CMP Journal 2026-03-16
Statistics
Nature: 2
Nature Nanotechnology: 1
Nature Physics: 2
arXiv: 77
Nature
Direct conversion from alkenes to alkynes
Original Paper | Synthetic chemistry methodology | 2026-03-15 20:00 EDT
Junhong Meng, Yiqi Liang, Ruilin Xu, Zengrui Cheng, Yilei Huang, Hongwei Shi, Yichi Chen, Xi Wang, Jialiang Wei, Teng Wang, Binzhi Zhao, Ning Jiao
Alkynes are widely used as feedstock chemicals and functional groups in organic chemistry1,2. However, while the hydrogenation from an alkyne to an alkene is well established, typical methods for the reverse reaction - conversion of an alkene to an alkyne, are based on elimination chemistry reported in the 1860s3 and use forcing conditions (strong base or high temperatures)4-6. This precludes more general application on functional molecules. Here we report a recyclable selenanthrene reagent that mediates alkenes desaturation to alkynes under mild conditions. This method shows broad compatibility with both classical leaving groups and sensitive functional groups, enabling application late-stage in the efficient synthesis of complex alkynes. Moreover, this platform enables Z/E alkenes configuration inversion or sorting that are inaccessible with existing methods, highlighting its potential for diverse downstream derivatizations.
Synthetic chemistry methodology, Stereochemistry
Insulin resistance prediction from wearables and routine blood biomarkers
Original Paper | Machine learning | 2026-03-15 20:00 EDT
Ahmed A. Metwally, A. Ali Heydari, Daniel McDuff, Alexandru Solot, Zeinab Esmaeilpour, Anthony Z. Faranesh, Menglian Zhou, Girish Narayanswamy, Maxwell A. Xu, Xin Liu, Yuzhe Yang, David B. Savage, Mark Malhotra, Conor Heneghan, Shwetak Patel, Cathy Speed, Javier L. Prieto
Insulin resistance (IR), a primary precursor to type 2 diabetes, is characterized by impaired insulin action in tissues1. However, diagnostic methods remain expensive and inaccessible, which hinders early intervention2,3. Here we present the WEAR-ME study, a large, remotely conducted study of IR (n = 1,165 participants; median body mass index (BMI) = 28 kg m-2, median age = 45 years, median haemoglobin A1c (HbA1c) = 5.4%) that uses time-series data from wearable devices and routine blood biomarkers to train deep neural networks against a ground-truth measure of IR (homeostatic model assessment of IR; HOMA-IR). Using a HOMA-IR cut-off of 2.9, our multimodal model achieved robust performance (area under the receiver operating characteristic curve (AUROC) = 0.80, sensitivity = 76%, specificity = 84%) with data from wearable devices, together with demographic and routine blood biomarker data. To enhance the use of time-series data from wearables, we fine-tuned a wearable foundation model (WFM) pretrained on 40 million hours of sensor data. In an independent validation cohort (n = 72), a model integrating WFM-derived representations with demographic data surpassed a demographics-only baseline (AUROC = 0.75 versus 0.66). Moreover, adding WFM-derived representations to a model with demographics, fasting glucose and a lipid panel substantially improved performance, compared with an identical model without data from wearables (AUROC = 0.88 versus 0.76). We integrate IR prediction into a large language model to contextualize the results and facilitate personalized recommendations. This work establishes a scalable, accessible framework for the early detection of metabolic risk, which could enable timely lifestyle interventions to prevent progression to type 2 diabetes.
Machine learning, Pre-diabetes
Nature Nanotechnology
Hybrid perovskite-nanograting photonic architecture enables supersolidity at room temperature
Original Paper | Bose-Einstein condensates | 2026-03-15 20:00 EDT
Yilin Meng, Wei Li, Kai Peng, Chaoyang Ti, Jianchen Dang, Xiaolong Wu, Xu Han, Wei Bao
The supersolid phase is a self-organized state of matter that simultaneously exhibits the crystalline order of a solid and the frictionless flow of a superfluid. Its formation requires the simultaneous breaking of phase and translational symmetries–a stringent condition that makes experimental observation challenging. Here we show that it is possible to achieve a room-temperature supersolid phase by integrating single-crystal halide perovskites with an exciton-polariton nanograting. This architecture supports a hybrid polaritonic bound-state-in-continuum state with a large bandgap (18.2 meV) and two side modes. As the pumping intensity increases, optical parametric oscillation drives the system from a bound-state-in-continuum polariton condensate into the two side modes, forming a self-organized supersolid phase characterized by a striped one-dimensional lattice spanning the condensate. Crucially, single-shot real-space imaging shows stochastic phase selection of the stripe pattern, evidenced by strong suppression of the density modulation on multishot averaging. The observation of supersolidity is further supported by long-range spatiotemporal coherence measured interferometrically and by a non-rigid supersolid lattice. The realization of supersolidity at room temperature in a polaritonic nanograting platform can be useful to control exotic quantum orders and for exploring spontaneous symmetry breaking, quantum coherence and collective excitations in driven quantum materials.
Bose-Einstein condensates, Optical materials and structures, Polaritons
Nature Physics
A bucket-brigade quantum random access memory
Original Paper | Physics | 2026-03-15 20:00 EDT
Fanhao Shen, Yujie Ji, Debin Xiang, Yanzhe Wang, Ke Wang, Chuanyu Zhang, Aosai Zhang, Yiren Zou, Yu Gao, Zhengyi Cui, Gongyu Liu, Jianan Yang, Yihang Han, Jinfeng Deng, Anbang Wang, Zhihong Zhang, Hekang Li, Qiujiang Guo, Pengfei Zhang, Chao Song, Liqiang Lu, Zhen Wang, Jianwei Yin
Quantum random access memory (QRAM) enables efficient access to classical data for quantum computers and is a prerequisite for many quantum algorithms in achieving quantum speed-up. Despite various proposals, there have not been many experimental realizations of QRAM. Here we use a superconducting quantum processor to implement a circuit-based bucket-brigade QRAM, which uses a binary tree of quantum routers to enable efficient addressing of the stored information. To facilitate the experimental implementation, we introduce an efficient gate decomposition scheme for quantum routers, which effectively reduces the depth of the QRAM circuit compared with the conventional controlled-SWAP implementation. We further propose an error mitigation method to improve the query fidelity of the QRAM. With these techniques, we are able to experimentally implement the QRAM architectures for addressing four and eight classical bits, achieving query fidelities up to 0.809 ± 0.025 and 0.604 ± 0.005, respectively. Additionally, we study the error propagation mechanism and the scalability of our QRAM implementation, which provides experimental evidence for the noise resilience of the bucket-brigade architecture. Our results highlight the potential of superconducting quantum processors for realizing a scalable QRAM architecture.
Physics, Quantum physics
Angular interplay of nematicity, superconductivity and strange metallicity in magic-angle twisted trilayer graphene
Original Paper | Electronic properties and materials | 2026-03-15 20:00 EDT
Naiyuan J. Zhang, Pavel A. Nosov, Ophelia Evelyn Sommer, Yibang Wang, Kenji Watanabe, Takashi Taniguchi, Eslam Khalaf, J.I.A. Li
Superconductivity in strongly correlated electron systems often exhibits broken rotational symmetry. However, transport anisotropy is typically already present in the metallic phase above the superconducting transition, raising the question of whether the rotation symmetry breaking in the superconducting state is intrinsic to the order parameter or inherited from an anisotropic normal state. Here we demonstrate that electronic nematicity–which is driven by Coulomb-mediated rotational symmetry breaking–serves as a crucial link to understanding the relationship between superconductivity and strange metallicity. We identify an angular interplay among nematicity, superconductivity and strange metallicity in magic-angle twisted trilayer graphene through angle-resolved transport measurement. Specifically, the preferred superconducting transport direction aligns with the principal axis of the metallic phase that exhibits the maximum resistivity, whereas the strange metal behaviour is locked to the principal axis of the metallic phase with the lowest resistivity. These results place strong constraints on the symmetry of the superconducting order parameter, revealing a pathway for probing the microscopic mechanisms that govern superconductivity in strongly interacting two-dimensional systems.
Electronic properties and materials, Superconducting properties and materials
arXiv
Excitonic Quantum Anomalous Hall Effect in Collinear Magnets Without Spin-Orbit Coupling
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2026-03-16 20:00 EDT
Xingxing Liu, ChaoYang Tan, Peng-Jie Guo, Zhong-Yi Lu, Zheng-Xin Liu
Spin-orbit coupling (SOC) is thought to be necessary in realizing quantum anomalous Hall (QAH) insulators in magnetic materials. In this Letter, we propose an exciton-condensation mechanism to realize QAH effect in collinear magnets with negligible spin-orbit coupling. This mechanism is realized by two steps: first prepare a spin-splitting nodal-ring band structure, and then gap out the nodal-ring via triplet exciton condensation. A nonzero Chern number can be obtained if the in-plane spin texture resulting from the triplet exciton condensation is noncollinear in momentum space. We show that the electron-phonon coupling can switch the spin texture from a colinear pattern to a noncolinear one and plays an essential role in realizing QAH effect. The above mechanism is not only suitable for ferrogmagnets but also applicable for altermagnets. Finally, through first-principles calculations we propose the bilayer material V2SeTeO to be a promising candidate of excitonic QAH insulator.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Strongly Correlated Electrons (cond-mat.str-el)
The Fisher Paradox: Dissipation Interference in Information-Regularized Gradient Flows
New Submission | Statistical Mechanics (cond-mat.stat-mech) | 2026-03-16 20:00 EDT
Michael Farmer, Abhinav Kochar, Yugyung Lee
We show that Fisher-regularized Wasserstein gradient flows exhibit a previously unrecognized interference mechanism in their dissipation identity: a cross-dissipation term whose sign becomes positive when the state width falls below a critical scale. In this regime the geometric Fisher channel transiently opposes descent of the baseline free-energy functional, producing what we term the Fisher Paradox. Restricting the flow to the Gaussian manifold yields an exact Riccati-type variance equation with a closed-form trajectory, exposing three dynamical regimes separated by two critical scales: sigma = 1 (cross-dissipation sign flip) and sigma = sqrt(epsilon) (Fisher takeover). The variance potential V(u) = u^2 - 2u - epsilon ln(u) contains a logarithmic centrifugal barrier that shifts the equilibrium attractor by Delta sigma approx epsilon/4. The interference persists for a duration t_cross ~ D_KL, linking the dissipation delay directly to the initial information distance. Finite-difference simulations on a 512-point grid confirm all analytical predictions to within 5.21 x 10^-4 mean relative error. Numerical experiments with bimodal and Laplace initial conditions confirm the effect persists beyond Gaussian closure, with direct implications for information-geometric dissipative dynamics.
Statistical Mechanics (cond-mat.stat-mech), Information Theory (cs.IT), Probability (math.PR)
8 pages, 7 figures, 2 tables
Interaction-Driven Ferrimagnetic Stripes in the Extended Hubbard Model
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2026-03-16 20:00 EDT
Chunhan Feng, Miguel A. Morales, Shiwei Zhang
Long-range interactions can qualitatively reorganize correlated-electron ground states. In the square-lattice Hubbard model, on-site repulsion produces antiferromagnetic spin and charge stripes upon doping. We show that including a nearest-neighbor repulsion $ V$ can dramatically alter this behavior. Using auxiliary-field quantum Monte Carlo and density matrix renormalization group methods, we find that, above a critical ratio $ V/U$ ($ \sim 0.25$ ), the system develops a modulated ferrimagnetic order intertwined with checkerboard charge-density-wave. Inside the ferrimagnetic domains, spin density alternates between positive (or negative) and nearly zero values. When the total spin is fixed to zero, positive and negative domains alternate in space; when spins are unconstrained, a ferrimagnetic state emerges with finite magnetization. Including a next-nearest-neighbor hopping $ t’$ changes the modulation wavelength but leaves the order robust. Our results demonstrate that even short-range nonlocal interactions can stabilize qualitatively new magnetic textures, with implications for cuprate materials and programmable quantum simulators.
Strongly Correlated Electrons (cond-mat.str-el), Quantum Gases (cond-mat.quant-gas)
Fracton Spin Liquid and Exotic Frustrated Phases in Ising-like Octochlore Magnets
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2026-03-16 20:00 EDT
Matthew Stern, Michael D. Burke, Michel J. P. Gingras, Judit Romhányi, Kristian Tyn Kai Chung
For nearly three decades frustrated magnetism research in three dimensions (3D) has centered on the pyrochlore geometry of corner-sharing tetrahedra and the classical spin liquid (CSL) known as spin ice. In this work, we propose that a lattice of corner-sharing octahedra – appropriately dubbed the octochlore lattice – may provide a next-generation platform for the study of 3D frustrated magnetism, with realizations in anti-perovskite and certain potassium-fluoride compounds. We study the phase diagram of Ising spins on the octochlore lattice with first- and second-neighbor interactions within each octahedron, which displays a rich variety of frustrated phases, including CSLs with extensive ground state degeneracies, as well as phases with subextensive ground state degeneracies intermediate between spin liquids and long-range order. In addition to a spin ice CSL, we identify a novel fracton CSL with excitations restricted to move along one-dimensional (1D) lines, which is a classical U(1) analog of the celebrated X-cube model, a paradigmatic realization of fracton topological order. The existence of these two CSLs is rationalized as condensation of 1D ferro-spinons bound states from a parent phase with subextensive degeneracy due to frustration of ferromagnetically polarized chains. We also find a spin nematic phase exhibiting two-stage dimensional reduction from cubic to tetragonal (uniaxial) and finally orthorhombic (biaxial) symmetry, driven by strong fluctuations arising from deconfined 1D antiferro-spinons. This work paves the way for the potential realization of fracton CSLs and the exploration of other exotic frustrated states in real materials.
