CMP Journal 2026-02-16
Statistics
Nature: 1
Nature Nanotechnology: 1
Nature Physics: 1
Nature Reviews Physics: 1
arXiv: 67
Nature
De novo design of GPCR exoframe modulators
Original Paper | Cryoelectron microscopy | 2026-02-15 19:00 EST
Shizhuo Cheng, Jia Guo, Yun-li Zhou, Xumei Luo, Gufang Zhang, Ya-zhi Zhang, Yixin Yang, Jiannan Xie, Ping Xu, Dan-dan Shen, Shaokun Zang, Huicui Yang, Xuechu Zhen, Min Zhang, Yan Zhang
G-protein-coupled receptors (GPCRs) are important therapeutic targets and have been targeted mainly through their orthosteric site, where the endogenous agonist binds1. However, allosteric modulation has emerged as a promising and innovative strategy in the realm of GPCR drug discovery1. Here, drawing inspiration from the natural regulation of GPCRs by transmembrane proteins, we have developed GPCR exoframe modulators (GEMs), de novo designed proteins that specifically target the transmembrane domain of GPCRs. Utilizing a hallucination-like design approach, we crafted GEMs with three strategic structural prompts to achieve the desired binding modes. We selected the dopamine D1 receptor as a prototypical model and systematically investigated four GEMs. Structural studies and functional assays revealed that these GEMs bind to the transmembrane domains and function as diverse allosteric modulators, including agonist-positive allosteric modulator, negative allosteric modulator and biased allosteric modulator. The ago-PAM GEM restores the activity of various D1 receptor loss-of-function mutants, suggesting a promising therapeutic target for GPCR-related disorders. Our work introduces GEMs that target the transmembrane domain as potent agents for allosteric GPCR modulation and highlights the potential of deep learning-based approaches in the design of function-oriented membrane proteins.
Cryoelectron microscopy, Protein design
Nature Nanotechnology
Spatial light modulator via optically addressed metasurface
Original Paper | Photonic devices | 2026-02-15 19:00 EST
Xuhao Fan, Wei Xiong, Ke Xu, Zhou Zhou, Xinger Wang, Zhilin Teng, Zongjing Li, Zexu Zhang, Xuan Yu, Zhongtian Nie, Jinsong Xia, Shih-Chi Chen, Cheng-Wei Qiu, Hui Gao
Emerging demands for dynamic wavefront modulation in holographic displays, augmented/virtual reality, and light detection and ranging require spatial light modulators (SLMs) with high pixel density and fast refresh rates. However, key parameters of existing liquid-crystal and metasurface-based SLMs, such as spatiotemporal product density, field of view and refresh rate, remain far below application requirements. Here we report an optically addressed metasurface SLM composed of independently tunable meta-atom supercells with a 756 nm pitch. This device reduces SLM pixel size to the submicrometre scale while achieving a spatiotemporal product density of 2.3 × 1012 pixels s-1 cm-2, thereby meeting the critical threshold for true holography. It enables real-time complex-amplitude holography, three-dimensional focusing and beam steering over a ±20.6° field of view in the visible spectrum.
Photonic devices, Sub-wavelength optics
Nature Physics
Topological Kondo insulator in MoTe2/WSe2 moiré bilayers
Original Paper | Quantum Hall | 2026-02-15 19:00 EST
Zhongdong Han, Yiyu Xia, Zhengchao Xia, Wenjin Zhao, Yichi Zhang, Kenji Watanabe, Takashi Taniguchi, Jie Shan, Kin Fai Mak
Topological Kondo insulators are a topologically protected insulating state induced by Kondo exchange interactions between itinerant electrons and local magnetic moments, as opposed to single-particle band inversion. They are characterized by an insulating bulk with Dirac surface states in three dimensions and helical edge states in two dimensions. Although experiments have supported the emergence of these insulators in the rare-earth compound SmB6, their observation in two-dimensional systems has not been demonstrated. Here we report the experimental evidence of a two-dimensional topological Kondo insulator in MoTe2/WSe2 moiré bilayers. Using dual-gated devices, we prepare a triangular lattice of local moments in the MoTe2 layer and a half-filled dispersive band in the WSe2 layer with a chiral Kondo coupling. Using transport and compressibility measurements, we show that the state supports metallic transport at high temperature and an insulating bulk with helical edge conduction protected by spin-Sz conservation at low temperature. Under high magnetic fields, the insulating state at low temperature becomes metallic. Our results demonstrate a highly tunable platform based on moiré materials for studying the interplay of strong interactions and topological order.
Quantum Hall, Topological insulators, Two-dimensional materials
Nature Reviews Physics
Collective dynamics on higher-order networks
Review Paper | Complex networks | 2026-02-15 19:00 EST
Federico Battiston, Christian Bick, Maxime Lucas, Ana P. Millán, Per Sebastian Skardal, Yuanzhao Zhang
Higher-order interactions that nonlinearly couple more than two nodes are important in many networked systems, and their effects on collective dynamics are increasingly being studied. Here, we provide an overview of this rapidly growing field and of the techniques that can be used to describe and analyse them. We focus in particular on new phenomena and challenges that emerge when non-pairwise interactions are considered. We conclude by discussing open questions and promising future directions on the collective dynamics of higher-order networks.
Complex networks, Nonlinear phenomena, Phase transitions and critical phenomena
arXiv
Observing dissipationless flow of an impurity in a strongly repulsive quantum fluid
New Submission | Quantum Gases (cond-mat.quant-gas) | 2026-02-16 20:00 EST
Milena Horvath, Sudipta Dhar, Elisabeth Wybo, Dimitrios Trypogeorgos, Yanliang Guo, Mikhail Zvonarev, Michael Knap, Manuele Landini, Hanns-Christoph Nägerl
The frictionless motion of an object through a fluid medium is commonly viewed as a hallmark of superfluidity. According to Landau, kinematic constraints prohibit superfluid behavior in one-dimensional (1D) bosonic systems. Here, using ultracold atoms, we show how a microscopic impurity can propagate through a strongly interacting 1D Bose gas without any friction, at odds with conventional expectations. We inject the impurity with initial velocities ranging from the subsonic to supersonic regime, and subsequently track its dynamics. For supersonic initial velocities, we observe the formation of a shock wave and a remarkably fast relaxation to a stationary regime, on a time scale that increases with decreasing impurity velocity. After reaching the stationary state, the impurity continues its motion through the system with a finite velocity. Our findings demonstrate how quantum effects can conspire to eliminate dissipation of a microscopic object immersed in a quantum fluid, thereby bringing novel insights into the propagation of matter and information in the quantum realm.
Quantum Gases (cond-mat.quant-gas), Strongly Correlated Electrons (cond-mat.str-el), Quantum Physics (quant-ph)
Compact localized states and magnetic flux-driven topological phase transition in a diamond-dodecagon lattice geometry
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2026-02-16 20:00 EST
We propose and investigate a novel two-dimensional (2D) tight-binding model defined on a diamond-dodecagon lattice geometry that hosts multiple flat bands (FBs) and supports topological phase transitions driven by a magnetic flux. This lattice exhibits three completely flat, non-dispersive bands in the band structure in the absence of magnetic flux due to destructive interference in the electron hoppings, leading to the emergence of compact localized states (CLS). These CLS are analytically constructed and exhibit real-space confinement of the electrons, arising solely due to the lattice’s geometrical frustration. It has been shown that these FBs are very robust against the introduction of weak random onsite disorder in the system. By tuning the uniform magnetic flux threaded through the diamond plaquettes, we demonstrate a tunable evolution of the band structure and show that certain bands develop nontrivial topological features with nonzero integer values of the Chern number. Additionally, we have computed the multi-terminal transport properties for this 2D lattice system, which display the flux-tunable resonances and transmission suppression linked to the FBs, establishing a clear interplay between the localization, topology, and transport. Our findings put forward the diamond-dodecagon lattice as a robust and tunable platform for studying the flat-band physics and magnetic flux-controlled topological phenomena, offering promising experimental feasibility in photonic lattices and ultracold atomic systems.
Strongly Correlated Electrons (cond-mat.str-el), Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Other Condensed Matter (cond-mat.other)
12 pages, 8 (7+1) figures; Comments are welcome
Controlled Zeno-Induced Localization of Free Fermions in a Quasiperiodic Chain
New Submission | Statistical Mechanics (cond-mat.stat-mech) | 2026-02-16 20:00 EST
Pinaki Singha, Nilanjan Roy, Marcin Szyniszewski, Auditya Sharma
We investigate measurement-induced localization in a continuously monitored one-dimensional Aubry–André–Harper model, focusing on the quantum Zeno regime in which the measurements dominate coherent dynamics. The presence of a quasiperiodic potential renders the problem analytically tractable and enables a controlled study of the interplay between monitoring and disorder. We develop an analytical description based on an instantaneous Schrödinger equation with a measurement-induced effective potential constructed self-consistently from individual quantum trajectories, without relying on postselection. In the quantum Zeno regime, an emergent dominant energy scale reduces the problem to a transfer-matrix formulation of an effective non-Hermitian Hamiltonian, which allows direct computation of the Lyapunov exponent. Complementarily, we extract the localization length numerically from long-time steady-state quantum state diffusion trajectories by reconstructing the intrinsic localized single-particle wave functions and analyzing their spatial decay. These numerical results show quantitative agreement with the effective theory predictions, with controlled corrections of order $ J^2/[\lambda^2+(\gamma/2)^2]$ (where $ J$ is the hopping amplitude, $ \gamma$ the measurement strength, and $ \lambda$ the quasiperiodic potential). Our results underscore the connection between the effective non-Hermitian description and the stochastic monitored dynamics, showing the interplay between Zeno-like localization, coherent hopping, and quasiperiodic-disorder-induced localization, while also laying the groundwork for understanding and exploiting measurement-induced localization as a tool for quantum control and state preparation.
