CMP Journal 2026-03-09
Statistics
Nature Materials: 4
Nature Nanotechnology: 2
Nature Physics: 1
arXiv: 72
Nature Materials
Room-temperature two-dimensional multiferroic metal with voltage-controllable magnetic order
Original Paper | Ferroelectrics and multiferroics | 2026-03-08 20:00 EDT
Dacheng Tian, Shulin Zhong, Jianyu Dong, Song Zhou, Zhiwen Liu, Kai Chen, Wenhua Zhang, Liang Cao, Xiaoyue He, Xiu Li, Tengyu Guo, Kunrong Du, Haifeng Feng, Yu Wang, Peng Cheng, Yiqi Zhang, Baojie Feng, Kehui Wu, Suhuai Wei, Yi Du, Yunhao Lu, Lan Chen
Realizing two-dimensional multiferroics with robust magnetoelectric coupling for electric-field-controlled magnetism at room temperature poses substantial challenges, as ferroelectricity and magnetism inherently conflict. Here we report air-stable bilayer CrTe2 that exhibits intrinsic room-temperature multiferroicity. Structural and magnetic characterization reveals an alternating ferromagnetic and antiferromagnetic bilayer architecture, driven by interlayer charge transfer that spontaneously breaks inversion symmetry and generates a switchable out-of-plane ferroelectric polarization. Scanning probe microscopy confirms the non-volatile control of magnetization states with an electric field, enabling electrical writing and magnetic reading functionalities. This mechanism, rooted in interlayer charge transfer, rather than conventional spin-orbit coupling, provides a foundation for engineering multiferroics with layered systems. The demonstration of a two-dimensional multiferroic material with magnetoelectric coupling under ambient conditions provides opportunities for energy-efficient memory devices and quantum sensing technologies.
Ferroelectrics and multiferroics, Surfaces, interfaces and thin films, Two-dimensional materials
An iontronic reservoir for highly robust neuromorphic prosthesis
Original Paper | Electrical and electronic engineering | 2026-03-08 20:00 EDT
Mengjiao Pei, Tian Gao, Li Liu, Wenlong Li, Haotian Long, Yifei Luo, Zhaogang Teng, Hangyuan Cui, Xiang Li, Qinyong Dai, Kailu Shi, Lesheng Qiao, Baocheng Peng, Qianye Xing, Manhua Wen, Mengtao Han, Zhenhua Wan, Yun Li, Bin Xue, Yi Cao, Yi Shi, Qing Wan, Xiaodong Chen, Changjin Wan
Neuromorphic prosthesis demands not only the assembly of neural architectures and functions but also robustness against unpredictable failures in dynamic physiological environments. While self-healing electronics have been demonstrated to restore synapse-like functions, their application to higher-order cognitive functions remains limited. Here we present a hydrogel-based iontronic reservoir that demonstrates exceptional physical and functional robustness for neuromorphic prosthesis. The nonlinear dynamics of the hydrogel-electrode interface can serve as a physical reservoir to preprocess time series, with minimized susceptibility to physical damage. Our system based on the hydrogel-based iontronic reservoir achieves 95% accuracy in speech recognition and can restore such capability within 0.02 s after reattaching the fractured points, outperforming biological systems in the neurorehabilitation process. Moreover, its pH-sensitive dynamics enable adaptive closed-loop neural stimulation control in a rat model, validating its potential for neural rehabilitation and sensorimotor function restoration. We expect such a hydrogel-based iontronic reservoir to improve both processing efficiency and robustness for next-generation neuroprosthetics and human-machine interfaces.
Electrical and electronic engineering, Electronic devices
Proton shuttle-assisted triplet energy transfer
Original Paper | Organic-inorganic nanostructures | 2026-03-08 20:00 EDT
Zhaolong Wang, Jingyi Zhu, Kaifeng Wu
Electronic transition/motion coupled with proton transfer has a key role in natural and artificial energy conversion and storage materials. Previous examples include proton-coupled electron transfer and singlet energy transfer, but not triplet energy transfer. Here we report a mechanism termed proton shuttle-assisted triplet energy transfer. The system comprises ZnSe-based quantum dots surface anchored with phenol-pyridine dyadic acceptors. Ultrafast measurements and kinetic isotope effects establish that the photoexcitation of ZnSe leads to hole transfer from ZnSe to phenol, which is coupled with proton transfer from phenol to pyridine. A subsequent step of electron transfer from ZnSe to phenoxyl radical, coupled with back proton transfer from pyridinium, accomplishes a net process of spin-triplet migration from ZnSe to phenol-pyridine. Adding a strongly electron-withdrawing trifluoromethyl substituent on pyridine can switch the sequence of proton-coupled electron and hole transfer steps. Compared with a methylated analogue acceptor lacking the shuttle, the assistance of proton shuttle substantially increases the energy transfer rate and efficiency.
Organic-inorganic nanostructures, Photochemistry
Quantum control of Hubbard excitons
Original Paper | Electronic properties and materials | 2026-03-08 20:00 EDT
Denitsa R. Baykusheva, Deven Carmichael, Clara S. Weber, I-Te Lu, Filippo Glerean, Tepie Meng, Pedro B. M. De Oliveira, Christopher C. Homes, Igor A. Zaliznyak, G. D. Gu, Mark P. M. Dean, Angel Rubio, Dante M. Kennes, Martin Claassen, Matteo Mitrano
Quantum control of the many-body wavefunction is a central challenge in quantum materials research, as it could yield a precise control knob to manipulate emergent phenomena. Floquet engineering, the coherent dressing of quantum states with periodic non-resonant optical fields, has become an important strategy for quantum control. Most applications to solid-state systems have targeted weakly interacting or single-ion states, leaving the manipulation of many-body wavefunctions largely unexplored. Here we use Floquet engineering to achieve quantum control of a strongly correlated Hubbard exciton in the one-dimensional Mott insulator Sr2CuO3. A non-resonant mid-infrared optical field coherently dresses the exciton wavefunction, driving its rotation between bright and dark states. We use resonant third-harmonic generation to quantify ultrafast π/2 rotations on the Bloch sphere spanned by these exciton states. Our work advances the quest towards programmable control of correlated states and exciton-based quantum sensing.
Electronic properties and materials, Nonlinear optics, Ultrafast photonics
Nature Nanotechnology
Protonic nickelate device networks for spatiotemporal neuromorphic computing
Original Paper | Electrical and electronic engineering | 2026-03-08 20:00 EDT
Yue Zhou, Shaan Shah, Tamal Dey, Yucheng Zhou, Ashwani Kumar, Sashank Sriram, Siyou Guo, Siddharth Kumar, Ranjan Kumar Patel, Eva Y. Andrei, Ertugrul Cubukcu, Shriram Ramanathan, Duygu Kuzum
Computation in biological neural circuits arises from the interplay of nonlinear temporal responses and spatially distributed dynamic network interactions. Replicating this richness in hardware has remained challenging, as most neuromorphic devices emulate only isolated neuron- or synapse-like functions. Here we introduce an integrated neuromorphic computing platform in which both nonlinear spatiotemporal processing and programmable memory are realized within a single perovskite nickelate material system. By engineering symmetric and asymmetric hydrogenated NdNiO3 junction devices on the same wafer, we combine ultrafast, proton-mediated transient dynamics with stable multilevel resistance states. Networks of symmetric NdNiO3 junctions exhibit emergent spatial interactions mediated by proton redistribution, while each node simultaneously provides short-term temporal memory, enabling nanosecond-scale operation with an energy cost of ~0.2 nJ per input. When interfaced with asymmetric output units serving as reconfigurable long-term weights, these networks allow both feature transformation and linear classification in the same material system. Leveraging these emergent interactions, the platform enables real-time pattern recognition and achieves high accuracy in spoken digit classification and early seizure detection, outperforming temporal-only or uncoupled architectures. These results position protonic nickelates as a compact, energy-efficient, CMOS-compatible platform that integrates processing and memory for scalable intelligent hardware.
Electrical and electronic engineering, Electronic devices
AND logic nanoparticle for precision immunotherapy of metastatic cancers
Original Paper | Bioconjugate chemistry | 2026-03-08 20:00 EDT
Shuyue Ye, Shuang Chen, Vijay Basava, Katy Torres, Yangyang Zhao, Gang Huang, Mingyi Chen, Jinming Gao
Success in systemic immunotherapy against metastatic cancer hinges on the ability to achieve tumour-specific immune activation over normal tissues. Single-gate stimuli-responsive systems are not adequate at differentiating tumour versus normal tissue signals. Here we report an AND-gated nanoparticle that requires acidic pH and hypoxia signals to activate the stimulator of interferon genes (STING) pathway in systemic therapy of metastatic cancers. The dual stimuli-responsive nanoparticle consists of a small-molecule STING agonist conjugated to a pH-sensitive polymer through a hypoxia-sensitive linker. Biochemical analyses confirmed the (pH-hypoxia) AND logic truth table in STING activation. The nanoparticle agonist significantly reduced metastatic burdens in multiple immune-cold tumour models while exhibiting minimal systemic toxicity. Mechanistic investigation revealed that STING activation in tumour-resident type I dendritic cells drives CD8+ T cell priming and infiltration, which synergizes with immune checkpoint inhibitors. This AND logic nanoplatform offers a safe and efficacious therapeutic for STING-mediated immunotherapy against metastatic cancers.
Bioconjugate chemistry, Drug delivery, Nanoparticles, Polymer synthesis
Nature Physics
Geometric origin of particle and dislocation dynamics during grain boundary migration
Original Paper | Colloids | 2026-03-08 20:00 EDT
Berend van der Meer, Mathieu G. Baltussen, François A. Lavergne, Arran Curran, Marjolein Dijkstra, Roel P. A. Dullens
Grain boundaries are complex defects in polycrystalline systems and their migration has a key role in determining the properties of such solids. Understanding grain boundary motion in terms of both particle and dislocation dynamics remains a central problem. Here we establish a fundamental geometric principle governing grain boundary migration at the microscopic level: particles preferentially transition between grains at specific lattice equivalence points identified through a refined O-lattice construction. We validate this principle using loop-shaped grain boundaries in two-dimensional colloidal crystals created with holographic optical tweezers and computer simulations. Building on this principle, we develop a geometric framework that accurately predicts the microscopic dynamics of both particles and dislocations during grain boundary migration. Our results shed light on the microscopic mechanism of grain boundary migration and reveal the intrinsic connection between the dynamics of particles and dislocations.
Colloids, Condensed-matter physics
arXiv
Fingerprinting fractons with pump-probe spectroscopy
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2026-03-09 20:00 EDT
Wei-En Tseng, Oliver Hart, Rahul Nandkishore
We demonstrate how pump-probe techniques enable specific diagnostics of fracton phases of matter by exploring how lineon-planon braiding in the paradigmatic X-cube phase may be probed spectroscopically. Our discussion builds on works explaining how to probe anyonic exchange statistics spectroscopically in traditional spin liquids. However, the extension to fracton phases reveals qualitatively new features coming from the existence of multi-anyon bound states, which alter the long-time asymptotic behavior of the signal. In particular, the signal we examine is sensitive to (i) the existence of nontrivial braiding statistics in three dimensions, (ii) the fact that some of the fractionalized excitations can form bound states, and (iii) that some of the fractionalized excitations are lineonic in nature (i.e., mobile only in one dimension). Thus, one can spectroscopically detect not only the existence of anyonic braiding statistics in fracton phases, but can crisply distinguish it from anyons in traditional (non-fractonic) spin liquids.
Strongly Correlated Electrons (cond-mat.str-el)
Evolution of the Superfluid Density in Infinite-Layer Nickelates
New Submission | Superconductivity (cond-mat.supr-con) | 2026-03-09 20:00 EDT
Bai Yang Wang, Shannon P. Harvey, Kyuho Lee, Yijun Yu, Yonghun Lee, Motoki Osada, Chaitanya Murthy, Srinivas Raghu, Harold Y. Hwang
Nickelate superconductors provide a valuable new platform for the study of unconventional superconductivity that is complementary to the cuprates. One of the central puzzles about high-temperature superconductors is what factors determine the scale of their superconducting transition temperature ($ T_\mathrm{c}$ ). To address this question for infinite-layer nickelates, we present a systematic mutual inductance study of the superfluid density across the doping-dependent superconducting dome of $ \mathrm{Nd}_{1-x}\mathrm{Sr}x\mathrm{NiO}2$ . We observe a weak superfluid stiffness that exhibits an approximately square-root correlation with $ T\mathrm{c}$ . We also find a strong interplay between Nd magnetism and the superconducting phase, manifested as a substantial low-temperature suppression of superfluid density. These observations highlight the importance of superconducting phase fluctuations in limiting $ T\mathrm{c}$ and unexpectedly strong coupling between the Nd 4$ f$ moments and the superfluid.