Strongly Correlated Electrons (cond-mat.str-el)
28 pages, 13 figures, 3 tables
Pruning-induced phases in fully-connected neural networks: the eumentia, the dementia, and the amentia
New Submission | Disordered Systems and Neural Networks (cond-mat.dis-nn) | 2026-03-16 20:00 EDT
Haining Pan, Nakul Aggarwal, J. H. Pixley
Modern neural networks are heavily overparameterized, and pruning, which removes redundant neurons or connections, has emerged as a key approach to compressing them without sacrificing performance. However, while practical pruning methods are well developed, whether pruning induces sharp phase transitions in the neural networks and, if so, to what universality class they belong, remain open questions. To address this, we study fully-connected neural networks trained on MNIST, independently varying the dropout (i.e., removing neurons) rate at both the training and evaluation stages to map the phase diagram. We identify three distinct phases: eumentia (the network learns), dementia (the network has forgotten), and amentia (the network cannot learn), sharply distinguished by the power-law scaling of the cross-entropy loss with the training dataset size. {In the eumentia phase, the algebraic decay of the loss, as documented in the machine learning literature as neural scaling laws, is from the perspective of statistical mechanics the hallmark of quasi-long-range order.} We demonstrate that the transition between the eumentia and dementia phases is accompanied by scale invariance, with a diverging length scale that exhibits hallmarks of a Berezinskii-Kosterlitz-Thouless-like transition; the phase structure is robust across different network widths and depths. Our results establish that dropout-induced pruning provides a concrete setting in which neural network behavior can be understood through the lens of statistical mechanics.
Disordered Systems and Neural Networks (cond-mat.dis-nn), Machine Learning (cs.LG), Neural and Evolutionary Computing (cs.NE)
14 pages, 15 figures
3D to 2D localization in supertwisted multilayers
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2026-03-16 20:00 EDT
Jeane Siriviboon, Pavel Volkov
We study the electronic properties of multilayer “spirals” of two-dimensional materials with continuously increasing twist angle. The electronic states are shown to undergo a universal 3D-to-2D transition on increasing the in-plane momentum $ {\bf k}\parallel$ away from the $ \Gamma$ point. The states with $ k\parallel>k_c$ are localized along the z axis due to mismatch between electronic dispersions of the twisted layers, whereas those with $ k_\parallel<k_c$ are extended. We support our results by mapping of the system on the Aubry-André model and deduce the experimental signatures of 3D to 2D localization in transport experiments.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
Parity and time-reversal invariant Ising spin ordering
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2026-03-16 20:00 EDT
Yue Yu, Jin Matsuda, Hikaru Watanabe, Ryotaro Arita, Daniel F. Agterberg
The interplay of antiferromagnetic order, momentum-dependent Bloch spin-splitting, time-reversal (T), and parity (P) symmetries in non-relativistic systems has emerged as a central theme for spintronics. Two well-known examples are P-preserving and T-violating altermagnets and P-violating and T-preserving odd-parity magnets. These both exhibit an Ising, or uniaxial, Bloch spin-splitting. Here we introduce a new class of coplanar AFMs that generate a P and T symmetric, translation-invariant Ising spin order in real space. Naively, such AFMs are not expected to exhibit unusual phenomena. Here we show that the spin-rotational symmetry breaking generated by these AFMs allows: pure non-relativistic longitudinal (or transverse) spin-conductivities, the generation of non-relativistic altermagnetic spin-splittings through circularly polarized light, and the generation of non-relativistic odd-parity spin-splittings through parity symmetry breaking, by, for example, applied electric fields. We identify 16 candidate materials in the Magndata database for which our theory applies and provide effective microscopic models and DFT-based results that highlight the large emergent responses.
Strongly Correlated Electrons (cond-mat.str-el), Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Materials Science (cond-mat.mtrl-sci)
Electronic correlations and dynamical screening with ab initio quantum embedding
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2026-03-16 20:00 EDT
Chia-Nan Yeh, Francesco Petocchi, Alexander Hampel, Philipp Werner, Olivier Parcollet, Antoine Georges, Miguel Morales
First-principles descriptions of correlated quantum materials require a simultaneous treatment of strong local many-body effects and nonlocal dynamical screening. We present an efficient fully self-consistent implementation of $ GW$ +EDMFT that combines nonlocal effects at the $ GW$ level with a non-perturbative treatment of local correlations within extended dynamical mean-field theory (EDMFT), while providing a controlled double-counting prescription. Crucially, self-consistency in both the Green’s function and the dynamically screened interaction is essential to achieve a consistent description of screening processes across energy scales. The efficient computation of this self-consistent solution is enabled here by compressing two-particle correlation functions using interpolative separable density fitting (ISDF). Applying the scheme to the Mott insulator SrMnO$ _3$ and the correlated metal LaNiO$ _3$ , we show that full self-consistency resolves the overscreening inherent to constrained-RPA approaches. By suppressing spurious low-energy screening channels, a Mott-insulating state in quantitative agreement with experiment is obtained for SrMnO$ _3$ . These results establish fully self-consistent $ GW$ +EDMFT as a predictive ab initio framework for strongly correlated quantum materials.
Strongly Correlated Electrons (cond-mat.str-el), Materials Science (cond-mat.mtrl-sci)
6 pages, 4 figures
Zero-field superconducting vortices and Majorana zero modes pinned by magnetic islands in correlated Rashba systems
New Submission | Superconductivity (cond-mat.supr-con) | 2026-03-16 20:00 EDT
Panagiotis Kotetes, Brian M. Andersen
We propose a route for pinning zero-field superconducting vortices in systems which are exchange-coupled to magnetic islands and feature Rashba spin-orbit coupling. We consider islands with sizes which greatly exceed those of the vortex cores and possess out-of-plane magnetic moments. A crucial ingredient of our approach is that it considers superconductors which are governed by magnetic correlations without, however, exhibiting long range magnetic order. The arising total magnetization is inhomogeneous and its gradients generate a nonzero vorticity in the superconducting phase. Vortices become energetically stable due to the energy reduction brought about from the generation of electronic magnetization. Using our developed framework, we make concrete predictions for the emergence of zero-field vortices and Majorana zero modes in superconducting topological insulator surfaces and planar Rashba superconductors. Our theory uncovers a nonstandard path for trapping composite vortex-Majorana excitations in systems which appear to be within experimental reach.
Superconductivity (cond-mat.supr-con), Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
27 pages, 5 figures
Unified theory of orientation averaging in X-ray spectroscopies: understanding polarization dependence in a Cartesian tensor approach
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-03-16 20:00 EDT
Sihan Zhang, Oana Bunău, Marius Retegan, Pieter Glatzel
X-ray absorption spectroscopy (XAS) and resonant inelastic X-ray scattering (RIXS) are powerful probes of electronic structure owing to their chemical and orbital selectivity. For powder samples, however, interpreting RIXS spectral intensities remains challenging as the measured signal is an average over all orientations. Existing theoretical treatments rely largely on spherical-tensor formalisms, which often involve complex derivations and case-specific analyses. Meanwhile, recent advances in quantum-chemistry methods have made the evaluation of transition tensors in Cartesian coordinates both accurate and straightforward. Here, we present a general theoretical framework that translates Cartesian transition tensors into physically meaningful, orientation-averaged intensities for powder samples. The formalism allows predicting angular and polarization dependences \textit{ab initio} for both XAS and RIXS and is extendable to other spectroscopies. The resulting predictions show excellent agreement with RIXS experimental data at the Ce L$ _3$ edge.
Materials Science (cond-mat.mtrl-sci)
Nonequilibrium assembly of Lennard-Jones particles on a sphere
New Submission | Soft Condensed Matter (cond-mat.soft) | 2026-03-16 20:00 EDT
Ivan Yu. Golushko, Olga V. Konevtsova, Daria S. Roshal, Sergei B. Rochal
Studying physical mechanisms and common geometric principles underlying known spherical packings is crucial for rational design of synthetic nanocontainers. Here we model the growth of small spherical shells containing n<72 identical particles that have their own curvature and interact with each other via the Lennard-Jones potential. The shell assembly is assumed to be nonequilibrium and sequential: at each step, a new particle is attached to the most energetically favorable position, after which the system relaxes. Along with well-known structures of the smallest icosahedral viral protein shells, the proposed mechanism generates a wide range of shells exhibiting square-triangular surface order. Most of such shells are the models of synthetic or natural protein complexes that have octahedral or tetrahedral symmetries and perform various functions. We compare the obtained structures with those resulting from the equilibrium assembly and corresponding to global energy minima. Also, we consider the temperature-dependent stochastic assembly and use the double-minimum Lennard-Jones-Gauss potential to mimic anisotropic particle interactions.
Soft Condensed Matter (cond-mat.soft)
28 pages, 5 figures, accepted to the Journal of Chemical Physics B
Breakdown of Avila’s theory in the diamond chain with quasiperiodic disorder
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2026-03-16 20:00 EDT
Manish Kumar, Ivan M. Khaymovich, Auditya Sharma
The mobility edges (MEs) that separate localized, multifractal and ergodic states in energy are a central concept in understanding Anderson localization. In this work we study the effect of several mutually commensurate quasiperiodic frequencies on the mobility-edge formation. We focus on the example of the addition of a constant offset to the quasiperiodic potential of the one-dimensional all-bands-flat diamond chain. We show that this additional offset can transform the anomalous mobility edges (AMEs), i.e. the energies, separating localized and multifractal states, into conventional mobility edges, separating localized from delocalized states. Also this appears to be the first example which shows the failure of Avila’s global theory to analytically predict the ME location. We observe this violation both quantitatively, through the ME location mismatch, and qualitatively, via the formation of multiple MEs, not predicted by the theory.
Strongly Correlated Electrons (cond-mat.str-el), Disordered Systems and Neural Networks (cond-mat.dis-nn), Quantum Physics (quant-ph)
17 pages, 14 Figures, 1 Table
Optimal Experimental Design for Reliable Learning of History-Dependent Constitutive Laws
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-03-16 20:00 EDT
Kaushik Bhattacharya, Lianghao Cao, Andrew Stuart
History-dependent constitutive models serve as macroscopic closures for the aggregated effects of micromechanics. Their parameters are typically learned from experimental data. With a limited experimental budget, eliciting the full range of responses needed to characterize the constitutive relation can be difficult. As a result, the data can be well explained by a range of parameter choices, leading to parameter estimates that are uncertain or unreliable. To address this issue, we propose a Bayesian optimal experimental design framework to quantify, interpret, and maximize the utility of experimental designs for reliable learning of history-dependent constitutive models. In this framework, the design utility is defined as the expected reduction in parametric uncertainty or the expected information gain. This enables in silico design optimization using simulated data and reduces the cost of physical experiments for reliable parameter identification.
We introduce two approximations that make this framework practical for advanced material testing with expensive forward models and high-dimensional data: (i) a Gaussian approximation of the expected information gain, and (ii) a surrogate approximation of the Fisher information matrix. The former enables efficient design optimization and interpretation, while the latter extends this approach to batched design optimization by amortizing the cost of repeated utility evaluations. Our numerical studies of uniaxial tests for viscoelastic solids show that optimized specimen geometries and loading paths yield image and force data that significantly improve parameter identifiability relative to random designs, especially for parameters associated with memory effects.
Materials Science (cond-mat.mtrl-sci), Machine Learning (cs.LG), Numerical Analysis (math.NA), Computational Physics (physics.comp-ph), Computation (stat.CO)
Recent Computational Advances in Dense Suspension Mechanics
New Submission | Soft Condensed Matter (cond-mat.soft) | 2026-03-16 20:00 EDT
Orhun Ayar, Bhargav Sriram Siddani, Ishan Srivastava, Abhinendra Singh
Dense suspensions of particles dispersed in liquids are central to industrial and geophysical processes and serve as model systems for out-of-equilibrium soft matter. At high particle concentrations, they exhibit stress-dependent rheology, including discontinuous shear thickening and shear jamming, arising from frictional contacts. Nonlinear physics arises from the interplay among direct contacts, interfacial chemistry, and fluid-mediated hydrodynamics. The relative importance of these mechanisms depends on particle properties and flow conditions, making predictive modeling inherently multi-scale and, therefore, computationally challenging. Recent advances in computational methods have transformed our ability to simulate the physics of dense suspensions across scales. In this Perspective, we discuss state-of-the-art simulation frameworks that integrate the mechanics of dry granular materials, mediated by contact friction, with suspension hydrodynamics to provide predictive models of dense suspension rheology. We highlight recent computational developments for simulating dense suspensions at varying levels of fidelity, ranging from particle-resolved to continuum models, as well as models that investigate their mesoscale organization during flow. Together, these approaches reveal a hierarchical structure in which microscale constraints give rise to mesoscale frictional networks that ultimately govern macroscopic flow. By synthesizing developments across computational mechanics and soft matter physics, this Perspective highlights emerging directions toward a predictive, multi-scale modeling framework of dense suspensions in realistic geometries and complex flow environments.
Soft Condensed Matter (cond-mat.soft)
14 pages, 6 figures
First-principles study of doping influence on twin formation in Ni-Mn-Ga nonmodulated martensite
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-03-16 20:00 EDT
Petr Šesták, Martin Heczko, Ladislav Straka, Alexei Sozinov, Martin Zelený
We investigate how chemical substitution reshapes the energetics of twin formation in non-modulated (NM) Ni-Mn-Ga martensite. Using density functional theory, we compute generalized planar fault energy (GPFE) curves for the $ (101)[10\bar{1}]$ shear system in stoichiometric Ni$ {2}$ MnGa and in a set of doped supercells containing Cu, Co, Fe, or Zn on different sublattices. The GPFE landscape is used as a microscopic descriptor of twinning behavior: the first barrier reflects intrinsic stacking-fault formation (twin nucleation), whereas subsequent barriers govern twin thickening and boundary motion. We show that the impact of dopants is strongly site dependent. Substitutions Cu$ \rightarrow$ Mn, Cu$ \rightarrow$ Ni, Co$ \rightarrow$ Ni, and Zn$ \rightarrow$ Mn lower the nucleation barrier and generally soften the GPFE profile, indicating more favorable conditions for twin formation and propagation; these cases also correlate with a reduced tetragonality $ c/a$ , which implies a smaller twinning shear and a reduced energetic cost of twin formation. In contrast, Cu$ \rightarrow$ Ga, Co$ \rightarrow$ Mn, Co$ \rightarrow$ Ga, Fe$ \rightarrow$ Ga, and Zn$ \rightarrow$ Ga increase GPFE barriers and hinder twinning, even though such substitutions are often used to enhance martensite stability and raise $ T{m}$ . Fe$ \rightarrow$ Mn leaves barrier heights largely unchanged, while Fe$ \rightarrow$ Ni produces an anomalous GPFE response indicative of unstable twin configurations. Finally, inspired by the nanotwinning characterisation of 10M/14M modulation, we link the depth of the two-layer nanotwin minimum to modulation stability. The substitutions Fe$ \rightarrow$ Mn, Cu$ \rightarrow$ Ni, and Zn$ \rightarrow$ Mn result in a lower energy minimum compared to the structure without the double-layered twin. The other substitutions favor the twin-free NM structure.
