.
Materials Science (cond-mat.mtrl-sci)
Patterns of load, elastic energy and damage in network models of architected composite materials
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-03-10 20:00 EDT
Christian Greff, Leon Pyka, Michael Zaiser, Paolo Moretti
We investigate the role of architected thin films in the interfacial failure properties of bi-layer composites. Our results show that, while graded structures can be used to prescribe failure at the interface, they do not offer significant advantages in terms of fracture toughness. Hierarchically patterned layers can localize failure at the interface and simultaneously enhance interface toughness, by enforcing a buffer region where elastic energy is dissipated in the form of diffuse damage, so that no stress concentration can drive crack growth. To analyze these mechanisms, the associated patterns of local load redistribution and the soft deformation modes, we develop a network formalism that brings together concepts of discrete differential geometry and spectral graph theory.
Materials Science (cond-mat.mtrl-sci), Disordered Systems and Neural Networks (cond-mat.dis-nn)
18 pages, 8 figures
Enhancing superconductivity using thermal bosons
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2026-03-10 20:00 EDT
Ekaterina Vlasiuk, Manfred Salmhofer, Eugene Demler, Richard Schmidt
We investigate how the strong coupling of a superconductor to thermal bosons can enhance its superconducting critical temperature. To tackle this problem, we use a renormalization group approach that allows us to describe the competition between density fluctuations and the build-up of boson-induced attraction between fermions. Capturing the mutual influence of bosonic and fermionic sectors, the self-consistent renormalization group framework predicts a robust increase of the critical temperature across a wide range of interactions. We find a nontrivial dependence of the critical temperature on the boson mass and we establish a phase diagram for enhanced superconductivity driven by bosons being either in the condensed or thermal state. We outline possible experimental realizations in cold atomic systems and discuss implementations using electron-exciton mixtures in van der Waals material heterostructures.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Quantum Gases (cond-mat.quant-gas), Strongly Correlated Electrons (cond-mat.str-el), Quantum Physics (quant-ph)
7+7 pages, 4+5 figures
Quasiparticle spectroscopy in tantalum films with different Ta/sapphire interfaces
New Submission | Superconductivity (cond-mat.supr-con) | 2026-03-10 20:00 EDT
Bicky S. Moirangthem, Kamal R. Joshi, Anthony P. Mcfadden, Jin-Su Oh, Amlan Datta, Makariy A. Tanatar, Florent Lecocq, Raymond W. Simmonds, Lin Zhou, Matthew J. Kramer, Ruslan Prozorov
One of the crucial aspects of current research in quantum information science is the identification and control of loss mechanisms in superconducting circuits. Although microwave measurements directly quantify device performance, additional techniques that probe quasiparticle excitations in superconducting films are needed to understand the microscopic mechanisms underlying dissipation and decoherence. Here, we present results from quasiparticle spectroscopy of Ta/sapphire films by measuring the Meissner-state magnetic susceptibility using a precision frequency-domain resonator specifically designed for thin films. We find direct evidence for additional low-energy excitations in samples with lower internal quality factors. These excitations are consistent with deep subgap states due to two-level systems, Yu-Shiba-Rusinov states near the gap edge, and perhaps other pair-breaking mechanisms. The developed non-destructive frequency-domain quasiparticle spectroscopy is a valuable addition to the quantum materials toolbox.
Superconductivity (cond-mat.supr-con), Materials Science (cond-mat.mtrl-sci)
A Compact XOR Gate Implemented With a Single Straintronic Magnetic Tunnel Junction
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2026-03-10 20:00 EDT
The XOR Boolean logic gate is widely used in many applications such as encryption (XOR ciphers), binary addition (half- and full-adders), error detection (parity bits), etc. but is challenging to construct because of its demanding conditional dynamics. It typically requires multiple logic switches or other types of gates, which results in a large gate footprint and low logic density. Here, we present the design of an XOR gate with a single straintronic magnetic tunnel junction which reduces the footprint dramatically. Such a gate is non-volatile and hence suitable for non-von-Neumann architectures, processor-in-memory, etc. The switching time of the gate is ~200 ps and the energy dissipation per gate operation is ~225 aJ. Cascading of successive stages is accomplished via a CMOS device which plays no role in the gate dynamics but is needed for gain to provide logic level restoration, fan-out and isolation between input and output. This 1 MTJ-1 CMOS design has an energy dissipation that is an order of magnitude smaller than what has been reported for traditional all-transistor XOR designs.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
Reply to the comment on “Instability of the ferromagnetic quantum critical point and symmetry of the ferromagnetic ground state in 2D and 3D electron gases with arbitrary spin-orbit splitting’’
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2026-03-10 20:00 EDT
Dmitry Miserev, Daniel Loss, Jelena Klinovaja
We reply on the comment of D. Belitz and T. R. Kirkpatrick on our article ``Instability of the ferromagnetic quantum critical point and symmetry of the ferromagnetic ground state in 2D and 3D electron gases with arbitrary spin-orbit splitting’’.
Strongly Correlated Electrons (cond-mat.str-el)
2 pages; reply to arXiv:2601.19959
Bridging the lab-to-fab gap in non-fullerene organic solar cells via gravure printing
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-03-10 20:00 EDT
Svitlana Taranenko, Chen Wang, David Holzner, Robert Eland, Christopher Wöpke, Toni Seiler, Alexander Ehm, Fabio Le Piane, Roderick C. I. Mackenzie, Dietrich R. T. Zahn, Carsten Deibel, Arved Carl Hübler, Maria Saladina
Organic solar cells have reached record efficiencies with non-fullerene acceptors, yet their translation to industrial printing remains a critical bottleneck. Here we report the highest efficiency achieved for a fully roll-to-roll-compatible gravure-printed non-fullerene organic solar cell. High-performance blends are typically optimised under laboratory coating conditions, while roll-to-roll manufacturing imposes fundamentally different constraints on ink stability, drying dynamics, and multilayer integration. Whether these constraints intrinsically limit device physics has remained unresolved. Here, we demonstrate a gravure-printed PM6:Y12 solar cell architecture using commercially available materials and establish a quantitative framework that disentangles optical, recombination, and transport losses in printed devices. We find that favourable bulk morphology and exciton harvesting can be preserved under gravure printing and non-halogenated solvents. The dominant efficiency penalties arise instead from optical interference within the printed layer stack and slow charge transport. Our results demonstrate that the performance gap between laboratory and printed solar cells is originating from device architecture rather than the intrinsic physics of modern non-fullerene systems, providing a mechanistic roadmap for roll-to-roll manufacturing of non-fullerene solar cells.
Materials Science (cond-mat.mtrl-sci)
Anharmonicity and Charge-Noise Sensitivity of Fraunhofer Qubit
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2026-03-10 20:00 EDT
Longyu Ma, Tony Liu, Javad Shabani, Kasra Sardashti, Vladimir E. Manucharyan, Maxim G. Vavilov
We present a theory of a flux-tunable superconducting qubit, the “Fraunhofer qubit,” based on the Fraunhofer interference in a wide ballistic Josephson junction. As magnetic flux threads the junction, the Josephson potential is effectively averaged over a phase window proportional to flux. For perfectly transmitting junctions, as flux approaches one flux quantum h/2e, the flux averaging transforms the potential near its minimum from a quadratic to a triangular shape, resulting in significantly enhanced anharmonicity. This enhancement persists for junctions with lower transparency conducting channels. Microscopic tight-binding simulations that include inhomogeneous electrostatic potential and disorder confirm the enhancement of anharmonicity. These results establish a framework for flux control in hybrid superconducting circuits, providing an operating point where anharmonicity and charge-noise protection can be optimally balanced.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
8 pages, 5 figures
AIMD-L: An automated laboratory for high-throughput characterization of structural materials for extreme environments
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-03-10 20:00 EDT
Todd C. Hufnagel, Pranav Addepalli, Anuruddha Bhattacharjee, Rohit Berlia, Jaafar El-Awady, David Elbert, Lori Graham-Brady, Axel Krieger, Harichandana Neralla, T. Joseph Nkansah-Mahaney, Mostafa M. Omar, Hyun Sang Park, K.T. Ramesh, Matthew Shaeffer, Eric Walker, Piyush Wanchoo, Timothy P. Weihs
Rapid developments in artificial intelligence and machine learning as applied to materials science are creating an urgent need for experimental data, which can be provided by high-throughput and autonomous laboratories. To date most demonstrations of such laboratories have focused on functional materials, with less attention paid to structural materials. We present here the Artificial Intelligence in Materials Design Laboratory (AIMD-L), an automated, high-throughput facility for characterizing the microstructure and properties of structural metals and ceramics, with an emphasis on materials in extreme environments.
AIMD-L has two custom instruments for characterization of structural materials: HELIX for shock studies of materials, and MAXIMA for X-ray diffraction and X-ray fluorescence spectroscopy. Specifically designed for high-throughput studies, HELIX and MAXIMA are each capable of collecting data at rates two to three orders of magnitude faster than conventional systems. A third experimental station, SPHINX, is a commercial nanoindenter modified for integration into the automated workflow of AIMD-L. A user (which may be human or an AI agent) directs the experiments to be carried out by means of a centralized control program. The experimental stations are linked by a conveyance that moves samples around the lab, with a robot at each station for sample transfer in/out of the instrument. The experimental stations also communicate with a common data layer that streams data autonomously from each instrument to a data portal, where their arrival triggers automated workflows for data reduction and analysis. The processed data are immediately available to the human operator or agentic AI, forming a closed loop for rapid decision-making and experimental control.
Materials Science (cond-mat.mtrl-sci), Instrumentation and Detectors (physics.ins-det)
15 pages, 10 figures, submitted to Matter
Adsorption-Controlled Epitaxy and Twin Control of $γ$-GaSe on GaAs (111)B
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-03-10 20:00 EDT
Joshua Eickhoff, Wendy L. Sarney, Sina Najmaei, Daniel A. Rhodes, Jason Kawasaki
The III-Se layered semiconductors, including InSe and GaSe, are promising optoelectronic materials due to their relatively high electron mobilities at room temperature, nonlinear optical responses, ferroelectricity, self-passivated van der Waals surfaces, and ability to alloy and synthesize heterostructures for bandgap engineering. Adsorption control is a widely utilized strategy for controlling the stoichiometry and phase formation of these materials; however, the bounds of the adsorption-controlled growth window for GaSe have not been systematically established. Additionally, challenges with control over polytype and twinning remain. Here, we use molecular beam epitaxy to experimentally map the adsorption-controlled growth window of GaSe films on vicinal GaAs (111)B substrates. The observed phase boundaries show qualitative agreement with Ellingham diagram predictions. All films crystallize in the $ \gamma$ ($ R3m$ ) polytype. Increasing growth and annealing temperature leads to decreased mosaicity measured by x-ray rocking curve and smoother surfaces measured by atomic force microscopy, at the expense of a transition from singly oriented $ \gamma$ to twinned $ \gamma$ with $ 60\degree$ rotated domains.
Materials Science (cond-mat.mtrl-sci)
Correlations Between the Dielectric Properties, Domain Structure Morphology and Phase State of Bi1-xSmxFeO3 Nanoparticles
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-03-10 20:00 EDT
Oleksandr S. Pylypchuk, Vladislav O. Kolupaiev, Victor V. Vainberg, Vladimir N. Poroshin, Ihor V. Fesych, Lesya Demchenko, Eugene A. Eliseev, Anna N. Morozovska
Nanoscale multiferroics are basic model objects for studying polar, magnetic and magnetoelectric properties and mutual couplings. Bismuth-samarium ferrite (Bi1-xSmxFeO3) is a model orthoferrite, whose polar, magnetic and magnetoelectric properties have been studied for the bulk and thin film samples. The properties of Bi1-xSmxFeO3 nanoparticles have been much less studied, despite the nanoparticles can be used in a wide range of applications, such as energy storage, magnetic hyperthermia and advanced nanoelectronics. In this work we performed experimental measurements and analysis of the temperature dependence of the Bi1-xSmxFeO3 nanopowders dielectric properties. Calculations of the ferro-ionic coupling influence on the dielectric properties, domain structure morphology and phase states are performed in the framework of the Ginzburg-Landau-Devonshire-Stephenson-Highland approach. Theoretical results explain the main trends of experimentally observed temperature dependences of the effective dielectric permittivity, which allows us to understand the correlations between the temperature behavior of dielectric properties, domain structure morphology and phase state of Bi1-xSmxFeO3 nanoparticles.
Materials Science (cond-mat.mtrl-sci)
16 pages, 5 fihures
Capturing nuclear quantum effects in high-pressure superconducting hydrides and ice with nuclear-electronic orbital theory
New Submission | Superconductivity (cond-mat.supr-con) | 2026-03-10 20:00 EDT
Logan E. Smith, Paolo Settembri, Alessio Cucciari, Lilia Boeri, Gianni Profeta, Sharon Hammes-Schiffer
Nuclear quantum effects are essential for correctly describing hydrogen-rich materials at high pressures. Superconducting hydrides and ice are prime examples of such systems, requiring the inclusion of lattice anharmonicity and nuclear quantum effects to correctly predict and describe the structures and phase transition pressures observed experimentally. Herein, we show that the nuclear-electronic orbital density functional theory (NEO-DFT) method, which treats specified nuclei quantum mechanically on the same level as the electrons, is capable of accurately describing nuclear quantum effects in superconducting hydrides and ice. NEO-DFT predicts the hydrogen-bond symmetrization pressure in H$ _3$ S and D$ _3$ S, benchmarking against the more expensive stochastic self-consistent harmonic approximation (SSCHA) method, and predicts the correct symmetric Fm$ \bar{3}$ m structure for LaH$ _{10}$ at a wide range of pressures. NEO-DFT also predicts the ice VIII to ice X phase transition pressures for H$ _2$ O and D$ _2$ O in agreement with experimental measurements. The accuracy, computational efficiency, and broad applicability of the NEO method opens the door for expanded large-scale studies into these types of systems.
Superconductivity (cond-mat.supr-con)
12 pages, 3 figures
Non-equilibrium formulation of helicity-dependent thermal field for ultrafast magnetization dynamics
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2026-03-10 20:00 EDT
Far-from-equilibrium magnetization dynamics can be accessed when a magnetic material is subject to a femtosecond excitation, such as an optical laser or an electric current. Numerically, the demagnetization of magnetic materials is typically modeled by atomistic spin dynamics. Micromagnetic models generally fail to reproduce ultrafast demagnetization in a grid independent manner. Here, we propose a non-equilibrium thermal field whose features depend on atomic spin flip probabilities. Under the assumption that each spin flip is equivalent to a quantum of angular momentum, equivalent temperatures on the order of thousands of Kelvin are achieved. Demagnetization is quantitatively reproduced for several cell sizes. The presented approach can be further refined and extended towards a grid-independent and multiscale modeling of ultrafast magnetization dynamics.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
Universal electronic manifolds for extrapolative alloy discovery
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-03-10 20:00 EDT
Pranoy Ray, Sayan Bhowmik, Phanish Suryanarayana, Surya R. Kalidindi, Andrew J. Medford
This study presents a computationally efficient framework for accelerated alloy discovery that uses the non-interacting electron density to capture intrinsic structure-property relationships in refractory high-entropy alloys (HEAs). Unlike state-of-the-art approaches relying on expensive, self-consistent density functional theory calculations, our method employs the non-interacting electron density as the primary structural descriptor. By extracting physical features through directionally resolved two-point spatial correlations and compressing them via Principal Component Analysis, we efficiently map the design space. Coupling these descriptors with Bayesian active learning, we achieve a normalized mean absolute error (NMAE) of <2% for the bulk modulus of Al-Nb-Ti-Zr alloys using only 10 training samples. Furthermore, we demonstrate that the model learns an electronic packing manifold that is transferable across distinct chemical species within refractory HEAs. Validated on a distinct 7-component refractory system (Mo-Nb-Ta-Ti-V-W-Zr) containing four elements entirely absent from the training data, the framework enables rigorous zero-shot extrapolation. Moreover, by augmenting the base model with just 20 samples from the target domain, we achieve high-fidelity predictions (NMAE < 3%) for 7-component alloys, reducing data acquisition costs by orders of magnitude compared to standard workflows. These results establish the non-interacting electron density as a rigorous, extrapolative descriptor for vast compositional landscapes.
Materials Science (cond-mat.mtrl-sci), Data Analysis, Statistics and Probability (physics.data-an)
Flat Topological Nodal Lines in Heavy-Fermion Compound CeCoGe$_3$
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2026-03-10 20:00 EDT
Yuting Wang, Weikang Wu, Jianzhou Zhao
The interplay between strong electronic correlations, unconventional superconductivity, and symmetry-protected topology provides a fertile ground for discovering exotic quantum states. In this work, we investigate the correlated electronic structure and topological properties of the heavy fermion material CeCoGe$ 3$ using density functional theory combined with dynamical mean-field theory calculations. Our results reveal a crossover from high temperature incoherent states to low temperature coherent heavy quasiparticles, accompanied by a mass enhancement of $ m^\ast/m{\text{DFT}}\sim 52.6$ at $ T=25$ K. The interplay between electronic correlation, spin-orbit coupling and the noncentrosymmetric $ I4mm$ crystal symmetry stabilize flat topological nodal lines within 10 meV of the Fermi level, which could contribute a significant density of states. The proximity of topological nodal lines to the Fermi surface suggests a potential role in mediating pressure induced unconventional superconductivity. Our work establishes CeCoGe$ _3$ as a prototype topological nodal line Kondo semimetal. The coexistence of strong correlation, non-trivial band topology and superconductivity indicate CeCoGe$ _3$ as a potential candidate for realizing topological superconductivity.
Strongly Correlated Electrons (cond-mat.str-el)
Exotic Cooperative Quantum Optics of Moire Exciton Superlattices
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-03-10 20:00 EDT
The unique properties of two-dimensional moire systems have been widely studied from many perspectives. However, relatively little work has explored how the real space structure of the moire systems can directly engender novel properties and functionalities. In this work, we exploit the feature that moire excitons naturally form an ordered superlattice with a lattice constant comparable to the wavelength of the resonant light, which enables intriguing cooperative optical responses. Particularly, we show that the collective moire exciton states can have either strongly enhanced (superradiant) or suppressed (subradiant) radiative decay rate, depending on their in-plane wavevector. These super- and subradiant states can be efficiently switched by a gate-induced electric field gradient. Moreover, the cooperative transmittance $ T$ of the nanometer-thick moire system can be switched from $ T \approx 0$ (opaque) to $ T \approx 1$ (transparent) with less than $ 2~%$ heterostrain or a $ 1^{\circ}$ adjustment in the twist angle $ \theta$ . These features are robust against non-radiative losses and inhomogeneity, making the moire system a highly versatile platform for cooperative quantum optics with potential applications in e.g., single photon storage and switching.