Superconductivity (cond-mat.supr-con)
Ultra-slow orbital and spin dynamics in an electrically tunable quantum dot molecule
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2026-03-09 20:00 EDT
Christopher Thalacker, Michelle Lienhart, Markus Stöcker, Nadeem Akhlaq, Irina Ivanova, Nikolai Bart, Arne Ludwig, Johannes Schall, Stephan Reitzenstein, Dirk Reuter, Steffen Wilksen, Christopher Gies, Krzysztof Gawarecki, Paweł Machnikowski, Kai Müller, Jonathan Finley
Tunnel-coupled optically active quantum dot molecules (QDMs), have the potential to operate as spin-photon-interfaces with coupled spins that interact with two different photon frequencies at the same time. A prerequisite is to deterministically prepare two (electron or hole) spins in the QDM and be able to electrically tune the orbital state couplings. Here, we demonstrate the sequential optical charging of a single QDM with two electron spins while simultaneously maintaining the ability to widely tune orbital couplings using static electric fields and optically drive the system for quantum light generation. We optically prepare one- and two-spin states, initialize via optical pumping and explore orbital and spin relaxation dynamics for one and two-spin states as a function of the energy detuning and hybridization of orbital states. For two-spin states, remarkably long S-T relaxation times are observed extending beyond $ \sim 100\mu s$ with strong dependence on the relative energy of ground and excited two-spin states. Qualitative agreement is observed with $ \mathbf{k \cdot p}$ calculations of phonon-mediated spin-relaxation. Our results provide new quantitative understanding of the dynamics of one and two-spin states and confirm their suitability of QDMs for creating multidimensional photonic cluster states by exploiting tunable spin-spin exchange couplings at zero magnetic fields combined with optical driving.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Quantum Physics (quant-ph)
24 pages, 15 figures
Identification of an Unreported Structure Type in GdNiSn4 and Its Implications for Materials Prediction
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-03-09 20:00 EDT
Xin Zhang, Scott B. Lee, Sudipta Chatterjee, Hanqi Pi, Yi Yang, Fatmagül Katmer, Emily G. Ward, Daniel E. Widdowson, Charles C. Tam, Sarah Schwarz, Connor J. Pollak, Jaime M. Moya, Grigorii Skorupskii, Vitaliy A. Kurlin, Stephen D. Wilson, B. Andrei Bernevig, Leslie M. Schoop
Crystal structures define how matter is organized at the atomic level. In the realm of crystalline inorganic materials, new structure types are rarely found, and most experimentally-realized structural motifs were established decades ago. Considerable efforts are underway to discover new crystalline inorganic compounds, often aided by artificial intelligence (AI). However, thus far, these methods have not yielded convincing new structure types, but rather substitutional variations of existing compounds. Here we introduce a new structure type adopted by the compound GdNiSn4, discovered the old-fashioned way. We test whether current state-of-the-art AI-based material generation models can predict this material in its correct structure and find that they fail to do so. We carefully analyze the new structure and argue that it can be viewed as a stack of two known structure types. We explore electronic and steric factors underlying its stability and propose strategies to improve future AI-guided materials discovery. Furthermore, we report complex magnetic properties in GdNiSn4, highlighting its potential interest for future studies of unconventional magnetism.
Materials Science (cond-mat.mtrl-sci)
Physics of active polymers: scaling analysis via a compounding formula
New Submission | Soft Condensed Matter (cond-mat.soft) | 2026-03-09 20:00 EDT
Takahiro Sakaue, Enrico Carlon
Active polymeric systems exhibit a rich spectrum of non-equilibrium phenomena arising from stochastic forces that explicitly break detailed balance. Despite the rapid growth of experimental and numerical studies, analytical progress remains limited. To date, theoretical understanding relies largely on variants of the active Rouse model, whose formal solutions, though exact, are often obscured by summations over Rouse modes and therefore provide limited direct physical insight. In this work, we develop a transparent scaling theory that captures the tagged-monomer mean-squared displacement (MSD) in active polymers through a compounding formula: the MSD of a monomer in the chain is expressed as that of an isolated active particle, modulated by a connectivity factor encoding tension propagation along the polymer backbone. This approach isolates the role of activity from that of polymer connectivity and reveals the emergent dynamical regimes in a physically intuitive manner. We test the scaling predictions against exact calculations for a broad class of generalized active polymer models driven by diverse noise statistics. The agreement demonstrates the robustness of the scaling framework across microscopic details. Our results provide a simple and extensible theoretical structure that can be applied to complex and analytically intractable active polymer systems, thereby offering a unifying perspective on non-equilibrium polymer dynamics.
Soft Condensed Matter (cond-mat.soft), Statistical Mechanics (cond-mat.stat-mech)
17 pages, 6 figures
Operational Emergence of a Global Phase under Time-Dependent Coupling in Oscillator Networks
New Submission | Statistical Mechanics (cond-mat.stat-mech) | 2026-03-09 20:00 EDT
Collective synchronization is often summarized by a complex order parameter $ R e^{i\Psi}$ , implicitly treating the global phase $ \Psi$ as a meaningful macroscopic coordinate. Here we ask when $ \Psi$ becomes \emph{operationally well-defined} in oscillator networks whose coupling varies in time. We study damped (and optionally inertial) phase-oscillator models on graphs with time-dependent coupling $ K(t)$ , covering standard Kuramoto dynamics as a limit and including network and spatial topologies relevant to engineered settings.
We propose an operational emergence criterion: a macroscopic phase is emergent only when it is robustly estimable, which we quantify via gauge-fixed phase-lag fluctuations under weak noise and finite sampling. This yields a quantitative threshold controlled by $ NR^2$ and makes explicit why $ \Psi$ is ill-posed in incoherent states even when formally definable. Nonautonomous coupling introduces a ramp timescale that competes with relaxation. Using a Laplacian-mode reduction near coherence, we derive a graph-spectral rate criterion: ordering tracks the protocol when $ K(t)\lambda_2$ dominates the ramp rate, while faster ramps induce freeze-out. Numerically, we extract an operational freeze-out time from an energy-based tracking diagnostic and show that, for non-spatial networks, the residual incoherence at freeze-out collapses when plotted against the spectral protocol parameter $ \lambda_2\tau$ across Erdős–Rényi and small-world graph families. Finally, on periodic lattices we show that topological sectors and defect-mediated ordering obstruct complete alignment, leading to protocol-dependent, long-lived partially synchronized states and systematic deviations from spectral collapse.
Statistical Mechanics (cond-mat.stat-mech), Chaotic Dynamics (nlin.CD), Physics and Society (physics.soc-ph)
16 pages, 7 figures
SAFT-P: A plaquette level perturbation for self-assembly in patchy colloids
New Submission | Soft Condensed Matter (cond-mat.soft) | 2026-03-09 20:00 EDT
Hamza Coban, Alfredo Alexander-Katz
We introduce SAFT-P, a plaquette-level extension of Statistical Associating Fluid Theory for patchy particles. By treating local clusters as associating superparticles and contracting their free energy back to monomer densities, SAFT-P retains information about patch topology that is lost in conventional SAFT. Grand-canonical Monte Carlo simulations of binary and ternary mixtures show that SAFT-P captures topology-dependent critical points and coexistence curves and discriminates between particles with identical valence but different patch layouts. Beyond topology, incorporating plaquette-scale correlations also improves predictions in regimes where patch specific interactions are absent. Results indicate that resolving correlations at the plaquette scale provides an analytical route to model complex condensates and self-assembly with topology-sensitive local structure.
Soft Condensed Matter (cond-mat.soft), Chemical Physics (physics.chem-ph)
Active Learning for Tractable and Reproducible Pulsed Laser Deposition
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-03-09 20:00 EDT
Jackson S. Bentley, Christopher Rouleau, Ilia N. Ivanov, T. Zac Ward, Jiaqiang Yan, Anghea Dolisca, Rob G. Moore, Gyula Eres, Richard F. Haglund, Sumner B. Harris, Matthew Brahlek
This paper shows how data-driven machine learning approaches can improve growth control, reproducibility, and physical insight in the pulsed laser deposition (PLD) growth of correlated oxides. Despite well-known relationships between growth conditions and material properties, consistently producing high-quality films of complex materials like LaVO$ _3$ remains difficult due to the highly non-equilibrium nature of PLD and the defects and competing phases that accumulate during growth. Here, we use an active learning framework based on Gaussian process Bayesian optimization that incorporates measured bulk and surface lattice properties along with impurity phase information to efficiently map the multidimensional growth space of LaVO$ _3$ by PLD. By tuning the relative weighting of these properties, the model identifies an optimized region where phase-pure films of LaVO$ _3$ exhibit two-dimensional surfaces, near-ideal lattice parameters, and minimal sub-band gap optical absorption. The trained model reveals clear competition among different defect formation mechanisms that are connected to unseen parameters like supersaturation and surface mobility, thus giving insight into the highly non-equilibrium process of PLD growth. Together, this demonstrates that property-guided machine learning can accelerate materials optimization while providing a new way to address fundamental growth mechanisms in PLD that enable understanding and utilization of quantum phenomena found in complex oxides.
Materials Science (cond-mat.mtrl-sci)
6 figures and 18 pages in main text, including references; 8 figures and 11 pages in the supplement
The toric code under antiferromagnetic isotropic Heisenberg interactions
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2026-03-09 20:00 EDT
Won Jang, Robert Peters, Thore Posske
We investigate the impact of an isotropic antiferromagnetic Heisenberg perturbation on the toric code, focusing on the resulting quantum phase transition and the nature of the phase that emerges beyond topological order. Using neural-network quantum states (NQS), we compute ground states over a wide range of Heisenberg couplings while fully respecting the exact symmetries of the model. In the weak-coupling regime, the numerical results are in excellent agreement with an effective low-energy description derived from a Schrieffer-Wolff (SW) transformation, providing analytic control over the perturbative breakdown of topological order. We show that the Heisenberg perturbation only renormalizes local operators at low orders, whereas mixing between topological sectors occurs only at a perturbative order proportional to the system size. At intermediate values of the Heisenberg interaction, the topological phase breaks down. We estimate the critical point through a combination of the fidelity susceptibility and the logarithmic susceptibility of non-contractible Wilson loops for various system sizes. Furthermore, we utilize the topological entanglement entropy to provide a comprehensive characterization of the phase transition. Beyond the transition, an antiferromagnetic $ \pm X/\pm Z$ Néel phase emerges, characterized by a fourfold-degenerate symmetry-broken manifold, which is explicitly probed using staggered-magnetization-based diagnostics. Our results show how local two-spin interactions, which naturally arise in realistic implementations of the toric code, drive the breakdown of topological order. Moreover, we establish the SW approach as a systematic framework for analyzing such perturbations in combination with variational many-body methods.
Strongly Correlated Electrons (cond-mat.str-el), Disordered Systems and Neural Networks (cond-mat.dis-nn), Quantum Physics (quant-ph)
Charge-ordered states in twisted MoTe$_2$
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2026-03-09 20:00 EDT
Sparsh Mishra, Tobias M. R. Wolf, Allan H. MacDonald
We analyze interaction-driven charge-density-wave (CDW) states in the spin-valley polarized first valence miniband of twisted MoTe$ _2$ (tMoTe$ _2$ ) using an adiabatic mapping from the continuum model to an effective Landau-level (LL) problem. When projected to the lowest LL, the leading spatial harmonic of the moiré-periodic potential changes sign at a magic twist angle $ \theta_c$ where the band reaches its minimum bandwidth. By solving self-consistent Hartree-Fock equations in a multi-LL Hilbert space, we find that triangular-lattice CDW states with density maxima on MX (or XM) sites or on MM sites are favored on opposite sides of the magic angle at most filling factors and that stripe order appears near $ \nu_h=1/2$ . We show that CDW states at $ \nu_h >1/2$ can carry a nonzero total Chern number, providing a natural route to reentrant integer quantum Hall effects and discuss the energy competition between fractional Chern insulator and CDW states.
Strongly Correlated Electrons (cond-mat.str-el)
6 pages, 3 figures, Supplementary material 9 pages
Coexisting Paramagnetic Spins and Long-Range Magnetic Order in Ba$4$(Ru${0.92}$Ir$_{0.08}$)$3$O${10}$
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2026-03-09 20:00 EDT
Farhan Islam, Jiasen Guo, Wei Tian, Bing Li, Xudong Huai, Thao T. Tran, Gang Cao, Zachary Morgan, Feng Ye
We investigate the effect of dilute Ir substitution on the magnetism of the trimer-based ruthenate Ba$ _4$ Ru$ _3$ O$ {10}$ using neutron diffraction, magnetic susceptibility measurements, atomistic simulations, and first-principles calculations. Neutron diffraction shows that Ir doping preserves the zigzag antiferromagnetic structure and the ordered-moment magnitude of the parent compound, in which the moments reside exclusively on the two outer Ru(2) sites of each $ \rm Ru_3O{12}$ trimer, while the central Ru(1) site remains nonmagnetic. The Néel temperature is reduced from $ \approx!105$ K to 84.0(1) K upon 8% Ir substitution, while magnetic susceptibility reveals a pronounced low-temperature Curie-like upturn, indicating the coexistence of paramagnetic spins with long-range antiferromagnetic order. Density-functional calculations shows that Ir preferentially occupies the central Ru(1) site, where its extended $ 5d$ orbitals disrupt the Ru-Ru molecular-orbital network and intra/inter-trimer exchange pathways. Atomistic simulations incorporating this paramagnetic dilution reproduce the suppressed ordering temperature and the coexistence of ordered and paramagnetic components.
Strongly Correlated Electrons (cond-mat.str-el)
The Evolution of Magnetism in a Thin Film Pyrochlore Ferromagnetic Insulator
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-03-09 20:00 EDT
Margaret A. Anderson, Megan E. Goh, Yang Zhang, Kyeong-Yoon Baek, Michael Schulze, Mario Brutzam, Christoph Liebald, Chris Lygouras, Dan Ferenc Segedin, Aaron M. Day, Zubia Hasan, Donald A. Walko, Hua Zhou, Peter Bencok, Alpha T. N’Diaye, Charles M. Brooks, Ismail El Baggari, John T. Heron, S. M. Koopayeh, Daniel Rytz, Christo Guguschev, Julia A. Mundy
The pyrochlore vanadates are compelling candidates for next-generation dissipationless devices. Lu2V2O7 and Y2V2O7 are ferromagnetic insulators (Tc ~ 70 K) that are believed to exhibit the magnon Hall effect and are expected to host topological magnons. Their completely dissipationless magnon edge states could be harnessed to realize low-power information transport in spintronic or magnonic devices. As a crucial step in the realization of devices, we synthesize the first thin films of pyrochlore Y2V2O7 on isostructural Y2Ti2O7 substrates and explore the evolution of their magnetic properties down to the ultrathin limit. All films are insulating ferromagnets with transition temperatures of up to the bulk value (Tc ~ 68 K) that decrease with thickness according to finite-size effects. Our films also exhibit a change in anisotropy from in-plane to out-of-plane easy axis coincident with the development of partial strain relaxation and nonzero magnetic hysteresis in an applied field. This evolution demonstrates the impact of strain on magnetic anisotropy and paves the way to tunable magnon topology.