Materials Science (cond-mat.mtrl-sci)
26 pages, 6 figures
Structural flexibility dictates reactivity of single-atom catalysts
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-03-16 20:00 EDT
Jakub Planer, Dominik Hrůza, Tadeáš Lesovský, Ayesha Jabeen, Jan Čechal, Zdeněk Jakub
Unravelling the origins of single-atom catalyst reactivity is a central challenge in heterogeneous catalysis research. A key question is whether the activity arises solely from atomic isolation or from distinct structural and electronic configurations of the single atoms. Here, we use precisely defined Fe-N$ _3$ and Fe-N$ _4$ model catalyst sites synthesized on an inert support to quantify the effect of coordination geometry on chemical reactivity. Both the Fe-N$ _3$ and Fe-N$ _4$ models have the same electronic configuration (high-spin Fe$ ^{2+}$ with S=2), and even their d-orbital occupancies and positions with respect to Fermi level are almost identical. Despite this electronic similarity, the adsorption energy of CO differs by more than 0.6 eV between the Fe-N$ _3$ and Fe-N$ _4$ sites, as indicated by density functional theory computations and confirmed by atomically-resolved scanning tunneling microscopy experiments. We trace this reactivity difference to the structural flexibility of the Fe-N$ _3$ sites, which allows strengthening of the Fe 3d$ _{xz/yz}$ -CO 2$ {\pi}$ \ast back-bonding by lifting the Fe atom from the -N$ _3$ plane. These results demonstrate that coordination geometry plays a crucial role in defining the reactivity of single-atom catalysts, and that such effects cannot be predicted by analysis of the sites’ electronic structures alone.
Materials Science (cond-mat.mtrl-sci)
Ambient-pressure 151-K superconductivity in HgBa2Ca2Cu3O8+δ via pressure quench
New Submission | Superconductivity (cond-mat.supr-con) | 2026-03-16 20:00 EDT
Liangzi Deng (1), Thacien Habamahoro (1), Artin Safezoddeh (1), Bishnu Karki (1), Sudaice Kazibwe (1), Daniel J. Schulze (1), Zheng Wu (1), Matthew Julian (2), Rohit P. Prasankumar (2), Hua Zhou (3), Jesse S. Smith (3), Pavan R. Hosur (1), Ching-Wu Chu (1) ((1) Department of Physics and Texas Center for Superconductivity at the University of Houston (TcSUH), Houston, Texas, USA, (2) Enterprise Science Fund, Intellectual Ventures, Bellevue, Washington, USA, (3) X-ray Science Division, Argonne National Laboratory, Lemont, Illinois, USA)
Superconductivity has been a vigorously researched topic since its discovery in 1911. Raising the superconducting transition temperature (Tc) has been the main driving force behind such long-sustained efforts due to its potential for impacting humanity and the fundamental knowledge gained from understanding this macroscopic coherent quantum state at high temperatures. The successful development of high-Tc superconductivity will make possible extraordinarily efficient generation, delivery, and utilization of energy, and could also enable the development of controlled fusion while impacting other burgeoning fields like quantum computation and quantum electronics. However, progress has been hindered by a longstanding plateau in the record ambient-pressure Tc, unchanged since 1993. Subsequent significant advancements in Tc have been achieved only under high pressures, preventing the realization of superconductivity’s full potential. To directly address this challenge, we developed a pressure-quench protocol (PQP) to stabilize pressure-induced/-enhanced superconducting states at ambient pressure. Here we achieve a record ambient-pressure Tc of 151 K in the cuprate HgBa2Ca2Cu3O8+{\delta} via PQP. The experimental results are further supported by synchrotron X-ray diffraction measurements and phonon and electronic structure calculations. This breakthrough opens new avenues for stabilizing and exploring ambient-pressure high-Tc superconducting states and other quantum states that have been previously only accessible under pressure, paving the way for deeper understanding and practical applications of high-Tc superconductivity and beyond.
Superconductivity (cond-mat.supr-con)
27 pages, 4 manuscript figures, 8 supporting information figures
Proceedings of the National Academy of Sciences USA 123, e2536178123 (2026)
Advanced architectures for coupling III-V nanowires to photonic integrated circuitry
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2026-03-16 20:00 EDT
Edith Yeung, Kataryna Sorensen, David B. Northeast, Maziyar Milanizadeh, Philip J. Poole, Robin L. Williams, Dan Dalacu
This work implements a hybrid device based on a semiconductor quantum dot embedded within a nanowire to bridge a non-continuous curved waveguide structure. The geometry takes advantage of evanescent coupling between the photonic structures to recover single photons emitted from both outputs of the device. Auto- and cross-correlation measurements were performed on different output facets of the device. We demonstrate single-photon emission from both ends of the nanowire for both neutral, X and XX, and charged X-, excitonic complexes. We further demonstrate the cascaded XX-X emission by collecting each complex from a different facet. This work lays the foundation for on-chip architectures which utilize multi-directional integration of quantum emitters.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
Simulation of shear strain at arbitrary angles as a probe of packing instabilities
New Submission | Soft Condensed Matter (cond-mat.soft) | 2026-03-16 20:00 EDT
Chloe W. Lindeman, Sidney R. Nagel
Disordered solids distort and fail as particle contacts become unstable and rearrange under sufficiently large shear strains. Such instabilities can occur at different locations and, because of their proximity, can interact with one another. We develop a tool for simulations with periodic boundary conditions that allows strains to be applied at a continuously variable angle, $ \theta$ . We show that instabilities can persist over a broad angular ranges of applied shear to form instability lines in phase space. By applying strain at different $ \theta$ , we examine the correlations between the instabilities encountered at different angles and different positions in the sample. We find instabilities that pass through one another, others that change continuously as the angle is varied, and yet others that end by smoothly decreasing their magnitudes to zero as the instability fades away. Examining hysterons, i.e., instabilities that undo themselves upon reversing the direction of shear, we find that as $ \theta$ is varied towards the point where the instability disappears, the separation between the forward and backward instabilities shrinks to zero so as to produce an enhanced number of very small hysterons.
Soft Condensed Matter (cond-mat.soft), Materials Science (cond-mat.mtrl-sci), Statistical Mechanics (cond-mat.stat-mech)
5 pages, 3 figures (and one appendix)
Annihilation of Dirac points and its topological obstruction in a photonic Kagome lattice
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2026-03-16 20:00 EDT
Zhaoyang Zhang, Matthieu Finck, Changchang Li, Shun Liang, Jerome Dubois, Yumin Tian, Jiahao Wen, Yanpeng Zhang, Guillaume Malpuech, Dmitry Solnyshkov
Dirac points (DPs) are topological singularities that determine the extraordinary properties of two-dimensional materials. They are generally classified by discrete topological invariants, which determine the possibility of DPs’ annihilation upon their collision. Here, we study the behaviors of DPs within a photonic Kagome lattice created in atomic vapor. With optically engineering the potential difference among three sites constituting the Kagome unit cell while preserving time-reversal symmetry and the stability of an isolated DP, the DPs move in reciprocal space. By employing conical diffraction to measure their position and the topological invariant (Euler number), we demonstrate an obstruction to DPs’ annihilation during collision and a transition to a case where the Euler number changes and annihilation occurs. Such topological transition is induced by a non-Abelian frame rotation of the eigenstates around the Brillouin zone torus. The associated conversion of the DP quaternionic charges during their motion explains the change of Euler number.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Optics (physics.optics)
Real-time detection of critical slowing-down at the superconducting phase transition
New Submission | Superconductivity (cond-mat.supr-con) | 2026-03-16 20:00 EDT
Guillermo Nava Antonio, Théo Courtois, Corentin Pfaff, KM Shivangi Shukla, Asle Sudbø, Stéphane Mangin, Thomas Hauet, Chiara Ciccarelli
We employ optical pump-THz probe spectroscopy to chart the ultrafast superconductivity suppression in NbN over a broad range of excitation fluences. Our measurements uncover a pronounced lengthening of the superconductivity quenching time when the absorbed optical energy is close to the condensation energy of the superconductor, which constitutes a non-equilibrium analog of critical slowing-down on a timescale comparable to that of superconducting fluctuations. Time-dependent Ginzburg-Landau simulations reproduce this behavior and ascribe it to the flattening of the free energy landscape at the dynamical phase transition boundary. Our findings represent a direct observation in real time of slowed-down superconductivity dynamics in proximity to a critical point and open a pathway for investigating out-of-equilibrium critical phenomena with time-resolved THz spectroscopy.
Superconductivity (cond-mat.supr-con)
9 pages, 4 figures
Theory of hybrid defects, with coupled orientational order parameters, on flat and curved surfaces
New Submission | Soft Condensed Matter (cond-mat.soft) | 2026-03-16 20:00 EDT
Lincoln Paik, Jonathan V. Selinger
Many physical systems involve two types of orientational order, which are coupled together. For example, ferroelectric nematic liquid crystals have coupled polar and nematic order, and tilted hexatic phases have coupled polar and hexatic order. In these systems, defect structures can be quite complex. Here, we investigate phases with two types of two-dimensional orientational order, $ m$ -atic and $ n$ -atic, where $ m$ and $ n$ are two distinct integers. We simulate these phases in a flat disk with strong radial anchoring, and on a spherical surface, because both of these geometries require the presence of defects. If the coupling between the two types of order is weak, then the defects are connected by a network of diffuse walls, and the system forms a stable domain structure. As the coupling increases, the domain walls become sharper and shorter. For very strong coupling, the higher-order defects merge into the lower-order defects, forming stretched defect cores.
Soft Condensed Matter (cond-mat.soft)
Impact of currents on non-equilibrium coexistence in chemically driven mixtures
New Submission | Statistical Mechanics (cond-mat.stat-mech) | 2026-03-16 20:00 EDT
E. Meyberg, J.F. Robinson, T. Speck
Virtually every biological function emerges through the organization of molecules in time and space. Consequently, a major challenge in statistical physics is to uncover the universal principles governing macromolecular self-organization within the crowded, non-equilibrium environment of the cell. Here, we investigate a class of models where molecules maintain a conserved total concentration but can switch “identities”, thereby modulating their intermolecular interactions. By enforcing thermodynamic consistency via the local detailed balance condition, we derive the steady-state criteria determining coexisting concentrations in a binary mixture. For non-constant transition rates and using a sharp-interface approximation, we obtain jump conditions that generalize Gibbs’ coexistence criteria of equal pressure and chemical potential. We demonstrate that these jumps balance the chemical potential differences of individual species against their currents, which are confined to the interfacial region.
Statistical Mechanics (cond-mat.stat-mech)
Crystallizing electrons with artificially patterned lattices
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2026-03-16 20:00 EDT
Trevor G. Stanfill, Daniel N. Shanks, Michael R. Koehler, David G. Mandrus, Takashi Taniguchi, Kenji Watanabe, Vasili Perebeinos, Brian J. LeRoy, John R. Schaibley
Wigner crystals are typically confined to ultralow temperatures where thermal motion is frozen out. Moiré superlattices in twisted two-dimensional materials have extended their stability to higher temperatures and densities, but rely on delicate stacking that fixes the lattice geometry and limits tunability. Here we demonstrate a lithographic approach that bypasses these constraints. Using high-resolution nanofabrication, we pattern a nanoscale triangular lattice directly into a graphene gate integrated with a monolayer MoSe2 semiconductor. This engineered potential landscape localizes electrons into generalized Wigner crystal states that persist up to 15 K and densities of 2X10^12 cm-2, representing an order of magnitude improvement over pristine monolayer MoSe2. Gate-voltage control allows real-time switching between stable and unstable crystalline states, with the latter exhibiting stochastic telegraph noise from nearly degenerate configurations. This work demonstrates the ability of this platform to transform Wigner crystals from fragile, static phases into reconfigurable quantum matter.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Strongly Correlated Electrons (cond-mat.str-el)
Xe gas bubble re-solution in U-10Mo nuclear fuel
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-03-16 20:00 EDT
ATM Jahid Hasan, Linu Malakkal, Mathew Swisher, Benjamin Beeler
The U.S. High-Performance Research Reactor program aims to convert high-power research reactors from highly enriched uranium to low-enriched uranium using a monolithic U-10Mo fuel design. A critical aspect of U-10Mo fuel performance is fission gas bubble behavior. These bubbles grow by trapping gas atoms (particularly Xe) but can disintegrate via irradiation-induced “re-solution”. The interplay between the trapping and re-solution rates governs bubble evolution, impacting fuel performance and safety. In this study, binary collision approximation (BCA) and molecular dynamics (MD) simulations were performed to quantify the Xe gas bubble re-solution rate in U-10Mo fuel. First, the energy loss of fission fragments (FFs) through electronic and nuclear stopping was evaluated. The effect of electronic stopping on re-solution was then analyzed using MD simulations coupled with the two-temperature model. Results indicate that thermal spikes generated by electronic stopping do not contribute to gas bubble re-solution in U-10Mo. To quantify re-solution due to nuclear stopping, BCA simulations of FFs in U-10Mo were performed to obtain the average FF incidence probability, energy, and angle as a function of distance from the FF origin. Subsequent simulations assessed FF–bubble interactions in U-10Mo for different FF energies and bubble radii. From these analyses, an overall re-solution rate $ b$ was calculated at equilibrium bubble pressure per unit fission rate density, yielding values ranging from $ 4.4 \times 10^{-26}$ m$ ^3$ /fission for the largest bubbles to $ 8.8 \times 10^{-25}$ m$ ^3$ /fission for the smallest. The effect of bubble pressure on the re-solution rate was also evaluated, revealing an inverse relationship between the two.