Statistical Mechanics (cond-mat.stat-mech)
19 pages, 4 figures, 1 table
Investigating the Electronic and Magnetic Properties of Na$x$Fe${1/2}$Mn$_{1/2}$O$_2$ Cathode Materials with X-ray Compton Scattering
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-02-16 20:00 EST
Veenavee Nipunika Kothalawala, Kosuke Suzuki, Johannes Nokelainen, Ilja Makkonen, Erica West, Lassi Roininen, Jere Leinonen, Pekka Tynjälä, Petteri Laine, Juho Välikangas, Ulla Lassi, Assa Aravindh Sasikala Devi, Matti Alatalo, Yuki Mizuno, Naruki Tsuji, Hikaru Usami, Yuju Nagasaki, Tsuyoshi Takami, Yoshiharu Sakurai, Hiroshi Sakurai, Mohammad Babar, Venkat Vishwanathan, Arun Bansil, Bernardo Barbiellini
We discuss electronic and magnetic properties of Na$ _x$ Fe$ _{1/2}$ Mn$ _{1/2}$ O$ _2$ , a promising Na-ion battery cathode material. Using x-ray Compton scattering, SQUID magnetometry, and density-functional-theory based modeling, we probe how electrons and spins evolve during sodiation. By comparing Compton profiles of sodiated and desodiated samples, we show that oxygen 2$ p$ orbitals drive the redox process, while transition-metal 3$ d$ electrons become more delocalized, explaining the metallic phase at $ x=2/3$ . These profile differences define a quantitative descriptor for the sodiation range associated with improved conductivity. Electron holes on oxygen, reflected in oxygen magnetization, confirm the important role of oxygen in the electrochemical activity of the cathode.
Materials Science (cond-mat.mtrl-sci)
12 pages, 8 figures
Symmetries of Spin-Splitting Induced by Spin-Orbit Coupling in Non-magnetic Crystals
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-02-16 20:00 EST
Fan Yang, Rafael M. Fernandes, Turan Birol
Spin-orbit coupling (SOC) leads to splitting of otherwise spin-degenerate bands in noncentrosymmetric materials, even if time-reversal symmetry is present. While this gives rise to well-known phenomena such as the Rashba and Dresselhaus effects, various other terms are allowed based on the point group of the crystal and the electronic Hamiltonian. In this study, we utilize point group representations to illustrate that four different types of SOC terms (Rashba, Dresselhaus, Weyl, and Ising) can emerge in periodic solids. We construct reciprocal space energy expressions for each type of SOC-induced splitting of opposite spin bands, and follow a similar procedure to also obtain minimal tight-binding models that capture all types of spin-splittings for subgroups of the cubic parent group $ m\bar{3}m$ . Furthermore, we also obtain a complete list of nodal features in the electronic band structure in these systems, distinguishing between crystallographic-symmetry-imposed nodal lines and those imposed by time-reversal-symmetry only. Finally, we conclude by presenting a list of materials that host each type of inversion-breaking SOC effects. Our classification of the spin-splitting symmetries in non-magnetic systems with SOC is the counterpart of the recent classification of spin-splitting symmetries in unconventional magnetic systems without SOC, such as altermagnets and odd-parity magnets. More broadly, our work provides a basis for studying superconductivity and other collective electronic phenomena that are impacted by SOC-induced band splittings in noncentrosymmetric materials.
Materials Science (cond-mat.mtrl-sci), Strongly Correlated Electrons (cond-mat.str-el)
Information lattice approach to the metal-insulator transition
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2026-02-16 20:00 EST
William Skoglund, Elton Giacomelli, Yiqi Yang, Jens H. Bardarson, Erik van Loon
Correlation functions and correlation lengths are frequently used to describe phase transitions in quantum systems, but they require an explicit choice of observables. The recently introduced information lattice instead provides an observable-independent way to identify where and at which scale information is contained in quantum lattice models. Here, we use it to study the difference between the metallic and insulating regime of one-dimensional tight-binding chains. We find that the information per scale follows a power law in metals at low temperature and that Friedel-like oscillations are visible in the information lattice. At high temperature or in insulators at low temperature, the information per scale decays exponentially. Thus, the information lattice is a useful tool for analyzing the metal-insulator transition.
Strongly Correlated Electrons (cond-mat.str-el), Quantum Physics (quant-ph)
A Transformer-based Model for Rapid Microstructure Inference from Four-Dimensional Scanning Transmission Electron Microscopy Data
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-02-16 20:00 EST
Kwanghwi Je, Ellis R. Kennedy, Sungin Kim, Yao Yang, Erik H. Thiede
Properties of crystalline materials are closely linked to microstructure arising from the spatial arrangement, orientation, and phase of nanocrystals. Rapid characterization of crystalline microstructure can accelerate the identification of these links and the development of materials with desired properties. Here, we combine a machine learning framework with four-dimensional scanning transmission electron microscopy (4D-STEM) to enable fast inference of crystalline microstructure over large fields of view. The framework employs a transformer-based architecture to predict crystallographic orientations and phases from 4D-STEM diffraction patterns, yielding spatially resolved maps of microstructural features at the nanoscale. With this framework, crystallographic orientations are inferred up to two orders of magnitude faster than widely used correlative template-matching approaches. This capability enables high-throughput characterization of complex crystalline materials and facilitates the establishment of structure-property relationships central to materials design and optimization.
Materials Science (cond-mat.mtrl-sci), Instrumentation and Detectors (physics.ins-det)
32 pages, 6 figures,
A variational critical-state theory of friction
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-02-16 20:00 EST
Mary Agajanian, Nadia Lapusta, Anna Pandolfi, Michael Ortiz
Friction plays a fundamental role in many natural processes, including earthquakes, landslides, and volcanic eruptions. Earthquakes occur when highly compressed fault surfaces accumulate large enough shear stresses, causing the faults to move relative to one another, or slip. The slip is accommodated within a thin layer of comminuted granular material – called fault gouge – between the fault surfaces. As a result, characterizing the mechanical behavior of fault gouge in response to shear is a major open problem in earthquake source physics. Modeling gouge is complicated by large deformations, inelasticity, rate dependence, and volumetric changes. As such, researchers typically rely on empirical formulations to capture the effective response. Here, we systematically develop a variational, finite-kinematics framework for fault gouge. We first describe a general theory for a rigid-viscoplastic, pressure-sensitive material, where the plasticity evolution follows from the principle of maximum dissipation. Then, we specialize the governing equations for a Cam-Clay material within a shearing and dilating layer. We rely on convexity considerations and experimental observations from consolidation tests of granular layers to calibrate the model and develop explicit solutions for the rate- and state- dependent response of the model to shear tests under constant compressive normal stress and prescribed shearing rate. To validate the model, we select common rate functions and compare numerical material point tests and theoretical solutions to standard laboratory experiments of shearing granular layers. Lastly, we discuss connections of the model to empirical rate-and-state friction laws.
Materials Science (cond-mat.mtrl-sci)
Composite colloidal assembly by critical Casimir forces
New Submission | Soft Condensed Matter (cond-mat.soft) | 2026-02-16 20:00 EST
T.E. Kodger, N. Farahmand Bafi, M. Labbé-Laurent, E. Steijlen, A. Maciolek, P. Schall
We investigate the phase behaviour of mixtures of two populations of colloidal particles dispersed in a binary solvent system near its critical composition. The surfaces of particles are chemically modified to elicit a specific solvent affinity for one of the solvents. In this way, fluid-mediated interactions, which involve the critical Casimir effect, become particle population specific. As a result, the colloidal mixture shows a complex crystallization behavior reminiscent of the crystallization of atomic alloys. We show that the exquisite temperature dependence and reversibility of the critical Casimir interaction allows sampling the entire phase diagram of the binary system, and can be even used to anneal the crystalline microstructure analogous to temperature cycling of atomic alloy phases.
Soft Condensed Matter (cond-mat.soft)
7 pages, 7 figures
Magnetotransport Spectroscopy of Strongly Rashba-Split Hole Subbands Reveals Many-Body Interactions
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2026-02-16 20:00 EST
F. Sfigakis, N. A. Cockton, M. Korkusinski, S. R. Harrigan, G. Nichols, Z. D. Merino, T. Zou, A. C. Coschizza, T. Joshi, A. Shetty, M. C. Tam, Z. R. Wasilewski, S. A. Studenikin, D. G. Austing, J. B. Kycia, J. Baugh
We report the results of magnetotransport experiments carried out on low-disorder 2D hole gases (2DHG) in the strongly correlated liquid regime, hosted in dopant-free (100) GaAs/AlGaAs single heterojunctions. Over a wide range of 2DHG densities (from 0.7 $ \times$ 10$ ^{15}$ /m$ ^2$ to $ 2 \times 10^{15}$ /m$ ^2$ ), Fourier analysis of low-field (B < 1 T) Shubnikov-de Haas oscillations reveals two spin-orbit-split heavy-hole (HH) subbands with distinct effective masses contributing to transport. Surprisingly, the lighter-mass HH subband exhibits a parabolic dispersion with Fermi wavevector below the anticrossing between the heavy-hole and light-hole subbands, while the heavier HH subband is non-parabolic throughout. Quantitative comparison with numerical calculations based on the Luttinger model reveals that both effective masses are enhanced by a common factor ($ \approx$ 2.3), which we attribute to many-body interactions. This common scaling factor has a very weak dependence on the 2DHG density, likely due to band hybridization. Our measured hole masses are compared with published cyclotron resonance and magnetotransport values. We propose a cohesive framework reconciling the long-standing three-way discrepancy between Luttinger theory, magnetotransport, and cyclotron resonance measurements of density-dependent effective masses in partially spin-orbit-polarized heavy-hole systems in GaAs.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
Re-evaluating photoluminescent defects in Cu$_2$O
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-02-16 20:00 EST
Alistair Brewin, Matthew P A Jones, Stewart J Clark
Cuprous oxide (Cu$ _2$ O) is of interest for several technologies, including solar cells, and more recently, quantum devices via Rydberg excitons. It’s performance in these capacities is strongly affected by defects in the crystal. The current best diagnostic for the presence of defects in a sample is the photoluminescence (PL) spectrum, which shows a number of strong lines at energies below the band gap, with brightnesses dependent on the sample. However, the assignment of PL lines to particular defects has not been substantiated by modern theory. Using density functional theory (DFT), we investigate from first principles which native defects introduce electronic states within the Cu$ _2$ O band gap, and therefore would produce lines in the PL spectrum. We find that the accepted assignments of lines to simple oxygen and copper vacancies are unsupported, and propose a new assignment based on oxygen and copper interstitials, and (one of the possible) split copper vacancies, a significant step towards the use of PL as a diagnostic tool for Cu$ _2$ O crystal growth.