Materials Science (cond-mat.mtrl-sci), Strongly Correlated Electrons (cond-mat.str-el)
Magnetoelastic signatures of conical state and charge density waves in antiferromagnetic FeGe
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2026-03-09 20:00 EDT
L. Prodan, J. Sourd, L. Chioncel
We present a unified magnetoelastic framework describing ultrasound velocity anomalies in antiferromagnetic FeGe under low magnetic fields applied along the $ c$ axis. A global multi-field analysis reveals the pronounced low-temperature anomaly near 35 K originates from hybridization between longitudinal acoustic phonons and a field-dependent magnetic mode associated with the exchange-driven conical spin structure, while the shoulder near 100 K arises from a field-independent charge density wave (CDW) susceptibility channel. The fitted parameters exhibit strong internal scaling relations, allowing the data to collapse onto universal magnetic and CDW scaling curves. By explicitly connecting the magnetic scaling variable to the cone angle measured by neutron diffraction, we establish a quantitative link between ultrasound softening and the evolution of the transverse spiral component of the double-cone structure. Our results therefore unify elastic and neutron-scattering observations within a single phenomenological framework and demonstrate that $ \Delta v/v$ provides a sensitive probe of coupled magnetic and electronic instabilities in FeGe.
Strongly Correlated Electrons (cond-mat.str-el)
10 pages, 3 figures, 1 table
Exchange anisotropy-driven noncollinear magnetism and magnetic transitions in MnTiO3 ilmenite
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2026-03-09 20:00 EDT
Srimal Rathnayaka, Luke Daemen, Despina Louca
Evidence for multiple magnetic transitions and unconventional spin exchange interactions in the ilmenite insulator MnTiO3 is provided via neutron scattering. On cooling, while G-type antiferromagnetic (AFM) order sets in first at 63 K with a k1 = (000) characteristic wave vector, a weaker second magnetic transition with k2 = (00 3/2 ) appears near 42 K, giving rise to a noncollinear structure. Intrinsic buckling of the honeycomb lattice along c creates bond anisotropy and a distorted crystal field that can lead to exchange paths that modulate orbital overlap and spin-orbit coupling. The inelastic spectrum is best described by magnetic exchange anisotropy that breaks the local symmetry of the honeycomb, with competing AFM Heisenberg, Dzyaloshinskii-Moriya and alternate intra-planar ferromagnetic (FM) interactions, that may yield a weakly-coupled ladder system.
Strongly Correlated Electrons (cond-mat.str-el), Materials Science (cond-mat.mtrl-sci)
6 pages, 4 figures
Moiré-induced symmetry breaking of charge order in van der Waals heterostructures
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2026-03-09 20:00 EDT
Sandra Sajan, Laura Pätzold, Tarushi Agarwal, Clara Pfister, Haojie Guo, Sisheng Duan, P. V. Sruthibhai, Mariana Rossi, Maria N. Gastiasoro, Sara Barja, Ravi P. Singh, Tim Wehling, Miguel M. Ugeda
Layered materials that stack different lattice symmetries are rare in nature. Misfit layered chalcogenides, which combine square and hexagonal lattices of rocksalt monochalcogenides and transition-metal dichalcogenides, provide a platform to explore how incommensurability and explicit symmetry breaking impact collective electronic phases. Here we use low-temperature scanning tunneling microscopy/spectroscopy to probe the misfit compounds (MS)$ _{1+\delta}$ TaS$ _{2}$ with M = Pb, Sn and track how the misfit interface reshapes the electronic ground state of the embedded 1H-TaS$ _{2}$ monolayers. High-resolution STM imaging and Fourier analysis reveal that the charge-density wave (CDW) is incommensurate and fragments into nanometer-sized domains. Strikingly, the CDW exhibits a pronounced and anisotropic response to the uniaxial moiré potential imposed by the misfit layer: its coherence lengths and ordering wavevectors become inequivalent, demonstrating a strong nonlinear coupling between the intrinsic CDW instability and the symmetry-breaking moiré field. First-principles-informed multiscale modeling shows that this reorganization arises from the combined effect of interlayer charge transfer and the spatially anisotropic energy landscape introduced by the misfit interface. In contrast, superconductivity is comparatively insensitive to the moiré, revealing a uniform, single full-gap consistent with s-wave pairing. Our results establish heterosymmetry stacking as a route to engineer correlated states in van der Waals materials.
Strongly Correlated Electrons (cond-mat.str-el), Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Materials Science (cond-mat.mtrl-sci), Superconductivity (cond-mat.supr-con)
Efficiently gate-tunable ferromagnetism in ferromagnetic semiconductor-Dirac semimetal p-n heterojunctions
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2026-03-09 20:00 EDT
Emma Steinebronn, Saurav Islam, Abhinava Chatterjee, Bimal Neupane, Alex Grutter, Christopher Jensen, Julie A. Borchers, Timothy Charlton, Wilson J. Yanez-Parreno, Juan Chamorro, Tanya Berry, Supriya Ghosh, K. A. Nivedith, K. Andre Mkhoyan, Tyrel McQueen, Yuanxi Wang, Chaoxing Liu, Nitin Samarth
We use molecular beam epitaxy to develop a gate tunable p-n heterojunction that interfaces a canonical Dirac semimetal, Cd$ _3$ As$ _2$ , and a ferromagnetic semiconductor, In$ _{1-x}$ Mn$ _x$ As, with perpendicular magnetic anisotropy. Measurements of the anomalous Hall effect in top-gated Cd$ _3$ As$ 2$ /In$ {1-x}$ Mn$ x$ As devices show that the ferromagnetic Curie temperature ($ T\mathrm{C}$ ) can be efficiently tuned using a modest gate voltage of $ \sim 10$ V, corresponding to a sensitivity to electric field ($ E$ ) of $ \Delta T{\mathrm{C}}/\Delta E \sim 10$ K/MV/cm). The voltage tuning of $ T\mathrm{C}$ saturates near the charge neutrality point of Cd$ _3$ As$ _2$ and vanishes at positive gate voltage in appropriately designed heterostructures. This non-monotonic behavior cannot be explained solely by hole-mediated ferromagnetism in the In$ _{1-x}$ Mn$ _x$ As alone, suggesting an interaction between the Dirac semimetal and the ferromagnetic semiconductor. Our results identify Cd$ _3$ As$ _2$ /In$ _{1-x}$ Mn$ _x$ As heterojunctions as a potentially attractive platform for studying emergent phenomena arising from the interplay between broken symmetry, topology, and magnetism in a topological semimetal.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
Influence of Hopping Integrals and Spin-Orbit Coupling on Quantum Oscillations in Kagome Lattices
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2026-03-09 20:00 EDT
Xinlong Du, Yuying Liu, Chao Wang, Juntao Song
Motivated by recent experiments on CsTi$ _3$ Bi$ _5$ and RbTi$ _3$ Bi$ _5$ ~[Rehfuss \textit{et al.}, Phys.\ Rev.\ Mater.\ \textbf{8}, 024003 (2024)], we theoretically investigate the effects of hopping integrals and spin-orbit coupling (SOC) on quantum oscillations in kagome lattice models. Our tight-binding models successfully capture the distinct quantum oscillation features observed in experiments, when a relatively strong SOC is included. It is more important that, by discussing the effect of the next-nearest-neighbor term $ t_2$ , we provide a coherent explanation for their different topological responses. For the case of $ t_2 = 0$ , the small hybridization gap between adjacent bands with opposite Berry curvatures allows magnetic breakdown to occur under a strong magnetic field, enabling charge carriers to tunnel between the bands and thereby effectively masking the intrinsic topological character. In contrast, for $ t_2 \neq 0$ , the hybridization gap is significantly enlarged by $ t_2$ , which suppresses magnetic breakdown and confines electrons to individual orbits with opposite Berry curvatures, thereby revealing the nontrivial Berry phase ($ \phi_B \approx \pi$ ). Consequently, we identify the lattice-driven hopping $ t_2$ as a critical control parameter that regulates the experimental observability of the topological phase in CsTi$ _3$ Bi$ _5$ and RbTi$ _3$ Bi$ _5$ . These findings underscore the key role of the $ t_2$ term and show that tuning lattice parameters can effectively control topological signatures in quantum transport.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
Twist-Controlled Modulation of Quantum Emitters in a Van der Waals Bilayer
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-03-09 20:00 EDT
Angus Gale, Seungjun Lee, Seungmin Park, Evan Williams, Helen Zhi Jie Zeng, James Liddle-Wesolowski, Young Duck Kim, Milos Toth, Tony Low, Igor Aharonovich
Stacking and twisting two dimensional materials has garnered enormous attention across the condensed matter and the nanophotonic communities. The surge of interest stems from the emergence of novel photophysical phenomena that arise due to the interlayer coupling of the individual layers. Here, we demonstrate that the twist degree of freedom can modulate a single quantum emitter at room temperature. We employ a van der Waals homobilayer of hexagonal boron nitride (hBN) and model the emission properties of quantum emitters as a function of the twist angle. Density functional theory results show that the embedded emitters are strongly influenced by the twist angle and the stacking of the top hBN layer. We consequently engineer these systems experimentally, and demonstrate in-situ tuning of embedded quantum emitters by mechanically twisting the top hBN layer, achieving tunability of over 30 nm (~ 100 meV). Our work demonstrates that mechanical twisting can be harnessed to modulate the embedded quantum emitters in a vdW material, marking a crucial step towards a programmable on-chip quantum circuitry.
Materials Science (cond-mat.mtrl-sci)
Electrically tunable circular photocurrent via local-field induced symmetry breaking at a metal-MoTe2 interface
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-03-09 20:00 EDT
Butian Zhang, Kexin Wang, Jun-Tao Ma, Yiya Guo, Chengyu Yan, Xin Yi, Luojun Du, Youwei Zhang, Hua-Hua Fu, Shun Wang
Transition metal dichalcogenides (TMDCs) constitute a promising platform for symmetry-engineered responses to circularly polarized light. The high crystal symmetry of centrosymmetric 2H-phase TMDCs inherently forbids the circular photogalvanic effect, thereby necessitating external stimuli such as electric fields or strain to lower the symmetry for its activation. While Schottky junctions provide a ubiquitous built-in field for potentially inducing circular photocurrents, the mechanism for the generation and control of circular photocurrents in TMDCs is not understood. In this study, we fabricated a localized gold-MoTe2 heterostructure and demonstrate a pronounced circular photocurrent at the interface under normal incidence. The photocurrent is attributed to circular photogalvanic effect governed by the strength and direction of the built-in electric field, enabling continuous modulation via an external bias. First-principles calculations show that the gold interface induces a spin splitting in the valence bands of MoTe2, establishing a valley-dependent spin ordering. The observed circular photocurrent from multilayer 2H-MoTe2 under normal incidence indicates the breaking of C3 rotational symmetry by the local in-plane field. These results establish an effective strategy for developing voltage-tunable circularly polarized photodetectors and valleytronic devices.
Materials Science (cond-mat.mtrl-sci)
Multi-sphere shape generator for DEM simulations of complex-shaped particles
New Submission | Soft Condensed Matter (cond-mat.soft) | 2026-03-09 20:00 EDT
Felix Buchele, Thorsten Pöschel, Patric Mueller
MSS is an algorithm to determine the radii and positions of spheres that fill a given volume. In the context of granular materials, MSS is a particle generator for DEM simulations of complex-shaped particles. Here, each particle of a given shape is represented by a set of spheres that collectively approximate the particle. This technique of particle shape representation is often referred to as the multi-sphere approach. We show that, for a given number of spheres, MSS provides a closer approximation to the target shape at lower computational costs than other DEM multi-sphere particle generators reported in the literature.