Materials Science (cond-mat.mtrl-sci), Optics (physics.optics), Quantum Physics (quant-ph)
7 pages, 4 figures
A general statistical framework for vacancy and self-interstitial properties in concentrated multicomponent solids
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-03-10 20:00 EDT
Jacob Jeffries, Hyunsoo Lee, Anter El-Azab, Enrique Martinez
A rigorous understanding of the thermodynamic properties of point defects, namely vacancies and self-interstitials, is crucial for the discovery and screening of structural materials in clean energy applications. In this work, we extend a previously-developed statistical framework for predicting the thermodynamics of single-site impurities to further predict the thermodynamics of self-interstitial dumbbells in an arbitrarily complex alloy. We then apply this extended framework to compute effective formation energies in fully disordered Fe-Cr and Cu-Ni alloys. Notably, we predict that some self-interstitial dumbbell types that are high-energy in pure Fe become stabilized by Cr. We additionally describe a symmetry-breaking effect, wherein high solute concentrations distort the defect free energy surface, yielding misaligned self-interstitials.
Materials Science (cond-mat.mtrl-sci), Statistical Mechanics (cond-mat.stat-mech)
16 pages, 7 figures
Pressure-Induced Metal-Insulator and Paramagnet-Altermagnet Transitions in Rutile OsO2 Single Crystals
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2026-03-10 20:00 EDT
Guojian Zhao, Ziang Meng, Wencheng Huang, Peixin Qin, Shaoheng Ruan, Liang Ma, Lin Zhu, Yuzhou He, Li Liu, Zhiyuan Duan, Xiaoning Wang, Hongyu Chen, Sixu Jiang, Jingyu Li, Xiaoyang Tan, K. Ozawa, Bosen Wang, Jinguang Cheng, Qinghua Zhang, Jianfeng Wang, Chaoyu Chen, Zhiqi Liu
Altermagnets with compensated spin structures and nonrelativistic spin splitting have emerged as a new class of magnetic materials. Rutile OsO2 has been theoretically predicted to be altermagnetic, but experimental studies have been limited by synthesis challenges. We have succeeded in synthesizing high-quality single crystals of rutile OsO2. Electrical transport studies reveal that OsO2 is highly conductive and exhibits clear Fermi liquid behavior, indicating strong electron-electron scattering. Magnetic measurements show that the crystals are isotropically paramagnetic. Density-functional theory calculations indicate that bulk OsO2 is semimetallic with coexisting electron and hole pockets, with its magnetic ground state strongly dependent on the on-site Coulomb correlation U. Angle-resolved photoemission spectroscopy studies unveil that the bulk bands do not yet show altermagnetic spin splitting. Interestingly, resistivity is rather pressure sensitive: at 44 GPa, a clear metal-insulator transition occurs. Hybrid functional calculations reveal that applying pressure significantly increases the Hubbard U value, driving a phase transition from a paramagnetic metal to an altermagnetic metal, and eventually to an altermagnetic insulator. These findings suggest that tuning external pressure effectively modulates the magnetic ground state of OsO2, providing a pathway to realize altermagnetism in this material.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Materials Science (cond-mat.mtrl-sci), Strongly Correlated Electrons (cond-mat.str-el), Applied Physics (physics.app-ph)
20 pages, 7 figures, published at Newton
Newton, 2, 100441 (2026)
Bulk OsO2 Single Crystals: Superior Catalysts for Water Oxidation
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-03-10 20:00 EDT
Guojian Zhao, Zhihao Li, Ziang Meng, Shucheng Wang, Li Liu, Zhiyuan Duan, Xiaoning Wang, Hongyu Chen, Yuzhou He, Jingyu Li, Sixu Jiang, Xiaoyang Tan, Qinghua Zhang, Qianfan Zhang, Peixin Qin, Zhiqi Liu
Although rutile RuO2 has been a well-known and almost the best oxygen evolution reaction (OER) catalyst, the OER properties for the similar rutile oxide OsO2 with the same group element with Ru have been unknown, mainly due to long-standing synthesis difficulties. In this work, we report the successful synthesis of high-quality OsO2 single crystals, and the ground micrometer-size single crystals are chemically stable in alkaline solutions and exhibit robust OER performance. In sharp contrast, OsO2 nanopowder reacts quickly with KOH solutions and cannot work for OER. Compared with commercial RuO2 nanopowder, the OsO2 single crystals show comparable catalytic current densities, remarkably lower overpotentials at high current densities and better stability. These findings question the universal applicability of nanoscaling and highlight crystal integrity as a key descriptor for achieving stable and efficient OER electrocatalysis.
Materials Science (cond-mat.mtrl-sci), Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Strongly Correlated Electrons (cond-mat.str-el)
36 pages,18 figures, published online at Advanced Functional Materials
Crystal electric field excitations and spin dynamics in a spin-orbit coupled distorted honeycomb magnet BiErGeO$_5$
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-03-10 20:00 EDT
S. Mohanty, S. Guchhait, S. S. Islam, Surya P. Patra, M. P. Saravanan, J. A. Krieger, T. J. Hicken, H. Luetkens, D. T. Adroja, Goran J. Nilsen, M. D. Le, R. Nath
The magnetic properties and crystal electric field (CEF) scheme of BiErGeO$ 5$ are investigated via magnetization, heat capacity, muon spin relaxation (muSR), and inelastic neutron scattering (INS) experiments on a polycrystalline sample. The Er$ ^{3+}$ ions form a quasi-two-dimensional distorted honeycomb network with a Kramers doublet ground state. Magnetic susceptibility and heat capacity reveal short-range antiferromagnetic correlations, manifested as a broad maximum around 1.4 K. Heat-capacity data further confirm the onset of a magnetic long-range order at $ T N = 0.4$ K. The INS spectra exhibit eight CEF excitations and the CEF analysis yields the $ g$ -factor anisotropy with $ g_{xy}/g_{z} = 1.38$ and exchange anisotropy with $ J_{xy} = 2.96$ K and $ J_{z} = 1.56$ K. The experimental temperature and field dependent magnetization and heat capacity are also reproduced by the simulation using CEF energy scheme. Zero-field muSR measurements down to 30 mK, do not exhibit coherent oscillations or a static 1/3 tail. The spectra are well described by two exponential relaxation components, indicating two magnetically inequivalent muon environments. The relaxation rates display a nearly temperature-independent plateau below $ T_{\rm N}$ and follow an Orbach-type activated behavior at higher temperatures involving excited CEF levels, consistent with the INS results. Longitudinal-field $ \mu$ SR measurements reveal only weak decoupling up to 1.5 T, indicating persistent slow spin fluctuations below $ T_{\rm N}$ .
Materials Science (cond-mat.mtrl-sci)
17 pages, 12 figures
Higgs gap modes in superconducting circuit quantisation
New Submission | Superconductivity (cond-mat.supr-con) | 2026-03-10 20:00 EDT
Yun-Chih Liao, Ben J. Powell, Thomas M. Stace
We extend a recently developed projective circuit quantisation approach to incorporate superconducting Higgs modes associated to gap dynamics. This approach starts from a microscopic fermionic Hamiltonian for mesoscopic superconductors, and projects the system onto its low-energy “BCS” Hilbert space. We derive analytical results for the superconducting Higgs mass, “spring” constant, and oscillation frequency of the gap dynamics, which we validate numerically. We compute anharmonic corrections to the Higgs frequency for higher excitations of small superconducting islands, and compare our results to previous long-wavelength calculations.
Superconductivity (cond-mat.supr-con), Quantum Physics (quant-ph)
5 pages, 5 figures
Nematic Bubbles and the Breaking of Spherical Symmetry
New Submission | Soft Condensed Matter (cond-mat.soft) | 2026-03-10 20:00 EDT
Gaetano Napoli, Silvia Paparini
The emergence of nematic order on deformable closed surfaces plays a pivotal role in the morphogenesis of active biological matter, such as the regeneration of Hydra. In this work, we present a continuum model that couples the two-dimensional Landau-de Gennes order tensor, describing in-plane nematic ordering, with the mechanics of a mass-conserving, deformable spherical shell. By investigating the isotropic-to-nematic phase transition driven by a reduction in temperature, mimicking the natural induction of nematic order in actomyosin fibres, we perform both linear and weakly non-linear bifurcation analyses. The onset of nematic ordering spontaneously breaks spherical symmetry, yielding distinct equilibrium morphologies governed by the shell’s deformability. Axisymmetric configurations, featuring two +1 defects at the poles, emerge via a discontinuous bifurcation, resulting in a globally stable prolate shape, alongside a metastable oblate shape. Non-axisymmetric configurations, featuring four +1/2 defects arranged in a square, arise via a continuous bifurcation. Shell softness drives the first-order character of the transition, while in the limit of infinite stiffness all bifurcations become continuous. Integer defects strongly couple with local mass redistribution, manifesting as shell thinning or thickening, whilst half-integer defects induce no such local deformation. These findings provide a purely mechanical framework for understanding body-axis formation and defect-mediated morphogenesis in biological vesicles.
Soft Condensed Matter (cond-mat.soft)
Impacts of Fermi Level Pinning at Hole-Selective Contacts in CdSeTe/CdTe Solar Cells
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-03-10 20:00 EDT
Ariful Islam, Nathan D. Rock, Kh. Aaditta Arnab, Nicholas Miller, James Becker, Michael A. Scarpulla
P-type doped CdTe free surfaces Schottky contacts, and even interfaces with isostructural p-ZnTe frequently exhibit downward band bending and moderate to high recombination velocities. Fermi level pinning by donor-like states can explain these band diagram features, as well as device response characteristics such as 1st quadrant rollover in current-voltage (JV) versus temperature (JVT). Parasitic downward band bending also produces voltage-dependent photocurrent collection, producing fill factor (FF) efficiency losses, JV dark/light non-superposition (or JV take-off), and irregularities in Jsc-Voc and Suns-Voc measurements. Herein, we develop a device physics model of state-of-the-art CdSeTe/CdTe solar cells consistent with known characterization of materials and devices, including the optical, thermalization, and trapping effects of band tail states and isolated defects. We use this model to demonstrate that Fermi-level pinning at the p-ZnTe/p-CdSeTe hole contact by donor-like defects reproduces the aforementioned observables, and conclude that (for contemporary few-um absorber thicknesses and low mobilities) it primarily affects FF rather than Voc. We investigate the performance gains possible from hypothetical passivated, hole-selective layers at the ZnTe/CdTe interface, which eliminate the downwards band bending caused by donor-like defects. For thinner devices and larger minority carrier diffusion lengths, these strategies will become more important for continued efficiency improvements.
Materials Science (cond-mat.mtrl-sci)
20 pages, 7 fgures
Realizing microrheological response of configurable viscoelastic media with a dynamic optical trap
New Submission | Soft Condensed Matter (cond-mat.soft) | 2026-03-10 20:00 EDT
The local viscoelastic (VE) environment governs the motion of an embedded microsphere and consequently, pertinent dynamical phenomena. However, studying such phenomena with varying VE properties remains challenging for various reasons, including the strong coupling among the VE parameters and their dependence on experimental conditions, such as temperature. Here, we demonstrate the experimental realization of configurable VE media with broad variations, wherein the VE properties can be systematically and independently tuned, employing a dynamic optical trap. Specifically, the dynamics of a particle in a slowly diffusing optical trap provides the linear microrheological response of single-relaxation VE fluids, namely, Jeffreys or Maxwell-Voigt (MV) fluids, where the trap strength and its diffusion coefficient regulate the elastic response and the low-frequency viscosity, respectively. We validate this approach by comparing the experimentally observed dynamics of the trapped bead with those of a probe particle in real single-relaxation complex fluids, analytical predictions, and simulation results following harmonically bound Brownian particle with long-time diffusion model describing MV fluids. We extend the applicability of this scheme for realizing the microrheological response of double-relaxation VE media by incorporating appropriately correlated noise in the trap trajectory, signifying its validity for any linear VE media with multiple relaxations. Our scheme can be further extended to realize probe particle dynamics in an active VE environment, e.g., an entangled network of active polymers, by translating the trap along an active Brownian trajectory. Therefore, our scheme enables systematic microrheological studies in VE regimes that are otherwise challenging to realize or not readily accessible with real materials.
Soft Condensed Matter (cond-mat.soft), Statistical Mechanics (cond-mat.stat-mech), Optics (physics.optics)
8 pages, 5 figures
High Thermal Conductivity in Back-End-of-Line Compatible AlN Thin Films
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-03-10 20:00 EDT
Xufei Guo, Zirou Chen, Zifeng Huang, Yuxiang Wang, Jinwen Liu, Zhe Cheng
With thermal issues becoming a major challenge to the development of integrated circuits (ICs), high-thermal-conductivity (high-TC) materials are gaining interest from both the industry and academia, especially for high-density back-end-of-line (BEOL) structures. Aluminum nitride (AlN) is an insulating material with high TC, suitable for thermal management in electronic devices. Furthermore, polycrystalline AlN thin films can be deposited at BEOL-compatible low temperatures (lower than 400 C) while retaining relatively high TC, rendering AlN a promising candidate for BEOL heat dissipation. Still, AlN deposition should aim at achieving high TC on a variety of substrates used in IC processes. In this work, we obtained 600- and 1200-nm BEOL-compatible AlN thin film samples on Si, SiO, SiN, and Al2O3 substrates for structural and thermal characterizations. Specifically, time-domain thermoreflectance (TDTR) measurements revealed consistently high TC (higher than 45 W m-1 K-1) on different substrates. Moreover, finite element analysis (FEA) simulations of AlN capped on top of an indium-tin-oxide (ITO) transistor showed a reduction of up to 44% in peak device temperature. Our work provided experimental and calculational evidence for the practicality of leveraging AlN as a high-TC, BEOL-compatible heat spreader material.
Materials Science (cond-mat.mtrl-sci), Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
Coexistence Regime and Thermal Crystallization in the cavity-mediated extended Bose-Hubbard Model
New Submission | Quantum Gases (cond-mat.quant-gas) | 2026-03-10 20:00 EDT
Wei-Wei Wang, Jin Yang, Barbara Capogrosso-Sansone, Jian-Ping Lv, Chao Zhang
By means of path integral- Monte Carlo, we study the finite-temperature behavior of the extended Bose-Hubbard model with cavity-mediated long-range interactions at unit filling. At zero temperature, the system supports superfluid, Mott-insulating, supersolid, and charge-density-wave phases, with a strongly first-order transition between superfluid and charge density wave states characterized by a broad coexistence region. Focusing on this coexistence regime, we explore how the dominant order evolves with temperature. When the system is initialized in a superfluid state, the superfluid density is progressively suppressed upon heating, and a normal fluid is stabilized. Upon further increasing the temperature, a thermally assisted emergence of crystalline order occurs which eventually melts into the normal fluid. In contrast, simulations initialized in a charge-density-wave configuration display a smooth thermal melting of density order, with no reemergence of superfluid coherence. Overall, our results show that metastability persists at low temperatures, but ultimately disappears at higher temperatures, where thermally induced crystallization takes place.
Quantum Gases (cond-mat.quant-gas)
Harvest Ambient Heat via Constraint-Shaped Phase-Change Cycles: Micro $ΔT$, Subcooled Liquid, and Liquid-Only Compression
New Submission | Statistical Mechanics (cond-mat.stat-mech) | 2026-03-10 20:00 EDT
Conventional heat engines require two reservoirs; their efficiency is bounded by the Carnot limit. In a well-defined theoretical framework where the working fluid undergoes phase change in the presence of asymmetric constraints, that limit does not apply: the appropriate description is constraint-reshaped entropy distributions $ P_{\infty}(S;\lambda)$ . We give \emph{one} complete \emph{theoretical} design: micro temperature difference (1–2,$ ^\circ$ C), subcooled liquid, liquid-only compression, and asymmetric constraint phase change (R134a). The cycle absorbs heat from a \textbf{single} heat source (the environment; $ q_{\mathrm{in}} = 0.9,\mathrm{kJ}/\mathrm{kg}$ per cycle), delivers net useful work ($ w_{\mathrm{net}} = +0.514,\mathrm{kJ}/\mathrm{kg}$ ), and uses only standard components. The analysis is rigorous: energy and mass balance are closed; all property data are from NIST and are reproducible at the cited URL. We show that, within this framework, this constitutes single-heat-source power generation.
Statistical Mechanics (cond-mat.stat-mech), Applied Physics (physics.app-ph), Classical Physics (physics.class-ph)
Bistability of electron temperature in atomically thin semiconductors in the presence of exciton photogeneration
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2026-03-10 20:00 EDT
We study the dynamic equilibrium between trions and excitons in monolayers of transition metal dichalcogenides in the presence of resident charge carriers and continuous photogeneration of excitons. We show that heating of the system via Drude absorption of low-frequency radiation leads to bistability of the steady-state equilibrium. The first is a low-temperature state, in which almost all resident charge carriers are bound into trions. The second state occurs at high temperatures, where most trions are dissociated; in this regime, the heating is more efficient due to the higher Drude conductivity of unbound charge carriers compared to trions. Switching between these two states occurs on a timescale of tens to hundreds of picoseconds and is accompanied by a jump in various observables such as temperature, current, and the intensity of exciton or trion luminescence.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Materials Science (cond-mat.mtrl-sci), Other Condensed Matter (cond-mat.other)
9 pages, 4 figures
Orbital-Selective Engineering of Strain-Tunable Chern Insulators in Momentum Space
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-03-10 20:00 EDT
Jin Gao, Rongrong Chen, Lei Yang, ChengLong Jia, Kun Tao, Li Xi, Desheng Xue
Unlike conventional approaches where topological order is statically fixed post-synthesis, we demonstrate that a single external knob-strain-can independently modulate topological order and functional responses in the Tc-adsorbed penta-hexa silicene (Tc_PH-Si) monolayer, with both properties governed by a single microscopic mechanism: momentum-space orbital-selective engineering of Tc-dxz_Si-px hybridization. Combining first-principles calculations and tight-binding models, we show that biaxial strain drives a complete topological pathway: C=1 (0) to C=0 (-2) to C = -1 (-3 to -4) to C = 0 metallic state (-6). This is exemplified by two pivotal states: a topologically critical point yet functionally optimal state at -2 strain (C=0) hosting a direct bandgap (0.17 eV) and d11 = 8.34 pm_V, and a topologically nontrivial but equally optimal state at -4 strain (C = -1) with d11 = 11.01 pm_V-three times that of MoS2. Berry curvature analysis reveals that functionality arises from local orbital hybridization strength, while topology originates from its global phase distribution. This establishes a new paradigm for materials design, transforming static functional materials into dynamically tunable quantum platforms.
Materials Science (cond-mat.mtrl-sci)
Field-theoretical approach to estimate mean gap and gap distribution in randomly rough surface contact mechanics
New Submission | Soft Condensed Matter (cond-mat.soft) | 2026-03-10 20:00 EDT
Yunong Zhou, Hengxu Song, Zhichao Zhang, Yang Xu
We extend the statistical field-theoretical framework of rough surface contact mechanics to characterize the interfacial gap between an elastic half-space and a randomly rough surface incorporating exponential repulsion. Building upon a cumulant expansion to second-order, we derive an explicit analytical relation between the mean gap and the applied normal pressure. This result provides a closed-form expression for the drift and diffusion coefficients in a convection-diffusion equation governing the scale-dependent evolution of the gap distribution. Solving this equation with appropriate initial and boundary conditions yields the gap distribution under varying external pressures. Both the mean gap and the gap distribution are found to be in good agreement with Green’s function molecular dynamics (GFMD) simulations. Our results demonstrate that the field-theoretical approach enables quantitative predictions not only for contact stresses but also for interfacial gap in rough surface contacts.