Materials Science (cond-mat.mtrl-sci)
Ferroaxial magnets: time-reversal-even mirror symmetry violation from spin order
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-03-16 20:00 EDT
Hikaru Watanabe, Yue Yu, Jin Matsuda, Daniel F. Agterberg, Ryotaro Arita
We investigate ferroaxial magnets, a new class of spin-order-driven multiferroic magnets in which magnetic ordering induces mirror-symmetry breaking while preserving both time-reversal and spatial-inversion symmetries. These systems exhibit a ferromagnet-like axial anisotropy that allows optical control of the ferroaxial polarization, while their macroscopic time-reversal symmetry makes them attractive for antiferromagnetic spintronics. Using spin crystallographic group analysis, we identify the candidate materials and the nonrelativistic ferroaxial nature stemming from the strong exchange splitting of magnets. Furthermore, a symmetry-based identification shows magnetic materials that host ferroaxial order and metallic conductivity, realizing the ferroaxial metal state that undergoes a ferroaxial phase transition while remaining metallic. As a direct probe for the ferroaxial metal, we propose a third-order nonlinear Hall effect originating from the transverse coupling between the electric field and Berry curvature dipole mediated by the ferroaxial anisotropy. Our results establish ferroaxial magnets as a platform for nonrelativistic multiferroicity and spintronic applications.
Materials Science (cond-mat.mtrl-sci)
8pages, 4 figures
Polymer-Residue Accessibility Shapes Sequence Dependence of Critical Temperatures for Phase Separation
New Submission | Soft Condensed Matter (cond-mat.soft) | 2026-03-16 20:00 EDT
J. Pedro de Souza, Benjamin Sorkin, Amala Akkiraju, Athanassios Z. Panagiotopoulos, Howard A. Stone
Biological polymers, such as intrinsically disordered proteins, play a central role in cellular biology, including mediating phase separation and controlling activity of biological condensates. The physical properties and functions of biopolymers are determined by their residue sequence. Recently, significant computational and theoretical efforts have been devoted to characterizing the combinatorially complex sequence dependence of biopolymer phase diagrams. Here, we quantitatively show that monomer accessibility is central to determining the strength of pair interactions. We formulate an analytical perturbative approach, phenomenologically precluding two polymers’ centers of mass from overlapping within a correlation hole. This theory yields the correction to the strength of mean-field interactions in terms of a residue-accessibility parameter (RAP), which accounts for the limited availability of inner monomers to interactions. Despite the simplicity of the approach, RAP rationalizes the variations in critical temperatures found in extensive Monte-Carlo simulations for thousands of two-letter polymer solutions of varying length and sequence. RAP may thus be effective for deciphering the polymer-sequence dependence of phase diagrams given any polymer length, set of monomer types, and polymer mixtures.
Soft Condensed Matter (cond-mat.soft), Statistical Mechanics (cond-mat.stat-mech), Biological Physics (physics.bio-ph), Chemical Physics (physics.chem-ph)
10 pages, 4 figures
Accelerating materials discovery using foundation model based In-context active learning
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-03-16 20:00 EDT
Jeffrey Hu, Rongzhi Dong, Ying Feng, Ming Hu, Jianjun Hu
Active learning (AL) has emerged as a powerful paradigm for accelerating materials discovery by iteratively steering experiments toward the most promising candidates, reducing costly synthesis-and-characterization cycles. However, current AL relies predominantly on Gaussian Process (GP) and Random Forest (RF) surrogates with complementary limitations: GP underfits complex composition–property landscapes due to rigid kernel assumptions, while RF produces unreliable uncertainty estimates in small-data regimes, precisely where most materials datasets reside (with < 500 samples). Here we propose foudaiton model based In-Context Active Learning (ICAL), replacing conventional surrogates with TabPFN, a transformer-based foundation model pre-trained on millions of synthetic tasks to meta-learn a universal prior over tabular data. TabPFN performs principled Bayesian inference in a single forward pass without dataset-specific retraining, delivering well-calibrated predictive uncertainty where GP and RF fail most severely. Benchmarked against GP and RF across 10 materials datasets spanning copper alloy hardness and electrical conductivity, bulk metallic glass-forming ability, and crystal lattice thermal conductivity, TabPFN wins on 8 out of 10 datasets, achieving a mean saving of 52% in extra experiments/evaluations relative to GP and 29.77% relative to RF. Cross-validation analysis confirms that TabPFN’s advantage stems from superior uncertainty calibration,achieving the lowest Negative Log-Likelihood and Area Under the Sparsification Error curve among all surrogates. Our work demonstrates that a pre-trained foundation model can serve as a highly effective surrogate for accelerating active learning-based materials discovery.
Materials Science (cond-mat.mtrl-sci), Machine Learning (cs.LG)
18 pages
Spectroscopic Studies of two-dimensional Superconductivity
New Submission | Superconductivity (cond-mat.supr-con) | 2026-03-16 20:00 EDT
Qiang-Jun Cheng, Xu-Cun Ma, Qi-Kun Xue, Can-Li Song
Two-dimensional superconductivity has become a major frontier in condensed matter physics. It holds the key to the mechanism of high-temperature superconductors and offers an exceptional arena to stabilize emergent quantum states enabled by enhanced electron correlations in reduced dimensionality. These states are frequently characterized by spatial modulations and intertwined with competing orders, calling for studies that combine real-space imaging with local spectroscopy. Scanning tunneling microscopy and spectroscopy meets this need by directly accessing local density of states with lattice-scale resolution. In this review, we summarize recent advances of the study on several representative unconventional superconductors using this technique, focusing on direct characterization of high-temperature superconducting planes, pair-density waves, and topological superconductivity in both artificial heterostructures and intrinsic materials. We conclude by outlining current challenges and future directions motivated by the microscopic insights.
Superconductivity (cond-mat.supr-con)
22 pages,11 figures
Elucidating magnetic structure with optical dopants: erbium-doped Gd$_2$SiO$_5$
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2026-03-16 20:00 EDT
Luke S. Trainor (1 and 2), Masaya Hiraishi (1 and 2), J.-R. Soh (3 and 4), Jevon J. Longdell (1 and 2) ((1) Department of Physics, University of Otago, Dunedin, New Zealand, (2) Dodd-Walls Centre for Photonic and Quantum Technologies, Dunedin, New Zealand, (3) Quantum Innovation Centre (<a href=”http://Q.InC“ rel=”external noopener nofollow” class=”link-external link-http”>this http URL</a>), Agency for Science, Technology and Research (A*STAR), Singapore, Singapore, (4) Centre for Quantum Technologies, National University of Singapore, Singapore, Singapore)
The narrowness of the optical transitions of rare-earth-ion dopants makes them highly sensitive probes of their environment. We measured the optical transitions Er$ ^{3+}$ dopants to determine the previously unknown magnetic ordering of Gd$ {2}$ SiO$ {5}$ – a promising host for quantum applications of rare-earth dopants. By measuring the transitions’ magnetic-field dependence we determined an antiferromagnetic ordering with spins oriented along or slightly canted from the crystal’s $ a^\ast$ axis. The optical transitions are narrower than the coupling to gadolinium spins revealing information about the coupling strengths. We further optically measured a Néel temperature of $ 1.86\pm0.01\mathrm{stat.}\pm0.07\mathrm{syst.}$ K, and assembled a phase diagram in applied field and temperature showcasing a triple point where two gadolinium sites order semi-independently from each other. At high applied field the erbium dopants show long optical coherence times up to 0.4 ms at 3 T; at low fields these are probably limited by three low-frequency magnon modes below 10 GHz, observed directly. This study can be used to benchmark a method of magnetic structure determination.
Strongly Correlated Electrons (cond-mat.str-el), Quantum Physics (quant-ph)
17 pages, 11 figures
Memory-aware acceleration of orientational dynamics in nanoparticle suspensions
New Submission | Soft Condensed Matter (cond-mat.soft) | 2026-03-16 20:00 EDT
Miguel Ibáñez, Raúl A. Rica-Alarcón, María L. Jiménez
The relaxation of stochastic systems after sudden perturbations is constrained by speed limits and often reveals memory effects that hinder attempts to accelerate their dynamics. Here we demonstrate Kovacs-type nonmonotonic relaxation in the electro-orientation of non-spherical nanoparticles and show how this memory effect limits simple acceleration protocols. Experimentally, the orientational dynamics is monitored optically through field-induced birefringence, which is proportional to the nematic order parameter. When an AC electric field is first set to an extreme value until the birefringence reaches its target and is then switched to the target field (matched two-step protocol), the relaxation exhibits a characteristic Kovacs shoulder. We interpret this behavior within a theoretical framework based on the Smoluchowski equation for the orientational probability density. In the high-frequency AC regime, orientational relaxation is governed by induced dipoles, and the observed memory effect originates from polydispersity, which generates a spectrum of rotational diffusion coefficients and hence multiscale relaxation. Building on this insight, we design protocols that mitigate the detrimental effect of memory by sequentially suppressing the slowest active relaxation mode. Experiments on nanoparticle suspensions with different properties confirm these mechanisms, and we demonstrate substantial reductions in relaxation time compared with single quenches and matched two-step protocols with NaMt suspensions. More broadly, these results illustrate how memory effects emerge when many degrees of freedom are steered with a single control parameter and provide an experimentally accessible strategy for controlling multiscale stochastic dynamics.
Soft Condensed Matter (cond-mat.soft), Statistical Mechanics (cond-mat.stat-mech)
Linear Magnetoresistance as a Probe of the Neel Vector in Altermagnets with Vanishing Anomalous Hall Effect
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2026-03-16 20:00 EDT
Despite time-reversal breaking in momentum space, several altermagnets remain electrically silent to the primary characterization tool anomalous Hall effect, due to crystalline symmetries, jeopardizing their experimental identification. Here, we show that time-reversal odd magnetoresistance exhibiting butterfly-like hysteresis with linear magnetic field dependence near the zero field provides a robust transport signature of altermagnetism even when the anomalous Hall effect vanishes. Using semiclassical theory and symmetry analysis, we demonstrate that this effect is generic across altermagnets and validate it through first-principles calculations in CrSb. Our results establish linear magnetoresistance as an alternative detection of the Berry curvature and Neel order in unconventional antiferromagnets.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Materials Science (cond-mat.mtrl-sci)
5 pages, 2 figures, comments are welcome
Elastoresistivity Signatures of Nematic Fluctuations in Layered Antiferromagnet CoTa3S6
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2026-03-16 20:00 EDT
Tao Lu, Zili Feng, Mengxing Ye, Takashi Kurumaji, Linda Ye
Nematic phases that break rotational symmetry are widely observed in quantum materials, and clarifying their origin and relationship with other symmetry-breaking phases remains an important but challenging task. In this work, we investigate nematic fluctuations in CoTa$ _3$ S$ _6$ using elastoresistivity experiments to resolve the nature of the proposed nematic phase intertwined with collinear and non-coplanar antiferromagnetic orders. We observe a divergence-like antisymmetric elastoresistivity that rapidly develops below the stripe antiferromagnetic transition, consistent with a distinct nematic degree of freedom coupled to the magnetic order. While nematic fluctuations are strongly modulated by an external out-of-plane magnetic field and the onset temperature of resistivity anisotropy shows pronounced strain dependence, the antiferromagnetic transition temperatures remain nearly unchanged under either magnetic field or strain. Additionally, complementary magnetoresistance measurements reveal characteristic signatures of three-state nematicity in a hexagonal system. Our findings demonstrate CoTa$ _3$ S$ _6$ as a unique case of intertwined nematic and AFM orders with distinct origins.
Strongly Correlated Electrons (cond-mat.str-el)
10 pages, 4 figures
Discovery of a hybridization-wave electronic order in a van der Waals Kondo lattice
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2026-03-16 20:00 EDT
Lu Cao, Jiefei Shi, Lanxin Liu, Xuan Luo, Yu-Ping Sun, Yi-feng Yang, Yugui Yao, Jinhai Mao, Yuhang Jiang
Kondo lattice systems, in which localized magnetic moments coherently hybridize with itinerant electrons, exhibit a rich landscape of emergent quantum phenomena. Within this framework, the hybridization strength itself has been theoretically proposed as a spatially modulated order parameter, giving rise to a so-called hybridization wave. However, direct experimental evidence of this quantum state has remained an outstanding challenge. Here, we report the direct observation of a hybridization wave in the layered transition metal dichalcogenide 6R-TaS2, a naturally occurring heterostructure composed of alternating 1T- and 1H-TaS2 layers. Using scanning tunneling microscopy and spectroscopy (STM/STS), we identify the hybridization gap in 1T layer, demonstrating the establishment of a coherent Kondo lattice. Notably, we discover that the hybridization gap present a uniaxial unit-cell doubling modulation, which breaks the both translational and rotational symmetries of the underlying Star-of-David superlattice. Such unit-cell doubling is not caused by structural topography, and therefore, constitutes the real-space visualization of the hybridization-wave order. Furthermore, the hybridization wave correlates with an energy-dependent nematic order that shares the same periodicity and orientation, revealing intertwined electronic instabilities. Our findings not only validate a long-standing prediction but also establish layer-engineered van der Waals materials as a versatile platform for exploring and controlling hybridization-driven quantum phases.
Strongly Correlated Electrons (cond-mat.str-el), Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Materials Science (cond-mat.mtrl-sci)
16 pages, 4 figures
Torsional oscillation of carbon nanotubes driven by electron spins
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2026-03-16 20:00 EDT
Koji Yamada, Wataru Izumida, Mamoru Matsuo, Takeo Kato
We theoretically investigate the current-induced excitation of torsional vibrations in a suspended carbon nanotube (CNT) quantum dot. By considering a CNT clamped between half-metallic ferromagnetic electrodes with an antiparallel magnetization configuration, we demonstrate that the spin-rotation coupling enables the transfer of angular momentum from electron spins to the mechanical torsional mode under a constant source-drain voltage. Using a master-equation approach to analyze the coupled dynamics of the dot levels and a quantized torsional oscillator, we evaluate the steady-state current and phonon distribution. We find that when the Zeeman splitting matches the torsional phonon energy, the system exhibits a sharp resonant behavior in the current, accompanied by a significant increase in the phonon population. Our estimates for realistic device parameters indicate that this spin-driven mechanism can drive CNT torsional vibrations with detectable amplitudes. This work provides a theoretical basis for current-controlled actuation of nanoelectromechanical systems via the spin angular momentum of electrons.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
11 pages, 7 figures
Slow spin-lattice relaxation dynamics in YbVO4 revealed by extended thermal impedance spectroscopy from AC susceptibility and AC magnetocaloric measurements
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-03-16 20:00 EDT
Yuntian Li, Jiayi Hu, Dominic Petruzzi, Linda Ye, Mark P. Zic, Arkady Shekhter, Ian R. Fisher
Alternating (AC) magnetic fields can induce not only an alternating magnetization in materials, but also an alternating temperature via the magnetocaloric effect. The latter effect is typically neglected when performing AC susceptibility measurements, but consideration of both effects on an equal footing is necessary in order to reliably distinguish between internal and external causes of magnetic response and accurately extract quantitative information about relaxation processes. In order to address this, we have developed a method to measure the AC magnetocaloric effect that is compatible with AC susceptibility measurements, and also a framework to analyze these data in combination. We demonstrate the efficacy of this approach using YbVO4, a material for which strong single-ion anisotropy leads to slow spin-lattice relaxation at low temperatures via a phonon bottleneck effect. We report AC magnetic susceptibility and AC magnetocaloric effect measurements for this material as a function of field and frequency at a temperature of 3 K. We analyze the data using a discretized thermal model, and extract the field-dependence of the intrinsic spin-lattice relaxation rate. This demonstration experiment illustrates a general approach to quantitatively address multiple measured quantities in driven systems using a unified thermal circuit analysis. The thermal analysis methods presented in this report can be extended to study other magnetic, dielectric, and elastic materials exhibiting a complex response to an external driving field in the presence of internal and external relaxation, particularly when an energy dissipation process is within an accessible frequency regime.