Soft Condensed Matter (cond-mat.soft), Materials Science (cond-mat.mtrl-sci)
10 pages, 11 figures
Triple Antidot Molecules
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2026-03-09 20:00 EDT
Naomi Mizuno, Dmitri V. Averin, Xu Du
We report the realization and modeling of a triple-antidot molecule hosting three interacting quantum Hall quasiparticles, with tunnel coupling between antidots tunable via the magnetic field. The measured tunneling conductance spectrum reveals the molecular energy levels arising from the inter-antidot coupling and Coulomb interaction. A tunneling model is established which shows good qualitative agreement with experimental observations. This work lays the foundation for the realization of complex systems of antidots for quantum Hall quasiparticles with non-trivial quantum statistics.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Quantum Physics (quant-ph)
Chirality Breaking of Majorana Edge Modes Induced by Chemical Potential Shifts
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2026-03-09 20:00 EDT
Quantum anomalous Hall insulator-superconductor heterostructures are predicted to host chiral Majorana fermions as edge modes, which is essential for topological quantum computing applications. Although the edge states have been extensively studied at zero chemical potential $ \mu = 0$ , the practically relevant regime with a shifted chemical potential ($ \mu \neq 0$ ) remains less explored. Here, we present an analytical treatment of the edge states for $ \mu \neq 0$ , deriving an approximate but highly accurate solution applicable to realistic experimental parameters. Surprisingly, we find that the energy dispersion of the edge band exhibits nonlinearity and transforms into a twisted, braid-like structure within specific parameter ranges. This unique braid-like band leads to non-chirality of the edge modes, allowing propagation in both directions.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
Theory of central peak and acoustic anomaly in cubic BaTiO3 close to ferroelectric transition
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-03-09 20:00 EDT
We present a Ginzburg-Landau theory on statics and dynamics of BaTiO$ 3$ -type ferroelectrics in
the paraelectric phase with the cubic structure, where the order parameter is the polarization $ \bi p$ . Unique effects are caused by the electrostrictive (ES) coupling between
$ {\bi p}$ and the elastic displacement $ \bi u$ . We show that the ES coupling gives rise to a central peak in the Fourier-Laplace transform of the displacement time-correlation function at small wave numbers. It emerges and grows with a narrow width as the transition is approached. Such central peaks have long been observed in a number of scattering experiments in various ferroelectrics, but their origin has not been well understood. From the acoustic part of the displacement dynamic correlation we obtain the frequency-dependent elastic moduli $ C{11}^\ast(\omega)$ , $ C_{12}^\ast(\omega)$ , and $ C_{44}^\ast(\omega)$ , whose singular parts arise from the ES coupling, We then calculate the singular sound velocity and
attenuation. In the central peak and the elastic moduli, the frequency $ \omega$ appears in the scaled form $ \omega\tau_D$ , where $ \tau_D$ is the Debye relaxation time in the frequency-dependent dielectric constant.
{Keywords}: ferroelectric transition, central peak, acoustic anomaly, electrostrictive coupling
Materials Science (cond-mat.mtrl-sci)
35 pages, 4 figures
Nonlinear magnetoelastic wave dynamics and field tunable soliton excitations in hexagonal multiferroic media
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2026-03-09 20:00 EDT
Saumen Acharjee, Kallol Kavas Hazarika, Rajneesh Kakoti
We investigate nonlinear magnetoelastic wave dynamics and electrically tunable soliton excitations in hexagonal multiferroic media. By varying the magnetoelastic coupling strength and using a coupled magnetoelastic-ferroelectric continuum model, we found that the system evolves from weakly nonlinear quasiperiodic oscillations to strongly anharmonic yet phase-coherent multimode dynamics. Our results suggest that the dynamics remain bounded and approach distorted limit-cycle behavior rather than chaotic motion despite the enhanced nonlinearity. The excitation spectra and the band dispersion relations reveal that this nonlinear evolution originates from strong magnon-phonon hybridization and coupling-induced renormalization of collective excitation branches, leading to coherent energy exchange among magnetic, elastic, and polarization subsystems. In addition, the coupled dynamics can be reduced to an effective magnetoelastic nonlinear Schrödinger equation and support localized excitations such as bright and dark solitons and Kuznetsov-Ma type breathers. Furthermore, it is found that an external electric field modifies both the effective nonlinear coefficient and the dispersion curvature, enabling continuous control of soliton amplitude, width, and stability. The field also induces a saddle-node bifurcation in the magnetization phase space, defining a critical threshold separating multistable and monostable regimes. Our results establish a theoretical framework for electrically tunable nonlinear spin-lattice excitations and soliton engineering in multiferroic systems.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Pattern Formation and Solitons (nlin.PS)
17 pages, 9 figures
Riemannian geometric classification and emergent phenomena of magnetic textures
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-03-09 20:00 EDT
We propose a new classification of magnetic textures from the viewpoint of differential geometry. Magnetic textures are conventionally classified into collinear, coplanar, and noncoplanar magnets. These classes are typically characterized by the vector spin chirality (VSC) and the scalar spin chirality (SSC), which indicate noncollinearity and noncoplanarity, respectively. However, this conventional classification is incomplete: in particular, noncoplanar textures cannot be fully characterized by the SSC alone, as exemplified by conical magnets. To refine this classification, we analyze the curves and surfaces traced by spins in real space using differential geometry and introduce two novel scalar spin chiralities that properly characterize noncoplanarity: the geodesic scalar spin chirality and the torsional scalar spin chirality. These quantities are directly connected to differential geometry: the former reflects the geodesic curvature while the latter is related to the torsion. Based on these chiralities, we identify three distinct classes of noncoplanar magnetic textures. Furthermore, analogous to the roles of the VSC and the conventional SSC in emergent electrodynamics, the geodesic SSC gives rise to novel emergent phenomena. By constructing a semiclassical theory including nonadiabatic effects and higher-order spatial gradients of magnetic textures, we demonstrate that the geodesic SSC induces an emergent band asymmetry, leading to nonreciprocal responses as a quantum geometric effect. This mechanism is a purely orbital effect, requiring no spin-orbit coupling, and the resulting discussion runs in parallel with the conventional picture of the topological Hall effect driven by the SSC. The geometric viewpoint developed here will provide broad new insights into classification, quantum geometry, emergent electrodynamics, and a wider variety of emergent phenomena.
Materials Science (cond-mat.mtrl-sci), Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Strongly Correlated Electrons (cond-mat.str-el)
Critical dynamics govern the evolution of political regimes
New Submission | Statistical Mechanics (cond-mat.stat-mech) | 2026-03-09 20:00 EDT
Joshua Uhlig, Paula Pirker-Díaz, Matthew Wilson, Ralf Metzler, Karoline Wiesner
The emergence and decline of democratic systems worldwide raises fundamental questions about the dynamics of political change. Contrary to the idea of a stable endpoint of liberal democracy, recent backsliding towards less democratic regimes highlights the non-stationary nature of regime evolution. Here, we analyse the historical trajectories of countries within a two-dimensional regime space derived from the principal components of the Varieties of Democracy dataset. We observe weakly non-ergodic dynamics unfolding in an effective landscape characterised by sparse and shifting basins of stability. Step sizes and sojourn times characterising this dynamics follow heavy-tailed distributions near the critical regime, in which mean values appear to diverge. These facts point to the intermittent and heterogeneous nature of the regime change dynamics. A continuous time random walk model reproduces the dynamics of the three most recent decades with remarkable accuracy. Together, these results suggest that some aspects of political regime evolution follow universal stochastic principles, while remaining punctuated by unique historical pathways.
Statistical Mechanics (cond-mat.stat-mech), Physics and Society (physics.soc-ph)
Dynamical scaling method improved by a deep learning approach
New Submission | Statistical Mechanics (cond-mat.stat-mech) | 2026-03-09 20:00 EDT
Yusuke Terasawa, Yukiyasu Ozeki
We propose a dynamical scaling analysis improved by a deep learning approach. While Gaussian process regression has been widely employed for estimating scaling parameters, its computational cost for parameter optimization becomes a limitation in dynamical scaling analysis, where large datasets are involved. In contrast, the present method employs a neural network, which significantly reduces the computational cost and enables the use of the entire dataset that was inaccessible with Gaussian process regression. We applied the method to the 2D Ising model and the 2D 3-state Potts model, achieving higher accuracy and computational efficiency than conventional approaches.
Statistical Mechanics (cond-mat.stat-mech)
Spectra-Scope : A toolkit for automated and interpretable characterization of material properties from spectral data
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-03-09 20:00 EDT
Amalya C. Johnson, Chris Fajardo, Leena Sansguiri, Weike Ye, Steven B. Torrisi
Spectroscopy is a central pillar of materials characterization, providing useful information on properties like structure, composition, or excited state dynamics of a system. However, many spectroscopic techniques present challenges in development of interpretable, performant, and reliable supervised learning models due to the wide range of possible nonlinear correlations that can exist between the signal and the response variable (target) of interest. Here, we present Spectra-Scope, an open-source AutoML framework for automatic characterization of material properties from spectroscopy data using interpretable machine learning (ML) models. The software is implemented in Python and a no-code web application. It comprises tools for data preprocessing, nonlinear feature extraction, machine learning model training, and feature downselection. Users can easily train different types of simple, interpretable ML models on a set of feature transformations quickly and with modest computational resources. In this work, we outline the methods of Spectra-Scope and its effectiveness across diverse datasets, with applications to materials and agricultural spectroscopy data. We show that Spectra-Scope can reproduce performance of comparable models in the literature, and highlight how our emphasis on interpretability can be used to rationalize the behavior of individual models and understand the physical processes behind spectral features.
Materials Science (cond-mat.mtrl-sci)
Restoring the Point-and-Charge Gradient Expansion for the Strong Interaction Density Functionals
New Submission | Other Condensed Matter (cond-mat.other) | 2026-03-09 20:00 EDT
L. A. Constantin, F. Naeem, 3 E. Fabiano, F. Sarcinella, F. Della Sala
The strong-interaction functionals $ W_\infty[n]$ and $ {W’}\infty[n]$ play an important role in the adiabatic-connection method of Density Functional Theory. The strictly-correlated electron approach can be used to exactly compute these functionals, yet calculations are computationally very expensive even for small electronic systems, and thus semilocal approximations have been proposed. In this work we develop a meta-generalized gradient approximation (meta-GGA) model for the strong-interaction functionals, enhanced point-and-charge (ePC), constructed from exact constraints. In particular, the ePC restores the second-order gradient expansion of the PC model, that is relevant for the equilibrium properties of Wigner crystals, and ensures the non-negativity of $ {W’}\infty[n]$ . We assess the ePC model for atoms and various model systems: Hooke’s atoms, two-electron exponential densities, s- and p-hydrogenic shells, quasi-two-dimensional infinite barrier model, perturbed uniform electron gas and H$ _2$ dissociation. We prove a good overall accuracy of the ePC model, that achieves a broader applicability than any previous semilocal models.
Other Condensed Matter (cond-mat.other)
17 pages, 14 figures
Phys. Rev. B 113, 085121 (2026)
Tight-Binding Device Modeling of 2-D Topological Insulator Field-Effect Transistors With Gate-Induced Phase Transition
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2026-03-09 20:00 EDT
Yungyeong Park, Yosep Park, Hyeonseok Choi, Subeen Lim, Dongwook Kim, Yeonghun Lee
Topological insulator field-effect transistors (TIFETs) built on 2-D quantum spin Hall insulators are being considered as advanced logic transistors due to their potentially superior performance originating from the dissipationless edge transport. This paper presents a device modeling based on the tight-binding model and the nonequilibrium Green’s function formalism to simulate the current-voltage characteristics of the TIFETs. We then use the device simulator to demonstrate the effect of channel length on device performance. The device modeling will not only enable a direct estimation of TIFET performance but also shed light on the nontraditional switching operation via the topological phase transition.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
IEEE Trans. Electron Devices 71, 5739 (2024)
Absolute negative mobility in a one-dimensional overdamped system driven by active fluctuations
New Submission | Statistical Mechanics (cond-mat.stat-mech) | 2026-03-09 20:00 EDT
K. Białas, P. Hänggi, J. Spiechowicz
Absolute negative mobility (ANM) is one of the most paradoxical transport phenomena in which a setup moves on average in a direction opposite to the applied force. According to the state of the art a minimal system exhibiting this effect in a one-dimensional dynamics involves an inertial particle subjected to a constant bias when dwelling in a nonlinear symmetric periodic potential in a nonequilibrium} and nonstationary state generated by an external driving. In this work we remarkably reduce its complexity and show that it may occur in a system composed of an overdamped particle in piecewise linear symmetric periodic potential in an equilibrium state provided that it is driven by active fluctuations in the form of white Poisson shot noise. Our result may help to explain exotic transport behavior emerging in biological cells where dynamics is typically overdamped and assisted by active fluctuations derived from various metabolic activities. It can be also exploited for effective separation strategies in a microscopic world thus transforming fluctuations from a nuisance into a functional resource.
Statistical Mechanics (cond-mat.stat-mech), Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Soft Condensed Matter (cond-mat.soft)
Anisotropic extension of the Parratt formalism
New Submission | Other Condensed Matter (cond-mat.other) | 2026-03-09 20:00 EDT
Neutron and X-ray reflectometry are important methods for studying thin multilayer systems. The Parratt method and the method of characteristic matrices, also referred to as transfer matrices, are used for simulation, evaluation of experimental results, and designing optical systems, like mirrors. The Parratt method had been derived for isotropic systems. The method of characteristic matrices can also handle anisotropic problems, but it is burdened with numerical instabilities, which may arise in the case of thick samples at grazing angle incidence.
In this paper, we derive a generalized Parratt method applicable to anisotropic systems. Furthermore, as we show, this is devoid of the numerical instabilities arising in the method of characteristic matrices. We derive formulae for both reflectivity and transmissivity. The stability of the new approach is demonstrated by comparing calculated results obtained via different methods. The problem of rough interfaces is also addressed, and the results gained by different approximations for some systems are compared.