Materials Science (cond-mat.mtrl-sci), Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
Time Reversal Symmetry Breaking and {\it Fragile Magnetic Superconductors}
New Submission | Superconductivity (cond-mat.supr-con) | 2026-02-16 20:00 EST
Roughly twenty reports (as of 2025) of time-reversal-symmetry breaking (TRSB) states in low critical temperature (T$ _c$ ) superconducting (SC), otherwise conventional Fermi liquid, metals have emerged primarily from muon spin relaxation ($ \mu$ SR) data. The detected fields, inferred from the current interpretation of depolarization data, are similar in magnitude and not far above the lower limit of detection, corresponding to magnetizations of no more than 10$ ^{-3}$ $ \mu_B$ /atom. These materials comprise a new class of {\it fragile magnetic superconductors} modeled as triplet pairing. The measured SC state properties, excepting only the fields detected below T$ _c$ , are representative of low T$ _c$ singlet BCS SCs, not showing unusual coherence lengths or critical fields. While it is recognized that the muon does affect the sample by displacing nearby atoms and impacting magnetic interaction parameters, the measurement process, changing the system from sample $ \rightarrow$ sample+$ \mu^+$ thereby breaking TRS, may deserve further scrutiny. This overview provides a survey of the environment of the muon, from the normal state to the superfluid state, where the induced supercurrent and Yu-Shiba-Rusinov gap states provide coupling of the muon moment to the superfluid. The unusual topological superconductor LaNiGa$ _2$ , currently modeled as non-unitary triplet, is used as a case study. Supposing that the prevailing $ \mu$ SR inference of a small spontaneous field within the bulk of theSC obtains, the current picture of (possibly non-unitary) triplet pairing is discussed and an attractive alternative for LaNiGa$ _2$ is noted.
Superconductivity (cond-mat.supr-con)
30 pages tex and appendices, 5 figures
Starch granules are instructive scaffolds for synergistic reinforcement and dissipation in hydrogel composites
New Submission | Soft Condensed Matter (cond-mat.soft) | 2026-02-16 20:00 EST
Shirlaine Juliano, Jasmine Samaniego, Ian M Lillie, Geraldine Ramirez, Peter M Iovine, Rae M Robertson-Anderson
A fundamental challenge in soft material design is the competition between rigidity and dynamicity, as stiffening mechanisms typically suppress energy dissipation. Here, we demonstrate that starch granules serve as instructive scaffolds that overcome this constraint, enabling the synergistic amplification of both elastic reinforcement and dynamic dissipation in hydrogels. We show that engineering the charge and structure of the filler-matrix interface enhances this synergistic response, which we propose arises from a dual-action physical mechanism: filler-induced polymer bundling of the polymer matrix provides structural reinforcement, while transient filler-matrix hydrogen bonding facilitates dissipation. Moreover, we reveal that binary blends of disparate filler species unexpectedly suppress these emergent properties, which we argue arises from enhanced entropic mixing. Our results provide a physical framework to overcome current design limitations in soft composites and sculpt their viscoelastic response from synergistic enhancement to strategic suppression for applications ranging from high-performance soft robotics to biomimetic tissue engineering.
Soft Condensed Matter (cond-mat.soft)
Effects of magnonic Kerr nonlinearity on magnon-polaritons with a soft-mode
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2026-02-16 20:00 EST
We theoretically study the effects of magnonic Kerr nonlinearity on magnon-polaritons (MPs) with a soft-mode in easy-axis ferromagnets coupled to a microwave cavity. Using an effective circuit model capable of describing MPs up to the nonperturbative strong-coupling regime, we show that chaotic and frequency-comb-like behaviors of MPs emerge at the original modes crossing point. Furthermore, we demonstrate that the Kerr nonlinearity induces a finite excitation gap in the soft-mode, particularly in the strong-coupling regime.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Chaotic Dynamics (nlin.CD), Quantum Physics (quant-ph)
6 pages, 4 figures
AIP Advances 16, 025228 (2026)
Photogalvanic Effects in Surface States of Topological Insulators under Perpendicular Magnetic Fields
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2026-02-16 20:00 EST
Haoyu Li, Kainan Chang, Wang-Kong Tse, Jin Luo Cheng
We present a theoretical study of the nonlinear magneto-optical shift conductivity in the surface states of the prototypical topological insulator Bi$ _2$ Se$ _3$ under a perpendicular quantizing magnetic field. By describing the electronic states as Landau levels and using a perturbative approach, we derive the microscopic expression for the shift conductivity $ \sigma^{(2);\alpha\beta\gamma}(-\omega,\omega)$ , where $ \alpha,\beta,\gamma=\pm$ stand for the circular polarization of light and $ \omega$ is the light frequency; the spectra are further decomposed into contributions from the interband and intraband optical transitions, for which the selection rules are identified. Considering that the system possesses $ C_3$ point group of symmetry, the nonzero components of the conductivity tensor are $ \sigma^{(2);-++}=[\sigma^{(2);+–}]^\ast$ . Therefore, a pure circularly polarized light generates zero shift current. In the clean limit, the conductivities are nonzero only for discrete photon energies because of the discrete Landau levels and energy conservation, and they become Lorentzian lineshapes with the inclusion of damping, which relaxes the condition of energy conservation. The dependence of the spectra on the damping parameters, the magnetic fields, and the chemical potentials is investigated in detail. Our results reveal that the shift current is highly tunable by the chemical potential and the magnetic field. These results underscore the potential of topological insulators for tunable, strong nonlinear magneto-optical applications.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
Mechanism-driven CO2 Capture and Activation on Two-dimensional Transition-metal Diborides
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-02-16 20:00 EST
Jakkapat Seeyangnok, Rungkiat Nganglumpoon, Joongjai Panpranot, Udomsilp Pinsook
The urgent need to mitigate rising atmospheric CO2 levels motivates the search for stable, efficient, and tunable adsorbent materials. In this study, we employ first-principles density functional theory to investigate the adsorption of CO2 molecules on two-dimensional hexagonal transition-metal diboride monolayers, M2B2 (M = Sc, Y, Ti, Zr, Nb). The adsorption energies, structural distortions, and bonding characteristics are systematically analyzed to understand how the metal center governs CO2 activation. The calculated adsorption energies range from -1.84 to -2.16 eV (or -1.98 to -4.42 eV), with Ti2B2 and Sc2B2 exhibiting the strongest CO2 binding, while Y2B2, Zr2B2, and Nb2B2 show moderately strong chemisorption. Adsorption induces significant molecular activation, evidenced by elongated C-O bonds (1.27-1.29 Angstrom) and bent O-C-O angles (129-132 degrees), compared to the linear gas-phase configuration (1.17 Angstrom, 180 degrees). Charge analysis further reveals substantial electron transfer from the monolayer to CO2, consistent with strong chemisorption and structural deformation. Correspondingly, the shift toward less negative IpCOHP(Ef) values indicates a pronounced weakening of the internal C-O bonds, reflecting increased population of antibonding pi\ast orbitals. Ab initio molecular dynamics simulations show that the activated CO2 species is thermally sensitive: while most M2B2 surfaces retain stable adsorption at 300 K, Ti2B2 drives spontaneous CO2 dissociation into CO and O, revealing a temperature-assisted activation pathway. These findings highlight how the choice of transition metal tunes electronic interactions, adsorption energetics, and activation pathways on M2B2 surfaces. Overall, this work identifies two-dimensional transition-metal diborides as promising candidates for next-generation CO2 capture and activation technologies.