Soft Condensed Matter (cond-mat.soft), Statistical Mechanics (cond-mat.stat-mech)
Tribology International, 111894 (2026)
Reversible Ionic Aggregation Kinetics in Concentrated Electrolytes
New Submission | Soft Condensed Matter (cond-mat.soft) | 2026-03-10 20:00 EDT
Here we develop and test a formalism for reversible ionic aggregation kinetics in an example concentrated electrolyte. Specifically, building on previous equilibrium work of McEldrew and co-workers in the context of concentrated electrolytes, and non-equilibrium properties of thermoreversible polymers and patchy particle systems, we develop the formalism for how ionic associations in electrolytes change subject to a step-change in conditions. This is achieved through solving a macroscopic rate equation of open/occupied association sites, which is a solution of the reversible Smoluchowski aggregation equation. We compare the derived equations against atomistic molecular dynamics simulations of a salt-in-ionic liquid. Good qualitative agreement is obtained, but quantitative differences are found, which highlights the multiple time scales of the associations that exist in concentrated electrolytes. We hope this formalism acts as the starting point for investigating these properties in other electrolytes, and developing it further to investigate the non-Newtonian behaviour of concentrated electrolytes, double layer charging, and the slow dynamics of these electrolytes in confinement.
Soft Condensed Matter (cond-mat.soft)
Hybrid light-matter excitations and spontaneous time-reversal symmetry breaking in two-dimensional Josephson Junctions
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2026-03-10 20:00 EDT
V. Varrica, G. Falci, E. Paladino, F. M. D. Pellegrino
In the context of hybrid superconductor-semiconductor systems, Josephson junctions based on two-dimensional materials, such as graphene, offer promising opportunities because of their scalability and gate-tunable electronic properties. In this work, we investigate the inductive coupling between a quantum LC resonator and a superconducting loop embedding a short, ballistic, planar Josephson junction, with the graphene-based case as a representative example. Within a mean-field formalism, we analyze how the properties of the global system depend on the light-matter interaction coupling, the Fermi level of the two-dimensional material, and temperature. Our findings reveal that the current-phase relation can show features indicative of spontaneous time-reversal symmetry breaking. Furthermore, starting from the mean-field theory, we determine the low-energy spectrum of collective hybridized light-matter excitations.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Superconductivity (cond-mat.supr-con), Quantum Physics (quant-ph)
23 pages, 10 figures
Spin Neural Network Potential for Magnetic Phase Transitions in Uranium Dioxide
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-03-10 20:00 EDT
Keita Kobayashi, Hiroki Nakamura, Mitsuhiro Itakura
Uranium dioxide (UO2) is a prototypical nuclear fuel material, yet predicting its thermophysical properties across a wide temperature range remains challenging. One factor contributing to this difficulty is the complex magnetic ordering at low temperatures, where spin-orbit coupling produces strong coupling between spin and lattice degrees of freedom. Direct DFT simulations of magnetic phase transitions at finite temperatures are computationally prohibitive. Here, we develop a spin neural network potential (SpinNNP) that explicitly incorporates spin degrees of freedom together with spin-orbit coupling to describe the magnetic states of this http URL datasets were generated using magnetic constrained DFT+U calculations with spin-orbit coupling, covering a wide range of non-collinear spin configurations. The SpinNNP accurately reproduces DFT energies, atomic forces, spin forces, and lattice constants. Machine learning molecular dynamics simulations with spin dynamics successfully capture the antiferromagnetic-paramagnetic transition. Although the predicted magnetic ground state differs from experiment due to known limitations of the underlying DFT description, the transition temperature obtained is of the correct order of magnitude compared with experiment. These results demonstrate that machine-learning potentials can enable large-scale spin-lattice simulations of actinide oxides and provide a practical route toward predictive modeling of complex magnetic materials.
Materials Science (cond-mat.mtrl-sci)
11 pages, 2 figures, 2 tables
A defect in diamond with millisecond-scale spin relaxation time at room temperature
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-03-10 20:00 EDT
Sounak Mukherjee, Anran Li, Johannes Eberle, Sean Karg, Zi-Huai Zhang, Mayer M. Feldman, Yilin Chen, Mark E. Turiansky, Mengen Wang, Yogendra Limbu, Tharnier O. Puel, Yueguang Shi, Matthew L. Markham, Rajesh L. Patel, Patryk Gumann, Michael E. Flatte, Chris G. Van de Walle, Stephen A. Lyon, Nathalie P. de Leon
Spin defects in diamond are promising platforms for quantum sensing. The longest electron spin relaxation times ($ T_1$ ) at room temperature for solid-state defects are observed in nitrogen vacancy centers in diamond, which can reach 6.67 ms, and substitutional nitrogen (“P1 centers”) in diamond, which exhibit a $ T_1$ of 2 ms. No other solid-state defect has exhibited millisecond-scale spin relaxation times at room temperature thus far. Here, we characterize the spin properties of the WAR5 defect in diamond with pulsed electron spin resonance. The observed $ T_1$ is one of the longest for solid-state spin defects: 0.97(27) ms at room temperature and 14.38(19) min at 4 K. The observed coherence time ($ T_2$ ) is 246(7) $ \mu$ s, which can be extended to 6.49(34) ms at 4 K with dynamical decoupling. Furthermore, we demonstrate optical spin polarization with a range of wavelengths from 405 nm to 500 nm and propose potential zero-phonon line candidates.
Materials Science (cond-mat.mtrl-sci), Quantum Physics (quant-ph)
Coherent-state ansatz for the Holstein polaron in one and two dimensions
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2026-03-10 20:00 EDT
Connor M. Walsh, Igor Boettcher, Frank Marsiglio
The Holstein model often serves as an archetype for electron-phonon interactions and polaron formation in solids. However, precise descriptions of the Holstein polaron are difficult when the phonon frequency is small and the electron-phonon coupling is strong, due to the presence of many phonons in the ground state. We present a semi-analytical approximation that consists of a variational ansatz with clouds of phonons surrounding the electron in the form of coherent states. This becomes particularly simple and exact in the Lang-Firsov limit. We determine the domain of validity away from this limit, and further explore the improvement achieved with a removal of the requirement that the phonon clouds form coherent states. Both approximations work extremely well at strong coupling, and both work surprisingly well also at weak coupling. The coherent-state ansatz provides a simple and intuitive picture of the polaron ground-state wavefunction, and in addition predicts accurate values for the ground-state energy and effective mass.
Strongly Correlated Electrons (cond-mat.str-el), Superconductivity (cond-mat.supr-con)
16 pages, 8 figures
Impact of Layer Structure and Strain on Morphology and Electronic Properties of InAs Quantum Wells on InP (001)
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-03-10 20:00 EDT
Zijin Lei, Yuze Wu, Christian Reichl, Stefan Fält, Werner Wegscheider
High-quality InAs quantum wells grown on InP are a promising platform for topological quantum information processing due to their large g-factor, strong Rashba spin-orbit interaction, and their compatibility with in-situ-deposited superconductors. In this work, we investigate InAs/InGaAs quantum wells grown on InP (001) wafers, focusing on how the layer structure and strain influence the electronic properties and surface morphology. By combining quantum transport measurements with atomic force microscopy, we show that the layer design predominantly affects the mobility anisotropy, which aligns well with the surface morphology. Surface characterization further reveals the mechanism of quantum well collapse when the layer thickness exceeds the strain limit. In addition, transport measurements demonstrate that quantum confinement has a clear impact on band nonparabolicity.
Materials Science (cond-mat.mtrl-sci), Applied Physics (physics.app-ph), Quantum Physics (quant-ph)
7 pages, 6 figures
Averaging Molecular Dynamics simulations to study the slow-strain rate behavior of metals
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-03-10 20:00 EDT
Sarthok Kumar Baruah, Sabyasachi Chatterjee, Amit Acharya, Gerald J. Wang
The application of molecular dynamics (MD) simulations to quasistatic loading is severely limited by the large separation between atomic vibration timescales and experimentally relevant deformation rates. In this work we employ the Practical Time Averaging (PTA) framework to overcome this limitation and enable atomistic simulations of crystalline solids under quasistatic loading conditions. PTA exploits the intrinsic separation of timescales by defining slow variables as time-averaged observables of the fast atomistic dynamics and their evolution on the slow loading timescale, thereby avoiding explicit integration of the fast dynamics.
Using this approach, we simulate uniaxial deformation, in both tension and compression, of 4 to 20 nm cubic specimens of face centered cubic aluminum nanocrystals at applied strain rates approaching quasistatic conditions. We define slow variables as the averaged kinetic energy, potential energy, and normal stress in the loading direction, and track their evolution on the slow timescale. The stress-strain curves show yielding close to the theoretical stress for homogeneous nucleation, followed by successive load drops and rises caused by dislocation nucleation, motion, and exit from free surfaces. The “smaller is harder” effect is evident from the stress-strain response and from the variation of yield stress with sample size. Serrations in the response are more pronounced for smaller samples. The effects of applied strain rate and initial temperature are also studied. The method also captures the evolution of intricate dislocation microstructures on the slow timescale by tracking time-averaged atomic positions. The PTA framework enables simulations at strain rates several orders of magnitude lower than those accessible to conventional MD, demonstrating significant speedup in computational time while retaining full atomistic resolution.
Materials Science (cond-mat.mtrl-sci)
Offer of a reward does not always promote trust in spatial games
New Submission | Statistical Mechanics (cond-mat.stat-mech) | 2026-03-10 20:00 EDT
Haidong Zhang, Chaoqian Wang, Shuo Liu, Charo I. del Genio, Stefano Boccaletti, Xin Lu
Trust is one of the cornerstones of human society. One of the evolutionary pressure mechanisms that may have led to its emergence is the presence of incentives for trustworthy behavior. However, this type of reward has received relatively little attention in the context of spatial trust games, which are often used to build models in evolutionary game theory. To fill this gap, we introduce an inter-role reward mechanism in the spatial trust game, so that an investing trustor can choose to pay an extra cost to reward a trustworthy trustee. With extensive numerical simulations, we find that this type of reward does not always promote trust. Rather, while moderate rewards break the dominance of mistrust, thereby favoring investment, excessive rewards eventually stimulate a nonreturn strategy, ultimately suppressing the evolution of trust. Additionally, lower reward costs do not necessarily promote trust. Instead, more costly, but not excessive, rewards enhance the advantage of the original investment, consolidating the clusters of rewarders and improving trust. Our model thus provides evidence about the counterintuitive nature of the relationship between trust and rewards in a complex society.
Statistical Mechanics (cond-mat.stat-mech), Computer Science and Game Theory (cs.GT), Cellular Automata and Lattice Gases (nlin.CG)
25 pages, 9 figures, accepted for publication in Physical Review Research
Alleviating Projection-Space Sensitivity in DFT+U via Renormalized U
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2026-03-10 20:00 EDT
Although the DFT+U method significantly improves the description of correlated electronic systems, its accuracy is known to depend strongly on the input parameters including local projection space used for the Hubbard correction. As a result, calculations performed with different projection sizes can yield quantitatively different – and sometimes divergent – results. In this work, we investigate the dependence of the effective Coulomb interaction $ U_{\mathrm{eff}}$ on projection size using constrained DFT calculations for rutile TiO$ 2$ and $ \beta$ -MnO$ 2$ . We find that as the projection size increases, the self-consistently calculated $ U{\mathrm{eff}}$ decreases significantly – by as much as $ 33$ %. This trend is attributed to renormalization of the Coulomb interaction through orbital relaxation and enhanced screening. When $ U{\mathrm{eff}}$ values recalculated for each projection size are employed, the results for lattice parameters, electronic structure, and relative phase stability become consistent across different projection sizes. These findings can provide a practical route to alleviate projection-size dependence in DFT+U calculations.
Strongly Correlated Electrons (cond-mat.str-el), Materials Science (cond-mat.mtrl-sci)
Interband pairing in two-band superconductors with spin-orbit and Zeeman couplings
New Submission | Superconductivity (cond-mat.supr-con) | 2026-03-10 20:00 EDT
Interband pairing in multiband superconductors is often neglected because of its higher energetic cost compared with intraband pairing. We show that, in multiband systems, a Zeeman magnetic field can stabilize interband pairing through the near degeneracy of spin-split branches from different bands, even within a minimal on-site attractive interaction. Using hexagonal tight-binding models with locally broken inversion symmetry, we find a Zeeman-driven transition between a conventional intraband s-wave state and an interband-dominated superconducting Mixing state. The resulting quasiparticle spectrum is intrinsically gapless, leading to anomalous thermodynamic behavior, including a T-linear specific heat at low temperatures, reflecting a finite zero-energy density of states.
Superconductivity (cond-mat.supr-con)
8 pages, 8 figures
Microstructural origins of energy storage during plastic deformation of 310S TWIP steel
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-03-10 20:00 EDT
Sandra Musiał, Michał Maj, Marcin Nowak
The microstructural mechanisms governing energy storage during plastic deformation of twinning-induced plasticity (TWIP) steels remain insufficiently understood, particularly under conditions of strain localization. This study provides a crystallographic-scale interpretation of energy storage in 310S TWIP steel exhibiting complex deformation mechanisms. Electron backscatter diffraction (EBSD) was used to characterize the evolution of local crystallographic orientation and microtexture during uniaxial tensile deformation using two complementary approaches: tracking the same surface region at successive strain levels and analysing regions corresponding to known local plastic strain. Deformation was initially dominated by dislocation slip, while twinning activity increased significantly beyond an equivalent plastic strain of approximately 0.3. Progressive deformation produced pronounced lattice rotations and the development of a dual-fibre texture consisting of a dominant 111 parallel to RD component and a secondary 100 parallel to RD component associated with deformation twinning. Correlation with previously quantified energy storage behaviour obtained from coupled digital image correlation and infrared thermography measurements reveals that intensified twinning and texture evolution in strain-localized regions are accompanied by a marked reduction in the energy storage rate. The results indicate that twin-matrix refinement and lattice rotation progressively reduce the material’s capacity to store deformation energy and create favourable conditions for shear-band-mediated deformation.
Materials Science (cond-mat.mtrl-sci)
Elasticity-mediated Morphogenesis in Interfacial Colloidal Assemblies
New Submission | Soft Condensed Matter (cond-mat.soft) | 2026-03-10 20:00 EDT
Vaibhav Raj Singh Parmar, Sayantan Chanda, Rituparno Mandal, Ranjini Bandyopadhyay
We study the self-assembly of colloidal microgel particles at a quasi-two-dimensional air-water interface of a drying droplet. Using bright-field microscopy, we demonstrate that increasing particle elasticity drives interfacial organization from repulsion-stabilized crystallization to attraction-dominated gelation, via diverse metastable structures including clusters, voids and anisotropic aggregates. Molecular dynamics simulations using an effective potential that captures the interplay between hydrophobic, capillary, steric and dipolar interactions, reproduce the overall phenomenology of the observed colloidal morphogenesis. Our findings establish particle elasticity as a key parameter governing non-equilibrium structural organization of colloids at an interface.
Soft Condensed Matter (cond-mat.soft), Applied Physics (physics.app-ph)
6 pages, 4 figures, additionally includes supplemental material
Active Fluid Patterning in Inhomogeneous Environments
New Submission | Soft Condensed Matter (cond-mat.soft) | 2026-03-10 20:00 EDT
Douglas MacMyn Brown, Alexander Mietke
Active stresses in biological cells and tissues drive many developmental processes. However, increasing experimental evidence suggests that additional mechanical interactions with surrounding material can play a crucial role in guiding these processes. We introduce a minimal model of this scenario and investigate how pattern formation in an active material can be controlled by an inhomogeneous environment. Specifically, we consider an active fluid in which a chemical species regulates local active stresses and is redistributed by the resulting flows. We show that active stress patterns within such a fluid exhibit frictiotaxis and systematically characterize how inhomogeneous external friction affects mechanochemical pattern formation instabilities. We find that hydrodynamic screening plays a crucial role in mediating the cross-talk between friction patterns and active fluid self-organization and identify a mechanochemical frustration mechanism that gives rise to pattern oscillations caused by inhomogeneous friction.
Soft Condensed Matter (cond-mat.soft), Biological Physics (physics.bio-ph)
12 pages manuscript and supplementary information, 5 figures
The role of austenite twins on variant selection during decomposition in low carbon steels
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-03-10 20:00 EDT
Ruth M. Birch, Ben Britton, Warren J Poole
Thermomechanical Controlled Processing (TMCP) is widely used to control the microstructure and properties of linepipe or high strength low alloy steels (HSLA). These steels are often joined by welding and used in demanding environments such as the Arctic. In these materials, the thermal path the steel experiences is critical for understanding microstructural evolution during processing. A key step is the solid-state phase transformation during cooling from the high-temperature austenite to the room-temperature microstructure which significantly influences the final mechanical properties. Specifically, the population of different variants and grain shapes that form affect the types and morphology of the grains, and grain boundary network which influence strength and toughness of the final component. In this paper, we apply 3D microscopy using a Xe-plasma focussed ion beam scanning electron microscope (pFIB-SEM) which is equipped with electron backscatter diffraction (EBSD) in a static configuration to characterize the room temperature microstructure of a steel sample, and then use a ‘2.5D’ prior austenite grain (PAG) reconstruction code to explore the relationship between the austenite phase and the room temperature microstructure. A significant result for the present work is the collection, and analysis, of data from a large volume (150 x 150 x 100 {\mu}m3, with a (200 nm)3 voxel size) which enables analysis of a complete prior austenite grain. Analysis of variants within this grain demonstrates that high-temperature twin boundaries likely govern variant selection and grain growth in the child microstructure. This suggests opportunities to engineer novel microstructures by controlling the high-temperature grain boundary character.
Materials Science (cond-mat.mtrl-sci)
Qubit discretizations of d=3 conformal field theories
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2026-03-10 20:00 EDT
We propose that scaling dimensions of d=3 conformal field theories can be studied on a system of qubits with near term quantum simulation platforms. Our proposal chooses couplings of quantum many-body problems on a polyhedral lattice at which the conformal state-operator correspondence can be observed most accurately in the spectrum. We validate our protocol on the Ising model where we extract the scaling dimensions of a number of scaling operators with a few percent accuracy from the spectrum of a system of just 20 qubits. The procedure makes only minor assumptions beyond general conformal invariance – it may hence be applied widely. Requirements and challenges to realize this proposal on quantum computers are discussed. Our results demonstrate that for current or near term qubit platforms, three dimensional conformal field theories present a unique opportunity – a forefront problem that is difficult on classical computers but may be solved through quantum simulation.