Other Condensed Matter (cond-mat.other)
Long-Lived Interlayer Excitons and Type-II Band Alignment in Janus MoTe2/CrSBr van der Waals Heterostructures
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-03-09 20:00 EDT
Mohammad Ali Mohebpour, Peter C Sherrell, Catherine Stampfl, Carmine Autieri, Meysam Bagheri Tagani
Identifying two-dimensional heterostructures with exceptional electronic and optical properties remains an active area of research in advanced optoelectronics. Here, we present a comprehensive first-principles investigation of the electronic, optical, and excitonic properties of a MoTe2/CrSBr van der Waals heterostructure using density functional theory combined with fully relativistic GW and Bethe-Salpeter equation calculations. The close lattice matching between the two monolayers enables the formation of stable heterobilayers with two inequivalent interfaces (Te-S and Te-Br) arising from the Janus nature of CrSBr. Both interfaces are dynamically and thermally stable and exhibit type-II band alignment with a direct quasiparticle gap, promoting efficient spatial separation of electrons and holes. The heterostructure hosts interlayer excitons with lifetimes 18-45 ps significantly longer than those of the intralayer excitons in the isolated MoTe2, 3.6 ps, and CrSBr, 8.1 ps, monolayers. Moreover, the optical gap, exciton binding energy, and exciton lifetime of the heterostructure are strongly modulated by the built-in electric field associated with the Janus layer. These results establish the MoTe2/CrSBr heterostructure as a versatile platform for engineering long-lived interlayer excitons and highlight its potential for next-generation optoelectronic and light-harvesting applications.
Materials Science (cond-mat.mtrl-sci), Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
28 pages, 9 figures
Spectral study of the pseudogap in unitary Fermi gases
New Submission | Quantum Gases (cond-mat.quant-gas) | 2026-03-09 20:00 EDT
Chuping Li, Lin Sun, Kaichao Zhang, Junru Wu, Yuxuan Wu, Dingli Yuan, Pengyi Chen, Qijin Chen
The existence of a pseudogap in unitary Fermi gases has recently been established and measured experimentally [Li et al., Nature 626, 288 (2024)]. This lends strong support for the pairing origin as the mechanism of the pseudogap in Fermi superfluids. Here we present a spectral study of unitary Fermi gases, and show how the data can be understood quantitatively, when compared with theoretically calculated momentum-resolved rf or microwave spectra, and the pseudogap extracted from the spectra. We use an iterative treatment of the fermion self energy and hence the spectral function, beyond previous pseudogap approximation, based on a pairing fluctuation theory that incorporates both particle-particle and particle-hole T matrices, with self-consistent self energy feedback. Our results not only provide a microscopic explanation of the experimental data but also strengthen the support for both the pairing-induced pseudogap physics and the pairing fluctuation theory of Fermi superfluidity.
Quantum Gases (cond-mat.quant-gas)
6 pages, 5 figures
Stochastic resonance in higher-order networks driven by colored noise
New Submission | Statistical Mechanics (cond-mat.stat-mech) | 2026-03-09 20:00 EDT
Zhongwen Bi, Dan Zhao, Qi Liu, Jürgen Kurths, Yong Xu
We investigate stochastic resonance (SR) in an ensemble of coupled overdamped bistable oscillators driven by colored noise. The networks incorporate the weighted contributions of both pairwise coupling and 2-simplex coupling. Our findings show that these higher-order interactions further exacerbate the suppression effect of colored noise on SR, reducing the peak of resonance curves and shifting the optimal noise intensity toward higher values. To clarify the underlying mechanism, we establish a close connection between SR and the four-stage variation in network synchronization level. Specially, the synchronization extremes explain the effect of higher-order coupling and colored noise on SR. Our analysis reveals that higher-order interactions do not reverse, but primarily promote the spatial propagation of suppression effects due to colored noise.
Statistical Mechanics (cond-mat.stat-mech)
Floquet scars and prethermal fragmentation in a driven spin-one chain
New Submission | Statistical Mechanics (cond-mat.stat-mech) | 2026-03-09 20:00 EDT
Krishanu Ghosh, Diptiman Sen, K. Sengupta
We study the periodic dynamics of a spin-one chain driven using a square-pulse protocol with amplitude $ Q_0$ and frequency $ \omega_D$ . The Hamiltonian of the spin chain hosts a thermodynamically large number of $ Z_2$ -valued conserved quantities $ W_{\ell}$ on the links $ \ell$ . This allows us to study the Floquet dynamics of this chain within a given sector with fixed values of $ W_{\ell}$ . For the sector with all $ W_{\ell}=1$ , we find signatures of quantum many-body scar states for $ \hbar \omega_D \gg Q_0$ ; they lead to oscillatory dynamics and fidelity revival for specific initial states. Upon lowering $ \omega_D$ , we find an ergodic regime exhibiting fast thermalization consistent with the prediction of the (Floquet) eigenstate thermalization hypothesis. In addition, we identify special drive frequencies $ \omega_n^{\ast}= Q_0/(2n \hbar)$ (where $ n = 1, 2, 3, \cdots$ ) at which the Floquet Hamiltonian exhibits prethermal strong Hilbert space fragmentation (HSF) with the largest fragment being ergodic; in contrast, a weak HSF is found at $ \omega’n= Q_0/[\hbar(2n+1)]$ (where $ n = 0, 1, 2, \cdots$ ). We also study the sector with $ W{\ell} ={\cdots 1,1,-1,1,1,-1 \cdots }$ which shows strong HSF at $ \omega_n^{\ast}$ but no fragmentation at $ \omega’_n$ . Our analysis indicates that the strong HSF in this sector harbors an integrable largest fragment. We provide numerical support for our analytical and perturbative results using exact-diagonalization (ED) studies on finite chains of length $ L\le 24$ . Our numerical results for entanglement entropy, fidelity, and correlation functions of the driven chain provide definitive signatures of prethermal strong HSF for both sectors.
Statistical Mechanics (cond-mat.stat-mech), Quantum Physics (quant-ph)
18 pages, 11 figures
Phase-resolved imaging of coherent phonon-magnon coupling
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2026-03-09 20:00 EDT
Yannik Kunz, Florian Kraft, David Breitbach, Torben Pfeifer, Matthias Küß, Stephan Glamsch, Manfred Albrecht, Mathias Weiler
We use a direct phase-resolved optical technique to study the coherence of spin waves (SWs) that are driven by surface acoustic waves (SAWs) via resonant magnetoelastic coupling. For this, we employ a piezoelectric lithium tantalate (LiTaO$ _{3}$ ) substrate, equipped with micropatterned interdigital transducers for SAW excitation, which interact with SWs in a 5 nm thin and 20 $ \mu$ m wide Co$ _{40}$ Fe$ _{40}$ B$ _{20}$ -waveguide. We detect the SAW and the SW using a phase-locked micro-focused optical polarization detection experiment and use the characteristic polarization dependence to separate the SAW and SW signals. Our measurements directly image the resonant and coherent excitation of the SW by the SAW.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
Magnetoelastic signatures of thermal and quantum phase transitions in a deformable Ising chain under a longitudinal and transverse magnetic field
New Submission | Statistical Mechanics (cond-mat.stat-mech) | 2026-03-09 20:00 EDT
We investigate a deformable spin-1/2 Ising chain subjected to either a longitudinal or a transverse magnetic field, which incorporates a magnetoelastic coupling linearly dependent on a lattice distortion parameter. Within the harmonic and static adiabatic approximations, the variational Gibbs free energy is evaluated exactly using transfer-matrix and Jordan-Wigner fermionization techniques and then minimized self-consistently with respect to the lattice distortion parameter. This approach enables a unified description of magnetic and elastic properties including the magnetization, magnetic susceptibility, lattice distortion, inverse compressibility, and relative change in the sound velocity. In a longitudinal magnetic field, the deformable Ising chain displays a line of discontinuous thermal phase transitions terminating at a critical point. The discontinuous transitions are accompanied by metastable states, which give rise to a hysteresis loop at low temperatures. In contrast, the deformable Ising chain in a transverse field undergoes exclusively a continuous quantum phase transition at zero temperature with no indication of thermal phase transitions. The magnetic susceptibility and inverse compressibility exhibit cusp- and dip-like anomalies at discontinuous phase transitions, while a diverging susceptibility and vanishing inverse compressibility characterize the continuous phase transitions. An elastic softening of the deformable chain near thermal and quantum phase transitions manifest itself also through a significant sound attenuation.
Statistical Mechanics (cond-mat.stat-mech), Strongly Correlated Electrons (cond-mat.str-el)
18 pages, 10 figures
Fermi surface and topology of multiband superconductor BeAu
New Submission | Superconductivity (cond-mat.supr-con) | 2026-03-09 20:00 EDT
Riccardo Vocaturo, Klaus Koepernik, Dániel Varjas, Oleg Janson, Maia G. Vergniory, Jeroen van den Brink
The chiral material BeAu was recently identified as a multiband type-I superconductor with a critical temperature of 3.2 K. As a member of the B20 crystal family (space group $ P2_13$ ), its band structure hosts multifold fermions at high-symmetry points, unpaired Weyl points and even nodal surfaces. This renders BeAu an appealing system to investigate the interplay between superconductivity and topology. Here we present a comprehensive first-principles analysis of BeAu’s electronic structure focusing on its Fermi surface’s topology and the implications for superconductivity. Together with the presence of four- and six-fold fermions at high-symmetry points, we identify several additional isolated Weyl points near the Fermi level. We also determine the associated topological edge states – the surface Fermi arcs. Computing the Chern number associated to different Fermi surface sheets, we show that BeAu harbors a $ \nu = 4$ topological superconducting phase in the presence of $ s$ -wave pairing of alternating sign ($ s_\pm$ pairing). Notably, we also identify a Fermi surface with a Chern number of +6; the highest value reported to date. Finally, our analysis reveals strong inhomogeneity in the orbital character of electronic states at the Fermi level, suggesting a link to the observed multigap superconductivity.
Superconductivity (cond-mat.supr-con), Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
8 pages, 5 figures
Electric field switching of chiral phonons
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-03-09 20:00 EDT
Michael Grimes, Clifford J. Allington, Hiroki Ueda, Carl P. Romao, Kurt Kummer, Puneet Kaur, Li-Shu Wang, Yao-Wen Chang, Jan-Chi Yang, Shih-Wen Huang, Urs Staub
Lattice vibrations carrying angular momentum, known as chiral phonons, have emerged as a promising route to control and understand complex material properties, yet their deterministic manipulation remains largely unexplored. Here we demonstrate electric-field switching of phonon angular momentum in the technologically relevant ferroelectric BaTiO3. Using circularly dichroic resonant inelastic X-ray scattering (CD-RIXS) at the oxygen K edge, we directly probe the phonon angular momentum and compare the measured dichroism with first-principles predictions of phonon-mode chirality. We find excellent agreement, revealing a momentum-dependent circular-dichroism contrast that exhibits a reversible gyroelectric effect, stable for at least 15 hours. Our results establish a robust mechanism for non-volatile control of chiral phonons and point towards new opportunities for phonon-based information and energy technologies.
Materials Science (cond-mat.mtrl-sci), Strongly Correlated Electrons (cond-mat.str-el)
18 pages, 4 figures, 1 table
Validation of constant mean free path and relaxation time approximations for metal resistivity: explicit treatment of electron-phonon interactions
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-03-09 20:00 EDT
Subeen Lim, Yumi Kim, Gyungho Maeng, Yeonghun Lee
The figure of merit $ \rho \lambda$ the product of resistivity and mean free path (MFP) evaluated from first-principles calculations, is widely adopted to screen promising interconnect metals with high electrical conductivity at ultranarrow dimensions. However, the $ \rho \lambda$ has been calculated without addressing the validity of the assumption that the MFP is independent of the wavevector $ \mathbf{k}$ . Here, we assess the validity of the constant MFP approximation, by estimating the $ \mathbf{k}$ -dependent MFPs for (an)isotropic elemental metals, with explicit treatment of electron-phonon interactions. Additionally, we verify the validity of the constant relaxation time approximation (CRTA) for resistivity calculations. We show that both the constant MFP approximation and CRTA are reasonable even for highly anisotropic Fermi surfaces. Our results support the practical use of those approximations in transport studies, where explicit electron-phonon calculations are not feasible.
Materials Science (cond-mat.mtrl-sci)
J. Phys. Condens. Matter 38, 015503 (2026)
Extracting work from hidden degrees of freedom
New Submission | Soft Condensed Matter (cond-mat.soft) | 2026-03-09 20:00 EDT
Lokesh Muruga, Felix Ginot, Sarah A. M. Loos, Clemens Bechinger
Thermodynamics establishes that information acquired through measurement can be converted into work, as exemplified by Maxwell’s demon and Szilard engines. Most experimental realizations of information engines, however, implicitly assume Markovian environments, in which information exchanged with the surroundings is irreversibly lost. Many physical systems instead exhibit environmental memory, with hidden degrees of freedom retaining correlations with the system’s past and giving rise to non Markovian dynamics. Whether and how such concealed memory can be harnessed as a thermodynamic resource has remained an open question. Here we experimentally demonstrate work extraction from environmental memory. Using time resolved measurements on an optically trapped Brownian particle in equilibrium, we implement a time delayed double measurement protocol that retrieves information via backflow from hidden bath degrees of freedom. We show that this information backflow alters relaxation dynamics, can be quantified independently of initial state effects, and when appropriately exploited enhances work extraction. Notably, we identify regimes in which the extracted work exceeds the energy stored in the observable degree of freedom alone. Our results establish environmental memory as an experimentally accessible thermodynamic resource and reveal how non Markovian dynamics can be systematically explored to improve the performance of information engines operating in time-correlated environments.