Materials Science (cond-mat.mtrl-sci)
18 Pages, 12 Figures
Three-body Fermi-liquid corrections for Andreev transport through quantum dots
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2026-02-16 20:00 EST
Akira Oguri, Masashi Hashimoto, Yoshimichi Teratani
We study crossed Andreev reflection occurring in quantum dots connected to one superconducting lead and two normal leads at low temperatures $ T$ . Specifically, we derive an exact formula for the conductance up to order $ T^2$ in the large superconducting gap limit, which is expressed in terms of the transmission probabilities of Cooper pairs and interacting Bogoliubov quasiparticles. Our formulation is based on the latest version of Fermi-liquid theory for the Anderson impurity model, which has clarified the quasiparticle energy shifts of order $ \omega^2$ and $ T^2$ – that is, corrections of the same order as those arising from the finite lifetime of quasiparticles – can be exactly taken into account through three-body correlations of impurity electrons. We also demonstrate how the three-body contributions evolve and affect the Cooper-pair tunneling as the Andreev level moves away from the Fermi level, using the numerical renormalization group approach. The results demonstrate that the Cooper-pair contribution to the $ T^2$ term of the nonlocal conductance becomes comparable to the Bogoliubov-quasiparticle contribution in the parameter region where superconducting proximity effects dominate over the Kondo effect.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Strongly Correlated Electrons (cond-mat.str-el)
26 pages, 11 figures
Strain-enhanced edge ferromagnetism and bipolar magnetic semiconducting behavior in Janus graphene nanoribbons
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-02-16 20:00 EST
Ran Liu, Hongxing Liu, Junfeng Ren, Tianxing Ma
Using first-principles density functional theory and determinant quantum Monte Carlo methods, we show that Janus graphene nanoribbons with topological defect arrays ($ m=2$ ) exhibit robust intrinsic ferromagnetism across widths $ W=2-6$ , with bandgaps exceeding 200 $ meV$ and stable ferromagnetic ground states. Notably, uniaxial tensile strain significantly enhances their ferromagnetic properties: at 25% strain, the Curie temperature increases to $ 222K$ , a fivefold improvement over unstrained systems and the highest reported for graphene-based nanoribbons. Strain also induces a reversible transition to a bipolar magnetic semiconductor, with spin-flipped valence and conduction band edges beyond 10% strain. This dual functionality, strain-enhanced ferromagnetism and strain-induced spin flip, stems from strain-modulated $ p_{z}$ orbital hybridization and strong direct exchange interaction. Among these, $ W=5$ Janus graphene nanoribbons emerge as potential candidates for room-temperature spintronic devices and strain-programmable quantum transport systems.
Materials Science (cond-mat.mtrl-sci), Strongly Correlated Electrons (cond-mat.str-el)
Accepted for publication in publication in Physical Review B
Topology and edge modes surviving criticality in non-Hermitian Floquet systems
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2026-02-16 20:00 EST
The discovery of critical points that can host quantized nonlocal order parameters and degenerate edge modes relocate the study of symmetry-protected topological phases (SPTs) to gapless regions. In this letter, we reveal gapless SPTs (gSPTs) in systems tuned out-of-equilibrium by periodic drivings and non-Hermitian couplings. Focusing on one-dimensional models with sublattice symmetry, we introduce winding numbers by applying the Cauchy’s argument principle to generalized Brillouin zone (GBZ), yielding unified topological characterizations and bulk-edge correspondence in both gapped phases and at gapless critical points. The theory is demonstrated in a broad class of Floquet bipartite lattices, unveiling unique topological criticality of non-Hermitian Floquet origin. Our findings identify gSPTs in driven open systems and uncover robust topological edge modes at phase transitions beyond equilibrium.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Statistical Mechanics (cond-mat.stat-mech), Quantum Physics (quant-ph)
8 pages, 6 figures, manuscript submitted on 05 Dec 2025
Anomalous electrowetting of physicochemically heterogeneous surfaces
New Submission | Soft Condensed Matter (cond-mat.soft) | 2026-02-16 20:00 EST
Rumal Singh, Donjo George, Prashant Hitaishi, Samarendra P Singh, Sajal K Ghosh
In the present work, a physiochemically heterogeneous surface has been fabricated to investigate the electrowetting behaviour of the surface. The polystyrene (PS) micro-humps with varied size are developed on the polydimethylsiloxane (PDMS) surface, which show an anomalous electrowetting behaviour. The surfaces are observed to be more electro-wettable than it is predicted by the classical Lippmann-Young equation. The observations are well understood considering the chemical heterogeneity of the surface, exhibiting a surface energy mismatch between the PS micro-humps and the PDMS layer. Further, the anomaly is comprehended by following the ridge formation around the triple-phase contact line and the varied surface roughness. A surface parameter is introduced in the Lippmann-Young equation that follows the experimental data with varied values of the parameter representing the physicochemically heterogeneous surfaces. A positive value of the surface parameter indicates strong pinning while a negative value represents depinning of the droplet. This parameter explains the faster electrowetting than predicted by the Lippmann-Young equation.
Soft Condensed Matter (cond-mat.soft), Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Materials Science (cond-mat.mtrl-sci)
28 pages, 17 figure
Introduction to High-Temperature Superconductivity for Solid State Chemists
New Submission | Superconductivity (cond-mat.supr-con) | 2026-02-16 20:00 EST
Superconductivity is one of the most amazing properties that metallic conductors exhibit. Electrical resistance is completely eliminated below the critical temperature (Tc), which is the most important parameter in superconductivity. Since the discovery of copper oxide superconductors 39 years ago, many solid state chemists have made significant contributions to the field by discovering new compounds and producing high-quality samples for physical measurements. However, superconductivity research remains challenging for most solid state chemists because it requires knowledge of complicated solid state physics. This manuscript aims to provide a simple, intuitive introduction to superconductivity using only fundamental physics concepts that solid state chemists are familiar with. The author investigates a wide range of materials and classifies them according to the superconductivity mechanisms that may drive them. Specifically focusing on a series of copper oxide superconductors with the highest Tc at ambient conditions, the remarkable material dependence of Tc and the underlying, unconventional superconductivity mechanism that leads to the high Tc are thoroughly examined. Although our understanding of cuprate superconductivity is still fragmented, the author believes that once the branches and leaves are removed, the story will be fairly simple, similar to the phonon-based superconductivity mechanism revealed by the BCS theory. Furthermore, potential strategies for raising the Tc of cuprates and other superconductors are discussed. The author hopes that this article will pique interest in superconductors in young solid state chemists and encourage them to pursue the discovery of still unknown and unexplored room-temperature superconductors in the future.
Superconductivity (cond-mat.supr-con)
81 pages, 50 figures, submitted to Progress in Solid State Chemistry
Room-Temperature Terahertz Photoconductivity Polarity Switching in High Entropy Nickelates with Implications for Photonic Synapses
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-02-16 20:00 EST
Sanjeev Kumar, Brijesh Singh Mehra, Gaurav Dubey, Prakhar Vashishtha, Neeraj Bhatt, Jayaprakash Sahoo, Ravi Shankar Singh, Dhanvir Singh Rana
High entropy oxides (HEO) hold the potential to revolutionize the conventional material paradigms by leveraging high order of chemical disorder that induces highly desirable exotic phases for advanced applications. Here, we devise a methodology to enhance the efficiency of an artificial photonic synapse using a high entropy rare earth nickelate. Combined with epitaxial strain, we show that high entropy can further manipulate the phase of these locally disordered materials. Using time-averaged and time resolved Terahertz (THz) spectroscopy as dynamic probe, for the first time we show a rare combination of i) crystal axis dependent insulator to metal THz electronic phase transition and ii) coexistence of negative and positive THz photoconductivity at room temperature. Detailed analysis within theoretical models, including density functional theory (DFT)-based band structure calculations, suggest origin of these properties as disproportionate ordering of oxygen vacancies. Based on these findings, a conceptual THz-based artificial photonic synapse is proposed. This work underlines the pivotal role of HEO in advancing diverse THz functionalities, representing a critical step toward futuristic applications like THz-based high-speed computing and communication with an emphasis in THz frequency domain.
Materials Science (cond-mat.mtrl-sci)
Gapped out-of-phase plasmon modes in alternating-twist multilayer graphene
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2026-02-16 20:00 EST
We theoretically investigate the plasmon modes of alternating-twist multilayer graphene. In multilayer systems, interlayer coupling gives rise to distinctive plasmon modes, but calculations in moiré systems remain challenging due to their complex tunneling structures. Using the Kac-Murdock-Szegő Toeplitz formalism, we derive that the in-phase mode exhibits the conventional $ \sqrt{q}$ behavior, while the out-of-phase modes acquire plasmon gaps determined by specific interband transitions between Dirac cones with different velocities in the long-wavelength limit. We demonstrate that these out-of-phase modes remain undamped in the weak Coulomb-interaction limit when the twist angle exceeds a critical value ($ \theta \gtrsim 2.75^\circ$ for the alternating-twist trilayer case), regardless of the carrier density as long as the low-energy effective Dirac Hamiltonian remains valid. Furthermore, we consider the effect of a perpendicular electric field, and demonstrate how plasmon modes can be tuned by a gate voltage.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
11 pages, 8 figures, 1 table
Magnetoplasmons in $N$-layer structures
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2026-02-16 20:00 EST
Jinu Park, Taehun Kim, E. H. Hwang, Hongki Min
We provide a systematic framework to investigate the magnetoplasmons of multilayer two-dimensional electron systems by using the Kac–Murdock–Szegő (KMS) Toeplitz matrix to consider interlayer Coulomb interactions. In the absence of interlayer tunneling, we show that the single-layer magnetoplasmon branch splits into $ N$ collective modes – one in-phase mode and $ N-1$ out-of-phase modes – and derive their asymptotic behaviors in the long-wavelength limit, as well as in the limit of large layer separation and strong magnetic fields. When interlayer tunneling is present, we clarify the magnetoplasmon dispersion, both qualitatively and quantitatively, by identifying the magnetoplasmon mode associated with each interband transition, as well as tunneling magnetoplasmons arising from interband transitions with the same Landau level index. Our study presents the hybridization between the modes governed by underlying symmetries, along with an enhanced tunneling magnetoplasmon gap exceeding the associated interband gap. The KMS-based analytic formalism thus provides a comprehensive physical understanding of magnetoplasmons in multilayer structures.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
14 pages, 7 figures, and 1 table
Quantum Anomalous Hall Effect in Rhombohedral Multilayer Graphene/hBN Moiré Superlattices
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2026-02-16 20:00 EST
Jiannan Hua, Jing Ding, W. Zhu, Shui-gang Xu
The recent discovery of robust quantum anomalous Hall (QAH) effect in rhombohedral multilayer graphene (RMG) aligned with hexagonal boron nitride (hBN) has established a highly versatile platform for correlated topological matter. This review synthesizes the experimental and theoretical progress in understanding these interaction-driven topological phases. Experimentally, the landscape has rapidly expanded from initial Chern insulators in trilayer systems to fully quantized QAH states in thicker systems. Theoretically, it is believed that moiré potential and electron-electron interaction cooperate and produce the QAH effect in such systems. Theoretical calculations also bring interesting questions, such as the formation of an interaction-driven topological phase known as an anomalous Hall crystal (AHC). This review comprehensively covers the experimental hallmarks, the theoretical frameworks, including continuum models and many-body approaches, and the ensuing physical picture that reconciles the roles of interactions, displacement fields, and the moiré potentials. We conclude by outlining outstanding open questions and future directions, positioning RMG/hBN systems at the forefront of topological quantum matter.