Materials Science (cond-mat.mtrl-sci), Other Condensed Matter (cond-mat.other), Applied Physics (physics.app-ph)
Phonon-Induced Zero-bias Currents in Solids
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2026-03-16 20:00 EDT
Masao Ogata, Hidetoshi Fukuyama
Zero-bias current induced by injected phonons in metals and one-dimensional charge density wave (CDW) systems attached on the surface of the piezoelectric substrate is investigated microscopically based on the second order response theory. In contrast to the shift currents discovered by von Baltz and Kraut in which the zero-bias current is induced by AC electric field in systems without inversion symmetry, propagating phonons break the inversion symmetry in the presesnt case. The effects of both deformation potential and piezoelectric potential are taken into account. In the CDW system, zero-bias current appears below the transition temperature and its magnitude strongly depends on the position of the chemical potential. Possible experimental consequences are discussed.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
6 pages, 4 figures
Ab initio screening of quantum frustrated materials with kagome and triangular geometries
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2026-03-16 20:00 EDT
Byeong-Hyeon Jeong, Hee Seung Kim, SungBin Lee, Myung Joon Han
Geometrical frustration is a powerful route to realize exotic phases such as quantum spin liquids. Despite extensive efforts, systematic searches targeting specific frustration motifs and their potential to host unconventional magnetic ground states remain rare, thus highlighting the need for a more focused and predictive materials discovery approach. Here we present a new strategy combining high-throughput first-principles calculations, magnetic force theory, and spin Hamiltonian analysis. Starting from the 150,000 material database, we catalogue candidate materials that may host competing exchange interactions and new types of magnetic states with the focus on kagome or triangular lattices. Our workflow not only reproduces the majority of known frustrated magnetic materials, validating our approach, but also predicts novel candidate compounds with targeted frustration profiles that have not yet been experimentally synthesized. Among these, we identify six promising new materials: one triangular lattice compound, KMgNiIO6, and five kagome lattice compounds; Li4Fe3WO8, Li2V3F8, Li5VP2(O4F)2, and Li2MgCo3O8 (P2/m and C2/m). For each candidate, we identify detailed magnetic properties and further propose their potential magnetic ground states, revealing that some of them may host entirely new magnetic phases driven by their distinct frustration characteristics.
Strongly Correlated Electrons (cond-mat.str-el), Materials Science (cond-mat.mtrl-sci)
Under review
RF magnetron sputtering deposition of multilayers optical filters for ultra-broadband applications with a large number of thin layers
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-03-16 20:00 EDT
Maxime Duris (CIMAP - UMR 6252, NIMPH), Bryan Horcholle (NIMPH, CIMAP - UMR 6252), Cédric Frilay (CIMAP - UMR 6252, NIMPH), C. Labbe (CIMAP - UMR 6252, NIMPH), Xavier Portier (CIMAP - UMR 6252, NIMPH), Philippe Marie (CIMAP - UMR 6252, NIMPH), Sylvain Duprey (CIMAP - UMR 6252, NIMPH), Franck Lemarié (CIMAP - UMR 6252), Julien Cardin (CIMAP - UMR 6252, NIMPH)
We present recent achievement on manufacturing optical filter and multilayers done with two complementary RF magnetron sputtering approaches: deposition duration control and in situ optical reflectance monitoring. Those approaches were greatly improved thanks to ellipsometry and spectrophotometry cross-studies of optical refractive indexes of Nb2O5, TiO2 and SiO2 materials grown using two sputtering systems. At the same time, we conducted deposition studies of these three materials which have increased the manufacturing reliability and allowed us to consider developing complex optical multilayers with more than 100 layers.
Materials Science (cond-mat.mtrl-sci), Computational Physics (physics.comp-ph), Optics (physics.optics)
EOS Annual Meeting 2021, EOS, Sep 2021, Rome, Italy
Optimized growth of large-size, high quality $\text{ZrTe}_5$ single crystals enabling clear quantum oscillations in electrical transport
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-03-16 20:00 EDT
Hong Du, Yu Cao, Jiahao Chen, Tian Liang, Liang Liu, Ruidan Zhong
Quantum oscillation with nontrivial Berry phase is one of the characteristics of topological materials. As a Dirac semimetal candidate, zirconium pentatelluride ($ \text{ZrTe}_5$ ) stands out as an intriguing material for investigating topological phase transitions and Dirac fermion physics; however, the extreme sensitivity of its electronic properties to stoichiometric variations and crystalline defects has hindered consistent experimental observation. Here, we report an optimized Te-flux synthesis method designed to produce centimeter-scale, high-quality single crystals meanwhile minimizing extrinsic carrier contamination. Comprehensive morphology, structural and chemical characterization, including scanning electron microscopy, Laue backscattering and Rietveld refinement, confirms a high-purity $ Cmcm$ phase with excellent crystallinity. Furthermore, magnetotransport measurements reveal a remarkably low Shubnikov-de Haas oscillation onset field ($ B \approx 0.38$ T) and access to the the quantum limit at $ B \approx 1.3$ T, indicative of low carrier density and high carrier mobility. These results demonstrate that growth control is crucial for stabilizing intrinsic electronic behavior in $ \text{ZrTe}_5$ , establishing a robust platform for exploring topological phase transitions and exotic quantum phenomena in topological semimetals.
Materials Science (cond-mat.mtrl-sci)
Characterization of Exciton-exciton entanglement and correlations
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-03-16 20:00 EDT
Fangzhou Zhao, Carlos Mejuto-Zaera, Angel Rubio, Vojtěch Vlček
Excitons in the weakly interacting regime can be well-described by many-body perturbation theories such as the Bethe-Salpeter equation formalism. However, for materials such as transition metal dichalcogenides moiré heterostructures under strong illumination, with the emergence of dense excitonic states, the strong correlation and entanglement between electrons and holes may cause the many-body perturbation method to fail, and excitons may not be treated in the bosonic picture, but exhibit fermionic behaviors. In our work, we investigate the phase space where excitons, and the electrons and holes which constitute them, are weakly or strongly entangled, as well as their binding for different interaction profiles and the degree of localization of the electrons and holes. We corroborate the validity of using many-body perturbation theory in the exciton with interactions. Our work provides a general way to analyze the correlation and entanglement of multi-particle excitations in many-body systems, and gives a more comprehensive understanding of different phases for exciton entanglement and interactions in 1D systems.
Materials Science (cond-mat.mtrl-sci)
Cell-induced wrinkling patterns on soft substrates
New Submission | Soft Condensed Matter (cond-mat.soft) | 2026-03-16 20:00 EDT
Aleksandra Ardaševa, Varun Venkatesh, Daiki Matsunaga, Shinji Deguchi, Amin Doostmohammadi
Cells exert traction forces on compliant substrates and can induce surface instabilities that appear as characteristic wrinkling patterns. Here, we develop a mechanical description of cell-induced wrinkling on soft substrates using a thin film elastic framework based on the Föppl-von Kármán equations coupled to a phase-field model of a single cell. We model in-plane contractile stresses driven by cellular activity and study how their magnitude, spatial distribution, and symmetry determine the onset of wrinkling and the resulting pattern selection. The theory predicts transitions between distinct morphologies, such as radial, circumferential, and anisotropic wrinkle arrangements, and provides scaling relations for wrinkle wavelength and amplitude as functions of elastic parameters and imposed cellular forcing. We compare these predictions with available experimental observations of cell-driven wrinkling on compliant gels and find good agreement for both qualitative pattern classes and quantitative wavelength trends. Our results offer a minimal modelling framework to interpret wrinkling assays and connect observed surface patterns to underlying cellular forces.
Soft Condensed Matter (cond-mat.soft), Biological Physics (physics.bio-ph)
11 pages, 6 figures
Many-body correlations in Floquet steady-states: Frequency-resolved renormalization group of the driven Anderson impurity
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2026-03-16 20:00 EDT
Jan-Niklas Herre, Christoph Karrasch, Dante M. Kennes
We introduce a functional renormalization group framework formulated directly in the Floquet steady-state that systematically incorporates frequency-dependent interaction effects. By retaining the frequency structure of the two-particle vertex up to second order in interaction strength, our approach provides controlled access to dynamical response functions and nonequilibrium transport in driven, interacting systems. Using the periodically driven single-impurity Anderson model as a paradigmatic example, we benchmark our results against state-of-the-art Floquet Green’s function methods and find quantitative agreement for finite-frequency observables up to intermediate interaction strengths. Remarkably, we also show that static properties are often captured reliably by much simpler approximations, suggesting practical pathways for modeling driven quantum materials. Finally, we demonstrate that although periodic driving of the dot strongly broadens the Kondo resonance through inelastic scattering, it leaves the many-body Kondo cloud largely intact. This robustness suppresses Floquet replicas of the Kondo peak and leads to a partial persistence of Kondo pinning, highlighting the resilience of emergent many-body correlations under local periodic driving.
Strongly Correlated Electrons (cond-mat.str-el)
20 pages, 8 figures
Continuous unitary transformations using tensor network representations access the full many-body localized spectrum
New Submission | Disordered Systems and Neural Networks (cond-mat.dis-nn) | 2026-03-16 20:00 EDT
Qiyu Liu, Jan-Niklas Herre, Dante M. Kennes, Christoph Karrasch
We develop variational continuous unitary transformations (VCUTs), which integrate Wegner-Wilson flow equations with tensor network techniques to approximately diagonalize many-body localized (MBL) Hamiltonians. The diagonalizing unitary is represented as a matrix product operator whose bond dimension controls the accuracy. For the disordered Heisenberg chain, VCUTs accurately reproduces the full spectrum across the ergodic-to-MBL crossover at small system sizes and scales to $ L = 48$ sites. Beyond eigenenergies, the method can track the spatial entanglement structure of the diagonalizing unitary $ U(l)$ at each flow step, enabling identification of local integrals of motion deep in the MBL phase.
Disordered Systems and Neural Networks (cond-mat.dis-nn)
10 pages, 7 figures
Quantifying Perovskite Solar Cell Degradation via Machine Learning from Spatially Resolved Multimodal Luminescence Time Series
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-03-16 20:00 EDT
Giulio Barletta, Simon Ternes, Saif Ali, Zohair Abbas, Chiara Ostendi, Marialucia D’Addio, Erica Magliano, Pietro Asinari, Eliodoro Chiavazzo, Aldo Di Carlo
Perovskite solar cells (PSCs) have experienced a remarkable rise in power conversion efficiency (PCE) over the past 15 years, positioning them as a promising alternative or complement to silicon for large-scale photovoltaic deployment. However, beyond scalable fabrication, operational stability remains a major bottleneck for commercialization. Reliable and rapid methods to assess device health and degradation mechanisms - ideally compatible with field applications - are therefore essential. We present a deep-learning framework to estimate efficiency retention, $ R_\mathrm{PCE}=\mathrm{PCE}t/\mathrm{PCE}0$ , directly from multimodal luminescence imaging acquired during device aging. Each training sample includes electroluminescence (EL), open-circuit photoluminescence (PLoc), and short-circuit photoluminescence (PLsc) images at an aged state, together with device-specific reference images at $ t=0$ . This design enables the model to learn spatially resolved degradation patterns relative to the pristine condition. The dataset was collected over 5-70 hours using an automated, in-house measurement platform. We introduce LumPerNet, a compact convolutional neural network that regresses $ R\mathrm{PCE}$ from stacked multimodal image tensors, and benchmark it against an intensity-only multilayer perceptron baseline. Using a leakage-aware protocol with device-level hold-out testing and four-fold cross-validation, restricted to $ R\mathrm{PCE}\in[0.8,1.2]$ , LumPerNet achieves substantially improved and more robust performance (MAE -23.4%, RMSE -25.6%, $ R^2$ +0.417). Ablation studies highlight the importance of complementary physical contrast across modalities for generalization. Overall, this work establishes a reproducible pipeline linking automated luminescence imaging to electrical labels, enabling accelerated stability testing and non-invasive degradation monitoring in PSCs.
Materials Science (cond-mat.mtrl-sci)
32 pages, 14 figures
Magnetic-field-induced magnon portfolio in a van der Waals magnet
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-03-16 20:00 EDT
T. Riccardi, F. Le Mardélé, L.A. Veyrat de Lachenal, A. Pawbake, I. Plutnarova, Z. Sofer, G. Jacquet, F. Petot, A. Saùl, B. Grémaud, A. L. Barra, M. Orlita, J. Coraux, C. Faugeras, B. A. Piot
Magnonic excitations are investigated in chromium oxychloride (CrOCl), a van der Waal (vdW) antiferromagnet prone to a multitude of magnetic phase transitions, with absorption experiments in a broad continuous energy range. At low magnetic fields, the magnon spectra show a strong bi-axial anisotropy and inform on the relative weights of the effective exchange coupling and the system anisotropies. As the magnetic field increases, magnons characteristic of a canted phase are first observed, with peculiarities attributed to in-plane anisotropies and magnon-magnon coupling. Subsequently, a hysteretic magnon spectrum appears as the system transitions to a ferrimagnetic state, with two new magnon branches partly coexisting with the lower energy canted phase branch, indicating the formation of spatially separated magnetic phases. Further changes in the magnon spectrum in higher magnetic fields accompany transitions to the different canted magnetic phases previously reported. Our experiments show that competing exchange interactions and ground states broaden the options to generate different kinds of magnonic excitations in the same vdW material upon the variation of external parameters.