Strongly Correlated Electrons (cond-mat.str-el), Statistical Mechanics (cond-mat.stat-mech)
Thermal Hofstadter Butterflies
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2026-03-10 20:00 EDT
Natalia Cortés, Bastian Castorene, Francisco J. Peña, Damian Melo, Sergio E. Ulloa, Patricio Vargas
Fractal electronic spectra arising from the competition between lattice periodicity and magnetic flux are a fundamental hallmark of two-dimensional quantum systems. While the spectral properties of Hofstadter butterflies are well documented, their thermodynamic response has remained remarkably unexplored. We present an original characterization of the electronic entropy $ S_{e}$ , and specific heat $ C_{e}$ , at half-filling, for square, honeycomb, and triangular lattices under a magnetic field. We demonstrate that these observables exhibit fast and slow magneto-thermo oscillations and pronounced magnetocaloric effects. We identify striking self-similarity in $ S_e$ and $ C_e$ , tracing heart-shaped specific heat and tunnel-like entropy contours that repeat at specific lattice-dependent magnetic fluxes. Entropy minima at low temperatures play a remarkable role, acting as fingerprints for the butterfly spines, resolving the underlying fractal spectra. These findings may establish thermal measurements as high-resolution spectroscopic probes, providing a robust framework for recognizing fractal signatures through thermodynamics in diverse nanostructures.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Statistical Mechanics (cond-mat.stat-mech)
A Perspective on Training Machine Learning Force Fields for Solid-State Electrolyte Materials
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-03-10 20:00 EDT
Zihan Yan, Shengjie Tang, Yizhou Zhu
Machine learning force fields enable high-accuracy modeling of solid-state electrolytes (SSEs). This perspective evaluates dataset size, reference quality, and model architectures. We show that rigid SSE frameworks favor efficient learning, prioritizing data quality over quantity. Crucially, force RMSE does not reliably predict transport performance. By analyzing locality and benchmarking frameworks, we provide practical guidelines to accelerate the development of next-generation solid-state batteries.
Materials Science (cond-mat.mtrl-sci)
10 pages, 5 figures
Spin-selective elliptic optical dichroism and perfectly spin-polarized third-order nonlinear photocurrent in altermagnets
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2026-03-10 20:00 EDT
It is shown that the low-energy theory of a $ d$ -wave altermagnet is characterized by anisotropic Dirac cones with up and down spins based on a recently proposed tight-binding model. Spin-selective perfect elliptic dichroism occurs in this system, where only up-spin or down-spin electrons are excited by elliptically polarized light. Then, we derive a formula for the third-order photocurrent induced by applying both elliptically polarized light and static electric field, which is described in terms of quantum metric and the Berry curvature. Based on it, we predict only up-spin polarized current is induced. It is the leading order of photocurrent because the second-order photocurrent such as the injection current and the shift current are prohibited due to inversion symmetry inherent to altermagnets. It is intriguing that nonzero photocurrent is induced only by the anisotropy of the Dirac cones. Our results will be useful for future photo-excited spintronics based on altermagnets.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
6 pages, 3 figures
Defect Detection in Magnetic Systems Using U-Net and Statistical Measures
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-03-10 20:00 EDT
Ross Knapman, Atreya Majumdar, Nasim Bazazzadeh, Kübra Kalkan, Katharina Ollefs, Oliver Gutfleisch, Karin Everschor-Sitte
Local material inhomogeneities can strongly influence magnetization dynamics and macroscopic magnetic properties, yet detecting such defects from magnetic imaging data remains challenging when thermal fluctuations and experimental noise obscure static contrast. Here, we investigate defect detection in strongly fluctuating magnetization regimes where signatures of inhomogeneities largely average out in time-resolved measurements. Using finite-temperature micromagnetic simulations with randomly distributed defects and material parameters representative of \ce{Ni80Fe20}, we compute per-pixel temporal mean, temporal standard deviation, and latent entropy and use them as inputs for U-Net-based semantic segmentation models. We find that the most effective descriptor depends on the noise level and, importantly, that robust detection requires training data that reflect the expected noise statistics. These results provide practical guidance for designing noise-robust defect-detection workflows in magnetic imaging.
Materials Science (cond-mat.mtrl-sci), Instrumentation and Detectors (physics.ins-det)
7 pages, 4 figures
Effects of Rim Fluctuations in Classical Nucleation Theory of Virus Capsids
New Submission | Soft Condensed Matter (cond-mat.soft) | 2026-03-10 20:00 EDT
Alexander Bryan Clark, Paul van der Schoot, Henri Orland, Roya Zandi
Most spherical viruses exhibit icosahedral symmetry, yet the growth of viral shells remains poorly understood due to the short lifetimes and broad size distribution of assembly intermediates. Classical nucleation theory has been widely applied to describe this process, but it treats the boundary of a growing shell as rigid and structureless. Here, we extend classical nucleation theory by incorporating thermal fluctuations of the capsid rim using both discrete and continuum descriptions. Allowing the rim of a partially formed capsid to undergo small geometric undulations, we show that these fluctuations generate an entropic contribution that renormalizes the effective line tension. As a result, rim fluctuations can either promote or hinder capsid closure, depending on the subunit-subunit binding free energy, temperature, and fluctuation amplitude. We find that fluctuations generally lower the nucleation barrier when the binding free energy is below a threshold value, while for sufficiently strong binding, they can instead raise the barrier by stabilizing incomplete capsids through a finite-size entropy penalty associated with rim closure. By moving beyond the idealized capillarity approximation, our results provide a controlled extension of classical nucleation theory that clarifies how boundary fluctuations influence capsid nucleation and growth.
Soft Condensed Matter (cond-mat.soft), Biological Physics (physics.bio-ph)
ETHER: An Efficient Tool for Monte Carlo Simulations of Magnetic Systems
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2026-03-10 20:00 EDT
Monte Carlo (MC) simulations are powerful computational tools for investigating thermodynamic behavior and validating analytical approaches in complex physical systems. Here we present ETHER (Efficient Tool for THermodynamics Exploration via Relaxations), an open-source MC simulation package, developed for studying temperature-dependent magnetic properties in spin systems. ETHER enables large-scale MC simulations of various spin systems to analyze phase transitions, critical behavior, and complex magnetic structures. The package constructs spin-lattice networks from standard structural input files and supports exchange interaction definitions through user-specified neighbor lists. It also provides tools for easy visualization and post-processing of simulation outputs. Our code has been benchmarked thoroughly against results reported in the literature for common representative magnetic systems. This user-friendly code offers researchers a versatile platform for exploring thermodynamic properties of complex magnetic systems.
Strongly Correlated Electrons (cond-mat.str-el), Materials Science (cond-mat.mtrl-sci)
19 pages,12 figures
Optimizing quantum transport in multi-barrier graphene systems using differential evolution
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2026-03-10 20:00 EDT
Potential and mass barriers in graphene introduce electron scattering, modulating transmission probabilities. Complex multi-barrier setups allow electron transmission to be controlled with high precision, but have a huge design space of possible barrier geometries. This work presents a framework to optimize electronic transport in such systems using differential evolution algorithms. First, transfer matrix methods are employed to efficiently compute quantum transport through multi-barrier structures, before optimization is applied to find barrier configurations whose transmission profiles closely match a predefined target profile. To address the trade-off between the accuracy and complexity of resulting barrier configurations, regularization techniques are incorporated into the optimization process. Our approach demonstrates the potential for highly tunable electronic transport in graphene-based systems by exploiting evolution-inspired optimization techniques.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
12 pages, 5 figures, under review
Signatures of Topological Superconductivity and Josephson Diode Effects on the Magnetocurrent-Phase Relation of Planar Josephson Junctions
New Submission | Superconductivity (cond-mat.supr-con) | 2026-03-10 20:00 EDT
B. Pekerten, A. Chilampankunnel Prasannan, A. Matos-Abiague
We present a theoretical study of proximitized planar Josephson junctions (JJs) with Rashba spin-orbit coupling (SOC) subject to an in-plane magnetic field and demonstrate that the magneto-current-phase relation (magneto-CPR) provides a powerful and unified probe of their microscopic and topological properties. By analyzing the full phase and Zeeman-field dependence of the supercurrent, we show that magneto-CPR measurements allow one to reconstruct the ground-state phase that minimizes the system’s free energy in the absence of phase bias. This reconstructed phase generally displays 0-pi-like transitions as a function of the Zeeman energy, and we demonstrate that the magnitudes of the associated phase jumps provide quantitative information about the Rashba SOC. We further show that the mixed phase-field response encoded in the magneto-CPR enables the extraction of the second mixed spin susceptibility, which serves as a sensitive diagnostic of gap closings and can be used to construct a superconducting topological phase diagram in terms of the relative topological gap. In addition, the magneto-CPR yields the field dependence of the forward and reverse critical currents, allowing one to characterize the Josephson diode effect and its connection to the Zeeman field, Rashba SOC, and junction transparency. Our results establish magneto-CPR measurements as a versatile spectroscopic tool that can be used to extract key system parameters and provide evidence of topological superconducting phases in planar JJs.
Superconductivity (cond-mat.supr-con), Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
15 pages, 7 figures
Spin Group Symmetry Criteria For Unconventional Magnetism
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2026-03-10 20:00 EDT
Xun-Jiang Luo, Jin-Xin Hu, Mengli Hu, K. T. Law
Unconventional magnetism has typically been classified into two fundamental classes: even-parity magnets (EPMs) and odd-parity magnets (OPMs). These two classes exhibit identical and opposite spin splittings, respectively, under momentum inversion, while both maintain symmetry-compensated magnetization. In this Letter, we present a unified spin space group-based framework that establishes comprehensive symmetry criteria for both classes. Our framework not only yields a complete classification of EPMs and OPMs but also uncovers a wealth of new symmetry-driven mechanisms for them. Specifically, we classify both classes into three types based on their spin textures: collinear (type-I), coplanar (type-II), and noncoplanar (type-III), and we demonstrate that both classes can be realized across collinear, coplanar, and noncoplanar magnetic orders. We identify eight distinct symmetry-driven mechanisms for OPMs and seven for EPMs, among which some paradigms of unconventional magnetism, for instance, altermagnets naturally emerge as one specific mechanism of EPMs. Using these established criteria, we identify numerous candidate materials from the Magndata database, realizing some new symmetry mechanisms for OPMs and EPMs. Our work establishes a foundational symmetry framework for understanding, predicting, and designing unconventional magnetic materials.
Strongly Correlated Electrons (cond-mat.str-el), Materials Science (cond-mat.mtrl-sci)
19 pages, 4 figures, 5 tables
Fisher Curvature Scaling at Critical Points: An Exact Information-Geometric Exponent from Periodic Boundary Conditions
New Submission | Statistical Mechanics (cond-mat.stat-mech) | 2026-03-10 20:00 EDT
We study the scalar curvature of the Fisher information metric on the microscopic coupling-parameter manifold of lattice spin models at criticality. For a $ d$ -dimensional lattice with periodic boundary conditions and $ n = L^d$ sites, the Fisher manifold has $ m = d \cdot n$ dimensions (one per bond), and we find $ |\mathcal{R}(J_c)| \sim n^{d_R}$ with $ d_R = (d\nu + 2\eta)/(d\nu + \eta)$ , where $ \nu$ and $ \eta$ are the correlation-length and anomalous-dimension critical exponents. For 2D Ising ($ \nu = 1$ , $ \eta = 1/4$ ), this predicts $ d_R = 10/9$ , confirmed by exact transfer-matrix computations ($ L = 6$ –$ 9$ : $ d_R = 1.1115 \pm 0.0002$ ) and multi-seed MCMC through $ L = 24$ . For 3D Ising ($ \nu = 0.630$ , $ \eta = 0.0363$ ), the prediction $ d_R = 1.019$ is consistent with MCMC on $ L^3$ tori up to $ L = 10$ (power-law fit: $ d_R = 1.040$ ). For 2D Potts $ q = 3$ (predicted $ 33/29 \approx 1.138$ ), FFT-MCMC through $ L = 40$ shows $ d_\mathrm{eff}$ oscillating non-monotonically around $ \sim 1.20$ , consistent with $ O(1/(\ln L)^2)$ logarithmic corrections. For $ q = 4$ (predicted $ 22/19$ ), effective exponents oscillate with strong logarithmic corrections. The Ricci decomposition identity $ R_3 = -R_1/2$ , $ R_4 = -R_2/2$ holds to 5–6 digits for all models. This exponent is distinct from Ruppeiner thermodynamic curvature and reflects the collective geometry of the growing Fisher manifold. We provide falsification criteria and predictions for additional universality classes.
Statistical Mechanics (cond-mat.stat-mech)
6 pages, 3 figures. Replication package: this https URL
Weyl excitonic condensation
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2026-03-10 20:00 EDT
We consider a half-filled two-dimensional Su-Schrieffer-Heeger lattice and examine the role of the long-range Coulomb electron-hole attractive interaction. We demonstrate that, under specific conditions, a rare interplay of topological and excitonic-collective behavior emerges as a novel state of matter. A unique Bose-Einstein condensate of excitons forms, exhibiting co-presence of pseudo-spin chiral texture. The emerging complex order-parameter, a particle-hole pairing-gap, has non-zero real and imaginary parts throughout the Brillouin zone (BZ) but vanish separately on two different nodal lines, which intersect at two Weyl points. The Weyl nodes possess opposite pseudo-spin chiralities, which act as source and drain of a Berry-flux associated with the particle-hole pairing-wavefunction, and are the cause of Bogoliubov-deGennes Fermi-arc edge-states. We self-consistently calculate the full momentum-dependence of the particle-hole pairing gap throughout the entire BZ. Near the Weyl points, the pairing gap exhibits the unconventional time-reversal-symmetry breaking $ p_x+ip_y$ character. Finally, we discuss general potential experimental realizations of this novel state of matter.
Strongly Correlated Electrons (cond-mat.str-el)
10 double column pages, 9 figures
AI-Driven Phase Identification from X-ray Hyperspectral Imaging of cycled Na-ion Cathode Materials
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-03-10 20:00 EDT
Fayçal Adrar, Nicolas Folastre, Chloé Pablos, Stefan Stanescu, Sufal Swaraj, Raghvender Raghvender, François Cadiou, Laurence Croguennec, Matthieu Bugnet, Arnaud Demortière
Na-ion batteries have emerged as viable candidates for large-scale energy storage applica- tions due to resource abundance and cost advantages. The constraints imposed on their performance and durability, for instance, by complex phase transformations in positive electrode materials during electrochemical cycling, can be addressed and are thus not detrimental to their development. However, diffusion-limited Na-ion transport can drive spatially heterogeneous phase nucleation and propagation, leading to multiphase coexis- tence and locally non-uniform electrochemical activity, generating complex reaction path- ways that challenge both mechanistic understanding and predictive material optimization. These challenges can be addressed by investigating single-crystalline regions of materials, i.e. down to the scale of individual particles, although such analyses are often constrained by energetically and/or spatially sparse hyperspectral datasets. Here, we developed an AI-driven method to process hyperspectral data under sparse sampling conditions and generate multiphase maps with nanometer-scale resolution over a micrometer-scale field of view. We applied this processing on scanning transmission X-ray microscopy (STXM) data to determine the distribution and coexistence of phases in individual particles of NaxV2(PO4)2F3 cathode materials, at different states of charge. The methodology relies on a workflow which combines a Gaussian mixture variational autoencoder (GMVAE) algorithm with the Pearson corre- lation coefficient to identify the sodium content and map their spatial distribution. Our approach reveals nanoscale phase heterogeneity and evolution within individual particles, and improves the reliability of phase detection by identifying ambiguity zones, false assign- ments, and transition phases localized at grain boundaries.
Materials Science (cond-mat.mtrl-sci), Artificial Intelligence (cs.AI)
Emergent spin accumulation in non-Hermitian altermagnets
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2026-03-10 20:00 EDT
The recent interest in non-Hermitian (NH) systems has significantly broadened their application across condensed matter physics, offering a unique framework to explore out-of-equilibrium phenomena. Simultaneously, altermagnets have emerged as a distinct magnetic class, characterized by unconventional spin-split bands protected by crystal symmetries. In this work, we investigate the interplay between non-Hermitian dynamics and spin transport in these materials, focusing on the Edelstein effect. We demonstrate that the introduction of non-Hermiticity in $ d$ -wave altermagnets and $ p$ -wave unconventional magnets opens novel susceptibility components that are inaccessible in Hermitian counterparts. Our analysis reveals that these susceptibility channels are highly sensitive to the underlying symmetry of the order parameter. Crucially, our results show that the non-conservative nature of the system leads to the selective gain and loss of specific spin components, a phenomenon that can be tuned by the interplay between dissipation and the altermagnetic order. These components exhibit a distinct gain/loss profile that depends strictly on the Néel vector orientation, providing a new route for manipulating spin degrees of freedom through controlled non-conservative processes in emerging magnetic materials
Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
Fractional Topological Phases, Flat Bands, and Robust Edge States on Finite Cyclic Graphs via Single-Coin Split-Step Quantum Walks
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2026-03-10 20:00 EDT
Dinesh Kumar Panda, Colin Benjamin
We report the first realization of a fractional topological phase in a fully unitary, noninteracting discrete-time quantum walk implemented on finite cyclic graphs. Using a single-coin split-step cyclic quantum walk (SCSS-CQW), we uncover topological phenomena that are inaccessible within conventional cyclic quantum-walk dynamics. The protocol enables controlled engineering of quasienergy spectra, flat bands, and topological phase transitions through the step-dependency parameter and coin-rotation angle. We show that cyclic graphs with even and odd numbers of sites exhibit qualitatively different band structures, while rotational flat bands arise exclusively in $ 4n$ -site cycles; a general analytic condition for their emergence is derived. The SCSS-CQW produces fractional winding numbers $ \pm \frac{1}{2}$ (Zak phases $ \pm \frac{\pi}{2}$ ), in sharp contrast with the integer invariants of standard quantum walks. These fractional invariants lead to an unconventional bulk–boundary correspondence and support edge states beyond the usual integer topological classification. In the step-dependent protocol, transitions between distinct fractional winding sectors generate robust edge modes. Numerical simulations show that these states remain stable in the presence of both dynamic and static coin disorder as well as phase-preserving perturbations, while survival-probability analysis demonstrates their long-time persistence. Requiring only a constant number of detectors independent of the evolution time, the proposed scheme offers a minimal-resource and experimentally accessible platform for realizing fractional topology, flat bands, and protected edge states in small-scale synthetic quantum systems.
Strongly Correlated Electrons (cond-mat.str-el), High Energy Physics - Theory (hep-th), Applied Physics (physics.app-ph), Quantum Physics (quant-ph), Computation (stat.CO)
18 pages, 18 figures, 2 tables
Magnetic and electrical transport properties of the single-crystalline half-Heusler antiferromagnet DyNiSb
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2026-03-10 20:00 EDT
Abhinav Agarwal, Prabuddha Kant Mishra, Orest Pavlosiuk, Maciej J. Winiarski, Piotr Wisniewski, Dariusz Kaczorowski
High-quality single crystals of the half-Heusler compound DyNiSb were investigated for their low temperature thermodynamic and magnetotransport properties. Magnetic susceptibility, heat capacity, and electrical resistivity measurements revealed two distinct magnetic phase transitions at TN1 = 7.3 K and TN2 = 3.4 K, contrasting with previous reports on polycrystalline samples, which identified only a single transition near TN2 . Moreover, the studied samples were found to exhibit Metal like conductivity, at odds with a semiconducting behavior reported for the polycrystals. Magnetoresistance measurements performed in both transverse and longitudinal configurations revealed in small magnetic fields a weak antilocalization effect that diminishes with increasing temperature, giving way to a positive, monotonic magnetoresistance at high temperatures. Angular-dependent resistivity studies showed a crossover from fourfold to twofold symmetry with increasing magnetic-field strength, suggesting a field-induced reconstruction of the Fermi surface. Our findings highlight a complex magnetic and electrical transport behavior in DyNiSb, highly sensitive to structural disorder and easily tunable by external magnetic field.