Strongly Correlated Electrons (cond-mat.str-el)
Presence versus absence of charging energies in PbTe quantum dots
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2026-02-16 20:00 EST
Yuhao Wang, Lining Yang, Wenyu Song, Li Chen, Zehao Yu, Xinchen He, Zeyu Yan, Jiaye Xu, Ruidong Li, Weizhao Wang, Zonglin Li, Shuai Yang, Shan Zhang, Xiao Feng, Tiantian Wang, Yunyi Zang, Lin Li, Runan Shang, Qi-Kun Xue, Ke He, Hao Zhang
Charging energy ($ E_C$ ) is essential in quantum dot (QD) devices. Previous studies on PbTe QDs have reported both the presence and absence of $ E_C$ . To resolve this ambiguity, we vary the QD size, i.e. the cross-sectional area of PbTe nanowires, and track the evolution of $ E_C$ . For large crosssectional areas ($ \sim$ 16000 nm$ ^2$ ), the PbTe QDs exhibit no measurable $ E_C$ , while quantized levels are well resolved. Decreasing this area successively to 5000, 1500, and 500 nm$ ^2$ , $ E_C$ becomes finite and increases to 80, 160, and 210 $ \mu$ eV, respectively. We further demonstrate the strong tunability of local gates, which can tune the PbTe device from the QD regime to the regime of ballistic transport. These results address concerns regarding the large dielectric constant of PbTe and provide key insights in engineering advanced PbTe quantum devices.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
Investigating Disordered Granular Matter via Ordered Geometric Fragmentation
New Submission | Soft Condensed Matter (cond-mat.soft) | 2026-02-16 20:00 EST
Malkhazi A. Meladze (Independent Researcher, Auckland, New Zealand)
The evolution of occupied volume under progressive fragmentation of granular matter is studied using a purely geometric model. Rather than modeling disorder directly, properties of disordered granular assemblies are investigated by analyzing an associated family of highly ordered reference configurations that provide sharp upper bounds on accessible volume. Grains are idealized as fragments derived from a hypothetical elongated parent prism with square cross section, sequentially sliced and reassembled into configurations that maximize the enclosed volume.
Analytic expressions are derived for the maximal attainable volume at each fragmentation stage. The volume evolution is non-monotonic: initial fragmentation produces structures whose volume exceeds that of the original object, while further fragmentation leads to monotonic decrease converging to a limiting value of 5/4 times the initial volume, independent of the total number of fragments.
The model reveals pairs of reassembled configurations built from geometrically indistinguishable building blocks yet enclosing different volumes. These conjugate configurations constitute purely geometric analogues of distinct phases connected by rearrangement-induced transitions. Explicit relations link the idealized construction to experimentally measurable grain parameters. Comparison with experimental data on cylindrical rods shows the predicted upper bound falls within the observed packing density range, demonstrating that the model captures essential geometric features despite its simplicity.
Soft Condensed Matter (cond-mat.soft), Statistical Mechanics (cond-mat.stat-mech)
24 pages, 4 figures. Also available on HAL: this https URL
Nonparabolic dispersion of charge carriers in CsPbI$_3$ in the orthorhombic phase
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2026-02-16 20:00 EST
O. S. Sultanov (1, 2)D. K. Loginov (1), I. V. Ignatiev (1, 2), D. V. Pankin (3), M. B. Smirnov (2), M. S. Kuznetsova (1) ((1) Spin Optics Laboratory, <a href=”http://St.Petersburg“ rel=”external noopener nofollow” class=”link-external link-http”>this http URL</a> State University, (2) Faculty of Physics, St. Petersburg State University, (3) Center for Optical and Laser Materials Research, St. Petersburg State University)
The dispersion curves for the electrons and holes in CsPbI$ _3$ in the orthorhombic phase are calculated using the density functional theory (DFT), with the spin-orbit coupling taken into account. The effective masses of the charge carriers are obtained using the parabolic approximation of the dispersion curves in different directions in the $ k$ -space. It is found that the dispersion curves demonstrate strong nonparabolicity at energies above 0.2 eV for electrons and above 0.1 eV for holes, available for experimental study by the means of optical spectroscopy. We propose a model that describes the dispersion dependences of charge carriers at those energies, where the effective masses of the quasiparticles depend quadratically on the wave vector. An expression is obtained according to the model, which can accurately approximate the dispersion curves for the electron and the hole in all symmetric directions from the center to the boundary of the Brillouin zone.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
10 pages, 9 figures. The materials of this paper have been used for a report at the XXVII Russian Youth Conference on Physics of Semiconductors and Nanostructures, Opto- and Nanoelectronics
Nanoscale Electroviscous Lift Force
New Submission | Soft Condensed Matter (cond-mat.soft) | 2026-02-16 20:00 EST
Hao Zhang, Zaicheng Zhang, Thomas Guérin, Abdelhamid Maali
About forty years ago, it has been predicted that a charged particle, moving parallel to a charged wall in an electrolyte, should experience a lift force that, contrarily to electrostatic forces, is not screened at large distances. Up to now, such electroviscous lift force has not been directly measured. Here, we use Atomic Force Microscopy to directly measure the electroviscous lift force and quantify its dependency with the distance to the wall, the translation velocity or the particle’s size. Observing that existing theories exhibit large discrepancies with our experimental observations, we develop an analytical approach combining lubrication theory to a previously introduced formalism for small screening length. The experimentally observed lift forces are in good agreement with our theoretical predictions and reveal, for the first time, a saturation of the lift force for increasing velocities. Altogether, our results characterize, through direct measurements and analytical approach, the properties of electroviscous forces between charged particles in viscous electrolytes in non-equilibrium conditions.
Soft Condensed Matter (cond-mat.soft), Statistical Mechanics (cond-mat.stat-mech), Fluid Dynamics (physics.flu-dyn)
5 pages + 10 pages (SM)
Subcycle videography of lightwave-driven Landau-Zener-Majorana transitions in graphene
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2026-02-16 20:00 EST
Vincent Eggers, Giacomo Inzani, Manuel Meierhofer, Lasse Münster, Jakob Helml, Robert Wallauer, Sarah Zajusch, Suguru Ito, Leon Machtl, Hao Yin, Christian Kumpf, François C. Bocquet, Changhua Bao, Jens Güdde, F. Stefan Tautz, Ruper Huber, Ulrich Höfer
Strong light fields have unlocked previously unthinkable possibilities to tailor coherent electron trajectories, engineer band structures and shape emergent phases of matter all-optically. Unravelling the underlying quantum mechanisms requires a visualisation of the lightwave-driven electron motion directly in the band structure. While photoelectron momentum microscopy has imaged optically excited electrons averaged over many cycles of light, actual subcycle band-structure videography has been limited to small electron momenta. Yet lightwave-driven elementary processes in quantum materials often occur throughout momentum space. Here, we introduce attosecond-precision, subcycle band-structure videography covering the entire first Brillouin zone (BZ) and visualize one of the most fundamental but notoriously elusive strong-field processes: non-adiabatic Landau-Zener-Majorana (LZM) tunnelling. The interplay of field-driven acceleration within the Dirac-like band structure of graphene and periodic LZM interband tunnelling manifest in a coherent displacement and distortion of the momentum distribution at the BZ edge. The extremely non-thermal electron distributions also allow us to disentangle competing scattering processes and assess their impact on coherent electronic control through electron redistribution and thermalization. Our panoramic view of strong-field-driven electron motion in quantum materials lays the foundation for a microscopic understanding of some of the most discussed light-driven phenomena in condensed matter physics.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Materials Science (cond-mat.mtrl-sci), Optics (physics.optics)
Landau-Zener-Majorana tunneling; Strong-field; Graphene; Ultrafast; Subcycle; Momentum microscopy; ARPES
Exploring Wetting and Optical Properties of CuAg Alloys via Surface Texture Morphology Analysis
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-02-16 20:00 EST
Krzysztof Wieczerzak, Grzegorz Cios, Piotr Bała, Johann Michler, Benedykt R. Jany
Copper-silver (CuAg) alloys are increasingly explored for applications in high-performance electrical and electronic systems, owing to their unique combination of high electrical and thermal conductivity and enhanced mechanical strength. Nevertheless, a thorough understanding of how these alloys surface characteristics fundamentally influence properties remains largely underdeveloped. Here, we explored the complex interplay between surface texture morphology, layer composition, wetting, and optical properties of Cu, Ag, and CuAg thin films deposited on textured silicon substrates via magnetron sputtering. Employing data mining and machine learning techniques, we identified robust correlations between contact angle and surface fractal dimension across all layer types promoting Cassie-Baxter surface state formation. Our analysis revealed a significant connection between layer thickness and surface topography entropy deficit, suggesting a dynamic evolution of surface order/disorder during metal film growth. Furthermore, we observed that contact angle sensitivity to layer thickness implied a correlation with microstructure evolution. Through K-Means clustering, we successfully categorized the formed surface textures morphology. Finally, a Random Forest regression model was developed to accurately predict water contact angles (Mean Absolute Error around 5 deg) using only texture and optical parameters. The model, along with accompanying Python code, is publicly available. Our findings establish a pathway towards targeted surface texture morphology engineering for tailored material performance.