Soft Condensed Matter (cond-mat.soft), Statistical Mechanics (cond-mat.stat-mech)
10 pages, 4 figures, 1 table
Trap-Enhanced Steep-Slope Negative-Capacitance FETs Using Amorphous Oxide Semiconductors
New Submission | Other Condensed Matter (cond-mat.other) | 2026-03-09 20:00 EDT
Yungyeong Park, Hakseon Lee, Yeonghun Lee
Amorphous oxide semiconductors (AOSs) have recently gained attention as a promising channel material of back-end-of-line (BEOL)-compatible transistors for monolithic three-dimensional (3D) integrations. However, the degradation in device performance resulting from the high trap densities in AOS, compared to conventional crystalline channel materials, has remained an intractable issue. We introduce the negative-capacitance (NC) operation into the AOS-based transistors. Negative-capacitance field-effect transistors (NCFETs) have been proposed for low-power devices, enabling sub-60 mV/decade subthreshold swing SS induced by a ferroelectric layer. In this work, we develop an AOS NCFET model to investigate the influence of traps within the channel on the steep-slope operation. It is revealed that as the trap density of the channel increases, SS of the MOSFET increases, while the SS of the NCFET decreases. The physical interpretation for steep SS is attributed to the fact that the trapped charges enhance the negative potential drop of the NC layer, enabling the abrupt device switching. This finding will accelerate the development of BEOL transistors and other applications based on the AOS materials in conjunction with the NC effect.
Other Condensed Matter (cond-mat.other)
ACS Appl. Electron. Mater. 7, 5705 (2025)
Superconductivity as a Probe of Altermagnetism: Critical Temperature, Field, and Current
New Submission | Superconductivity (cond-mat.supr-con) | 2026-03-09 20:00 EDT
A. A. Mazanik, Rodrigo de las Heras, F. S. Bergeret
We study thin films that host coexisting collinear $ d$ -wave altermagnetic and superconducting orders in the presence of an external magnetic field that fully penetrates the films. We use the Ginzburg-Landau functional to analyze the response of the films to magnetic fields and an in-plane supercurrent. We demonstrate that the interplay between superconductivity and altermagnetism induces characteristic fourfold anisotropies in the critical temperature, parallel critical field, and critical current density of the films. These results establish experimentally accessible signatures of altermagnetism in superconducting films and in superconductor/altermagnetic insulator heterostructures.
Superconductivity (cond-mat.supr-con)
5 pages, 2 figures
Continuum field theory of matchgate tensor network ensembles
New Submission | Disordered Systems and Neural Networks (cond-mat.dis-nn) | 2026-03-09 20:00 EDT
Maksimilian Usoltcev, Carolin Wille, Jens Eisert, Alexander Altland
Tensor networks provide discrete representations of quantum many-body systems, yet their precise connection to continuum field theories remains relatively poorly understood. Invoking a notion of typicality, we develop a continuum description for random ensembles of two-dimensional fermionic matchgate tensor networks with spatially fluctuating parameters. As a diagnostic of the resulting universal physics, we analyze disorder-averaged moments of fermionic two-point functions, both in flat geometry and on a hyperbolic disk, where curvature reshapes their long-distance structure. We show that disorder drives universal long-distance behavior governed by a nonlinear sigma-model of symmetry class D with a topological term, placing random matchgate networks in direct correspondence with the thermal quantum Hall problem. The resulting phase structure includes localized phases, quantum Hall criticality, and a robust thermal metal with diffusive correlations and spontaneous replica-symmetry breaking. Weak non-Gaussian deformations reduce the symmetry to discrete permutations, generate a mass for the Goldstone modes, and suppress long-range correlations. In this way, typicality offers a route from ensembles of discrete tensor networks to continuum quantum field theories.
Disordered Systems and Neural Networks (cond-mat.dis-nn)
42 pages total (27 main text, 15 appendix), 8 figures
Tracing the film structure of an organic semiconductor with photoemission orbital tomography
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-03-09 20:00 EDT
Monja Stettner, Siegfried Kaidisch, Andrey V. Matetskiy, Eric Fackelman, Serguei Soubatch, Christian Kumpf, François C. Bocquet, Michael G. Ramsey, Peter Puschnig, F. Stefan Tautz
Photoemission orbital tomography (POT) is a powerful tool for investigating the orbitals and electronic band structure of oriented layers of organic molecules. In many cases, POT allows conclusions to be drawn regarding the geometric structure, but so far it has been mainly applied to (sub)monolayers and rarely to bilayers, raising the question of whether POT can also provide structure information for thicker films. Here, we use POT to analyze the band dispersion in up to eight layers of $ \alpha$ -sexithiophene (6T) adsorbed on Cu(110)-p($ 2\times1$ )O. This linear oligomer turns out to be a textbook example that exemplifies the concepts of intra- and intermolecular band dispersion in molecules. Moreover, the rich band and orbital structure information available from POT for this system enables us to trace subtle changes in the crystal structure as a function of layer thickness. Specifically, we find that the periodicity of an intermolecular band changes with film thickness, revealing an increase of the intralayer distance between the molecules with the number of layers. At the same time, the momentum distribution of photoemission from the highest occupied molecular orbital of 6T discloses a decrease of the molecular tilt angle. Following the evolution of tilt angle and lattice constant with layer thickness, we observe – purely based on electronic structure data – that the surface-templated monolayer structure relaxes into the structure of bulk 6T crystals. The experimental findings agree well with the results of density functional theory calculations.
Materials Science (cond-mat.mtrl-sci)
Mean-Field Convective Phase Separation under Thermal Gradients
New Submission | Statistical Mechanics (cond-mat.stat-mech) | 2026-03-09 20:00 EDT
Meander Van den Brande, François Huveneers, Kyosuke Adachi
Nonequilibrium conditions fundamentally change how systems undergo phase separation. In systems with temperature gradients, attractive particles have been shown to form periodic patterns and steady convective currents, but a clear theoretical explanation for this behavior is still missing. Here, we present a dynamical mean-field model that describes the mechanism behind this convective phase separation. Using linear stability analysis, we show that the transition from a uniform state to a periodic pattern is driven by the emergence of a dominant unstable mode. Numerical simulations confirm the predicted phase diagram and demonstrate that these convective currents are a robust feature of the steady state, appearing regardless of the initial conditions. These results provide a direct approach for understanding how temperature gradients drive the formation of steady-state convective patterns.
Statistical Mechanics (cond-mat.stat-mech), Pattern Formation and Solitons (nlin.PS)
6+5 pages, 4+3 figures
Spin Inertia as a Source of Topological Magnons: Chiral Edge States from Coupled Precession and Nutation
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-03-09 20:00 EDT
Subhadip Ghosh, Mikhail Cherkasskii, Ritwik Mondal, Alexander Mook, Levente Rózsa
Spin inertia has been demonstrated to give rise to high-frequency nutational excitations beyond the conventional low-frequency precessional modes. Here, we demonstrate that the hybridization between precessional and nutational magnons may give rise to topological phenomena in the spin-wave spectrum. This hybridization requires the presence of interactions breaking angular-momentum conservation, such as the pseudodipolar interaction. We show on the example of a honeycomb ferromagnet how topological gaps open between the precessional and nutational bands that host chiral edge states in slab geometries. Our work establishes a theoretical foundation for exploring inertial spin dynamics as a new route to engineer topological phases in magnetic materials.
Materials Science (cond-mat.mtrl-sci), Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
6 Pages, 4 figures
Competition between Charge Density Wave and Superconductivity in a Janus MXene Mo2NF2
New Submission | Superconductivity (cond-mat.supr-con) | 2026-03-09 20:00 EDT
Jakkapat Seeyangnok, Udomsilp Pinsook, Graeme J Ackland
Charge-density-wave (CDW) order and superconductivity often compete in low-dimensional materials, yet their interplay in Janus MXenes remains largely unexplored. Here, we present a comprehensive first-principles investigation of the structural, vibrational, and electronic properties of Mo2NF2. Phonon calculations reveal an unstable soft phonon mode at the M point in the high-symmetry structure, signaling a CDW instability. Analysis of phonon linewidths and the real and imaginary parts of the bare electronic susceptibility demonstrates that the CDW is not driven by simple Fermi-surface nesting but instead originates from strong momentum-dependent electron-phonon coupling. Structural relaxation yields a commensurate CDW phase characterized by bond-length modulations involving the Mo, N, and F sublattices. We further show that charge doping alone is insufficient to stabilize the soft phonon, whereas compressive biaxial strain exceeding -3 percent completely suppresses the CDW instability. Electron-phonon coupling calculations indicate that the CDW phase exhibits a reduced coupling constant lambda = 0.40 and logarithmic phonon frequency omega_log = 219 K, leading to a low superconducting transition temperature Tc about 1 K. In contrast, the strain-stabilized high-symmetry phase shows enhanced coupling (lambda = 0.53, omega_log = 272 K) and a higher Tc about 4 K. Our results establish Mo2NF2 as a strain-tunable platform where superconductivity emerges upon suppression of a competing CDW phase, highlighting the crucial role of lattice control in Janus MXenes.
Superconductivity (cond-mat.supr-con)
13 Pages, 6 Figures
Universal Dynamical Scaling of Strong-to-Weak Spontaneous Symmetry Breaking in Open Quantum Systems
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2026-03-09 20:00 EDT
Strong-to-weak spontaneous symmetry breaking (SWSSB) defines a mixed-state phase of matter–without a pure-state counterpart–in which nonlinear observables such as the Rényi-2 correlator develop long-range order while conventional linear correlations remain short-ranged. Here we study the emergence of SWSSB in one-dimensional open quantum systems governed by Lindbladian evolution, where the transition time diverges with system size and SWSSB appears only asymptotically in the steady state. By tracking the late-time growth of the Rényi-2 correlation length, we uncover a universal dynamical regime controlled purely by the symmetry class of the Lindbladian. Contrary to the conventional expectation that late-time dynamics are governed by the low-lying Liouvillian spectrum, we find that the time dependence of the SWSSB transition–exponential versus algebraic–is dictated solely by symmetry, independent of details of the Lindbladian, including whether the Liouvillian spectrum is gapped or gapless. For $ \mathbb{Z}_2$ -symmetric dynamics, the Rényi-2 correlation length grows exponentially in time–even when the spectrum is gapless–yielding an effective transition time $ t_c \propto \operatorname{ln} L$ and enabling rapid preparation of the $ \mathbb{Z}_2$ SWSSB steady state. In contrast, U(1)-symmetric dynamics exhibit algebraic scaling, $ t_c \propto L^{\alpha}$ , with a filling-dependent dynamical exponent: ballistic growth ($ \alpha \approx 1$ ) at finite filling crosses over to diffusive scaling ($ \alpha = 2$ ) in the zero-filling limit. These results establish symmetry–rather than spectral gap structure–as the controlling principle for SWSSB late-time dynamical scaling, and open a new route to nonequilibrium symmetry breaking in open quantum systems.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Strongly Correlated Electrons (cond-mat.str-el), Quantum Physics (quant-ph)
10 pages, 4 figures
Intrinsic decay rates and steady states of driven Josephson junction chains cavities
New Submission | Superconductivity (cond-mat.supr-con) | 2026-03-09 20:00 EDT
Lucia Vigliotti, Andrew P. Higginbotham, Maksym Serbyn
Josephson junction (JJ) chains combine the coherence of superconductivity with the controllability of microwave-frequency circuits, making them a powerful platform for circuit quantum electrodynamics. In this work we consider a long JJ chain that effectively realizes a multi-mode cavity with nonlinear dispersion and additional multi-mode interactions. Individual modes appearing due to the finite size of the chain can be experimentally probed via microwave spectroscopy, both in equilibrium and in driven far-from-equilibrium settings. We study the role of multi-mode interactions in degrading internal coherence – observable as excess linewidth – in both equilibrium and driven regimes. Focusing on two-into-two mode scattering as the leading relaxation process, we classify the relevant scattering processes and derive their expected temperature- and frequency-scaling under equilibrium conditions. For experimentally relevant parameters, we show that the equilibrium decay rate is dominated by non-resonant processes, however weakly driving a particular set of modes out of equilibrium enhances resonant scattering, leading to observable signatures in the distribution function and linewidth. Finally, in the strong non-equilibrium regime we report a crossover to a qualitatively different non-equilibrium steady state.
Superconductivity (cond-mat.supr-con), Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
25 pages, 15 figures
Unlocking extreme doping and strain in epitaxial monocrystalline silicon
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-03-09 20:00 EDT
Léonard Desvignes, Dominique Débarre, Ludovic Largeau, Géraldine Hallais, Gilles Patriarche, Giacomo Priante, Eric Ngo, Olivia Mauguin, Alberto Debernardi, Bernard Sermage, Francesca Chiodi
Hyperdoping, overcoming the solubility limit of dopants in a crystalline semiconductor, is a fertile method for the enhancement of the electrical, structural and optical devices’ performances and for the exploration of exotic phases such as superconductivity. We demonstrate an unprecedented control on the dopant concentration and lattice deformation via nanosecond laser doping in epitaxial boron doped silicon, achieving record carrier concentrations (8 at.%) and lattice deformations (3 %). Probing the microscopical hyperdoping limitations, we show that the relevant mechanisms are caught by a simple combinatorial model, which quantitatively explains both the experimental carrier concentration and lattice deformation evolution. First principle calculations complete and support such simple model. Indeed, at the high doping levels now attainable, the maximum carrier concentration is inherently limited by the probability of two or three substitutional dopants occupying neighboring lattice sites, forming partially inactive complexes that we detail. This description is valid in the case of perfect layers with no crystallographic defects and a fully substitutional dopant occupation, highlighting the quality of the epitaxial layers realized.