Strongly Correlated Electrons (cond-mat.str-el), Materials Science (cond-mat.mtrl-sci)
10 pages, 9 figures
Physical Review B, 2025
DeepConf: Machine Learning Conformer Reconstruction of Biomolecules from Scanning Tunneling Microscopy Images
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2026-03-10 20:00 EDT
Tim J. Seifert, Dhaneesh Kumar, Markus Etzkorn, Stephan Rauschenbach, Klaus Kern, Kelvin Anggara, Uta Schlickum
Improving the detailed understanding of the underlying properties and functions of biomolecules has recently attracted growing interest, enabled by the possibility of real-space imaging of single, intact macromolecules using Scanning Tunneling Microscopy (STM) in combination with electrospray ion beam deposition and soft landing. This combination provides key insights into biomolecular behavior, but it also imposes stringent requirements on rapid and reliable data analysis. A major limiting factor for applying machine learning to STM images is often the scarcity of training data, caused by the long acquisition times required for both experimental imaging and high-accuracy simulations. Here, we propose a framework for the rapid generation of three-dimensional structures of glycans, peptides, and glycopeptides and their corresponding STM-like image simulations, based on state-of-the-art, machine-learning-accelerated Density Functional Theory (DFT). We generate datasets for the polypeptide bradykinin and for a representative glycan molecule, and we train a conformer estimation model to predict a molecule’s three-dimensional structure from an STM image. On synthetic data, our approach achieves high accuracy, with median atomic deviations below $ 2,Å$ for peptides and below $ 4,Å$ for glycans. Application to experimental data predominantly yields a precise, reliable, and visually convincing determination of the local positions of molecular subunits. The application to experimental data represents an important milestone towards a fully automated structural search pipeline for complex, biologically relevant systems imaged with STM.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
Anomalous magnetotransport in the single-crystalline half-Heusler antiferromagnet ErPdSb
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2026-03-10 20:00 EDT
Abhinav Agarwal, Shovan Dan, Maciej J. Winiarski, Orest Pavlosiuk, Piotr Wisniewski, Dariusz Kaczorowski
We report the thermodynamic and magnetotransport properties of the half-Heusler antimonide ErPdSb, studied on single-crystalline samples in wide ranges of temperature and magnetic fields. The compound was found to order antiferromagnetically at 1.2 K. In the paramagnetic state, it shows semimetallic behavior with a broad hump in the temperature-dependent electrical resistivity around 70 K. The results of ab initio calculations of the electronic structure of ErPdSb indicated a bulk insulating nature. In small magnetic fields the magnetoresistance is driven by a weak antilocalization effect, while in strong fields it is negative and describable by the deGennes-Friedel formalism. The Hall effect data indicated that holes are the dominant charge carriers. At 2 K, the Hall conductivity exhibits a sizable anomalous contribution, which is obscured by multiband effects at higher temperatures. The angular magnetoresistance shows unusual features as functions of magnetic field and temperature, pointing to a possible field-induced reconstruction of the Fermi surface.
Strongly Correlated Electrons (cond-mat.str-el), Materials Science (cond-mat.mtrl-sci)
10 pages, 7 figures, 5 pages supplemental material
Physical Review B, 2025
Thermodynamics of Confined Knotted lattice Polygons
New Submission | Soft Condensed Matter (cond-mat.soft) | 2026-03-10 20:00 EDT
EJ Janse van Rensburg, E Orlandini, MC Tesi
A ring polymer in a confining space may exhibit at least two phases, namely an expanded (or solvent-rich phase) if its concentration is small, or a collapsed (or polymer-rich phase) when it is concentrated and compressed. These phases are discussed in reference \cite{deG79}, and have been modelled, traditionally, in the mean field using Flory-Huggins theory \cite{Flory42,Huggins42}. In three dimensions the ring polymer may also be knotted, or linked, and have its conformational degrees of freedom constrained by its topology. In a lattice model of confined knotted ring polymers there are indications that the thermodynamic properties of the ring polymer (for example, the osmotic pressure \cite{GJvR18,JvR19}) is a function of its topology. In this paper we explore a lattice knot model of a confined ring polymer as a function of its chemical potential. We show that a well-defined phase transition occurs between solvent-rich and polymer-rich phases when the lattice knot exhibits either the unknot topology or any other fixed knot type. Furthermore, we observe small yet significant variations in the free energy near the critical point when comparing trefoil knots with other non-trivial knot types. These findings indicate that the thermodynamic properties of confined ring polymers depend on their topological entanglement characteristics (namely, their knot type).
Soft Condensed Matter (cond-mat.soft), Statistical Mechanics (cond-mat.stat-mech)
Electric-Polarization Probe of the Magnon Orbital Moment Current in Altermagnet
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2026-03-10 20:00 EDT
Efficient transport of spin and orbital moments, and their electrical detection, are among the main challenges in spintronics and orbitronics. In magnetic insulators, these currents are mediated by magnons. In addition to carrying spin and orbital moment, the orbital motion of a magnon combined with its magnetic moment, generates an effective electric dipole moment. Here, we develop a theoretical framework for Seebeck- and Nernst-type transport of the magnon orbital moment (MOM) and its associated electric dipole moment (EDM). We identify a Drude-like scattering contribution and an intrinsic component governed by the generalized Berry curvatures of magnon bands. We show that a measurable transverse voltage generated by the EDM current provides a direct electrical detection scheme for magnon orbital transport. Applying our theory to an hexagonal altermagnet, we obtain an experimentally accessible voltage of approximately $ 0.4~\mu$ V. Our results establish a concrete electrical probe of magnon orbital transport and highlight magnons as potential low-dissipation information carriers for orbitronics.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Materials Science (cond-mat.mtrl-sci), Strongly Correlated Electrons (cond-mat.str-el)
13 pages and 5 figures. We invite comments and feedback
Machine Learning for Electrode Materials: Property Prediction via Composition
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-03-10 20:00 EDT
Hao Wu, Cameron Hargreaves, Arpit Mishra, Gian-Marco Rignanese
In this work, we benchmark three leading Machine Learning (ML) frameworks-MODNet, CrabNet, and a random forest model based on Magpie feature-for predicting properties of battery electrode materials using the Materials Project Battery Explorer dataset. We evaluate these models based on predictive accuracy, visualize numerical features using two-dimensional embeddings, and quantify performance using standard metrics. Our results demonstrate that CrabNet consistently outperforms the other models across all tests. To validate these findings, we employ robust statistical methods: bootstrap resampling and two cross-validation (CV) strategies (leave one cluster out and stratified 5-fold CV), comparing each model against a control baseline. In addition, we apply unsupervised clustering on MODNet-derived features using t-SNE and DBSCAN, revealing coherent material groupings without prior labels. This analysis confirms the robustness of the evaluated models and underscores the potential of ML-driven approaches for accelerating the electrode materials discovery. However, our study also identifies practical limitations and quantifies challenges associated with integrating ML models into materials science workflows. Despite these constraints, our findings suggest that ML models are highly effective for early-stage compositional screening in the battery industry. This work provides a foundation for future research on ML applications in materials discovery.
Materials Science (cond-mat.mtrl-sci)
28 pages, 12 figures
Four-state discrimination for a pair of spin qubits via gate reflectometry
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2026-03-10 20:00 EDT
Single-electron spin qubits defined in quantum dots are used as building blocks of a semiconductor-based quantum computer. Readout in a scaled-up version of such a quantum computer is expected to rely on the Pauli Spin Blockade (PSB) mechanism. A desired functionality of PSB readout is that it reveals two bits of information on the two spin qubits that are involved in the process, such that the four computational basis states can be discriminated. In this work, we propose and quantitatively analyze an experimental procedure, based on gate reflectometry, which enables this four-state discrimination in a single measurement. We provide an intuitive recipe to maximize the contrast between the quantum capacitances of the four basis states. Focusing on silicon double quantum dots equipped with a micromagnet, we quantify how amplifier noise and phonon-mediated relaxation influence readout fidelity. Our results highlight a realistic opportunity to mitigate the overhead of readout ancilla qubits in a spin-based quantum computer.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Quantum Physics (quant-ph)
9 pages main text + 8 pages appendix and bibliography
Understanding halide segregation in metal halide perovskites through defect thermodynamics
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-03-10 20:00 EDT
Abrar Fahim Navid, Zeeshan Ahmad
Halide segregation in metal halide perovskites limits their bandgap tunability and hinders their adoption in tandem solar cells and light emitting diodes. Here, we reveal the thermodynamic driving force behind halide segregation in mixed halide (Br-I) perovskites. By performing first-principles calculations on slab models with varying bromide and iodide distributions, we demonstrate that bromide ions preferentially occupy surface sites over bulk sites. Our simulations show that the segregation tendency is higher in MAPb(Br$ _x$ I$ _{1-x}$ )$ _3$ (MA=methylammonium) compared to FA$ _{0.8}$ Cs$ _{0.2}$ Pb(Br$ _x$ I$ _{1-x}$ )$ _3$ , highlighting the role of the A-site cation. To quantify this effect, we establish a descriptor for halide segregation: the difference in defect formation energies of Br antisite defects between the bulk and the surface, which confirms the role of the A-site cation at equimolar Br-I concentration. Furthermore, we identify the localization of photo-generated holes near iodide ions, which triggers their oxidation and accelerates the formation of iodide vacancies, thereby promoting segregation. Overall, this work establishes defect thermodynamics as a framework for understanding halide segregation and provides a structural basis for designing stable mixed halide perovskites.
Materials Science (cond-mat.mtrl-sci), Chemical Physics (physics.chem-ph)
25 pages, 6 figures + 13 pages of Supporting Information
Force Dipole Interactions in Membranes with Odd Viscosity
New Submission | Soft Condensed Matter (cond-mat.soft) | 2026-03-10 20:00 EDT
Sneha Krishnan, Udaya Maurya, Rickmoy Samanta
We develop a hydrodynamic framework for the interactions and collective dynamics of force dipoles embedded in a compressible fluid membrane supported by a shallow viscous subphase. Starting from the generalized two-dimensional Stokes equations with shear, dilatational, and odd (Hall) viscosities, we derive an exact real-space Green tensor using Hankel transforms. The resulting tensor is characterized by three hydrodynamic screening scales associated with shear, compressional, and odd-viscous modes, and smoothly reduces to the standard limiting cases of incompressible membranes and compressible parity-symmetric membranes, while also capturing the chiral response generated by odd viscosity. Using this Green tensor we obtain the velocity and vorticity fields generated by a force dipole and formulate the dynamical system governing interacting dipoles. The analysis reveals several distinct dynamical regimes and identifies observables that isolate the antisymmetric odd-viscous contribution to dipole interactions, including transverse drift and chiral relative motion.
Soft Condensed Matter (cond-mat.soft), Mathematical Physics (math-ph), Biological Physics (physics.bio-ph), Fluid Dynamics (physics.flu-dyn)
70 pages, detailed simulation figures and derivation of the screening mass scales in Appendix
Structural aging of a cohesive and amorphous granular solid under cyclic loading
New Submission | Soft Condensed Matter (cond-mat.soft) | 2026-03-10 20:00 EDT
William Hobson-Rhoades, Douglas J Durian, Yue Fan, Hongyi Xiao
We investigate how cyclic loading evolves the structure and deformation behaviors of a granular raft composed of particles floating at an air-oil interface. The raft has a disordered particle packing structure, and is cohesive due to capillary interactions between particles. Under uniaxial cyclic loading with a small strain amplitude, the raft’s packing structure experiences an aging process characterized by logarithmically increasing packing fraction and decreasing structural heterogeneity. The observed structural change is due to particle dynamics that are organized around morphologically evolving voids in the raft. The raft is then subjected to quasi-static tension or compression tests until failure. In comparison with non-aged rafts, the rafts that experienced cyclic loading show a higher strength, higher stiffness, and lower ductility, along with qualitatively different features, such as a stress overshoot in the loading curve.
Soft Condensed Matter (cond-mat.soft)
Designing Extremely Low-Power Topological Transistors with 1T’-MoS2 and HZO for Cryogenic Applications
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2026-03-10 20:00 EDT
Yosep Park, Yungyeong Park, Hyeonseok Choi, Subeen Lim, Yeonghun Lee
Large-scale quantum computing requires cryogenic electronic controllers such as control/readout circuit and routing circuit. However, current technologies face high power dissipation problems, hindering large-scale qubit integration. Here, we theoretically propose extremely low-power cryogenic topological transistors, i.e., negative-capacitance topological insulator field-effect transistors (NC-TIFETs). By combining a gate-field-induced two-dimensional 1T’-Molybdenum Disulfide (MoS$ 2$ ) topological channel with a hafnium-zirconium oxide (HZO) ferroelectric gate insulator, NC-TIFETs exhibit an extremely steep-slope transfer curve and ultra-high transconductance at low drain voltage ($ V{\mathrm{D}}$ ). Therefore, NC-TIFETs are the compelling candidate for minimizing power dissipation in the cryogenic electronic interfaces essential for large-scale quantum computing systems.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
Nano Lett. 26, 2684 (2026)
Band modulations and topological transitions in a one-dimensional periodic bead-on-string chain
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2026-03-10 20:00 EDT
Haocong Pan, Wei Wang, Chunling Liu
We study band modulations and topological transitions in a one-dimensional periodic bead-on-string chain. Using an exact transfer-matrix formulation of the wave equation with periodically modulated mass density, combined with numerical spectral searches and tabletop experiments, we characterize band gaps and localized midgap states. We interpret these states by mapping the system to the Su-Schrieffer-Heeger (SSH) model and its low-energy (1+1)-dimensional Dirac theory. This framework reveals that the robust states are topological solitons bound to boundaries or engineered domain walls in the Dirac mass. Through this mapping, we provide an intuitive account of how band structure controls topological phase changes in mechanically realizable lattices.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Classical Physics (physics.class-ph)
12 pages, 20 figures
First-principles identification of optically efficient erbium centers in GaAs
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-03-10 20:00 EDT
Gallium arsenide (GaAs) doped with erbium (Er), a material of interest for optoelectronics and quantum information, has been studied for decades. Yet the formation of Er luminescence centers in the semiconductor host and their properties are still not well understood. Here we present a systematic investigation of Er-related defects in GaAs, including defect complexes consisting of Er and native point defects or oxygen impurities, using first-principles hybrid-functional defect calculations. We find that these defects have electronic structure and energetics that are generally asymmetric with respect to n- and p-type doping and tend to favor electron trapping. On the basis of the calculated defect levels, formation energies, and nonradiative carrier capture coefficients, we identify Er-related defect centers that are efficient as trap-assisted nonradiative recombination centers for Er$ ^{3+}$ excitation under host photoexcitation or via minority carrier injection. Our results provide an understanding for why a particular center with Er coupled to two oxygen atoms, often referred to as Er-2O, is most efficient and for the effects of n- and p-type doping and of the Er/O ratio on the formation of optically active Er centers and on the Er luminescence observed in experiments.
Materials Science (cond-mat.mtrl-sci)
12 pages, 9 figures, 3 tables
Terahertz-nanoscale visualization of the microscopic spin-charge architecture of colossal magnetoresistive switching
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2026-03-10 20:00 EDT
Samuel Haeuser, Randall K. Chan, Richard H. J. Kim, Joong-Mok Park, Martin Mootz, Thomas Koschny, Jigang Wang
Resolving sub-10 nm spin switching and the associated terahertz (THz) electrodynamics during the colossal magnetoresistance (CMR) transition is a definitive frontier in reaching the fundamental spatial, temporal, and energy-dissipation limits of spin-based microelectronics and quantum logic architectures. Yet, the requirement of simultaneous control of high magnetic field, cryogenic environment, and nanometer-scale resolution has remained an elusive benchmark for terahertz nanoscopy, leaving the obscured nano-scale high-frequency dynamics of these transitions largely unexplored. Here, we overcome these limitations by utilizing a custom-built cryogenic magneto-THz scattering-type scanning near-field optical microscopy (cm-THz-sSNOM) platform to resolve the nanoscale, THz spectroscopic evolution of the magnetic field-driven CMR transition in a manganite single crystal $ \text{Pr}{2/3}\text{Ca}{1/3}\text{MnO}_{3}$ . Our measurements provide a real-space visualization of the local THz conductivity, capturing the moment that magnetic-field-induced spin switching triggers the phase transition from an antiferromagnetic insulator to a ferromagnetic metal. THz nano-imaging, together with an ellipsoidal near-field model, reveals a multi-scale transition initiated by 1-2 nm isolated spin-flip sites at low magnetic fields, which coalesce into $ \sim$ 15~nm conducting regions as the threshold field is approached. These results provide an in situ, previously inaccessible THz real-space view of CMR switching, establishing a general analysis framework for mapping spin-charge-lattice-orbit-coupled dynamics at spatial scales that transcend the nominal sSNOM resolution.
Strongly Correlated Electrons (cond-mat.str-el), Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Materials Science (cond-mat.mtrl-sci)
Melting behavior and dynamical properties of Cr2Ge2Te6 phase-change material
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-03-10 20:00 EDT
Suyang Sun, Yihui Jiang, Riccardo Mazzarello, Wei Zhang
Cr2Ge2Te6 (CrGT) is known as an intrinsic ferromagnetic semiconductor and a promising candidate for phase-change memory applications. In amorphous CrGT, Cr atoms form non-defective octahedral motifs with Te atoms, similar to those in the crystalline phase. The abundance of Cr[Te6] octahedra is regarded as the key structural factor in reducing the resistance drift coefficient of amorphous CrGT. However, the stage at which these octahedra emerge during melt-quench amorphization remains unclear. Here, we present ab initio molecular dynamics (AIMD) simulations to model the melting process of crystalline CrGT and to investigate the dynamical properties of liquid and supercooled liquid CrGT in detail. Upon heating, Ge atoms are observed to leave their lattice sites earlier than Cr and Te atoms, diffusing into the van der Waals gap and initiating the collapse of the layered structure. The Cr[Te6] octahedra are more robust, maintaining their structural pattern up to 1400 K despite continuous rupture and re-formation of Cr-Te bonds. At higher temperatures, Cr and Te atoms start to migrate independently. In supercooled liquid CrGT at 550 K, most Cr-centered octahedra remain intact, with only limited Cr-Te bond breaking. The collective motion of these octahedra in this temperature regime helps explain why crystallization in CrGT devices can be accomplished in tens of nanoseconds.