Materials Science (cond-mat.mtrl-sci), Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Other Condensed Matter (cond-mat.other)
Supplemental material will be available upon request
Finite-momentum superconductivity with singlet-triplet mixing in an altermagnetic metal: A pairing instability analysis
New Submission | Superconductivity (cond-mat.supr-con) | 2026-03-16 20:00 EDT
Hui Hu, Zhao Liu, Jia Wang, Xia-Ji Liu, Yoji Ohashi
We analyze the pairing instability of an altermagnetic metal on a square lattice driven by an attractive nearest-neighbor interaction. This interaction enables multiple pairing channels, including even-parity extended $ s$ -wave and $ d$ -wave states, as well as two odd-parity $ p$ -wave channels. We verify that altermagnetic spin-splitting in the single-particle dispersion gives rise to finite-momentum pairing between electrons with unlike spins, in agreement with earlier predictions. Quite unexpectedly, this pairing typically emerges across multiple channels with mixed parity. Consequently, the resulting finite-momentum Fulde–Ferrell–Larkin–Ovchinnikov (FFLO) superconducting phase is expected to exhibit a multi-component order parameter featuring singlet-triplet mixing. We examine several forms of altermagnetism, specifically $ d_{xy}$ -wave and $ d_{x^{2}-y^{2}}$ -wave altermagnetic couplings, and present the corresponding phase diagrams. Additionally, we investigate the triplet pairing between electrons with identical spins, and find that it consistently occurs at zero center-of-mass momentum and is unfavorable at weak altermagnetic coupling and low electron filling. The influence of on-site attractive interactions on mixed-parity pairing is also explored.
Superconductivity (cond-mat.supr-con), Strongly Correlated Electrons (cond-mat.str-el)
15 pages, 15 figures
Neutron-enhanced ion transport in cathode coating of Li-ion batteries
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-03-16 20:00 EDT
Ha M. Nguyen, Carson D. Ziemke, David Stalla, Bikash Saha, Narendirakumar Narayanan, Sebastián Amaya-Roncancio, Carlos Wexler, John Gahl, Yangchuan Xing, Thomas W. Heitmann
Polycrystalline solid-state ionic conductors (PolySSICs) are key energy materials for all-solid-state Li-ion batteries (LIBs). However, achieving room-temperature ionic conductivity comparable to that of liquid electrolytes ($ \sigma \sim 10^{-2}-10,\mathrm{S\cdot cm^{-1}}$ ) remains a major challenge. Here, we experimentally demonstrate that thermal neutron irradiation provides an effective strategy for engineering ion transport in a model PolySSIC, LiBO$ _2$ , a promising electrode coating material for LIBs. High-flux ($ \sim 10^{9}$ neutrons$ \cdot$ cm$ ^{-2}\cdot$ s$ ^{-1}$ ) thermal neutrons ($ \sim 25$ meV), delivered at Beam Port E of the University of Missouri Research Reactor (MURR), selectively transmute the strong neutron absorbers $ ^{10}\mathrm{B}$ and $ ^{6}\mathrm{Li}$ at their natural abundances ($ \sim19.9%$ and $ \sim7.5%$ ). This process generates lattice vacancies within polycrystalline grains while preserving long-range crystallographic order. In addition, $ \gamma$ photons produced during $ ^{10}$ B transmutation release electrons that suppress atomic displacement and partially neutralize the space charge associated with positively charged oxygen vacancies at grain boundaries. As a result, the ionic conductivity increases by nearly $ 20%$ in grains and more than $ 80%$ at grain boundaries. These results validate theoretical predictions and demonstrate a controllable strategy for enhancing ion transport in PolySSICs for solid ionic devices, including LIBs.
Materials Science (cond-mat.mtrl-sci)
36 pages, 8 figures, APS Global Physics Summit, Denver, CO, March 15-20,2026
Photon-mediated entanglement between spin qubits beyond the dispersive regime
New Submission | Other Condensed Matter (cond-mat.other) | 2026-03-16 20:00 EDT
Andrei Nikitchenko, Guido Burkard
Dispersively coupled distant qubits in a shared cavity can become entangled through virtual photon exchange with energy-conserving phase evolution of their quantum states. This interaction can potentially be accelerated by operating on resonance, allowing for the exchange of real photons. In this theoretical study, we examine photon-mediated entanglement between two distant spins of electrons confined in double quantum dots formed in a Si/SiGe heterostructure. We calculate the dynamics of the combined system comprised of both spin qubits and the cavity, assuming that both spin qubits can be tuned into and out of resonance with the host cavity. We demonstrate that the exchange of real photons between the two spin qubits can result in rapid entanglement that is robust against decoherence. These results pave the way for the development of quantum gates on resonantly coupled distant semiconductor spin qubits.
Other Condensed Matter (cond-mat.other)
Tutorial: Heat Capacity-A Powerful Tool for Studying Exotic States of Matter
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2026-03-16 20:00 EDT
K. Ramesh Kumar, Xudong Huai, Allen O. Scheie, Thao T. Tran
Heat capacity measurements are a powerful tool that researchers rely on when studying the relationship between microscopic degrees of freedom and macroscopic behavior in condensed matter. This uniqueness stems from heat capacity capturing contributions from lattice, electronic, and magnetic components, as well as energy-level populations, enabling an effective approach to studying phase transitions and excitations across different classes of materials. However, analyzing heat capacity data presents a common, appreciable challenge for new researchers. Although comprehensive theoretical aspects of heat capacity are presented in several elegant textbooks, practical application remains a daunting task. To overcome this challenge, this tutorial guides researchers in collecting, analyzing, and interpreting heat capacity data in contemporary quantum materials. We outline the connections between thermodynamics, heat capacity, and entropy, as well as measurement methodology and data analysis for representative examples, including phonon dynamics, spin waves, superconductors, magnetic skyrmions, proximate quantum spin liquids, and heavy-fermion materials. Our goal is to provide a concise, accessible guide that enables new researchers to utilize heat capacity as a quantitative lens for understanding exotic states of matter.
Strongly Correlated Electrons (cond-mat.str-el), Materials Science (cond-mat.mtrl-sci)
Orbital dimerization-induced first-order structural phase transition: a case study in La$_3$Ni$_2$O$_7$
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2026-03-16 20:00 EDT
First-order structural phase transition is a common phenomenon in materials that qualitatively alters their physical properties. Yet, the abrupt first-order nature is usually unexplained by realistic computations, implying an omission of important physics in describing the electronic structure of the nearby stable phases. Using the recently discovered nickelate superconductors La$ _3$ Ni$ _2$ O$ _7$ as a prototypical example, we demonstrate that such first-order nature is typically beyond intra-atomic correlation considered in state-of-the-art material computations. Instead, a full many-body treatment of low-energy active orbitals reveals a generic inter-atomic “orbital dimerization” mechanism of first-order structural phase transition, corresponding to abrupt energy reduction upon a spin-singlet bond formation. Such an inter-atomic correlation qualitatively changes not only the essential lattice bonding but also the characteristics of low-energy electronic properties across the transition. This strong mechanism and the developed computational framework are generally applicable to a wide variety of ionic materials, to produce valuable insights into atomic and electronic structures essential for their physical properties and functionalities.
Strongly Correlated Electrons (cond-mat.str-el), Materials Science (cond-mat.mtrl-sci)
6 pages, 3 figures
Electrohydrodynamic Stresses from Hydrogen-Bond Network Dynamics in Water
New Submission | Soft Condensed Matter (cond-mat.soft) | 2026-03-16 20:00 EDT
The resistance of hydrogen-bond networks to ambient flow in water produces viscoelectric stresses and contributes to electrostrictive pressure. Within Onsager’s nonequilibrium thermodynamic framework, a lattice-gas description of aqueous electrolytes is combined with a coarse-grained hydrodynamic representation of hydrogen-bonded molecular networks, where viscous dissipation is modeled through energetically equivalent Brownian entities. This formulation connects molecular structural information from experiments and molecular dynamics to a unified dipolar Poisson-Nernst-Planck-Stokes (dPNP-S) continuum theory, quantitatively reproducing the measured viscoelectric coefficient of Jin et al. (PNAS 2022) and contributions to electrostrictive pressure. These results identify a microscopic mechanism by which hydrogen-bond dynamics influence electrohydrodynamic flow.
Soft Condensed Matter (cond-mat.soft), Fluid Dynamics (physics.flu-dyn)
6 pages, 2 figures (each with 2 sub-figures), Prepared using RevTex4.2 LaTeX template
Dynamic charge oscillation in a quantum conductor driven by ultrashort voltage pulses
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2026-03-16 20:00 EDT
Lucas Mazzella, Seddik Ouacel, Inès Safi
Time-dependent driving with ultrashort voltage pulses brings quantum conductors into the non-adiabatic transport regime, where novel dynamical effects emerge. An example of this physics occurs in interferometric systems, where the transmitted charge oscillates as a function of the charge injected by an ultrashort voltage pulse. This behavior has been predicted in a variety of setups, including Fabry-Pérot and Mach-Zehnder interferometers, and more recently in quantum dots. It is commonly interpreted as resulting from interference between different propagating paths taken by the injected excitation. In this letter, we fully generalize the derivation of such dynamic charge oscillations beyond interferometric devices for a generic quantum conductor with the single assumption that its DC current is sublinear at large bias. Strikingly, they also extend perturbatively to strongly correlated conductors, showing in particular their robustness against arbitrarily strong Coulomb interactions. To illustrate the generality of our approach, we analyze in detail the case of a quantum point contact in the fractional quantum Hall regime, which fulfills the sublinearity condition. We demonstrate that this non-interferometric system exhibit dynamic charge oscillation. Finally, we propose a complementary interpretation of this phenomenon, rooted in the photo-assisted probabilities associated with the voltage pulse.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
Large dilatational hyperelasticity of glasses en route to cavitation failure
New Submission | Soft Condensed Matter (cond-mat.soft) | 2026-03-16 20:00 EDT
Pawandeep Kaur, Noam Ottolenghi, Edan Lerner, David Richard, Eran Bouchbinder
Materials deform elasto-plastically and fail under various loading conditions, typically quantified by the stress triaxiality, which is the ratio between the dilatational (hydrostatic) stress and the deviatoric (shear-like) one. We show that the elasto-plastic deformation of glasses approaching failure qualitatively differ for large and small stress triaxiality levels. Specifically, in the former limit, glasses reveal a strong hyperelastic (nonlinear elastic) response with minute plasticity, largely independently of the quenching rate across the glass transition. Yet, glassy disorder gives rise to significant elastic (reversible) nonaffine deformation, accompanied by the formation of micro-cavities. A small fraction of the latter is irreversible, i.e., survives unloading prior to the onset of failure, and may serve as nucleation sites for failure in the form of large-scale cavitation, upon which the glass loses a significant fraction of its load-bearing capacity. These results are contrasted with glass behavior in the limit of vanishing stress triaxiality and their universality across different glass formers is demonstrated. Finally, the implications of our findings for understanding glass deformation and failure under realistic stress conditions are discussed.
Soft Condensed Matter (cond-mat.soft), Materials Science (cond-mat.mtrl-sci), Statistical Mechanics (cond-mat.stat-mech)
Boundary-Mediated Phases of Self-Propelled Kuramoto Particles
New Submission | Soft Condensed Matter (cond-mat.soft) | 2026-03-16 20:00 EDT
Francesco Arceri, Vittoria Sposini, Enzo Orlandini, Fulvio Baldovin
Active agents can transfer energy to their environment through collective motion, generating accumulation patterns near confining obstacles. Here we investigate how the nature of the microscopic drive-self-propulsion or velocity alignment-selects distinct accumulation patterns, leading to either delocalized or compact clustered states. We first characterize the dynamical regimes emerging from the interplay of these two driving mechanisms under perfectly reflective or smooth boundary conditions. We then introduce boundary friction and observe a drastic change in the accumulation patterns, with new dynamical phases that are absent in the previous case. By connecting emergent macroscopic structures to their underlying microscopic interactions, this work provides a practical route to infer the dominant interaction ruling boundary-mediated collective behavior, with applications ranging from single-cell migration to bio-inspired robotics.
Soft Condensed Matter (cond-mat.soft), Statistical Mechanics (cond-mat.stat-mech), Biological Physics (physics.bio-ph), Computational Physics (physics.comp-ph)
8 pages, 5 figures in main text; 2 pages, 3 figures in supplement
A toy model of a protein prototype reveals nontrivial ultrametricity of the energy landscape
New Submission | Disordered Systems and Neural Networks (cond-mat.dis-nn) | 2026-03-16 20:00 EDT
A model for studying the ultrametricity of the energy landscape in a disordered heteropolymer is presented. It is treated as a simplified model of a protein molecule in which amino acid residues are modeled as point masses. Pairwise interactions include universal repulsion, the Lennard-Jones potential, the Coulomb potential with screening, and the elastic potential for bonds between adjacent residues. An analogy with spin glass models is used, allowing the application of replica theory methods. Unlike the standard approach to disordered systems, averaging over disorder is not performed. The overlap between replicas is defined as the Pearson correlation coefficient between the vectors of average pairwise energies, which corresponds to a comparison of thermodynamic averages in the spirit of spin glass theory. The results of a computational experiment conducted using the developed algorithm on a graphics processing unit (GPU) are presented. The simulations were performed using a 128-residue-long sequence, with 50 independent disorder realizations and 50 replicas for each sequence at a temperature of T = 1.0. It was found that for 90.0% of the sequences, the distance matrix between replicas contains more than half of the ultrametric triangles, and nontrivial ultrametricity predominates in 97.8% of them, indicating a hierarchical organization of the energy landscape. A repeated computational experiment for selected sequences confirms the reliability of the observations: 95.5% of them again demonstrated ultrametricity, of which 97.7% showed a predominance of the nontrivial type of ultrametricity. The obtained results confirm Frauenfelder’s hypothesis of protein ultrametricity and pave the way for a systematic study of ultrametric properties in more realistic protein models.