Materials Science (cond-mat.mtrl-sci)
Understanding the anisotropic response of $β$-Ga$_2$O$_3$ to ion implantation
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-03-09 20:00 EDT
Duarte Magalhães Esteves, Ru He, Sérgio Magalhães, Miguel Carvalho Sequeira, Ângelo Rafael Granadeiro da Costa, Julia Zanoni, Joana Rodrigues, Teresa Monteiro, Flyura Djurabekova, Katharina Lorenz, Marco Peres
While $ \beta$ -Ga$ _2$ O$ _3$ is considered a promising wide bandgap semiconductor, the impact of ion-induced defect formation and anisotropic elasticity remains poorly understood. Here, we combine a simulation and experiment X-ray diffraction (XRD) study of the strain-stress dynamics induced by ion implantation into $ \beta$ -Ga$ _2$ O$ _3$ single-crystals with different surface orientations. The strain accumulation in the out-of-plane direction is observed by XRD to occur in an anisotropic manner, with compressive strain along the [010] direction and tensile strain along the directions perpendicular to (100) and (001). An anisotropic stress/strain accumulation model is proposed and probed via Molecular Dynamics (MD), showing an excellent agreement with the experiments. For higher damage levels, pole figures obtained both experimentally and by MD via a novel reciprocal-space projection method reveal an orientation-independent $ \beta$ -to-$ \gamma$ phase transition, with a fixed crystallographic relationship between the polymorphs. By exploring the strain-stress dynamics in anisotropic systems, this work establishes a method to directly compare macroscale diffraction experiments and atomistic simulations and opens a new path to engineer the properties of such systems utilizing their anisotropic response to ion implantation/irradiation.
Materials Science (cond-mat.mtrl-sci), Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
31 pages, 11 figures, 1 table
Exotic Pressure-Driven Band Gap Widening in Carbon Chain-Filled KFI Zeolite and Its Pathway to High-Pressure Semiconducting Electronics and High-Temperature Superconductivity
New Submission | Superconductivity (cond-mat.supr-con) | 2026-03-09 20:00 EDT
C.T.Wat, K.C.Lam, W.Y.Chan, C.P.Chau, S.P.Ng, W.K.Loh, L.Y.F.Lam, X.Hu, C.H.Wong
Semiconducting devices face persistent challenges in operating at high pressure, as the band theory predicts that materials transition to a more metallic state under compression. However, our findings with carbon chains in KFI substrates reveal a conditional deviation from this norm. We not only witness the transition from polyyne (semiconductor) to cumulene (metal) at medium pressure, but we also observe an unexpected re-entrance of the polyyne at high pressures, where the band gap in the polyyne increases with pressure. In addition, the synthesis of long cumulene chains has posed a longstanding challenge in the quest for high-temperature organic superconductivity. We have identified critical conditions for synthesizing extended cumulene chains within zeolite frameworks, highlighting the interplay between unconventional charge density waves and significant torsions. The KFI zeolite facilitates the formation of carbon chains exceeding 5,000 atoms, in stark contrast to around 100 other zeolites that are limited to ~10 atoms. The cumulene@KFI system demonstrates a superconducting transition temperature reaching ~62 K, surpassing the highest reported values for bulk iron-based superconductors. This interplay between carbon structures and superconductivity not only advances our understanding of charge density waves but also heralds a new era in the study of novel applications
Superconductivity (cond-mat.supr-con), Computational Physics (physics.comp-ph)
Giant orbital magnetoresistance in the antiferromagnet CoO driven by dynamic orbital angular momentum interaction
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-03-09 20:00 EDT
Christin Schmitt, Sachin Krishnia, Edgar Galindez-Ruales, Luca Micus, Takashi Kikkawa, Hiroki Arisawa, Marjana Lezaic, Duc Tran, Timo Kuschel, Jairo Sinova, Eiji Saitoh, Gerhard Jakob, Olena Gomonay, Yuriy Mokrousov, Mathias Kläui
Recent predictions of orders of magnitude larger orbital current effects compared to spin currents have attracted significant interest. However, the full potential of giant orbital currents remains to be fully harnessed, since so far, the orbital currents need to be converted into spin currents before they can interact with the static magnetization that is dominated by spin angular momentum in conventional magnets. By using a magnet dominated by orbital angular momentum, we demonstrate a more than fifty-fold enhancement in orbital Hall magnetoresistance in CoO/Cu\ast, compared to conventional CoO/Pt. This is found to be driven by a unique interaction between dynamic orbital angular momentum from surface oxidized Cu\ast (i.e., the orbital current) and the static orbital angular momentum which constitutes the magnetic moments in the antiferromagnetic insulator CoO. A distinctive scattering mechanism for orbital currents at the CoO interface leads to a sign reversal in orbital magnetoresistance in CoO/Cu\ast compared to CoO/Pt. Our results show how by using orbital angular momentum-dominated materials such as CoO, we can harness the benefits of giant orbital currents that have not been possible using conventional spin-dominated magnets, for orbitronics-based devices, offering unprecedented energy efficiency for operations of antiferromagnets that combine ultimate stability with THz dynamics.
Materials Science (cond-mat.mtrl-sci)
Linear control theory for jammed particle systems
New Submission | Soft Condensed Matter (cond-mat.soft) | 2026-03-09 20:00 EDT
Erin G. Teich, Jason Z. Kim, Dani S. Bassett
Amorphous particulate matter constitutes a wide range of natural and synthetic materials. Despite this ubiquity, the way in which these systems’ disordered microstructure couples to their often subtle and complex dynamical behavior is not yet fully understood, with profound consequences for phenomena ranging from landscape evolution to cellular unjamming during tumor metastasis. With this paper, we introduce tools from linear control theory that quantify system response to external input, and demonstrate their utility in elucidating the dynamics of jammed amorphous materials under stress. Our results indicate that average controllability, the response of a system to perturbation, strongly correlates with particle rearrangement in systems subject to quasistatic shear, implying that average controllability is an accurate predictor of rearrangement dynamics in certain contexts. Moreover, we show that the time scale over which average controllability is calculated can be tuned to optimize its predictive capacity for particle rearrangement. Values of the optimal time scale provide physical insight into the system; namely, that multiple rearranging particles participate on average in vibrational eigenmodes of lower and lower energy as the system is sheared until the rearrangement event. Broadly, our study demonstrates that linear control theory is a promising mathematical framework for predicting and designing mechanical response in disordered media.
Soft Condensed Matter (cond-mat.soft)
Real-time exciton dynamics in two-dimensional materials under ultrashort laser pulses
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-03-09 20:00 EDT
Dmitry Tumakov, Daria Popova-Gorelova
The optical response of two-dimensional materials is often significantly impacted by excitonic effects due to the reduced screening of attractive Coulomb interactions in low-dimensional systems. Accurate modeling of exciton formation and real-time dynamics is essential to understanding their ultrafast optical properties. In this study, we theoretically investigate the exciton dynamics in a two-dimensional hexagonal boron nitride (h-BN) and a germanium sulfide (GeS) monolayers exposed to an ultrashort laser pulse. We analyze the system’s response to the external field in one- and two-photon excitation regimes. For our calculations, we combine a state-of-the-art ab initio approach to study exciton dynamics with a highly precise numerical scheme. We incorporate electron-hole interactions through a non-local self-energy operator derived from the many-body perturbation theory (MBPT) within the time-dependent adiabatic $ GW$ (TD-a$ GW$ ) approximation. We implement this approach using the full-electron LAPW+lo method in the all-electron exciting package. Our results elucidate the role of many-body effects in shaping ultrafast excitonic processes in two-dimensional materials, contributing to the fundamental understanding necessary for optoelectronic and photonic applications.
Materials Science (cond-mat.mtrl-sci)
AKLT Hamiltonian from Hubbard tripods
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2026-03-09 20:00 EDT
Claire Benjamin, Dániel Varjas, Gábor Széchenyi, Judit Romhányi, László Oroszlány
We investigate how the spin-1 Affleck-Kennedy-Lieb-Tasaki (AKLT) Hamiltonian can emerge from a microscopic fermionic model based on half-filled Hubbard tripods. We first show that a single tripod hosts a robust threefold-degenerate low-energy manifold corresponding to an effective $ S = 1$ degree of freedom. This manifold prevails over a broad range of interactions and remains stable against moderate disorder. We then combine exact diagonalization with fourth-order quasi-degenerate perturbation theory to derive an effective bilinear-biquadratic spin model for a pair of coupled tripods and identify coupling regimes where the target ratio is approached. In particular, tuning leg-center hopping together with two symmetry-inequivalent leg-leg hoppings yields the characteristic singlet-triplet degeneracy associated with a biquadratic-to-bilinear ratio close to 1/3. Extending the analysis to three tripods, we compare nonequivalent coupling geometries and find a strategy that suppresses unwanted longer-range and multispin terms while preserving the target nearest-neighbor couplings in the weak-coupling regime. These results establish a concrete bottom-up route from Hubbard clusters to valence-bond-solid spin physics in tunable quantum-dot arrays.
Strongly Correlated Electrons (cond-mat.str-el), Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Statistical Mechanics (cond-mat.stat-mech), Quantum Physics (quant-ph)
Revisiting the symmetry and optical phonons of altermagnetic $α$-MnTe
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-03-09 20:00 EDT
Ece Uykur, Marcos V. Gonçalves-Faria, Sahana Rößler, Victoria A. Ginga, Marcus Schmidt, Stephan Winnerl, Manfred Helm, Alexander A. Tsirlin
Using infrared (IR) and Raman spectroscopies combined with high-resolution x-ray diffraction, we address several controversial aspects of altermagnetic $ \alpha$ -MnTe. We show that mechanical stress applied to crystals of this material causes a drastic broadening of Bragg peaks that conceals signatures of additional phases present in the sample. Indeed, spatially resolved Raman spectroscopy reveals that the modes around 175 cm$ ^{-1}$ often reported in $ \alpha$ -MnTe are not reproducible across different positions and samples and originate from the secondary phase of MnTe$ 2$ . By combining spectroscopic probes with ab initio calculations, we establish the IR-active optical phonon of $ \alpha$ -MnTe around 155 cm$ ^{-1}$ ($ E{1u}$ ) and the Raman-active optical phonon around 100 cm$ ^{-1}$ ($ E_{2g}$ ) at room temperature. Two intense Raman modes around 120 and 140 cm$ ^{-1}$ are shown to be intrinsic, even though they can not be assigned to $ \Gamma$ -point optical phonons. These modes couple to magnetic order in $ \alpha$ -MnTe and also to the transient reflectivity resulting in coherent oscillations. Both 6-fold rotation symmetry and inversion symmetry are preserved in $ \alpha$ -MnTe within our experimental resolution.
Materials Science (cond-mat.mtrl-sci)
9 pages, 7 figures
Density of States Weighted Decoherence Probe Formalism for Charge Transport in DNA
New Submission | Other Condensed Matter (cond-mat.other) | 2026-03-09 20:00 EDT
Hashem Mohammad, M.P. Anantram
Nanoscale molecular systems such as DNA require an atomistic quantum treatment to accurately capture their electrical properties, owing to their small dimensions. A central challenge in modeling transport through these systems is the inclusion of phase-breaking scattering. Decoherence-probe methods enable such modeling for large systems, but existing implementations have limitations. Energy-independent scattering rates tend to overly broaden energy levels, yielding an unphysically large density of states (DOS) within energy gaps. Conversely, energy-dependent models may introduce spurious energy levels and transmission peaks and require additional fitting parameters. To address these issues, we use a DOSweighted decoherence model in which the scattering rate and equivalently, the associated decoherence probe self-energy is proportional to the local DOS. The model iteratively updates the decoherence selfenergy and the DOS until self-consistency is achieved. This approach yields energy and spatially dependent scattering rates that avoid spurious energy levels without the excessive broadening of DOS in energy gaps. We also examine the impact of partitioning schemes that prevent artificial pathways for charge transport and discuss how they can be avoided. Overall, the DOS-weighted model provides an improved and more physically grounded framework for simulating charge transport in DNA and potentially other weakly coupled molecular systems.
Other Condensed Matter (cond-mat.other), Biological Physics (physics.bio-ph)
Accepted for publication in Physical Review E
Skyrmion Cyclotron Resonance in Ferrimagnets
New Submission | Other Condensed Matter (cond-mat.other) | 2026-03-09 20:00 EDT
Eugene M. Chudnovsky, Dmitry A. Garanin
We show that a resonance due to gyroscopic motion of skyrmions, conceptually similar to the electron cyclotron resonance in metals, can be excited in a ferrimagnetic film by a spin current or microwaves. It must permit unambiguous measurement of the skyrmion mass for which a universal expression depending solely on the exchange interaction between spins belonging to two different ferrimagnetic sublattices is derived. The dependence of the skyrmion cyclotron frequency on parameters is computed for a TM/RE ferrimagnet, using CoGd as an example. The cyclotron frequency exhibits a dip near the angular momentum compensation point, where it hybridizes with the ferromagnetic resonance. The skyrmion cyclotron mode is studied for individual skyrmions and for skyrmion lattices, where the effect must be strong enough to be observed in microwave and spin-current experiments.
Other Condensed Matter (cond-mat.other)
6 Phys. Rev. pages, 4 figures
Parity readout in Majorana box qubits from the dispersive to the resonant regime
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2026-03-09 20:00 EDT
Sara M. Benjadi, Reinhold Egger
We study theoretical models for charge reflectometry and capacitive readout of the Majorana parity degree of freedom in Majorana box qubits, taking into account decoherence channels within the framework of the Lindblad master equation. Noting that a parity-dependent dynamical susceptibility $ \chi_z(\omega)$ governs both readout schemes, we provide a general expression for $ \chi_z(\omega)$ which covers the full crossover from the resonant regime to the off-resonant dispersive regime. In addition, we re-examine previous results which were obtained under a semiclassical factorization assumption. Using three different error measures, we show that this approximation is quantitatively justified in the dispersive regime. In the resonant regime, however, we find deviations from exact reference data, obtained by numerical solution for the steady state of the full Lindblad equation. These deviations are typically of the order of a few percent in the considered error measures.