Materials Science (cond-mat.mtrl-sci)
10 pages, 4 figures
Quantum Metric Senses A Persistent Spin Helix
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2026-03-10 20:00 EDT
Persistent spin helices are a manifestation of symmetry-protected spin textures in systems with balanced spin-orbit coupling. They enable long-lived spin structures that are of interest for spintronics and coherent spin manipulation. The quantum metric has recently emerged as a promising tool for characterizing the geometric structure of quantum states. Here, we demonstrate that the quantum metric provides a sensitive geometric probe of the persistent spin helix. Within the Rashba-Dresselhaus Hamiltonian, we analytically evaluate the quantum metric components and uncover a divergent geometric contribution that emerges precisely at the persistent spin helix condition. We reveal that this divergence originates from a hidden line degeneracy that forms when the strengths of Rashba and Dresselhaus spin-orbit coupling become equal. We further study the role of higher-order cubic spin-orbit interactions and determine how these corrections regularize the geometric response and control the scaling behavior of the quantum metric. Our results establish quantum geometry as a powerful framework for identifying and characterizing persistent spin helices and related symmetry-protected spin textures.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Materials Science (cond-mat.mtrl-sci)
5 pages, 3 figures
Non-Markovian heat production in ultrafast phonon dynamics
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-03-10 20:00 EDT
Fredrik Erikssonm Yulong Qiao, Erik Fransson, R. Matthias Geilhufe, Paul Erhart
High-intensity THz laser pulses enable the light-mediated control of lattice vibrations by resonantly driving selected phonon modes. On ultrafast timescales, memory effects influence the phonon dynamics and must be accounted for to describe the heat production associated with energy dissipation. Here, we establish a microscopic framework for non-Markovian phonon dynamics by deriving the noise and dissipation kernels governing a driven phonon mode. Using large-scale molecular dynamics simulations, we reconstruct these kernels directly from the many-body lattice dynamics and determine the corresponding heat production rate. Our results provide a quantitative picture of the crossover between Markovian and non-Markovian dynamics on picosecond timescales and show how the finite bandwidth of the driving field limits the dynamically relevant bath spectrum. Furthermore, we demonstrate that thermodynamic quantities such as heat production can be inferred directly from the dynamics of an individual phonon mode, enabling their experimental measurement using time-resolved spectroscopy.
Materials Science (cond-mat.mtrl-sci), Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Statistical Mechanics (cond-mat.stat-mech), Computational Physics (physics.comp-ph)
6 pages, 2 figures
Percolation on multifractal, scale-free weighted planar stochastic porous lattice
New Submission | Statistical Mechanics (cond-mat.stat-mech) | 2026-03-10 20:00 EDT
Proshanto Kumar, Md. Kamrul Hassan
We introduce the Weighted Planar Stochastic Porous Lattice (WPSPL), a geometrically disordered substrate generated by iteratively subdividing a unit square. At each step a block is selected with probability proportional to its area, divided into four parts, and one sub-block is retained (removed) with probability $ q$ ($ 1-q$ ). We show analytically that the WPSPL exhibits multifractality for each of its infinitely many nontrivial conserved quantities and demonstrate numerically that its snapshots at different times are statistically self-similar. The dual of the lattice forms a complex network with a power-law degree distribution. Motivated by these properties of this porous lattice, we study bond percolation on the WPSPL, determine the percolation threshold, and estimate the critical exponents $ \alpha$ , $ \beta$ , and $ \gamma$ associated with the specific heat, order parameter, and susceptibility, respectively. The exponents vary continuously with $ q$ , reflecting a family of distinct universality classes as the global dimension of the lattice depends on $ q$ . Remarkably, the Rushbrooke inequality, $ \alpha + 2\beta + \gamma \ge 2$ , is satisfied in near equality. Notably, the nonporous case ($ q=1$ ) has a global dimension $ 2$ but lies outside the universality class of conventional two-dimensional lattices. Our results highlight how geometric disorder, multifractality, scale-free coordination number disorder, and porosity produce unconventional critical behavior.
Statistical Mechanics (cond-mat.stat-mech), Computational Physics (physics.comp-ph)
13 pages, 10 captioned figures and one table
The giant anomalous Hall and Nernst effects in Kagome permanent magnets RCo5
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-03-10 20:00 EDT
Weian Guo, Pengyu Zheng, Rui Liu, Yiran Peng, Ying Yang, Zhiping Yin
Kagome lattice materials have attracted considerable attention due to their intriguing topological properties and potential applications in next-generation quantum and spintronic technologies. In particular, rare-earth permanent magnets with Kagome structure provide an ideal platform that combines robust magnetism with nontrivial quantum phenomena. However, their anomalous transport properties, particularly thermoelectric responses, remain insufficiently explored. In this work, we perform systematic first-principles calculations on the anomalous Hall and anomalous Nernst effects in Kagome permanent magnets RCo5 (R = Ce, La, Sm, Gd). We find that CeCo5 exhibits a pronounced anomalous Hall conductivity of about 1500 Omega^-1 cm^-1 while GdCo5 displays a substantial anomalous Nernst conductivity of 11 A m^-1 K^-1 within +/- 0.1 eV of the Fermi energy, both comparable to or surpassing the measured intrinsic values reported in many typical Weyl and Heusler magnets. These exceptional anomalous transport properties originate from Berry curvature hotspots near spin-orbit coupling induced band gaps. If validated, these theoretical predictions would be important for Berry-curvature-driven transport in magnetic intermetallics. Our results establish RCo5 compounds as versatile platforms for exploring Berry curvature-driven transport in tunable magnetic topological materials.
Materials Science (cond-mat.mtrl-sci), Strongly Correlated Electrons (cond-mat.str-el)
22 pages, 8 figures
Rethinking Charge Transport and Recombination in Donor-diluted Organic Solar Cells
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-03-10 20:00 EDT
Chen Wang, Christopher Wöpke, Toni Seiler, Jared Faisst, Mathias List, Meike Kuhn, Bekcy Joseph, Alexander Ehm, Dietrich R. T. Zahn, Yana Vaynzof, Eva M. Herzig, Roderick C. I. Mackenzie, Uli Würfel, Maria Saladina, Carsten Deibel
We systematically investigate PM6:Y12 bulk-heterojunction solar cells with donor fractions ranging from 1% to 45%, linking morphology, charge transport, and recombination to device performance. Complementary structural and spectroscopic methods reveal that a percolating PM6 network forms even at below 5% donor content, with lamellar stacking and vertical composition gradients that do not hinder the charge extraction. The reduction of the effective active layer conductivity towards low donor fractions obeys a three-dimensional percolation model, indicating that charge transport is governed by network topology rather without a pronounced percolation threshold. A transition from nongeminate Langevin recombination to a dispersive Smoluchowski-type loss occurs below 5% donor fraction. The latter regime is also nongeminate, i.e., pertains to recombination of the total charge carrier density. Correspondingly, we observe that the Langevin reduction in the higher donor fractions - mostly dominated by redissociation of electron-hole pairs after encounter - changes towards low donor fractions: in these cases, the nongeminate loss rate exceeds the prediction of the Langevin model. This regime coincides with increasing transport resistance due to topology-limited hole conduction, leading to reduced fill factors despite a high retained charge-generation efficiency. Our results demonstrate that strong donor dilution preserves photogeneration if a continuous donor network is maintained, and unveil how topology-controlled transport and non-Langevin recombination jointly define the performance limits of donor-diluted organic solar blends.
Materials Science (cond-mat.mtrl-sci)
Shape Selection in Nanopillar Formation
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-03-10 20:00 EDT
Marta A. Chabowska, Magdalena A. Załuska-Kotur
Crystal growth processes produce a diverse array of surface formations, primarily distinguished by their geometric shapes. While some structures strictly adhere to the underlying crystal symmetry, others exhibit universal circular or oval geometries. Utilizing Vicinal Cellular Automata (VicCA) modeling, we demonstrate that these morphological differences depend on the spatial distribution of the growth potential. Specifically, local potential variations concentrated around surface steps drive the formation of the lattice symmetry - following structures, whereas global potentials - often originating from defects-generate universal spherical or oval shapes. Furthermore, we illustrate how these morphologies are influenced by the growth parameters such as sticking coefficient or diffusion coefficient. Although the positioning of surface defects is difficult to control, we show that temperature and external particle flux can be effectively used to steer and manipulate surface pattern formation.
Materials Science (cond-mat.mtrl-sci)
4 pages, 4 figures, submitted to Solid State Communications
Probing scale-dependent liveliness with nonequilibrium thermospectroscopy
New Submission | Soft Condensed Matter (cond-mat.soft) | 2026-03-10 20:00 EDT
Probing the spatially heterogeneous activity across scales is a major challenge in living matter. Energy injection at diverse length scales leads to mode coupling, inter-modal energy transfer, and entropy production. We demonstrate the emergence of multiple effective (``active’’) temperatures in nonequilibrium molecular- and Brownian-dynamics simulations of an active polymer. Via a generalised Langevin equation for a labelled monomer we identify spectral noise temperatures and their relation to the underlying activity landscape. A harmonic trap of variable stiffness can serve as a minimally invasive prototypical spectroscopic device to selectively scan through the emergent effective temperatures and thereby resolve the scale-dependent activity.
Soft Condensed Matter (cond-mat.soft)
Role of photonic interference in exciton-mediated magneto-optic responses
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-03-10 20:00 EDT
Güven Budak, Christian Riedel, Akashdeep Kamra, Patrick Rinke, Christian Back, Matthias Stosiek, Florian Dirnberger
Coupled optical and magnetic excitations can give rise to remarkably strong magneto-optic responses. This is particularly evident in van der Waals magnets, such as the antiferromagnet CrSBr, where excitons and magnons emerge from the same electronic orbitals. While previous work has primarily focused on uncovering the magneto-electric origin of the resulting exciton-magnon interactions, the influence of photonic effects has received comparatively little attention. Here, we use numerical simulations to disentangle exciton-magnon coupling from the exciton-mediated magnon-photon interactions observed in optical experiments. Our simulations show the strong dependence of these interactions on photonic interference and dispersion effects near excitonic resonances. Such effects shape the optical response to coherent magnons and make it intrinsically non-linear in the magnon-induced exciton energy shift. Thermal magnons, which have a particularly pronounced impact on excitons, are found to even produce qualitatively different trends in optical signatures. Depending on weak or strong coupling of excitons and photons, the same exciton-magnon interaction can lead to a red-shift of optical modes, a nearly vanishing response, or their blue-shift. Finally, we demonstrate first steps towards optimizing the multi-parameter problem of efficient magnon-photon transduction using a machine-learning approach.
Materials Science (cond-mat.mtrl-sci)
Unexpected Planar Dislocation Boundary Formation in FCC Metals Captured by Dark-Field X-ray Microscopy and Continuum Dislocation Dynamics
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-03-10 20:00 EDT
Adam André William Cretton, Khaled SharafEldin, Axel Henningsson, Felix Frankus, Can Yıldırım, Carsten Detlefs, Flemming Bjerg Grumsen, Albert Zelenika, Anter El-Azab, Grethe Winther, Henning Friis Poulsen
Validating dislocation patterning models against in situ imaging experiments is a longstanding goal in materials physics. Here, we provide the first direct morphological comparison of such models. Using in situ Dark-Field X-ray Microscopy (DFXM), we map the local orientations in high-purity aluminium deformed along [100] and find unexpected planar dislocation boundaries aligned with {111} slip planes that form prior to the development of a conventional dislocation cell structure. To explain this behaviour, we generate synthetic DFXM contrast images from a continuum dislocation dynamics (CDD) simulation. This mesoscale model, using nickel as a high stacking fault energy (SFE) FCC analogue, independently predicts the formation of the same {111} planar boundary types. This correspondence demonstrates that state-of-the-art CDD and DFXM experimental data can be used synergistically - despite differences in strain rates and length scales - as a practical route for refining continuum theories of plasticity.
Materials Science (cond-mat.mtrl-sci)
9 pages, 4 figures
Enhancement of metallicity by Na doping in La$_3$Ni$2$O${7+δ}$
New Submission | Superconductivity (cond-mat.supr-con) | 2026-03-10 20:00 EDT
Yingying Gao, Wei Zhou, W. H. Guo, Chunqiang Xu, H. F. Chen, Z. D. Han, Xiaofeng Xu, Yinzhong Wu, Bin Qian
The observation of high-$ T_c$ superconductivity in bilayer nickelate La$ _3$ Ni$ _2$ O$ _7$ under high pressure provides a new venue for exploring novel unconventional superconductors and elucidating the mechanism of high-$ T_c$ superconductivity. Subsequently, numerous chemical substitution studies have been reported, aiming to stabilize superconductivity at ambient pressure, or significantly reduce the pressure threshold required for its occurrence. Here, we report the comprehensive study on sodium (Na) doping in the Ruddlesden-Popper nickelate La$ _3$ Ni$ _2$ O$ _{7+{\delta}}$ , where Na$ ^+$ substitutes for La$ ^{3+}$ at the A-site with varying doping concentrations. The structural, thermal, magnetic, and electronic transport properties of as-synthesized polycrystalline samples were systematically investigated. X-ray diffraction (XRD) analysis reveals that Na doping induces a structural transition from the ‘327’ Amam phase to the ‘4310’ Bmab phase when $ x\geq0.075$ , which is further corroborated by thermogravimetric analysis (TGA) measurements. Substitution of La$ ^{3+}$ with Na$ ^+$ gives rise to a gradual expansion of the ‘327’ phase lattice. Meanwhile, resistivity measurements indicate that the density wave (DW) transition is marginally suppressed and metallicity is significantly enhanced. Upon the application of pressure, DW transition can be further suppressed, whereas the low-$ T$ insulating behaviors remain insensitive to pressure. These results offer critical insights into the roles of elemental substitution and charge carrier doping in steering the competing electronic phases in layered nickelates.
Superconductivity (cond-mat.supr-con)
Layer-Dependent Orbital Magnetization in Graphene-Haldane Heterostructures
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2026-03-10 20:00 EDT
Sovan Ghosh, Bheema Lingam Chittari
Rhombohedral multilayer graphene (RMG) proximity-coupled to a Haldane substrate provides a platform to investigate the interplay between band topology, layer number, and electric-field control of orbital magnetism. Using a tight-binding model and the modern theory of orbital magnetization, we study the layer-dependent magnetic response in bilayer, trilayer, and tetralayer graphene under Haldane proximity. While monolayer graphene develops a global topological gap with quantized magnetization slope, multilayer systems remain metallic due to protected low-energy bands associated with unperturbed sublattices. Despite the absence of a global gap, finite valley-contrasting Berry curvature produces non-trivial layer-dependent Chern numbers. We decompose the total orbital magnetization into self-rotation ($ M_{\mathrm{SR}}$ ) and center-of-mass ($ M_C$ ) contributions, revealing their distinct behaviors across doping and applied interlayer bias. In bilayer graphene, magnetization remains negative and monotonic. Remarkably, trilayer and tetralayer graphene display a bias-induced sign reversal of orbital magnetization beyond critical thresholds ($ \Delta \simeq -55$ meV for 3LG, $ -50$ meV for 4LG) in the hole-doped regime, a feature completely absent in the bilayer. The effect persists across both hole and electron doping, demonstrating that layer count serves as a key tuning parameter for orbital magnetism. Our findings establish topologically proximitized multilayer graphene as a versatile platform for electric-field-manipulable orbitronic and valleytronic devices.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Materials Science (cond-mat.mtrl-sci)
All-in-plane image sensors free from readout integrated circuits
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2026-03-10 20:00 EDT
Kirill Kapralov, Ilya Mazurenko, Elizaveta Tarkaeva, Valentin Semkin, Oleg Kononenko, Maxim Knyazev, Viktor Matveev, Mikhail Kashchenko, Alexander Morozov, Ivan Domaratsky, Vladimir Kaydashev, Yana Litun, Aleksandr Kuntsevich, Alexey Bocharov, Dmitry Svintsov
High resolution image sensors require electrical access to each individual pixel for signal readout. Such access is especially challenging for ultra-miniaturized pixels, for heterogeneously integrated sensing and readout layers in long-wavelength detectors, and for novel light-sensing materials with unestablished integration to silicon chips. Here, we introduce and experimentally validate a novel imaging approach that does not require electrical connections to individual pixels. The sensor matrix involves photoresistive pixels connected neighbor-to-neighbor and packed into a rectangular lattice. The signal readout is based on electrical impedance tomography applied to the photoresistance: the photovoltage is measured at the matrix boundary at various positions of injected bias current, and the image is reconstructed algorithmically. We present experimental validations for moderate-size infrared imagers based on multilayer graphene (24 pixels) and amorphous vanadium oxide (264 pixels). The reconstruction procedure is mathematically stable, sustainable to variations of pixel resistivity and photosensitivity, and its complexity is that of linear system solution. The proposed method enables unprecedented architecture simplification of imaging devices.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
9 pages, 3 figures
Strain-driven magnetic anisotropy and spin reorientation in epitaxial Co V 2 O 4 spinel oxide thin films
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-03-10 20:00 EDT
Lamiae El Khabchi (IPCMS), Laurent Schlur (IPCMS), Jérôme Robert (IPCMS), Marc Lenertz (IPCMS), Cédric Leuvrey (IPCMS), Gilles Versini (IPCMS), François Roulland (IPCMS), Gilbert Chahine (SIMaP), Nils Blanc (NEEL - CRG), Daniele Preziosi (IPCMS), Christophe Lefèvre (IPCMS), Nathalie Viart (IPCMS)
CoV___O___ (CVO) stands out among spinel vanadates for its ultra-short V-V distances, placing it at the brink of itinerant electron behaviour-an ideal playground for strain engineering. In this work, we exploit this sensitivity by growing high-quality epitaxial CVO thin films on SrTiO___ (001) and MgO (001), inducing compressive and tensile strain, respectively. Using pulsed laser deposition under ultra-low oxygen pressure, we achieve high crystalline quality and straincontrolled tetragonal distortions: c > a under compression (STO) and c < a under tension (MgO). Resonant elastic X-ray scattering confirms a normal spinel structure, with cobalt occupying tetrahedral sites and vanadium octahedral ones. Both strain types reduce charge transport, driving the system into a highly resistive state. Magnetic measurements reveal strain-driven anisotropy switching: STO films transition from out-of-plane to in-plane easy axis below 90 K, while MgO films flip from in-plane to out-of-plane below 45 K. These results highlight CVO’s exceptional responsiveness to lattice strain, unlocking a path to finely tunable electronic and magnetic properties. With its strong spin-lattice coupling and potential in spin Hall magnetoresistance, strained CVO emerges as a compelling platform for next-generation lowpower spintronic devices.
Materials Science (cond-mat.mtrl-sci)
Physical Review Materials, 2026, 10 (1), pp.014408
Magnetic phase diagram and spin Hamiltonian of antiferromagnet Cs$_2$CoI$_4$
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2026-03-10 20:00 EDT
S.D. Nabi, L. Facheris, V. Romerio, V. Kocsis, K. Yu. Povarov, D. Sheptyakov, J. Lass, D.G. Mazzone, H. Kikuchi, T. Masuda, S.A. Barnett, D.R. Allan, Z. Yan, S. Gvasaliya, A. Zheludev
We report comprehensive thermodynamic and neutron scattering measurements on the $ S$ = 3/2 antiferromagnet Cs$ _2$ CoI$ _4$ , a member of the thoroughly studied family of frustrated magnets Cs$ _2MX_4$ ($ M$ = Cu, Co, Ru, $ X$ = Br, Cl, I, O). Unlike previously studied members, Cs$ _2$ CoI$ _4$ undergoes a structural phase transition, for which we determine the low-temperature crystallographic structure. The resulting symmetry reduction strongly affects both the magnetic exchange interactions and single-ion anisotropy. Despite the large parameter space, we propose a minimal magnetic Hamiltonian that reasonably captures the observed excitation spectrum, analyzed using extended SU(4) linear spin-wave theory.