Disordered Systems and Neural Networks (cond-mat.dis-nn), Statistical Mechanics (cond-mat.stat-mech), Numerical Analysis (math.NA)
26 pages, 3 figures
Noise-protected two-qubit gate using anisotropic exchange interaction
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2026-03-16 20:00 EDT
Zizheng Wu, Maximilian Rimbach-Russ
Hole spin qubits hosted in Germanium quantum dots are promising candidates for scalable quantum computing. The strong spin-orbit interaction can enable fast and all-electrical quantum control. Furthermore, the platform can implement universal quantum control using only baseband signals, which may mitigate the impact of crosstalk and microwave-induced heating. At the same time, spin-orbit interaction gives rise to an anisotropic exchange interaction, whose potential for implementing two-qubit gates has remained largely unexplored. However, the current performance of operating a hole-based quantum computer is mostly limited by dephasing due to low-frequency charge noise. In this work, we propose a novel two-qubit gate protocol for Germanium hole spin qubits operated in the gapless regime. This gate protocol exploits the anisotropic exchange interaction between neighboring spins and utilizes a composite pulse scheme implemented solely through electrical baseband signals. Using this approach, we predict high-fidelity two-qubit controlled-Z operations that can suppress exchange-energy fluctuations, offering a pathway toward fault-tolerant semiconductor quantum processors.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Quantum Physics (quant-ph)
15 pages, 9 figures
Imaging the high-frequency charging dynamics of a single impurity in a semiconductor on the atomic scale
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2026-03-16 20:00 EDT
Maialen Ortego Larrazabal, Jiasen Niu, Stephen R. McMillan, Paul M. Koenraad, Michael E. Flatté, Milan P. Allan, Ingmar Swart
As electronic devices approach the atomic limit, the charge dynamics of individual dopant atoms increasingly constrain performance, stability, and coherence. In scanning tunnelling microscopy (STM), donor ionization is typically interpreted as a static threshold process arising from tip-induced band bending. Here we show that the ionization of individual sulfur donors in InAs is intrinsically dynamic and governed by the local electric field. Using MHz-frequency STM noise spectroscopy with atomic-scale spatial mapping, we resolve pronounced random telegraph noise that is invisible in time-averaged tunnelling spectra. A bias-dependent model quantitatively links the noise spectra to microscopic ionization and neutralization processes of the donor states, enabling direct extraction of nanosecond charge-state lifetimes. The switching rate is strongly bias dependent, demonstrating that the electric field continuously drives charge-state transitions. Unexpectedly, we show that the degenerately doped bulk leads to a sharp bias-dependent onset of donor ionization as the donor level crosses the Fermi level, giving rise to a characteristic shoulder in the noise power spectrum that is captured by our model. These results establish donor ionization as a non-equilibrium dynamical process with nontrivial contribution by the bulk electrons, and identify impurity switching as a universal nanoscale charge-noise mechanism relevant to quantum devices.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Materials Science (cond-mat.mtrl-sci)
13 pages, 4 figures
Extending Topological Bound on Quantum Weight Beyond Symmetry-Protected Topological Phases
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2026-03-16 20:00 EDT
Yi-Chun Hung, Yugo Onishi, Hsin Lin, Liang Fu, Arun Bansil
The quantum metric encodes the geometric structure of Bloch wave functions and governs a wide range of physical responses. Its Brillouin-zone integral, the quantum weight, appears in the structure factor and provides lower bounds on observables such as the optical gap and dielectric constant. In symmetry-protected topological (SPT) phases, the nontrivial band topology imposes a lower bound on the quantum weight and constraints on the observables. Here, we generalize the topological bound on quantum geometry to encompass systems beyond the SPT phases. We show that topological invariants defined via the projected spectrum lower-bound the quantum weight with a symmetry-breaking correction to the quantum metric. Our proposed bound holds even when the underlying symmetries are broken, and it would be amenable to experimental verification via the optical conductivity sum rule under external fields. We illustrate our theory by adding a nonzero spin-orbit coupling term to a spin Chern insulator model, where we show that our proposed bound applies even though the conventional topological bound does not hold.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Materials Science (cond-mat.mtrl-sci), Quantum Physics (quant-ph)
13 pages, 4 figures
A Straight Forward Method to Read the Nuclear Qudit of $4f$ Single-Molecule Magnets : $^{163}$DyPc$_2$
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2026-03-16 20:00 EDT
Hongyan Chen, Simon Gerber, Philip Schmid, Nola Warwick, Charanpreet Singh, Svetlana Klyatskaya, Eufemio Moreno-Pineda, Mario Ruben, Wulf Wulfhekel
Nuclear spins in $ 4f$ single-molecule magnets (SMMs) are promising qubits or qudits candidates for quantum information processing due to their relative isolation and reduced susceptibility to environmental disturbances, while hyperfine coupling with the $ 4f$ moments enables readout and control. So far, the nuclear spin states of individual TbPc$ _2$ SMMs have been detected in transport measurements via the spin-cascade effect, in which transitions of the Tb$ ^{3+}$ magnetic moment coupled to the unpaired ligand electron manifest as conductance jumps in spin-polarized transport. The ligand electron also gives rise to a Kondo effect through its interaction with the metallic contacts. By sweeping a magnetic field along the easy axis of the Tb$ ^{3+}$ moment, the system is tuned to avoided crossings of the hyperfine levels, such that the magnetic field at which the conductance jumps occur indicates the nuclear spin state. Here, we present a method to read the nuclear spin of $ ^{163}$ DyPc$ _2$ ($ I=5/2$ ) using millikelvin spin-polarized scanning tunneling microscopy without the need for magnetic-field sweeps. Instead, hyperfine interactions modify the statistics of the telegraph noise generated by reversals of the Dy$ ^{3+}$ moment, thereby revealing the nuclear spin state. We observe nuclear spin relaxation times $ T_1$ in excess of minutes at \SI{35}{mK}. Furthermore, we drive nuclear spin transitions using a radio-frequency field and detect the resulting nuclear magnetic resonance directly in the tunneling current, as the conductance near the split Kondo peaks depends on the nuclear spin state.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
Topological electric field-defined quantum dots in bilayer graphene: An atomistic approach
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2026-03-16 20:00 EDT
We study topological bound states in quantum dots defined by an electric field in bilayer graphene. An external field is perpendicular to the bilayer and changes sign in a finite region that defines the quantum dot. The electric field opens a gap in the bilayer graphene, and the reversed field creates a domain wall with one-dimensional chiral gapless bands localized therein. The finite size of dots leads to the quantization of these bands and the appearance of discrete bound states localized at the dot boundary. We consider rectangular dots oriented along the armchair and zigzag directions. We go beyond a simple continuum one-valley model and use an atomistic tight-binding approach. This allows us to identify new effects related to the atomic structure of graphene, strengths of the electric field, valley mixing, and valley asymmetry.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
6 pages, 6 figures
Data-efficient surrogate modeling of spectral functions using Gaussian processes: An application to the $t$-$t’$-$t’’$-$J$ model
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2026-03-16 20:00 EDT
Sanket Jantre, Nathan M. Urban, Weiguo Yin, Niraj Aryal
Spectral functions encode key many-body information but are costly to compute with high fidelity. Machine-learning surrogates have emerged as a powerful alternative, yet many approaches require large training datasets. We develop a data-efficient surrogate for spectral functions using the $ t$ -$ t’$ -$ t’’$ -$ J$ model, which describes the motion of a hole in a quantum antiferromagnet. Using $ \sim$ 10$ ^5$ self-consistent Born approximation-based spectra from Lee, Carbone and Yin (Phys. Rev. B 107, 205132 (2023)), we train a deep-kernel Gaussian process surrogate model with sparse variational inference (DKL-SVGP) using only 10% of the available training spectra. We benchmark against feed-forward neural networks (FFNN) trained on the same reduced subset and on the full dataset. The proposed DKL-SVGP model consistently outperforms the reduced-data FFNN and, despite using only 10% of the training spectra, achieves spectrum-wise errors within the same order-of-magnitude as the full-data FFNN baseline. Worst-tail diagnostics show improved fidelity on difficult spectra, while peak-level analysis indicates that DKL-SVGP recovers dominant peak heights with comparable accuracy and improves peak-location agreement under a matched-peak evaluation that mitigates rare peak-swapping cases. Overall, these results highlight GP-based surrogates as a competitive and data-efficient approach for spectral-function prediction in scarce-data regimes.
Strongly Correlated Electrons (cond-mat.str-el), Disordered Systems and Neural Networks (cond-mat.dis-nn)
6 figures
SU(2) gauge theory of fluctuating stripe order in the two-dimensional Hubbard model
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2026-03-16 20:00 EDT
Henrik Müller-Groeling, Pietro M. Bonetti, Paulo Forni, Walter Metzner
We present an SU(2) gauge theory of fluctuating stripe order in the two-dimensional Hubbard model. The theory is based on a fractionalization of the electron operators in fermionic chargons with a pseudospin degree of freedom, and charge neutral spinons capturing fluctuations of the spin orientation. The chargons are treated in a renormalized mean-field theory. We focus on regions of the phase diagram where they undergo stripe order. The spinons are described by a non-linear sigma model with pseudospin stiffnesses determined by the chargons. They prevent breaking of the physical SU(2) spin symmetry at any finite temperature, resulting in a charge ordered pseudogap phase with a reconstructed Fermi surface and a spin gap. The spectral function for single-particle excitations exhibits a collection of Fermi arcs and other structures. The arcs appear in various regions of the Brillouin zone, but never exclusively around the Brillouin zone diagonals.
Strongly Correlated Electrons (cond-mat.str-el)
Band offsets in InP/ZnSe nanocrystals evaluated using two-photon transitions analysis
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2026-03-16 20:00 EDT
K.I. Russkikh, A.A. Golovatenko, A.V. Rodina
We present a semi-analytical theoretical kp-study of the energy structure and optical transitions in spherical core-shell InP/ZnSe nanocrystals. We use the eight-band Kane model and the six-band Luttinger Hamiltonian in the spherical approximation to calculate the electron and hole energy spectra, respectively. The influence of the Coulomb interaction is considered perturbatively. The one- and two-photon absorption spectra are calculated as functions of the band offsets between the InP core and ZnSe shell. Exciton states responsible for the main features in the two-photon absorption spectra of InP/ZnSe nanocrystals are identified and the spectral dependence of the linear-circular dichroism signal is predicted. We show that in the presence of inhomogeneous broadening, the transition to the ground two-photon-active exciton state can be hidden behind intense transitions to higher-lying states. A comparison of the calculated one- and two-photon absorption spectra with the available experimental data shows that, depending on the lattice strain in the InP core, the range of possible valence band offsets is 0.85-1 eV. The determined range exceeds the natural valence band offset of 0.57 eV and indicates the presence of electric dipoles formed by the preferential Zn-P bonds at the InP/ZnSe heterointerface.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
Putative quantum critical point in locally noncentrosymmetric CeCoGe$_2$ crystals
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2026-03-16 20:00 EDT
F. Garmroudi, C. S. T. Kengle, M. H. Schenck, J. D. Thompson, E. D. Bauer, S. M. Thomas, P. F. S. Rosa
Locally noncentrosymmetric heavy-fermion compounds may produce long-sought correlated quantum phases, such as spin-triplet superconductivity with non-Abelian quasiparticles, but identifying the right candidate systems is challenging. Here, using the In flux method, we synthesize CeCoGe$ _2$ single crystals, belonging to the highly tunable pseudotetragonal ($ Cmcm$ ) Ce$ TX_2$ family, which allows for substitutions at both the transition metal $ T$ and at the $ X$ sites. We identify a heavy-fermion ground state with a Sommerfeld coefficient $ \gamma\approx 120$ mJ mol$ ^{-1}$ K$ ^{-2}$ and a non-Fermi-liquid exponent of the electrical resistivity, which may indicate its proximity to the putative quantum critical point. However, no signs of superconductivity or magnetic order are detected down to 20 mK. Our analysis of electrical transport and structural properties indicates that coherent charge transport and the emergence of superconductivity observed under hydrostatic pressure in related compounds (CePtSi$ _2$ and CeRhGe$ _2$ ) are suppressed in CeCoGe$ _2$ by strong random potential scattering due to intrinsic Co vacancies (approximately 4% even in the highest-quality crystals). By tuning the growth stoichiometry and temperature profile, we demonstrate that the defect concentration can be controlled and has a pronounced effect on the residual resistivity. We hypothesize that superconductivity may be found in higher-quality CeCoGe$ _2$ crystals grown by different techniques.
Strongly Correlated Electrons (cond-mat.str-el), Materials Science (cond-mat.mtrl-sci), Superconductivity (cond-mat.supr-con)
Rate-Dependent Reversibility and Lithium Losses in Hybrid Anode-Collector Metal Electrodes
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-03-16 20:00 EDT
Arturo Galindo (1), Jesus Diaz-Sanchez (2), Sunil Kumar (3), Bouthayna Alrifai (3), Andrea Marchetti (1), Gaston Garcia (3), Celia Polop (2), Enrique Vasco (1) ((1) Instituto de Ciencia de Materiales de Madrid ICMM-CSIC, (2) Departamento de Fisica de la Materia Condensada-Universidad Autonoma de Madrid, (3) Centro de Micro-Analisis de Materiales CMAM-Universidad Autonoma de Madrid)
Understanding how practical lithium storage capacity varies with charge-discharge rate is crucial for designing durable anode free lithium batteries. We examine the lithiation behavior of single element metal electrodes-Al (alloying), Mg (solid solution intercalation), Ag (solid solution then alloying), and Cu (surface Li plating)-to determine how their mechanisms influence reversibility, measured by coulombic efficiency. Using electrochemistry combined with depth resolved ion beam profiling, we map local coulombic efficiency across current densities and identify dominant lithium loss pathways. Ag uniquely sustains fast kinetics and high reversibility at elevated rates due to rapid formation of gamma brass-type alloy phases. In contrast, Mg and Al show increasing irreversibility from kinetically or structurally driven Li trapping, while Cu exhibits the largest losses through porous, highly reactive plated lithium. These results reveal fundamental limits of anode free systems that depend on reversible Li plating without excess lithium and underscore the importance of metal selection for stable, high rate performance.