Strongly Correlated Electrons (cond-mat.str-el)
12 pages, 4 figures
Structural Commonalities in Different Classes of Non-Crystalline Materials
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-03-09 20:00 EDT
I. Rodriguez, D. Hinojosa-Romero, R. M. Valladares, A. Valladares, A. A. Valladares
In the past decades, the research community has explored diverse structures and new fabrication methods of non-crystalline solids. Glassy materials that belong to the semiconductor realm and to the metallic type are the most studied both experimentally and theoretically. The present work investigates similar structural trends whenever they exist and different trends among different classes. Amorphous semiconductors display Pair Distribution Functions (PDF) that are very similar among themselves, and this indicates that these network-forming materials have properties that are alike. Analogously, metallic systems have comparable PDFs but different from the network forming materials, as it should be, since the properties between these two classes are quite different. Here we pay attention to the first and second peaks of their structures. Whereas the semiconductor structures display a simple first and second peak with a near-zero value between them. In contrast, the metallic systems have a very well-defined non-zero value between the first and second peaks, and they also display what we have come to identify as an ‘elephant peak’. We also discuss semimetals and alloys.
Materials Science (cond-mat.mtrl-sci)
8 pages, 10 figures
Linearly Polarized Light-Induced Anomalous Hall Effect and Topological Phase Transitions in an Altermagnetic Topological Insulator
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2026-03-09 20:00 EDT
Yichen Liu, Tongshuai Zhu, Haijun Zhang
A recently identified class of collinear magnetic order, characterized by vanishing net magnetization yet unconventional spin splitting, known as altermagnets (AMs), has attracted significant research interest. Controlling the unconventional spin splitting and the associated band topology in AMs offers opportunities for realizing novel spin and topological transport phenomena. In this work, using Floquet engineering with periodically driven linearly polarized light (LPL), we explore light-induced control of an AM topological insulator. Remarkably, we find that AMs and conventional antiferromagnets (AFMs) exhibit distinct responses under LPL irradiation. Specifically, since LPL breaks neither time-reversal ($ \mathcal{T}$ ) symmetry nor parity-time-reversal ($ \mathcal{PT}$ ) symmetry, it is incapable of generating spin splitting or inducing an anomalous Hall effect (AHE) in conventional AFMs. In contrast, AMs intrinsically lack both $ \mathcal{T}$ and $ \mathcal{PT}$ symmetries. Their spin-up and spin-down bands are related by the combined symmetry of time reversal $ \mathcal{T}$ and a crystal rotation. We show that LPL readily breaks these symmetries, thereby triggering a finite AHE exclusively in AMs. Furthermore, LPL can drive the AM topological insulator into a fully spin-polarized Chern insulating phase. Our findings not only provide a robust experimental scheme to distinguish AMs from conventional AFMs, but also establish a promising pathway toward dissipationless spintronic applications.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Materials Science (cond-mat.mtrl-sci)
10 pages, 5 figures
Altermagnets Enable Gate-Switchable Helical and Chiral Topological Transport with Spin-Valley-Momentum-Locked Dual Protection
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2026-03-09 20:00 EDT
Xianzhang Chen, Jiayong Zhang, Bowen Hao, Jiahui Qian, Ziye Zhu, Igor Zutic, Zhenyu Zhang, Tong Zhou
We establish a unified, symmetry-driven framework that combines the alternating spin splitting of altermagnets with valley topology to realize and electrically interconvert helical and chiral topological phases within a single material platform. We first demonstrate a magnetic analogue of the quantum spin Hall effect in altermagnets, hosting helical spin-valley-momentum-locked (SVML) edge states characterized by a composite spin-valley Chern number Csv = 2. Large-scale quantum transport simulations show these SVML edge states exhibit fully quantized spin conductance robust against nonmagnetic and long-range magnetic disorder, reflecting their dual topological protection, while remaining vulnerable to short-range magnetic disorder. Exploiting that the counterpropagating SVML modes are linked by crystal rotation symmetry, we introduce a gate-tunable sublattice-staggered potential that selectively gaps one valley and converts the helical state into a chiral quantum anomalous Hall phase with Csv = 1, robust against all disorder types. Reversing the potential switches the transmitted spin-valley polarization. Our first-principles calculations identify monolayer V2STeO and VO families as realistic platforms supporting both helical and chiral topological phases and their electrical switching. These results establish altermagnets as electrically programmable platforms for robust topological devices across charge, spin, and valley.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Materials Science (cond-mat.mtrl-sci)
7 pages, 4 figures
Epitaxial stabilization of magnetic GdAuSb/LaAuSb superlattices
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-03-09 20:00 EDT
Patrick J. Strohbeen, Soohyun Im, Tamalika Samanta, Zachary LaDuca, Dongxue Du, Estiaque H. Shourov, Jessica L. McChesney, Fanny Rodolakis, Paul M. Voyles, Jason K. Kawasaki
We report the epitaxial stabilization of GdAuSb films and GdAuSb/LaAuSb superlattices via molecular beam epitaxy on (0001)-oriented Al$ _{2}$ O$ {3}$ substrates. GdAuSb crystallize in the Au-Au dimerized YPtAs structure type (space group $ P6{3}/mmc$ ), the same structure as the Dirac semimetal LaAuSb. Angle-resolved photoemission spectroscopy (ARPES) measurements show similar near $ E_F$ bandstructures for GdAuSb and LaAuSb, plus a rigid band shift for GdAuSb towards more hole-like behavior and core-like Gd $ 4f$ states $ \sim 9$ ~eV below the Fermi energy. LaAuSb/GdAuSb superlattices exhibit sharp superlattice fringes by X-ray diffraction and atomically-precise interfaces by scanning transmission electron microscopy. Superlattices display two transitions in temperature-dependent resistvity, compared to a single Néel temperature for thick GdAuSb films. Superlattices of $ Ln$ AuSb materials ($ Ln=$ rare earth) with atomically abrupt interfaces offer a new epitaxial platform for control of magnetic and topological order via tunable intralayer exchange and reduced dimensionality.
Materials Science (cond-mat.mtrl-sci)
Tomographic collective modes in a magnetic field
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2026-03-09 20:00 EDT
Two-dimensional Fermi liquids at low temperatures have been theoretically established to exhibit an odd-even effect in the collective quasiparticle relaxation rates where even-parity deformations of the Fermi surface decay at a much faster rate than odd-parity ones. A predicted consequence of this effect is a new tomographic transport regime that mixes hydrodynamic and collisionless transport. In the presence of a magnetic field, however, the tomographic regime is expected to evolve towards conventional transport regimes as soon as the cyclotron radius becomes smaller than the dominant odd-parity mean free path. In this work, we examine this transition from the point of view of collective modes, using a numerically exact solution of the linearized Boltzmann equation within a generalized relaxation time approximation for the odd-parity and even-parity modes. In the absence of a magnetic field, the transverse conductivity exhibits two diffusive tomographic collective modes, and we find that at a critical magnetic field one of these two tomographic modes disappears. Which tomographic mode persists depends on the Landau parameters, with the remaining mode becoming increasingly dominated by hydrodynamic modes at high fields. We corroborate our analysis using a variational approach for the Fermi surface deformation that captures the angular structure of the deformation and the critical magnetic field strength. The collective modes discussed here can in principle be observed by examining the damping of longitudinal and transverse current responses in finite magnetic fields.
Strongly Correlated Electrons (cond-mat.str-el), Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Quantum Gases (cond-mat.quant-gas)
15 pages, 7 figures, 1 appendix
Predicting Atomistic Transitions with Transformers
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-03-09 20:00 EDT
Henry Tischler, Wenting Li, Qi Tang, Danny Perez, Thomas Vogel
Accurate knowledge of the atomistic transition pathways in materials and material surfaces is crucial for many material science problems. However, conventional simulation techniques used to find these transitions are extremely computationally intensive. Even with large-scale, accelerated material simulations, the computational cost constrains the applicable domain in practice. Machine learning models, with the potential to learn the complex emergent behaviors governing atomistic transitions as a fast surrogate model, have great promise to predict transitions with a vastly reduced computational cost. Here, we demonstrate how transformers can be trained to predict atomistic transitions in nano-clusters. We show how we evaluate physical validity of the predictions and how a multitude of additional, different microstates can be generated by slightly varying the data provided to the model.
Materials Science (cond-mat.mtrl-sci), Machine Learning (cs.LG)
Presented at the 2025 Conference on Data Analysis (CoDA), February 25-28, Santa Fe, New Mexico
Inference of the 3D pressure field exerted by a single cell from a thin membrane transverse deformation
New Submission | Soft Condensed Matter (cond-mat.soft) | 2026-03-09 20:00 EDT
Quentin Bédel, Loïc Dupré, Nicolas Destainville
Numerous cell types relate to their immediate environment by exerting a three-dimensional pressure field on their environment, with components both longitudinal and transverse to the cell membrane. This pressure field can in principle be measured by traction force microscopy experiments. Compared to other approaches, the technique of Protrusion Force Microscopy gives access with high spatial resolution to the pressure field by measuring the deformation of a thin elastic membrane using atomic force microscopy (AFM). However, while the pressure field under interest is three-dimensional, the height profile measured by AFM is only one-dimensional. We propose a solution to this inverse problem and we explore its regime of applicability in the experimental context.
Soft Condensed Matter (cond-mat.soft)
To appear in EPJ E
Deterministic Electrical Switching in Altermagnets via Surface Antisymmetry Groups
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-03-09 20:00 EDT
A surface antisymmetry group framework is developed to establish design rules for deterministic electrical switching of the Néel vector in a film of a collinear bipartite antiferromagnet. In centrosymmetric $ d$ -wave altermagnets, where current-induced torques vanish in the bulk, staggered effective fields can nevertheless exist as an interfacial response, whose allowed tensor form is determined by the surface antisymmetry subgroup for the given surface orientation. Separately, the structure of the spin conductivity tensor determines which surface orientations allow transverse spin current generation via the spin-splitter effect. Taken together, these symmetry-enforced properties establish which surface orientations of $ d$ -wave altermagnets can serve as deterministically switchable spin current sources in spin-torque heterostructures. Because the design rules are based solely on the surface antisymmetry point group, the required staggered axial response is robust against averaging over symmetry-equivalent surface facets and equilibrium roughness.
Materials Science (cond-mat.mtrl-sci), Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
5 pages
Nanoscale Electronic Phase Separation Driven by Fe-site Ordering in Fe\textsubscript{5-x}GeTe\textsubscript{2}
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2026-03-09 20:00 EDT
Shreyashi Sinha, Ayan Jana, Suchanda Mondal, Ravi Prakash Singh, Manoranjan Kumar, Sujit Manna
Understanding how local structural order governs electronic correlations is essential for revealing the microscopic mechanism underlying emergent behavior in two-dimensional magnets. In the layered van der Waals ferromagnet Fe\textsubscript{5-x}GeTe\textsubscript{2}, intrinsic Fe-site disorder provides a natural platform to probe this interplay. Here, we establish a direct atomic scale correlation between Fe-site ordering and local electronic structure by combining high-resolution scanning tunneling microscopy with density functional theory calculations. Scanning tunneling microscopy resolves two coexisting surface phases, a $ \sqrt{3} \times \sqrt{3}$ superstructure associated with ordered Fe(1) configurations and an undistorted $ 1 \times 1$ hexagonal Te lattice in Fe(1)-deficient regions. Spatially resolved spectroscopy shows that the $ \sqrt{3}$ -ordered domains exhibit metallic behavior, whereas Fe(1) vacant areas display a suppressed density of states(DOS) near the Fermi level, indicative of pseudogapped electronic states. The nanoscale coexistence of these distinct electronic responses provides direct evidence of electronic phase separation driven by Fe-site ordering. First-principles calculations reveal that symmetry allowed hybridization between Fe 3d and Te 5p orbitals reconstructs the low-energy electronic structure, giving rise to the contrasting tunneling signatures of ordered and disordered phases. Bias-dependent local DOS simulations reproduce the experimentally observed contrast evolution and reveal that hybridization induced out of plane orbital character governs the spatial modulation of tunneling conductance. These results provide a microscopic framework linking atomic-scale structural order to nanoscale electronic inhomogeneity in van der Waals magnets.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Materials Science (cond-mat.mtrl-sci)
12 pages, 8 figures
Unifying description of competing chiral and nematic superconducting states in twisted bilayer graphene
New Submission | Superconductivity (cond-mat.supr-con) | 2026-03-09 20:00 EDT
Lucas Baldo, Patric Holmvall, Annica M. Black-Schaffer
We reveal a striking correspondence between electron- and phonon-driven pairing in twisted bilayer graphene (TBG) by mapping an atomistic electronically driven pairing model onto an effective inter-valley, intra-Chern description, originally proposed for phonon-mediated superconductivity. Within the unified framework of intra-Chern pairing, we analyze the competition between nematic and chiral superconducting states. The latter corresponds to the extreme Chern-polarized limit and thus hosts unpaired flat bands within the superconducting gap, which generally disfavors it relative to the nematic states. Crucially, nematic order is locally preferred at each momenta, but the optimal nematic directions are incompatible across the Brillouin zone due to the broken rotation symmetry. This momentum-space frustration enables a chiral ground state at large fillings or weak interactions. Our results thereby both provide a unified understanding of superconductivity in TBG, with a natural cooperation of electron- and phonon-mediated pairing, and clarify the microscopic origin of the competition between the chiral and nematic superconducting states.
Superconductivity (cond-mat.supr-con), Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
18 pages, 10 figures (main text); 9 pages, 5 figures (supplemental material)