Materials Science (cond-mat.mtrl-sci)
Lecture notes: From Gaussian processes to feature learning
New Submission | Disordered Systems and Neural Networks (cond-mat.dis-nn) | 2026-02-16 20:00 EST
Moritz Helias, Javed Lindner, Lars Schutzeichel, Zohar Ringel
These lecture notes develop the theory of learning in deep and recurrent neuronal networks from the point of view of Bayesian inference. The aim is to enable the reader to understand typical computations found in the literature in this field. Initial chapters develop the theoretical tools, such as probabilities, moment and cumulant-generating functions, and some notions of large deviation theory, as far as they are needed to understand collective network behavior with large numbers of parameters. The main part of the notes derives the theory of Bayesian inference for deep and recurrent networks, starting with the neural network Gaussian process (lazy-learning) limit, which is subsequently extended to study feature learning from the point of view of adaptive kernels. The notes also expose the link between the adaptive kernel approach and approaches of kernel rescaling.
Disordered Systems and Neural Networks (cond-mat.dis-nn)
The role of radiation-induced segregation in defect-phase formation in Ni-Ge and Ni-Si alloys
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-02-16 20:00 EST
Amit Verma, Yen-Ting Chang, Marie Charpagne, Pascal Bellon, Robert S. Averback
The interactions between chemical phase fields and structural defects play a key role in the properties of alloys. We illustrate the importance of these interactions in driven alloys, where defects are continuously being created, with particular focus on systems where radiation-induced segregation occurs. Specifically, we compare the microstructural evolution in undersaturated Ni-Si and Ni-Ge alloys during both 100 keV He and 2 MeV Ti irradiations. While the equilibrium phase diagrams of these systems are similar, and both systems show strong radiation-induced segregation, the evolving defect structures are remarkably different. Ni-Si reveals a high density of Frank loops, while Ni-Ge shows a complex array of dislocations. Moreover, a Ni3Ge precipitate shell is observed to coat He bubbles, while no segregation of Si is observed at such bubbles. We explain these differences in behaviors to solute drag by interstitial fluxes in Ni-Si vs solute drag by vacancy fluxes in Ni-Ge.
Materials Science (cond-mat.mtrl-sci)
15 pages of main text, including 5 figures, and 9 pages of supplementary material
Shift of the Bose-Einstein condensation transition in the presence of a second atomic species
New Submission | Quantum Gases (cond-mat.quant-gas) | 2026-02-16 20:00 EST
Pedro M. Gaspar, Vanderlei S. Bagnato, Patricia C. M. Castilho
Atomic interactions play an important role in the properties of ultracold atomic gases. In single component bosonic systems, its effect is already present at the critical point for the Bose-Einstein condensate phase transition by shifting it to lower temperatures as a consequence of effective repulsion between the atoms. When considering atomic bosonic mixtures, interesting effects arise from the competition between intra- and interspecies interactions such as the miscible-immiscible phase transition and the particular case of self-bounded quantum droplets. In such a scenario, it is natural to expect that these interactions will also affect the critical point of each species composing the mixture. In this paper, we obtain analytical expressions for the critical temperature shift of the phase transition to a Bose-Einstein condensate in the presence of a second species. We treat differently the cases in with the second species is above or below its own critical temperature and apply the obtained relations to the case of a $ ^{23}$ Na-$ ^{39}$ K bosonic mixture which can be realized in current running experimental setups. Our findings can be easily extended to other atomic mixtures trapped by arbitrary conservative traps.
Quantum Gases (cond-mat.quant-gas), Atomic Physics (physics.atom-ph)
6 pages. 2 figures
Dependence of the Mn sticking coefficient on Ga-rich, N-rich, and Ga/N-flux-free conditions in GaN grown by plasma-assisted molecular beam epitaxy
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-02-16 20:00 EST
YongJin Cho, Changkai Yu, Huili Grace Xing, Debdeep Jena
This brief report examines the influence of Ga/N flux conditions on Mn incorporation in GaN. Mn-doped GaN layers were grown at 680$ ^{\circ}$ C by molecular beam epitaxy on a Ga-polar GaN(0001) template substrate under Ga-rich, N-rich, and no-flux conditions (i.e., Mn $ \delta$ doping). Mn incorporation was highest under N-rich condition, lowest under Ga-rich condition, and intermediate in the absence of Ga and N fluxes. For the growth conditions examined in this study, the corresponding Mn sticking coefficients, relative to that of the N-rich condition, were determined to be 0.31 for no-flux growth and 0.01 for the Ga-rich growth.
Materials Science (cond-mat.mtrl-sci)
9 pages, 2 figures
A Variational Formulation for Deformable Particle Simulations and its Level Set Discrete Element Method Implementation
New Submission | Soft Condensed Matter (cond-mat.soft) | 2026-02-16 20:00 EST
Thomas Henzel, Konstantinos Karapiperis
We present a deformable Discrete Element Method (DEM) that extends the classical rigid-particle formulation through a reduced-order description of elastic grain-scale deformation. The method hinges on two developments. First, an energetic variational formulation based on the Lagrange–d’Alembert principle extends classical rigid-body dynamics to incorporate particle deformability by embedding translational, rotational, and deformation degrees of freedom within a unified energetic description. Second, particle deformation is realized within the Level Set DEM formalism through evolving level sets. The framework applies broadly to general particle geometries and topologies, and supports arbitrary deformation modes. The resulting deformable DEM retains the robustness, geometric and physical clarity, and scalability of classical DEM, while enabling physically grounded grain-scale deformability at a computational cost of the same order of magnitude as rigid DEM. Comparisons with full finite-element simulations demonstrate excellent agreement at both particle and system scales, establishing a general and extensible variational framework for modeling deformation in particulate systems.
Soft Condensed Matter (cond-mat.soft), Mathematical Physics (math-ph)
Interface-Driven Growth Mode Control of 2D GaSe on 3D GaAs Substrates with Distinct Crystallographic Orientations
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-02-16 20:00 EST
Aida Sheibani, Mohammad Zamani, Charles Paillard, Kanagaraj Moorthi, Fernando Maia de Oliveira, Serhii Kryvyi, Mourad Benamara, Hryhorii Stanchu, Calbi Gunder, Hugh Churchill, Yuriy I. Mazur, Gregory Salamo
Previous studies of the growth of two-dimensional (2D) gallium selenide (GaSe) by molecular beam epitaxy (MBE) on a gallium arsenide (GaAs) three-dimensional (3D) substrate have reported significant differences in growth morphology, polytype, and the nature of the interface. The results differ, ranging from GaSe 2D film growth at tilted 2D planes to observed spiral structures, thereby calling for a deeper understanding of the impact of the substrate interface on the growth of GaSe films. In this paper, we conduct a comprehensive reexamination of the growth mechanism of GaSe on GaAs substrates with (211)B and (001)B orientations, investigating the nature of the 2D/3D interface and the resulting morphology of the 2D GaSe films. We do this by investigating different methods of preparation of the GaAs substrate surface before the growth of GaSe by MBE, the importance of which has not been considered before. Our results resolve the mechanistic origin of tilted versus non-tilted 2D growth and establish a general interface-driven orientation selection rule linking substrate symmetry and dangling-bond coordination to layered heteroepitaxy. This framework provides a scalable interface-engineering pathway for deterministic control of layered chalcogenide heterostructures and enables wafer-scale integration with established semiconductor device platforms.
Materials Science (cond-mat.mtrl-sci)
Non-renormalization of the Hall viscosity of integer and Jain fractional quantum Hall phases by Coulomb interactions
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2026-02-16 20:00 EST
We proof the non-renormalization of the Hall viscosity by Coulomb interactions for integer and fractional quantum Hall Jain states building on previous results obtained for the Hall conductivity. We employ Wigner-Weyl calculus in order to represent the Hall viscosity in terms of a topological invariant comprised of Green functions and work within the composite fermion field theory model of Jain states of the fractional quantum Hall fluid presented by Lopez and Fradkin. The topological expression is first derived within the free field theory of electrons and explicitly calculated for this case as well as in the mean field approximation of the composite fermion theory Jain states. The topological orbital spin of composite fermions distinguishes their mean field treatment from that of electrons resulting in an additional topological contribution. We then argue that the introduction of Coulomb interactions does not lead to perturbative corrections of the Hall viscosity in both integer and fractional quantum Hall fluids. The proof relies on the assumptions of homogeneity and rotational invariance of an underlying sample modulo the vector potential giving rise to the homogeneous external magnetic field. These conditions imply a Hall viscosity per emergent quasiparticle number density quantized in units of one half times the average quasiparticle orbital spin or one quarter times the Wen-Zee shift. The latter features a contribution from the composite fermion topological orbital spin relative to that of electrons.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Strongly Correlated Electrons (cond-mat.str-el)
On the effect of Edge vs bulk effects in Graphene Nanoribbons
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2026-02-16 20:00 EST
Colm Durkan, Xiao Liu, Ed Saunders
Recent works have shown how the electrical properties of graphene nanoribbons (GNRs) show a size-dependence in terms of resistivity, charge neutrality point (CNP) and band structure once their widths drop below approximately 50 nm. It has been observed that the CNP switches sign below a certain GNR width, and in this article, we explore this via computational modelling of the electric field and the conductance of GNRs in the presence of an AFM tip. We show that CNP is expected to shift towards lower values as GNR width reduces as a result of the significantly enhanced electric field around edges, but that a change in sign is not expected. We also show experimentally via high-resolution Scanning Gate Microscopy (SGM) that there does not appear to be any significant difference between the edges and the bulk of a GNR, indicating that the switch in CNP is not due to differential doping, and may instead be due to variations in the band structure as a function of size.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Materials Science (cond-mat.mtrl-sci)
20 pages, 11 Figures
Limits of Thermal Conductance Quantization in Chiral Topological Josephson Junctions
New Submission | Superconductivity (cond-mat.supr-con) | 2026-02-16 20:00 EST
Daniel Gresta, Fernando Dominguez, Raffael L. Klees, Florian Goth, Laurens W. Molenkamp, Ewelina M. Hankiewicz
We investigate thermal and non-local electrical transport in four-terminal Josephson junctions formed by a normal region coupled to two transverse chiral superconducting leads, supporting phases characterized by Chern numbers $ {\cal C}=0,,1$ ,and,2. We identify the conditions under which a single chiral Majorana mode ($ {\cal C}=1$ ) produces a robust half-quantized thermal conductance, while non-local electrical conductance remains strongly suppressed by particle-hole symmetry. Thermal conductance quantization occurs near a superconducting phase difference $ \pi$ , but only in the low-doping regime of the central region and in the intermediate- to long-junction limits. At finite Zeeman fields, the thermal response broadly follows the topology of the isolated superconducting leads for the $ C=1$ phase while, in the $ {\cal C}=2$ phase, the thermal conductance generally deviates from quantization, depending on the momentum-space location of the Majorana modes. Our results establish clear criteria for probing chiral Majorana modes in Josephson junctions and highlight the essential role of momentum-space structure, finite-size geometry, and sample parameters in thermal transport.