Strongly Correlated Electrons (cond-mat.str-el)
15 pages, 17 figures
Atomic-resolution imaging of gold species at organic liquid-solid interfaces
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-03-10 20:00 EDT
Sam Sullivan-Allsop, Nick Clark, Wendong Wang, Rongsheng Cai, William Thornley, David G. Hopkinson, James G. McHugh, Ben Davies, Samuel Pattisson, Nicholas F. Dummer, Rui Zhang, Matthew Lindley, Gareth Tainton, Jack Harrison, Hugo De Latour, Joseph Parker, Joshua Swindell, Eli G. Castanon, Amy Carl, David J. Lewis, Natalia Martsinovich, Christopher S. Allen, Mohsen Danaie, Andrew J. Logsdail, Vladimir Falko, Graham J. Hutchings, Alex Summerfield, Roman Gorbachev, Sarah J. Haigh
Understanding solid-liquid interfaces at the atomic-scale is key to improved performance of heterogeneous catalysts, electrodes and membranes. Here we combine unique specimen design, record atomic resolution in situ electron microscopy, and artificial intelligence-enabled analysis to achieve a step change in quantitative understanding of interfacial atomic behaviour. We create the first graphene liquid cells with organic solvents and employ them to track over 106 gold adatoms and clusters at a graphene surface immersed in acetone and cyclohexanone. We reveal dynamic correlated behaviour of gold adatom monomers, dimers, trimers and clusters, strongly influenced by each other, the solvent properties, and the atomic lattice of the substrate, in good agreement with theoretical calculations. We use the results to interpret differences in catalytic activity towards the industrially important acetylene hydrochlorination reaction. This new capability for exploration of atomic scale chemistry could enable rational design of future catalysts, membranes and electrodes with improved functionality.
Materials Science (cond-mat.mtrl-sci)
13 pages, 5 figures
A thermodynamic metric quantitatively predicts disordered protein partitioning and multicomponent phase behavior
New Submission | Soft Condensed Matter (cond-mat.soft) | 2026-03-10 20:00 EDT
Zhuang Liu, Beijia Yuan, Mihir Rao, Gautam Reddy, William M. Jacobs
Intrinsically disordered regions (IDRs) of proteins mediate sequence-specific interactions underlying diverse cellular processes, including the formation of biomolecular condensates. Although IDRs strongly influence condensate compositions, quantitative frameworks that predict and explain their phase behavior in complex mixtures remain lacking. Here we introduce a thermodynamic model that quantitatively predicts the behavior of arbitrary combinations of IDRs across a wide range of concentrations, with accuracy comparable to state-of-the-art simulations. The model learns low-dimensional, context-independent representations of IDR sequences that combine to form mixture representations, producing context-dependent interactions. These representations define a thermodynamic metric space in which distances between IDRs correspond directly to differences in their thermodynamic properties. We show that the model predicts multicomponent phase diagrams in quantitative agreement with molecular simulations without being trained on free-energy or phase-coexistence data. The metric space provides geometrically intuitive predictions of IDR partitioning, multicomponent condensation, and context-dependent mutational effects, addressing several central problems in IDR biophysics within a single model. Systematic interrogation of the learned representations reveals how amino-acid composition and sequence patterning jointly determine mixture thermodynamics. Together, our results establish a unified and interpretable framework for predicting and understanding the behavior of complex mixtures of IDRs and other sequence-dependent biomolecules.
Soft Condensed Matter (cond-mat.soft), Materials Science (cond-mat.mtrl-sci), Statistical Mechanics (cond-mat.stat-mech), Biomolecules (q-bio.BM)
Includes Supplementary Information
On the estimating the superconducting volume fraction from the internal magnetic susceptibility
New Submission | Superconductivity (cond-mat.supr-con) | 2026-03-10 20:00 EDT
Aleksandr V. Korolev, Evgeny F. Talantsev
Zhang et al.$ ^1$ reported zero-field cooled (ZFC) and field cooled (FC) data measured in a highly compressed $ Pr_4Ni_3O_{10}$ single crystal. These measurements provide unambiguous confirmation of bulk superconductivity in pressurized Ruddlesden-Popper nickelates. Zhang et al.$ ^1$ applied an equation (described in Refs.$ ^{2,3}$ ) to recalculate ZFC data measured in a $ Pr_4Ni_3O_{10}$ (sample S3) in volume fraction $ f$ of the superconducting phase in the sample. In result$ ^1$ , $ f = 0.85$ was reported for sample S3 at pressure P = 40.2 GPa. The key postulate of the methodology for the calculation of $ f$ (see also works$ ^{4-6}$ ) is that $ f$ is equal to the amplitude of the internal magnetic susceptibility $ \vert \chi_{internal} \vert $ , or $ f = \vert \chi_{internal} \vert $ . Here we argue that this postulate is incorrect and present counterexample where the $ Pr_4Ni_3O_{10}$ sample S3 can exhibit $ f < 0.10$ and $ \vert \chi_{internal} \vert = 0.82 $ . In the result, we addressed recent Replies$ ^{2,3}$ on our Comments$ ^{7,8}$ . Considering that the postulate $ f = \vert \chi_{internal} \vert $ is widely used in superconductivity, we extend our request to reconsider the validity of this postulate in the entire field of superconductivity.
Superconductivity (cond-mat.supr-con)
11 pages, 1 figure
Structural phase transitions in double perovskite crystals studied by Brillouin light scattering
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-03-10 20:00 EDT
D. O. Horiachyi, M. O. Nestoklon, I. A. Akimov, D. R. Yakovlev, V. Vasylkovskyi, O. Trukhina, V. Dyakonov, M. Bayer
Inorganic lead-free double perovskites represent particular interest as non-toxic and stable material platform for optoelectronic applications. Here, we employ Brillouin light scattering spectroscopy to investigate the elastic properties and structural phase transitions in single crystals of Cs2AgBiBr6 and Cs2AgBiCl6. A complete set of elastic constants is determined from the Brillouin scattering measurements performed along three different crystallographic directions. Both materials exhibit similar elastic constants and weak elastic anisotropy in the cubic phase. At low temperatures, the lifting of degeneracy of transverse acoustic phonon modes is attributed to a lowering of crystal symmetry. From the temperature dependence of the acoustic phonon frequencies, we determine the structural phase transition temperature of about 43 K for Cs2AgBiCl6, compared to 122 K for the cubic-to-tetragonal phase transition in Cs2AgBiBr6.
Materials Science (cond-mat.mtrl-sci)
Colloidal Probe Atomic Force Microscopy Reveals Anomalous Underscreening: A Matter of Experimental Conditions
New Submission | Soft Condensed Matter (cond-mat.soft) | 2026-03-10 20:00 EDT
Thomas Tilger, Esther Ohnesorge, Michalis Tsintsaris, Kazue Kurihara, Hayden Robertson, Regine von Klitzing
There is considerable debate about anomalous underscreening in highly concentrated electrolytes: While surface force apparatus (SFA) measurements have confirmed anomalously long screening lengths, so far they have not yet been detected in experiments using colloidal probe atomic force microscopy (CP-AFM). CP-AFM measurements across aqueous LaCl$ _3$ solutions demonstrate that by adapting the experimental conditions to those of SFA studies, similarly large screening lengths can be achieved at high salt concentrations. This represents the first observation of anomalous underscreening with CP-AFM. These findings leave room for speculations about the ordering of the confined electrolyte.
Soft Condensed Matter (cond-mat.soft)
Bound Trions in Two-Dimensional Monolayers: A Review
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2026-03-10 20:00 EDT
Trions – Coulomb-bound three-particle excitations composed of two like-charge carriers and one oppositely charged carrier – are central quasiparticles in two-dimensional semiconductors. Reduced dielectric screening and quantum confinement strongly enhance their binding energies, making them robust and experimentally accessible. This review surveys theoretical and experimental advances in trion physics, emphasizing rigorous few-body approaches and the role of dielectric environment, anisotropy, and external electric and magnetic fields. We analyze computational methods for describing trions in two-dimensional configuration spaces and discuss how reduced dimensionality modifies their structure and stability. Connections to many-body phenomena, including screening, Landau-level mixing, and exciton–polaron crossover, are also highlighted.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Chemical Physics (physics.chem-ph), Quantum Physics (quant-ph)
35 pages, 6 figures
Synchronization of higher-dimensional Kuramoto oscillators on networks: from scalar to matrix-weighted couplings
New Submission | Statistical Mechanics (cond-mat.stat-mech) | 2026-03-10 20:00 EDT
Anna Gallo, Renaud Lambiotte, Timoteo Carletti
The Kuramoto model is the paradigmatic model to study synchronization in coupled oscillator systems. In its classical formulation, the oscillators move on the unit circle, each characterized by a scalar phase and a natural frequency, by interacting through a sinusoidal coupling. In this work, we propose a d-dimensional generalization in which oscillators are represented as unit vectors on the (d-1)-sphere and interact through a matrix-weighted network (MWN), a recently introduced framework where links are endowed with a matrix weight instead of a scalar one. We derive necessary conditions for global synchronization via a Master Stability Function approach: the existence of a synchronous solution requires identical frequency matrices across nodes and, in the MWN case, a coherence condition on the network structure. Through a suitable change of variables, the stability analysis reduces the full Nd-dimensional problem to a family of d-dimensional eigenvalue problems, each one parametrized by the eigenvalue of a suitable scalar weighted Laplacian, showing that the synchronous solution is locally stable for any positive coupling strength K on any connected network. Analytical results are complemented by numerical simulations.
Statistical Mechanics (cond-mat.stat-mech), Dynamical Systems (math.DS), Adaptation and Self-Organizing Systems (nlin.AO)
9 pages, 4 figures
Unveiling the Thermal and Aqueous Stability of 1D Lepidocrocite Titania
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-03-10 20:00 EDT
Risha A. Iythichanda, Sukanya Maity, Mustafa M. Aboulsaad, Tomas Edvinsson, Johanna Rosen, Per O.Å. Persson
One dimensional lepidocrocite titanium dioxide filaments are investigated with respect to their thermal and aqueous stability. Structural and phase evolution are examined using in situ heating in vacuum within transmission electron microscopy combined with electron energy loss spectroscopy, and at ambient conditions using Raman spectroscopy. The filaments retain their lepidocrocite structure up to 300 degree and above which localized sintering and amorphization occur at filament overlap junctions. With further heating, the amorphous regions crystallize into anatase, with Raman spectroscopy corroborating the onset of structural disorder. Long term aqueous storage up to 100 days at ambient conditions induces transformation into flake like anatase nanoparticles. This process is strongly suppressed under refrigerated storage, where no structural changes are observed over the same period. These results establish critical thermal and environmental stability thresholds that define operational advantages and limits for emerging applications of 1D lepidocrocite filaments.
Materials Science (cond-mat.mtrl-sci)
Microscopic theory of flexo Dzyaloshinskii-Moriya-type interaction
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2026-03-10 20:00 EDT
We study interaction between two magnetic impurities mediated by itinerant electrons on the surface of curved magnets based on perturbation theory. We show that Dzyaloshinskii-Moriya type interaction can arise from inhomogeneous spin texture by bending, without any spin-orbit coupling. Analytical expressions of the Dzyaloshinskii-Moriya type interaction are obtained. We demonstrate this effect in a one-dimensional ring model.
Strongly Correlated Electrons (cond-mat.str-el), Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
7 pages, 4 figures
Optical manipulation of valley coherence via Landau level transitions in black phosphorus and WTe2 monolayers
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2026-03-10 20:00 EDT
Xinyu Mu, Shihao Li, Xiaoying Zhou, Guangyi Jia
Valley coherence is of great significance for exploring fundamental quantum phenomena and developing next-generation valleytronic devices. Herein, we theoretically investigate the valley quantum interference engineered by inter-Landau level (LL) transitions in black phosphorus (BP) and WTe2 monolayers. In contrast to the non-Landau-quantized regime, valley quantum interference is enhanced by over 20-fold, or even significantly stronger, in virtue of striking anisotropic environment. Such anisotropy originates from the distinct electron transition probabilities along the armchair and zigzag directions of BP and WTe2 monolayers. Especially, BP is capable of more effectively strengthening the valley quantum interference response due to its greater directional disparity in electron transition probabilities. The interference fringes also present distinct spectral profiles (e.g., different dip and peak numbers in one interference period) owing to different transition selection rules in BP and WTe2 monolayers. In spite of these discrepancies, normalized interference intensities follow two exponential functions of magnetic field and Landau level index for all the transitions {\delta}n = n’- n = -4, -2, 0, +2, +4 (where n and n’ indicate the LL indexes of valence and conduction bands, respectively), and the interference spectra exhibit C2 rotational symmetry about the crystallographic azimuthal angle of 90°.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
Torque Hyperuniformity in Frictional Granular Matter - Theory and Experiments
New Submission | Soft Condensed Matter (cond-mat.soft) | 2026-03-10 20:00 EDT
Jin Shang, Jie Zhang, Itamar Procaccia
A question of some fundamental importance is whether a given assembly of frictional granules (say sand or powder) will exhibit stress autocorrelations with long-range anisotropic decay as determined by the elastic Green’s function. In Hamiltonian systems with central forces, mechanical balance and material isotropy demand the stress auto-correlation matrix to be fully determined by the pressure auto-correlation only. If the local pressure fluctuations are normal, it follows that stress autocorrelations decay at long distance like the elastic Green’s function. With friction, Hamiltonian symmetry is lost, and one may expect more constraints. Indeed, it was shown recently that for frictional amorphous solids mechanical balance and material isotropy demand the stress auto-correlation matrix to be fully determined by two spatially isotropic functions: the pressure and torque auto-correlations. Elastic-like decay of the stress autocorrelations follows from normal fluctuations of the pressure and from the torque fluctuations being hyperuniform. The theoretical discovery of these conditions required experimental confirmation, to test whether these conditions are generically obeyed in actual frictional amorphous solids. Recently the confirmation was announced for 2-dimensional amorphous assemblies of frictional disks under isotropic load, in which torque is caused by tangential forces only. In this paper we review that case and report confirmation of the theoretical predictions in 2-dimensional systems of disks under shear and in isotropically loaded frictional ellipses, where contributions to torque come also from normal forces. The paper ends with physical explanations of the hyperuniformity of the torque fluctuations and predictions for how the results are expected to extend to d-dimensions.
Soft Condensed Matter (cond-mat.soft)
9 pages, 8 figures
Stochastic Loop Corrections to Belief Propagation for Tensor Network Contraction
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2026-03-10 20:00 EDT
Gi Beom Sim, Tae Hyeon Park, Kwang S. Kim, Yanmei Zang, Xiaorong Zou, Hye Jung Kim, D. ChangMo Yang, Soohaeng Yoo Willow, Chang Woo Myung
Tensor network contraction is a fundamental computational challenge underlying quantum many-body physics, statistical mechanics, and machine learning. Belief propagation (BP) provides an efficient approximate solution, but introduces systematic errors on graphs with loops. Here, we introduce a hybrid method that achieves exact results by stochastically sampling loop corrections to BP and showcase our method by applying it to the two-dimensional ferromagnetic Ising model. For any pairwise Markov random field with symmetric edge potentials, our approach exploits an exact factorization of the partition function into the BP contribution and a loop correction factor summing over all valid loop configurations, weighted by edge weights derived directly from the potentials. We sample this sum using Markov chain Monte Carlo with moves that preserve the loop constraint, combined with umbrella sampling to ensure efficient exploration across all correlation strengths. Our stochastic approach provides unbiased estimates with controllable statistical error in any parameter regime.
Strongly Correlated Electrons (cond-mat.str-el), Statistical Mechanics (cond-mat.stat-mech), Quantum Physics (quant-ph)
13 pages, 5 figures
Second harmonic study of thermally oxidized mono- and few-layer 2H-MoS2
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-03-10 20:00 EDT
Katharina Burgholzer, Henry Volker Hübschmann, Gerhard Berth, Adriana Bocchini, Uwe Gerstmann, Wolf Gero Schmidt, Klaus D. Jöns, Alberta Bonanni
A comprehensive study of second harmonic generation on thermally oxidized MoS2 flakes with thickness ranging from monolayer up to seven layers is presented. Observing the fundamental nonlinear behavior for non-treated and oxidized MoS2 reveals that oxidation causes significant changes in the second harmonic (SH) response for all investigated structures. Excitation power dependent measurements to analyze the nonlinear behavior with respect to the oxidation time show progressive oxidation within the maximum oxidation time of six hours, under the considered oxidation conditions. Here, polarization dependent measurements reveal the structural changes due to oxidation. Additionally, it is found that the oxidation depth is restricted to the top most layer and the oxidation behavior exhibits a layer dependency. These findings are supported by theoretical band structure calculations. The results demonstrate that the thermal oxidation progress of two dimensional MoS2 can be monitored with non-resonant and non-invasive SH microscopy, by following distinct fingerprints of structural modification in the nonlinear response.
Materials Science (cond-mat.mtrl-sci)
Katharina Burgholzer and Henry Volker Hübschmann contributed equally
Non-local effects in charge and energy transport with dissipative electrodes
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2026-03-10 20:00 EDT
Recent advances in nano-thermometry motivate the extension of the Landauer-Büttiker scattering theory as to include the non-local dissipation associated with charge transport. Such a program is implemented by describing the inelastic scattering in the connecting electrodes within an electrostatically self-consistent scheme. The restriction to quasi-one-dimensional geometries, weak excitation and low temperature allows to obtain general expressions of the current density and the dissipated power, valid in different regimes, for the cases of an energy-independent mean-free-path or an energy-independent relaxation-rate. In particular, the dissipation asymmetry at both sides of a nano-device and the conditions for observing heating spots with a local maximum of the dissipated power are formulated in terms of the key parameters that define the nano-device and its environment.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
Modeling the Slow Arrhenius Process (SAP) in Polymers
New Submission | Soft Condensed Matter (cond-mat.soft) | 2026-03-10 20:00 EDT
Valeriy V. Ginzburg, Oleg V. Gendelman, Simone Napolitano, Riccardo Casalini, Alessio Zaccone
Amorphous glass-forming polymers exhibit multiple relaxation processes, including the structural {\alpha}-relaxation associated with the glass transition and faster secondary relaxations that typically follow Arrhenius behavior. Recently, a distinct slow Arrhenius process (SAP) has been observed at frequencies well below the {\alpha}-process. Although Arrhenian in its temperature dependence, the SAP involves much longer relaxation times and its microscopic origin remains unclear. Here, we extend the two-state, two-timescale (TS2) theory to describe both the {\alpha}-relaxation and the SAP within a unified framework. We propose that the SAP represents the high-temperature limit of an {\alpha}-like process in a coarse-grained fluid of dynamically correlated clusters. With renormalized interaction energies and coordination parameters, the same model quantitatively reproduces both {\alpha} and SAP data across multiple polymers without additional adjustable parameters and explains the observed Meyer-Neldel compensation behavior. The theory further predicts that the SAP should deviate from Arrhenius behavior at sufficiently low temperatures, transitioning to Vogel-Fulcher-Tammann-Hesse-like dynamics, thereby offering a physically transparent interpretation of cluster-scale relaxation in glass-forming polymers.