Materials Science (cond-mat.mtrl-sci), Applied Physics (physics.app-ph)
Out-of-equilibrium percolation transitions at finite critical times after quenches across magnetic first-order transitions
New Submission | Statistical Mechanics (cond-mat.stat-mech) | 2026-03-16 20:00 EDT
Andrea Pelissetto, Davide Rossini, Ettore Vicari
We show that an out-of-equilibrium percolation transition occurs after quenching ferromagnetic Ising-like systems across their magnetic first-order transitions. As a paradigmatic example, we consider a two-dimensional Ising system driven across its low-temperature first-order transition line by a quench of the magnetic field $ h$ from $ h_i<0$ to $ h>0$ . In the thermodynamic limit and for finite values of $ h$ , the post-quench evolution under a purely relaxational dynamics is characterized by a dynamic transition at a finite critical time $ t_c(h)$ from the metastable negatively magnetized phase to the positive one, marked by the percolation of the largest clusters of positive and negative spins. This out-of-equilibrium percolation transition displays a finite-size scaling behavior as in the standard random-percolation case. However, while the fractal dimension of the percolating clusters is consistent with the random-percolation value, the exponent controlling the approach to criticality differs and depends on $ h$ . We also show that the percolation critical behavior is related to the spinodal-like behavior of the magnetization in the small-$ h$ limit, which implies that the percolation time $ t_c(h)$ exhibits a spinodal-like exponential dependence on $ h$ .
Statistical Mechanics (cond-mat.stat-mech), High Energy Physics - Lattice (hep-lat)
8 pages
Nested Feature Spectrum Topology: Tripartite Topological Equivalence of Feature, Entanglement, and Wilson Loop Spectrum
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2026-03-16 20:00 EDT
Yi-Chun Hung, T. Tzen Ong, Hsin Lin
Topological phases of matter are traditionally characterized through symmetry-based classifications. In cases of symmetry breaking, the projected spectrum - obtained by projecting the ground state onto the eigenstates of a pertinent quantum observable, such as spin or orbital angular momentum - provides a clear method for classifying topological phases. This approach underpins well-known frameworks such as spin-resolved topology and feature spectrum topology. Here we introduce nested feature spectrum topology, in which projection operators are applied recursively to subsectors of the feature spectrum, generating a hierarchy of feature spectra. We uncover a fundamental tripartite equivalence among the topology of feature, the entanglement, and the Wilson loop spectra in non-interacting fermionic systems. This equivalence reveals that the feature spectrum encodes the entanglement between sectors of the quantum observable, such as the spin-up and spin-down states in spin-resolved topology. We further prove that spectral flow in the entanglement spectrum and the Wilson loop winding in the feature spectrum are equivalent manifestations of the feature-energy complementarity: the appearance of gapless spectral flow in either energy or projected spectra on the boundary. This complementarity refines the conventional bulk-boundary correspondence by demonstrating that topological boundary modes may persist in the feature spectrum even when energy spectra are gapped. Our results provide a deeper understanding and solid foundation for the origin of band topology in the feature spectrum.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Materials Science (cond-mat.mtrl-sci), Quantum Physics (quant-ph)
22 pages, 4 figures
Towers of quantum many-body scars under stochastic resetting
New Submission | Statistical Mechanics (cond-mat.stat-mech) | 2026-03-16 20:00 EDT
Lorenzo Gotta, Manas Kulkarni, Gabriele Perfetto
Towers of quantum many-body scars are sets of highly-excited eigenstates of nonintegrable Hamiltonians whose dynamics shows athermal behavior and persistent oscillations in time. The preparation of such states is, however, challenging due to their entanglement content. In this work, we show that local properties of such states can be prepared by interspersing the scarred dynamics with stochastic resets to much simpler unentangled product states. Stochastic resetting amounts to reinitializing the many-body wavefunction of the system at random times to a predefined state, which we choose to be in the scarred subspace. We derive several analytical results for the ensuing dynamics, e.g., for the time evolution of the fidelity and of local observables. Resetting damps the scarred oscillations and generates spatial off-diagonal long-range order in the ensuing stationary state. The latter shows mixedness that scales logarithmically as a function of the system size, which follows from the structure of the scarred eigenstates. We prove that such stationary states are locally equivalent, in the sparse-resetting limit, to a single pure scarred eigenstate, which is determined by the reset state. This protocol thereby might represent a route to the experimental preparation of the local properties of correlated and entangled states through resetting.
Statistical Mechanics (cond-mat.stat-mech), Quantum Gases (cond-mat.quant-gas)
24 pages, 5 figures
Zinc selenide single crystals co-doped with active TM-ions of chromium, cobalt and iron
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-03-16 20:00 EDT
Sergei Naydenov, Oleksii Kapustnyk, Igor Pritula, Dmitro Sofronov
The development of laser materials with absorption/emission spectra in the atmospheric transparency band 2-5 microns is of great interest for modern applications. Triple-doped zinc selenide crystals activated with chromium, cobalt, and iron ions were grown by the vertical Bridgman method under high argon pressure. Comparative X-ray diffractometry, infra-red spectroscopy, and other studies of grown crystals were conducted. Features of their growth, morphology, and optical properties related to the crystal structure were discovered.
Materials Science (cond-mat.mtrl-sci), Applied Physics (physics.app-ph), Atomic Physics (physics.atom-ph), Optics (physics.optics)
15 pages, 8 figures
Inverse Faraday Effect in Rashba two-dimensional electron systems: interplay of spin and orbital effects
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2026-03-16 20:00 EDT
The inverse Faraday effect (IFE) refers to the generation of a DC magnetization by circularly polarized light through the transfer of optical angular momentum to electronic degrees of freedom. In conducting systems, this response can arise from two microscopic channels - spin polarization of itinerant electrons and orbital magnetization generated by circulating charge currents. However, the orbital contribution to the inverse Faraday effect in spin-orbit-coupled conducting systems remains largely unexplored. We present a theoretical analysis of the IFE in disordered two-dimensional electron systems with Rashba spin-orbit coupling using both the quantum kinetic equation and Green’s-function diagrammatics. We find that in a noninteracting Rashba metal the orbital magnetization is strongly modified by spin-orbit coupling and can become comparable to, or exceed, the spin magnetization for realistic parameter regimes. When the radiation frequency approaches the Rashba spin splitting, both spin and orbital magnetizations exhibit resonant enhancement. These results clarify the microscopic origin of light-induced magnetization and highlight the interplay of spin and orbital mechanisms in optically driven magnetization dynamics in low-dimensional electronic systems.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Optics (physics.optics)
10 pages, 5 figures
Microscopic flexoelectricity in the canonical PMN relaxor
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-03-16 20:00 EDT
Previously reported neutron scattering investigations of the canonical relaxor ferroelectric perovskite oxide with a chemical formula Pb(Mg(1/3)Nb(2/3))O3 (PMN) are revisited in order to appreciate the role of the intrinsic bulk flexoelectricity. Despite the outstanding electromechanical properties of lead-based relaxors, the magnitude of the flexoelectric coupling coefficient derived here directly from the PMN neutron diffuse scattering data, does not exceed the range of values typical for conventional perovskite ferroelectrics. We explain how these findings are related in the framework of the Ginzburg-Landau-Devonshire and the ferroelectric soft mode theory. We propose that the relaxor properties of PMN might be related to the suppression of the transverse correlation length of the flexoelectrically hybridized translational-polarization fluctuations due to its closeness to the Lifshitz-point regime.
Materials Science (cond-mat.mtrl-sci), Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
6 pages,2 figures
A Spatial Localizer for Electrons in Insulators
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-03-16 20:00 EDT
Haylen Gerhard, Yifan Wang, Alexander Cerjan, Wladimir A. Benalcazar
The location of electrons governs phenomena ranging from chemical bonding and electric polarization to the topological classification of band insulators and the emergence of correlated states in quantum matter. While a prescription exists for finding local state representations of electrons in one-dimensional insulators, no comparably general theory exists in higher dimensions. Here, we introduce a general framework for finding the location of electrons in insulators in two and three dimensions based on the spectral properties of quantum-mechanical operators that we term Spatial Localizers. This framework naturally extends the notion of Wannier centers to insulators with boundaries, defects, and disorder, which we use to establish a position-space formulation of the bulk-defect correspondence for electronic charge. This framework also yields maximally localized electronic states. As two representative examples, we show that these states reduce to maximally localized Wannier functions in atomic insulators, whereas in Chern insulators they form coherent states that mirror the coherent-state structure of Landau levels in the quantum Hall effect.
Materials Science (cond-mat.mtrl-sci), Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
First-principles predictions of band alignment in strained Si/Si1-xGex and Ge/Si1-xGex heterostructures
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2026-03-16 20:00 EDT
Nathaniel M. Vegh, Pericles Philippopoulos, Raphaël J. Prentki, Wanting Zhang, Yu Zhu, Félix Beaudoin, Hong Guo
Accurate band offsets are essential for predictive continuum modeling of nanostructures such as quantum wells and quantum dots formed in strained Si/Si1-xGex and Ge/Si1-xGex heterostructures. Experimental offset data for these systems remain sparse away from endpoint compositions, making composition-dependent design difficult. We use atomistic first-principles density functional theory to compute valence- and conduction-band offsets across the full range 0 <= x <= 1. Random alloying is treated with special quasirandom structures, interface lineup terms are extracted from macroscopically averaged local Kohn-Sham potentials in thick periodic superlattices, valence-band spin-orbit coupling is included through species-resolved Mulliken weights, and conduction-band edges are refined using the screened hybrid Heyd-Scuseria-Ernzerhof functional. The resulting offsets show pronounced composition nonlinearity beyond the linear models explored in previous works, agree with experimental benchmarks, and reproduce the high-Ge slope change in the relaxed-alloy band gap. Analytic fitting expressions are provided for direct use in simulations, facilitating practical design of modern quantum technology devices.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Materials Science (cond-mat.mtrl-sci), Quantum Physics (quant-ph)
5 pages, 4 figures. Prepared for submission to Applied Physics Letters
Electromechanical Hysteresis in Phase Change Material Sb2S3
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-03-16 20:00 EDT
Jack Kaman, Evan Musterman, Kyle P. Kelley, Neus Domingo-Marimon, Volkmar Dierolf, Himanshu Jain
Antimony sulfide is an emerging phase change material for optical and electrical memory and computation elements. It has additionally been reported as a ferroelectric, with recent evidence from hysteresis in piezoresponse force microscopy. Here, we complete a rigorous set of piezoresponse force microscopy experiments on a congruently crystallized Sb2S3 glass-ceramic, where piezoelectric coupling should be forbidden in glassy Sb2S3. We replicate previous results and reveal that the behavior is absent in glassy Sb2S3 but show that the response originates primarily from non-piezoelectric contributions to the signal caused by an applied voltage. This hysteretic behavior in piezoresponse force microscopy is quite similar to some electrochemically active non-ferroelectric oxides, but uniquely, it appears here with a very clear spatial contrast that is decoupled from surface topography. This shows that the electromechanical signal reflects bulk-like properties and reveals differences in electrical behavior of crystalline and amorphous phases of Sb2S3.
Materials Science (cond-mat.mtrl-sci)
30 pages total including 3 pages of Supporting Information
Two-channel physics in a lightly doped antiferromagnetic Mott insulator revealed by two-hole spectroscopy
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2026-03-16 20:00 EDT
Pit Bermes, Sebastian Paeckel, Annabelle Bohrdt, Lukas Homeier, Fabian Grusdt
Understanding pairing in the strong-coupling regime of doped Mott insulators remains an open problem in the context of cuprate superconductors. We perform ultra-high resolution numerical simulations of spectral functions in the highly underdoped $ t-J$ model and discover two coupled branches of hole pairs emerging at low energies in the largely unexplored two-particle spectrum. As spin anisotropy is tuned from the Ising limit to the $ SU(2)$ -symmetric Heisenberg regime, the lowest $ d$ -wave pair evolves from a single bipolaronic branch into two hybridized branches separated by an avoided crossing. We explain this behaviour using an effective two-channel model involving a tightly bound bipolaronic state and a second channel associated with two magnetic polarons. The model reproduces the qualitative low-energy spectra and implies near-resonant $ d$ -wave interactions in the $ SU(2)$ -symmetric $ t-J$ model, consistent with proximity to an emergent Feshbach-type resonance. To probe these predictions experimentally, we propose a Raman spectroscopy scheme for the attractive Hubbard model that can be directly implemented using ultracold atoms in optical lattices. Our work establishes two-particle spectroscopy, beyond single-particle Green’s functions, as a powerful tool for revealing the microscopic origins of unconventional superconductivity.
Strongly Correlated Electrons (cond-mat.str-el), Quantum Gases (cond-mat.quant-gas), Quantum Physics (quant-ph)
7 pages, 4 figures
Magnetotransport in the presence of real and momentum space topology
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2026-03-16 20:00 EDT
We investigate magnetotransport in a time-reversal symmetry-broken, untilted Weyl semimetal in the simultaneous presence of momentum-space Berry curvature and real-space topology arising from a skyrmion-induced emergent magnetic field $ \mathbf{B}{\mathrm{emer}}$ . Using a semiclassical Boltzmann approach incorporating Berry-curvature corrections and intervalley scattering, we analyze the longitudinal magnetoconductivity and planar Hall conductivity in this mixed-topology regime. In the absence of $ B{\mathrm{emer}}$ , increasing intervalley scattering drives a strong sign reversal of the longitudinal magnetoconductivity. A finite $ \mathbf{B}{\mathrm{emer}}$ introduces an additional shift of the parabolic magnetic-field dependence, leading to a weak sign-reversal regime without altering the curvature. The coexistence of these effects naturally produces a strong-and-weak sign-reversal regime, demonstrating that intervalley scattering and real-space topology control distinct geometric features of the response. The emergent field further induces asymmetry in the angular dependence of both longitudinal and planar Hall conductivities. We show that a finite planar Hall response can arise solely from $ \mathbf{B}{\mathrm{emer}}$ when its direction is varied, providing a transport signature of real-space topology. Our results establish that the skyrmion-induced emergent field acts as an independent topological tuning parameter, revealing measurable consequences of the interplay between real- and momentum-space Berry curvature in Weyl systems.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
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