Superconductivity (cond-mat.supr-con), Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
12 pages, 12 figures
Divergent Impact Charging of Polymer Particles
New Submission | Soft Condensed Matter (cond-mat.soft) | 2026-02-16 20:00 EST
Simon Jantač, Holger Grosshans
When a particle contacts a surface of another material, it is commonly believed that the particle acquires an impact charge that scales inversely with its pre-impact charge and whose polarity is set by the materials. We show that this belief holds for conductive particles but fails for polymers. For polymers, the impact charge increases linearly with the particle’s pre-impact charge. Its polarity is not determined by the materials but by the pre-impact particle charge relative to a divergence point at which the net charge transfer reverses. We attribute this divergence to the attraction of surrounding ions to the particle surface. These attracted ions carry polarity opposite to that of the particle, and their amount scales with the particle charge. They transfer to the opposing surface during contact, thereby defining the impact charge. We propose a phenomenological model for the divergent impact charge arising from this mechanism. Finally, we reexamine previous measurements and show that they support this mechanism.
Soft Condensed Matter (cond-mat.soft), Chemical Physics (physics.chem-ph)
Molecular Beam Epitaxy of Al$\mathrm{{1-x}}$Sc$\mathrm{{x}}$N Nanowires: Towards Group-III Nitride Piezoelectric Nanogenerators with Enhanced Response
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-02-16 20:00 EST
Adriano Notarangelo (1), Rudeesun Songmuang (2), Mostafa Saleh (2), Nattawadi Buatip (2), Ileana Florea (3), Philippe Vennéguès (3), Aidan F. Campbell (1), Hans Tornatzky (1), Jonas Lähnemann (1), Thomas Auzelle (1), Lutz Geelhaar (1), Oliver Brandt (1), Philipp M. John (1) ((1) Paul-Drude-Institut für Festkörperelektronik, Leibniz-Institut im Forschungsverbund Berlin e.V., Hausvogteiplatz 5-7, 10117 Berlin, Germany, (2) Université Grenoble Alpes, CNRS, Grenoble INP, Institut Néel, 38000 Grenoble, France, (3) Université Côte d’Azur, CRHEA, CNRS, 06905 Sophia-Antipolis Cedex, France)
We study the molecular beam epitaxy of self-assembled Al$ \mathrm{{1-x}}$ Sc$ \mathrm{{x}}$ N nanowires on conductive TiN layers and demonstrate their application in piezoelectric nanogenerators. Wurtzite Al$ \mathrm{{1-x}}$ Sc$ \mathrm{{x}}$ N nanowires with uniform Sc incorporation are grown across a wide composition range (0<x<0.35). At substrate temperatures below 700 $ ^\circ{}$ C, these nanowires exhibit an inversely tapered morphology, whereas higher temperatures favor the nucleation of additional branches due to a phase separation of Al$ \mathrm{{1-x}}$ Sc$ \mathrm{{x}}$ N into wurtzite AlN and rock-salt ScN. Phase-pure Al$ \mathrm{{1-x}}$ Sc$ \mathrm{{x}}$ N nanowires are integrated into vertical nanogenerators, where the metallic TiN substrate serves as bottom electrode. The fabricated polymer-nanowire composite devices achieve effective piezoelectric charge coefficients of up to 8.5 pC N$ ^{-1}$ at x=0.32, thus exceeding the piezoelectric response of bulk AlN by nearly a factor of two. Although the charge response remains lower compared to Al$ \mathrm{{1-x}}$ Sc$ \mathrm{{x}}$ N thin films, the reduced effective dielectric permittivity of the nanowire-polymer composites compensates the reduction in piezoelectric charge coefficient, eventually yielding a higher voltage response and comparable energy harvesting efficiency. Finally, effective medium modeling reveals that the device architecture is the primary factor limiting performance, providing general design principles for highly efficient nanowire-based piezoelectric energy harvesters.
Materials Science (cond-mat.mtrl-sci), Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Applied Physics (physics.app-ph)
15 pages, 6 figures, 39 references
High-Tc Superconductivity in Functionalized Out-of-Plane Ordered Double Transition Metal MXenes
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-02-16 20:00 EST
Mohammad Keivanloo, Fateme Dinmohammad, Shashi B. Mishra, Mohammad Sandoghchi, Mohammad Javad Arshia, Mitsuaki Kawamura, Elena R. Margine, Muhammad Haris Mahyuddin, Hannes Raebiger, Reza Pamungkas Putra Sukanli, Kenta Hongo, Ryo Maezono, Mohammad Khazaei
Two-dimensional (2D) superconductors attracted growing interest in condensed-matter physics research. In this work, we explore the superconducting properties of surface-functionalized, out-of-plane ordered double transition-metal MXenes (o-MXenes), which exhibit distinctive structural and electronic characteristics. Using first-principles calculations, we investigate the effects of electronic structure, electron-phonon coupling (EPC), anharmonicity, and anisotropy effect in superconductivity properties of o-MXenes. We examine a wide range of o-MXene systems, M$ _{2}$ M$ ^\prime$ X$ _{2}$ T$ _{2}$ (M = Mo, W; M$ ^\prime$ = Sc, Ti, V, Mo, Zr, Nb, Ta; X = C, N), functionalized with F, O, Cl, and H groups. Out of 128 candidates, 32 compounds are found to be mechanically, dynamically, and thermodynamically stable, exhibiting superconducting transition temperatures (T$ _{c}$ ) from 0.1 K to 52 K. Notably, the Mo$ _{2}$ ScN$ _{2}$ O$ _{2}$ compound achieves the highest T$ _{c}$ of 52 K, with a superconducting gap of $ \sim$ 10 meV. Solving the anisotropic Eliashberg equation reveals that Mo$ _{2}$ ScN$ _{2}$ O$ _{2}$ is an anisotropic two-gap superconductor, and incorporating anharmonic effects decreases its T$ _{c}$ slightly. We further analyze flat-band-induced EPC enhancement and present EPC matrix elements as functions of phonon wavevector q for distinct vibrational modes that show anharmonic behavior of these materials.
Materials Science (cond-mat.mtrl-sci)
Diagnosing energy gap in quantum spin liquids via polarization amplitude
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2026-02-16 20:00 EST
Takayuki Yokoyama, Yasuhiro Tada
Identifying whether a many-body ground state is gapped or gapless is a fundamental yet challenging problem, especially in quantum spin liquids. In this work, we develop a gap-diagnostic scheme based on the polarization amplitude defined via a twist operator, evaluated within the infinite density-matrix renormalization group (iDMRG) framework. As a benchmark, analysis of the spin-$ 1/2$ XXZ chain demonstrates that the polarization amplitude clearly distinguishes the gapless Tomonaga-Luttinger liquid from the gapped Néel phase. We then extend this framework to infinite cylinders of the spin-$ 1/2$ XY-$ J_\chi$ model on the square lattice. We find that the polarization amplitude sharply detects the transition between the gapless XY phase and the gapped chiral spin liquid phase. These results show that polarization amplitudes provide a strong energy-gap diagnostic in two-dimensional frustrated quantum magnets, including quantum spin liquids.
Strongly Correlated Electrons (cond-mat.str-el), Statistical Mechanics (cond-mat.stat-mech)
9 pages, 7 figures
A molecular-spin photovoltaic device
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-02-16 20:00 EST
Xiangnan Sun, Saül Vélez, Ainhoa Atxabal, Amilcar Bedoya-Pinto, Subir Parui, Xiangwei Zhu, Roger Llopis, Fèlix Casanova, Luis E. Hueso
We fabricated a C60-based molecular spin photovoltaic device that integrated a photovoltaic response with the spin transport across the molecular layer. The photovoltaic response can be modified under the application of a small magnetic field, with a magnetophotovoltage of up to 5% at room temperature. Device functionalities include a magnetic current inverter and the presence of diverging magnetocurrent at certain illumination levels that could be useful for sensing. Completely spin-polarized currents could be created by balancing the external partially spin polarized injection with the photogenerated carriers.