Soft Condensed Matter (cond-mat.soft), Disordered Systems and Neural Networks (cond-mat.dis-nn), Materials Science (cond-mat.mtrl-sci)
Main text: 36 pages, 7 figures. Added Supporting Information: 12 pages, 11 figures. Will be submitted to Soft Matter
Magnetic landscape of NbTiN superconducting resonators under radio-frequency excitation
New Submission | Superconductivity (cond-mat.supr-con) | 2026-03-10 20:00 EDT
J. Baumgarten, N. Lejeune, L. Nulens, I. P. C. Cools, J. Van de Vondel, A. V. Silhanek
Planar superconducting resonators are essential components in quantum circuits and highly sensitive sensors. However, their performance is often compromised by magnetic flux penetration, as the interaction of flux quanta and the induced radio-frequency (RF) currents in the superconducting thin film leads to significant energy dissipation. At low operating temperatures, this issue is aggravated as thermomagnetic instabilities can trigger the sudden propagation of magnetic flux avalanches. An important open question is whether the RF excitation itself stimulates the nucleation and propagation of magnetic flux avalanches in the superconducting thin film. The literature remains inconclusive on this point, partly due to the lack of compelling evidence for this phenomenon. In this work, we address this issue by unprecedented direct visualization of magnetic flux penetration through Faraday rotation imaging under simultaneous RF excitation. We demonstrate that the avalanche activity exhibits a weak dependence on the RF intensity for RF excitations within the linear Campbell regime. However, magnetic flux bursts clearly influence the RF transmission properties of the device. Furthermore, it is possible to unambiguously associate a particular avalanche event with a jump in resonance frequency. This enables us to identify the loci of most deleterious events and understand the distinct origins of upward and downward frequency shifts. These observations are supported by electromagnetic simulations in which local changes of the kinetic inductance mimic flux avalanches and confirm the invasive character of the MOI technique. The insights gained from this study aim to contribute to the broader understanding of the magnetic resilience of superconducting resonators, with the goal of improving their efficiency and stability.
Superconductivity (cond-mat.supr-con)
13 pages, 5 figures, 72 references
Defect-induced multiferroicicy in bulk solid solutions of WSe$_2$ and WTe$_2$
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-03-10 20:00 EDT
H. Rojas-Páez, G. Villabón-Linares, J. Pazos, E. Ramos, R. Moreno, O. Herrera-Sandoval, J. A. Galvis, P. Giraldo-Gallo
Transition metal dichalcogenides provide a versatile platform for tunable ferroic phenomena at the atomic scale owing to their reduced dimensionality. Here we investigate the structural, magnetic, and ferroelectric properties of bulk solid solution W(Se1-xTex)2(1-delta) single crystals synthesized by chemical vapor transport. The room temperature behavior is analyzed as a function of tellurium concentration (x) and chalcogen defect fraction (delta). X ray diffraction and Raman spectroscopy reveal lattice expansion and symmetry reduction with increasing x, consistent with a 2H to 1Td structural transition above a critical composition xc about 18 percent. Piezoresponse force microscopy identifies piezoelectricity near stoichiometric compositions (delta less than 5 percent) and switchable ferroelectricity in the chalcogen deficient regime (delta greater than 20 percent). Magnetometry measurements show a corresponding evolution from paramagnetic to ferromagnetic behavior with increasing delta. Near stoichiometric Te poor samples exhibit piezoelectric and paramagnetic responses, whereas multiferroic states characterized by the coexistence of ferroelectric and ferromagnetic responses emerge at high vacancy concentrations. The performed characterizations indicate that x primarily governs structural symmetry, while delta controls the emergence of both ferromagnetic and ferroelectric responses. These trends are summarized in a configurational phase diagram highlighting the cooperative influence of dopants and defects on ferroic behavior. Overall, controlled stoichiometry and vacancy engineering offer an effective strategy to tailor ferroic responses in transition metal dichalcogenides.
Materials Science (cond-mat.mtrl-sci)
Collinear spin density wave state in distorted square-lattice GdNiSn$_4$
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2026-03-10 20:00 EDT
Charles C. Tam, Sarah Schwarz, Xin Zhang, Sudipta Chatterjee, Scott B. Lee, Rebecca Scatena, Leslie M. Schoop, Stephen D. Wilson
We characterize the magnetic ground state of the newly synthesized lanthanide intermetallic GdNiSn$ _4$ via resonant elastic x-ray scattering measurements. This compound forms distorted square nets of Gd that initially order magnetically below 23 K followed by a lower temperature transition at 16 K. Our scattering data identify the ground state order as a single-$ q$ incommensurate, collinear order that slides towards a commensurate wave vector above the 16 K transition. Magnetic symmetry analysis combined with azimuthal dependence resolves the ground state magnetic structure as a moment-modulated spin density wave state with Gd moments oriented parallel to the in-plane a-axis. We discuss connections between the observed magnetic order and electronic properties in this square-net compound.
Strongly Correlated Electrons (cond-mat.str-el)
Anisotropic implantation damage build-up and crystal recovery in $β$-Ga$_2$O$_3$
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-03-10 20:00 EDT
Duarte Magalhães Esteves, Sérgio Magalhães, Ângelo Rafael Granadeiro da Costa, Katharina Lorenz, Marco Peres
The present work aims at investigating the defect accumulation and recovery dynamics in the inherently anisotropic $ \beta$ -Ga$ _2$ O$ _3$ lattice. A systematic Rutherford Backscattering Spectrometry in Channelling mode (RBS/C) analysis of Cr-implanted samples was performed across multiple surface orientations and channelling directions. Distinct apparent defect accumulation and annealing rates were observed along different channelling axes, mainly attributed to the shadowing of certain types of defects along some directions. The efficient defect removal observed after annealing was correlated with the strain relaxation observed via High-Resolution X-ray diffraction (HRXRD) at temperatures as low as 500 °C, which is attributed to the removal of point defects. Annealing at higher temperature further improves crystalline quality but at a slower rate. In short, this work enhances the understanding of the effect of structural anisotropic properties of $ \beta$ -Ga$ _2$ O$ _3$ during ion implantation, as well as the crystal recovery during thermal annealing, highlighting the interplay between crystallography and defect dynamics.
Materials Science (cond-mat.mtrl-sci)
30 pages, 12 figures, 2 tables
Au and Ag nanoparticles produced by ion implantation in single-crystalline $β$-Ga$_2$O$_3$
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-03-10 20:00 EDT
Duarte Magalhães Esteves, Ana Sofia Sousa, Inês Freitas, Ângelo Rafael Granadeiro da Costa, Joana Madureira, Sandra Cabo Verde, Katharina Lorenz, Marco Peres
This work reports the successful formation of Ag and Au nanoparticles in $ \beta$ -Ga$ 2$ O$ 3$ single-crystals by ion implantation and annealing at 550 °C. X-ray diffraction measurements revealed that nanoparticles were formed after the annealing step, presenting a highly-ordered crystalline structure and conforming to a crystallographic relation with respect to the matrix: $ \left(0\overline{1}0\right)\beta \parallel \left(110\right){\mathrm{Ag/Au}}$ and $ \left[102\right]\beta \parallel \left[1\overline{1}2\right]{\mathrm{Ag/Au}}$ . The presence of these nanoparticles was also confirmed via absorbance measurements revealing the localised surface plasmon resonance peaks associated with these particles. Considering the multiple advantages and the versatility of metallic nanoparticles, their combination with the exceptional properties of $ \beta$ -Ga$ _2$ O$ _3$ paves the way for a wide range of applications.
Materials Science (cond-mat.mtrl-sci), Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
13 pages, 4 figures
Heavy-Fermion Behavior and a Tunable Density Wave in a Novel Vanadium-based Mosaic Lattice
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-03-10 20:00 EDT
Yusen Xiao, Zhibin Qiu, Qingchen Duan, Zhaoyi Li, Hengxin Tan, Shu Guo, Ruidan Zhong
The pursuit of geometrically frustrated lattices beyond conventional paradigms remains a central challenge in the design of quantum materials. Herein, we report the discovery of Cs3V9Te13 (CVT), a novel intermetallic compound that hosts a unique two-dimensional vanadium mosaic lattice, composed of an ordered tessellation of triangles, squares, and pentagons, bearing profound structural kinship with the celebrated kagome lattice. Remarkably, CVT exhibits behavior analogous to heavy fermion systems, characterized by a large Sommerfeld coefficient({\gamma} = 425 mJ mol-1 K-2) and a coherent density-wave-like (DW-like) transition at T\ast = 47 K. This establishes CVT as a rare and intriguing example of a strongly correlated system. Inspired by pressure-tuning in related compounds, we demonstrate that this ground state is exquisitely tunable via chemical pressure. Systematic substitution of Cs with smaller Rb ions suppresses the DW-like order while strongly weakening the heavy-electron response, ultimately driving the system into a distinct non-magnetic, semiconducting, quantum-disordered state above 60 mK. This work unveils a new arena for exploring the interplay between heavy-fermion physics, density waves, and quantum disorder. The mosaic lattice in Cs3V9Te13 provides an unprecedented, chemically controllable platform for navigating the phase space between distinct correlated electronic states.
Materials Science (cond-mat.mtrl-sci), Strongly Correlated Electrons (cond-mat.str-el)
Microwave response of electrically driven spins in a three-qubit quantum processor
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2026-03-10 20:00 EDT
Tanner M. Janda, Heun Mo Yoo, Connor Nasseraddin, Adam R. Mills, Zhaoyi Joy Zheng, Jason R. Petta
In electric dipole spin resonance (EDSR), a single spin is electrically driven in the field gradient produced by a micromagnet. While EDSR has enabled high fidelity gate operations in many devices, there are reports of unexpected non-linearities in the Rabi frequency as a function of microwave drive amplitude. We carefully measure the response of Loss-DiVincenzo (LD) single spin qubits to resonant drives as well as simultaneous resonant and off-resonant drives, as would be encountered in a realistic quantum processor. With the microwave amplitude carefully calibrated, we find that the Rabi frequency scales linearly with drive amplitude, even when all three spins are driven simultaneously. We also determine that heating-induced resonance frequency shifts from off-resonant drives are comparable to typical temporal drifts. Our results indicate that the previously observed nonlinear response is not a general feature of LD spin qubits.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Quantum Physics (quant-ph)
Fluid-Solid Pattern Formation and Strain Localisation via Shear Banding Instability in Model Biological Tissues
New Submission | Soft Condensed Matter (cond-mat.soft) | 2026-03-10 20:00 EDT
Aidan J. Nicholas, Suzanne M. Fielding
The rheological properties of biological tissues are core to processes such as cancer metastasis, wound healing and embryo development. The emergence of tissue and organ structures during morphogenesis requires the precise formation of spatial patterns. Dating back to Turing, pattern formation has been suggested to arise in tissues via spontaneous symmetry breaking instabilities in the concentration field of chemical morphogens. Within the vertex model of tissue mechanics, we show that spontaneous symmetry breaking may also arise via a mechanical instability in the strain field of a deformed tissue, leading to a patterned coexistence of fluid and solid regions, with a strong localisation of the strain into shear bands. The nature of the bands differs between tissues in which internal cell-cell dissipation dominates external drag against a substrate, and vice versa.
Soft Condensed Matter (cond-mat.soft)
4 pages, 4 figures
Revisiting the $J_1$-$J_2$ Heisenberg Model on a Triangular Lattice: Quasi-Degenerate Ground States and Phase Competition
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2026-03-10 20:00 EDT
Oleksandra Kovalska, Ester Pagès Fontanella, Benedikt Schneider, Hong-Hao Tu, Jan von Delft
It is generally believed that the spin-$ \tfrac{1}{2}$ triangular-lattice $ J_1$ -$ J_2$ Heisenberg model hosts a quantum spin liquid in the intermediate regime between the $ 120^\circ$ and stripe ordered phases. Density matrix renormalization group studies on cylinders have consistently found two nearly degenerate ground states, commonly interpreted as distinct topological sectors. Using state-of-the-art matrix product state simulations on YC6 cylinders, we compare the static and dynamical properties of these two sectors at $ J_2/J_1 = 0.125$ . Noticeable differences appear already in static correlations; moreover, high-resolution dynamical structure factors reveal qualitatively distinct low-energy excitations. These results suggest that the two ground states cannot be understood as merely topologically distinct sectors of a gapped $ \mathbb{Z}_2$ spin liquid.
Strongly Correlated Electrons (cond-mat.str-el)
9 pages, 9 figures
Discovery of intertwined pair density and charge density wave orders in UTe2
New Submission | Superconductivity (cond-mat.supr-con) | 2026-03-10 20:00 EDT
Zhen Zhu, Yudi Huang, Julian May-Mann, Kaiming Liu, Zheyu Wu, Shanta R. Saha, Johnpierre Paglione, Alexander G. Eaton, Andrej Cabala, Michal Vališka, Eduardo Fradkin, Vidya Madhavan
The strongly correlated spin-triplet superconductor UTe2 hosts an unusual landscape of magnetic-field-sensitive charge density wave (CDW) phases, positioning it as a compelling system for studying intertwined electronic orders. A central challenge is determining whether the observed charge modulations arise from a triplet pair density wave (PDW) order and, if so, how the anisotropic magnetic field response of triplet superconductivity is manifested in the CDW response. Here, using a scanning tunneling microscope equipped with a vector magnetic field, we systematically investigate the evolution and interrelation of distinct CDW orders. Complementing the previously identified incommensurate CDW peaks (qi=1,2,3), we resolve an additional set of nondispersive modulations (pi=1,2,3 and h1,2) with distinct temperature and magnetic field dependencies. The pi CDW peaks vanish near Tc, while the qi peaks survive well above Tc but are progressively suppressed by magnetic field in an anisotropic manner. The critical fields of the qi peaks mirror the directional hierarchy of Hc2, which suggests a PDW is present above the bulk Tc. This is consistent with a Landau free-energy picture where PDWs with wavevectors pi form above the bulk Tc, leading to composite CDW orders with wavevector qi. Below Tc, the coupling of PDWs and uniform superconductivity leads to the pi CDWs. Together, these findings establish UTe2 as a rare platform where both the parent PDW and descendant orders are directly resolved, enabling access to both the fundamental and emergent manifestations of PDW physics.
Superconductivity (cond-mat.supr-con), Strongly Correlated Electrons (cond-mat.str-el)
Main text: 17 pages, 4 figures; Supplementary Information: 13 pages, 12 figures
Nonlinear Mode Coupling in Silicon Nitride Membrane Resonators
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2026-03-10 20:00 EDT
Soumya Kanti Das, Nishta Arora, Hridhay A S, Akshay Naik, Chandan Samanta
Nonlinear interactions between vibrational modes play a crucial role in understanding the dynamical response of nanomechanical resonators. Here, we report the experimental observation and theoretical modeling of nonlinear mode coupling in a high-stress square silicon nitride membrane resonator. We quantify frequency shifts of the fundamental mode arising from tension-mediated geometric nonlinearity by increasing the amplitude of the fundamental mode and higher-order flexural modes. A quantitative theoretical framework based on Kirchhoff-Love plate theory is developed, which incorporates both intrinsic Duffing nonlinearity and nonlinear intermodal coupling and shows good agreement with experimental measurements for the (1,1)-(2,1) and (1,1)-(2,2) mode pairs. We further compute the nonlinear coupling matrix across mode families, revealing the role of mode symmetry and spatial overlap in governing intermodal interactions. These results establish nonlinear mode coupling as a controllable resource for multimode frequency tuning and mechanical transduction.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Applied Physics (physics.app-ph), Optics (physics.optics)
Total 18 pages, includes Supplementary Information
The quantum square-well fluid: a thermodynamic geometric view
New Submission | Statistical Mechanics (cond-mat.stat-mech) | 2026-03-10 20:00 EDT
J. L. López-Picón, L. F. Escamilla-Herrera, Alejandro Gil-Villegas, José Torres-Arenas
We investigate several aspects of the thermodynamic geometry for a quantum fluid with square-well interactions using a third-order perturbation theory framework based on the path-integral-necklace analogy. A comparison is made between the thermodynamic and geometric properties of the quantum fluid and its classical counterpart for the interaction ranges $ \lambda ^{\ast}= 1.3$ , 1.5, and 1.7. In particular, we analyze the scalar curvature behavior, criticality, and the corresponding Widom lines derived from curvature and several thermodynamic response functions. Quantum effects are shown to smooth supercritical anomalies of the scalar curvature and to shift its extrema for short-range interactions, while leaving the critical exponents of both the curvature and its heat capacity consistent with mean-field predictions. Widom lines associated with temperature-dependent response functions and with the curvature scalar exhibit pronounced classical-quantum differences for short interaction ranges; in contrast, those derived from the isothermal compressibility exhibit only minor variations. Overall, these results highlight the sensitivity of geometric information of thermodynamic systems due to quantum effects and the crucial role of the interaction range in shaping supercritical thermodynamic behavior.
Statistical Mechanics (cond-mat.stat-mech), Quantum Gases (cond-mat.quant-gas)
8 pages, 8 figures
Fermi-pressure-assisted cavity superradiance in a mesoscopic Fermi gas
New Submission | Quantum Gases (cond-mat.quant-gas) | 2026-03-10 20:00 EDT
Francesca Orsi, Ekaterina Fedotova, Rohit Prasad Bhatt, Mae Eichenberger, Léa Dubois, Jean-Philippe Brantut
We study the superradiant phase transition of a mesoscopic Fermi gas comprising between a few tens and a few thousand $ ^6$ Li atoms in a high-finesse cavity across a wide range of densities. We observe a non-monotonic variation of the superradiant threshold as a function of density, with a minimum reached when the Fermi and recoil wavevectors are comparable. The minimum corresponds to a crossover between Fermi pressure-assisted ordering and Pauli blocking of photon scattering, in good agreement with theory. This interpretation is confirmed by a study of the atom-number dependence of the ordering threshold and photon number scaling. Lastly, we demonstrate the operation of our mesoscopic system in a regime where light-induced forces are opposite for the two spin components, leading to an ordered phase with a spin-density-wave character. Our system opens the perspective of studying few-fermion systems with strong and coherent light-matter coupling.
Quantum Gases (cond-mat.quant-gas), Atomic Physics (physics.atom-ph), Quantum Physics (quant-ph)
Understanding thermal and quantum fluctuations in extended Kitaev-Yao-Lee spin-orbital model
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2026-03-10 20:00 EDT
Building upon the spin-1/2 Kitaev model on a honeycomb lattice, the Yao-Lee spin-orbital model provides exactly solvable quantum spin liquids with potentially better stability against perturbations due to the additional degree of freedom. Recently, the microscopic mechanism underlying the Yao-Lee interaction in honeycomb materials has been uncovered, leading to an extended Kitaev-Yao-Lee spin-orbital model when the celebrated Kugel-Khomskii interaction is included. Numerical studies of this model have identified various disordered phases, including a broad region of the nematic phase that is reminiscent of a spin-orbital liquid. Here, we investigate the origin and stability of this nematic phase via thermal and quantum fluctuations using classical Monte Carlo simulations and a generalized spin wave theory appropriate for the spin-orbital model. We demonstrate that the additional spin-orbital degree of freedom gives rise to strong thermal and quantum fluctuations in spin-orbital models, providing insight into the emergence of disordered phases.
Strongly Correlated Electrons (cond-mat.str-el)
8 pages, 4 figures