Materials Science (cond-mat.mtrl-sci), Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
4 figures & 13 pages main text; 4 figures & 7 pages SM
Science 357, 677 (2017)
Quantitative Photoemission Predictions of Semiconducting Photocathodes from Many-Body Ab Initio Theory
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-02-16 20:00 EST
Richard Schier, Chen Wang, Jonas Dube, Julius Kühn, Alice Galdi, Thorsten Kamps, Caterina Cocchi
The development of high-performance electron sources requires theoretical frameworks that accurately link the microscopic electronic properties of cathode materials to their macroscopic photoemission observables. Here, we present a many-body extension of the three-step photoemission model for semiconducting photocathodes, directly integrating the $ GW$ approximation and the solution of the Bethe-Salpeter equation on top of density functional theory (DFT). This approach overcomes the intrinsic limitations of standard DFT by explicitly accounting for quasiparticle and excitonic effects in the photoexcitation process. The quantum efficiency (QE) is evaluated by combining the ab initio absorption with an emission probability derived as an exciton-weighted average. We validate this model on representative alkali antimonides and demonstrate that a qualitative many-body description successfully captures complex spectral features that empirical models fail to reproduce. Furthermore, by incorporating macroscopic optical effects such as thin-film interference and polarization via Fresnel post-processing, we achieve quantitative agreement with experimental QE values without any adjustment. Minor discrepancies near the photoemission threshold are attributed to the idealized surface barrier adopted in the model and impurity effects in the samples, highlighting specific directions for future refinements. This work establishes a robust, parameter-free ab initio tool that bridges microscopic electronic correlation with macroscopic observables, providing a critical pathway for the rational design of next-generation electron sources.
Materials Science (cond-mat.mtrl-sci)
Variational study of the magnetization plateaus in the spin-1/2 kagome Heisenberg antiferromagnet: an approach from vision transformer neural quantum states
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2026-02-16 20:00 EST
Andreas Raikos, Sylvain Capponi, Fabien Alet
We analyze the magnetization curve of the spin-1/2 kagome Heisenberg model in a magnetic field. Using state-of-the-art variational wavefunctions based on neural networks, we confirm the presence of robust magnetization plateaus at $ m=1/3$ , $ 5/9$ and $ 7/9$ of the saturation value, stabilized by a spontaneous symmetry breaking of lattice translations with a $ \sqrt{3}\times \sqrt{3}$ unit cell. Regarding the more challenging $ m=1/9$ plateau, we find two competing valence bond crystals depending on the system size, both breaking translation as well as point group symmetries and with a larger $ 3\times 3$ unit cell. Such quantum states with local modulations of the magnetization average values could be observed experimentally in the near future.
Strongly Correlated Electrons (cond-mat.str-el)
16 pages, 9 figures
Modulated Anti-Ferroelectric Smectic Phases with Orthogonal and Tilted Structures
New Submission | Soft Condensed Matter (cond-mat.soft) | 2026-02-16 20:00 EST
Jordan Hobbs, Calum J. Gibb, William C. Ogle, Peter Medle Rupnik, Natan Osterman, Nerea Sebastián, Alenka Mertelj, Richard J. Mandle
The discovery of the ferroelectric nematic phase has brought with it a plethora of new polar liquid crystalline phases. One in particular is the anti-ferroelectric smectic A SmA\textsubscript{AF} phase. In this letter we show via observation and analysis of satellite peaks in the X-ray scattering pattern that the structure of the SmA\textsubscript{AF} phase involves a density modulation of $ \approx$ 10-20 nm lateral to the smectic layer normal. Further, we demonstrate a previously undiscovered phase where the anti-ferroelectric order is maintained into a tilted smectic phase demonstrating the robustness of the underlying frustration that leads to the modulated structure. We suggest that the modulations are only in a single dimension and appear parallel to the tilt plane. This new phase also shows a significantly different and complex response to an electric field from other discovered polar LC phases due to the ability to modulate both tilt and polarisation direction.
Soft Condensed Matter (cond-mat.soft)
Topology of the Fermi surface and universality of the metal-metal and metal-insulator transitions: $d$-dimensional Hatsugai-Kohmoto model as an example
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2026-02-16 20:00 EST
The earlier theory [1] of the quantum phase transitions related to the change of the Fermi Surface Topology (FST) is advanced. For such transitions the Fermi surface as a quantum critical manifold determined by the Lee-Yang zeros, the order parameter $ \mathcal{P}$ as the $ d$ -volume of the Fermi sea, and the special FST universality class were introduced in [1]. The exactly solvable Hatsugai-Kohmoto (HK) $ d$ -dimensional ($ d=1,2,3$ ) model of interacting fermions is analyzed. We explore the relation between the Lee-Yang zeros, the Luttinger and the plateau (Oshikawa) theorems. The validity of the Luttinger theorem in the HK model is confirmed. It is shown that the order parameter $ \mathcal{P}$ and the FST universality class describe the transitions between metal and band/Mott insulators, as well as the Lifshitz and van Hove gapless-to-gapless transitions. The gapless phases are established to be the Landau Fermi liquids (metals). In addition to the conventional paradigm with a continuous order parameter, we apply the homology theory to analyze the FST transitions. They are critical points of the Morse function. To quantify FST we use the Euler characteristic, which is calculated for each phase of the HK model. We claim that the FST universality class is robust with respect to interactions and other model details, under the condition that the critical points are non-degenerate.
Strongly Correlated Electrons (cond-mat.str-el), Statistical Mechanics (cond-mat.stat-mech), Quantum Physics (quant-ph)
34 pages (18 pp main text + 3 appendices), 13 figures
Negative thermal expansion in ice I polytypes
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-02-16 20:00 EST
Leonardo del Rosso, A. Dominic Fortes, Daniele Colognesi, Alberto Santonocito, Francesco Grazzi, Selene Berni, Milva Celli
The fundamental properties of ice have always attracted a lot of interest due to omnipresence of ice in many different natural contexts. Since cubic ice recently become experimentally accessible from a low-density gas hydrate precursor [1, 2], it has been possible to measure its density as a function of temperature in the whole thermodynamic range of metastability. We found strong analogies with respect to the other ice I polytype, i.e., hexagonal ice Ih [3], including the presence of a negative thermal expansion behavior at low temperature. Based on these results, a new enthalpy calculation quantifies the metastable nature of the cubic form and, consequently its inaccessibility from a “normal” ice Ih precursor.
Materials Science (cond-mat.mtrl-sci), Earth and Planetary Astrophysics (astro-ph.EP), Chemical Physics (physics.chem-ph)
13 pages, 3 figures and 1 table
Quantitative imaging of Abrikosov vortices by scanning quantum magnetometry
New Submission | Superconductivity (cond-mat.supr-con) | 2026-02-16 20:00 EST
Clemens Schäfermeier, Ankit Sharma, Christopher Kelvin von Grundherr, Andrea Morales, Jan Rhensius, Gabriel Puebla-Hellmann, Mirko Bacani
Understanding vortex matter in type-II superconductors is central to controlling dissipation and flux pinning in superconducting materials and devices. Here, we use cryogenic scanning nitrogen vacancy magnetometry (NVM) to image Abrikosov vortices in the cuprate superconductors BSCCO-2212 and YBCO under controlled field-cooled conditions. Measurements, which are performed using continuous-wave optically detected magnetic resonance (cw-ODMR) in a closed-cycle cryostat, yield quantitative magnetic-field maps with nanoscale spatial resolution. In BSCCO-2212 at 71 K, we resolve a well-ordered triangular vortex lattice, whose symmetry and spacing are confirmed through 2D Fourier analysis and are consistent with flux quantization. YBCO thin films imaged at 3 K exhibit a more disordered vortex arrangement reflecting stronger pinning, while maintaining quantitative agreement between measured vortex density and the applied magnetic field. These results render our cryogenic scanning NVM a reliable quantitative tool for real-space studies of vortices in high-$ T_c$ superconductors, in particular since such a remarkable magnetic resolution has been achieved within relatively short acquisition times of 2 to 4 h.
Superconductivity (cond-mat.supr-con), Instrumentation and Detectors (physics.ins-det), Quantum Physics (quant-ph)
Whitepaper
Mystery of the 175 cm$^{-1}$ Raman Mode in MnTe Altermagnet
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-02-16 20:00 EST
Bishal Thapa K. D. Belashchenko, Igor I. Mazin
MnTe has recently attracted exceptional attention due to its well-established altermagnetism, prompting a thorough reexamination of its properties. In particular, it was found that a Raman-active excitation at ~175 cm$ ^{-1}$ , routinely assigned to the E2g phonon, is incompatible with this interpretation. It was further hypothesized that this mode is a “leakage”, due to symmetry lowering, of an otherwise forbidden phonon. Here, using first-principles calculations, we decisively rule out this hypothesis and propose an alternative interpretation that the “mystery mode” is an electronic excitation, i.e., a plasmon, enabled by hole self-doping. The resolution of this mystery will require additional experiments and shed new light on the nature of electronic transport in MnTe.
Materials Science (cond-mat.mtrl-sci)
Topological Reorganization and Coordination-Controlled Crossover in Synchronization Onset on Regular Lattices
New Submission | Statistical Mechanics (cond-mat.stat-mech) | 2026-02-16 20:00 EST
The transition to global synchronization in coupled dynamical systems is governed by the interplay between coupling strength and structural topology. Although abrupt, first-order-like synchronization transitions have been extensively reported in heterogeneous networks, it is unclear whether comparable accelerated onset behavior can emerge purely from coordination geometry in spatially homogeneous, regular lattices. In this study, we investigate large-scale ($ N=10^5$ ) stochastic Stuart-Landau oscillator networks defined on regular lattices with controlled coordination number. Using topological data analysis (TDA), simplicial-complex characterization, and optimal-transport-based geometric diagnostics, we identify a coordination-controlled crossover in synchronization onset dynamics at approximately $ z_{c} \approx 7$ within the class of regular lattices considered. Low-coordination lattices ($ z < z_{c}$ ) exhibit persistent $ H_2$ topological features in the dynamical amplitude field that correlate with delayed coherence and surface-limited propagation. In contrast, higher-coordination lattices ($ z > z_{c}$ ) display rapid fragmentation of these features, reduced interface roughness, and predominantly positive Ricci curvature. This is consistent with enhanced path redundancy and improved transport efficiency. In this regime, the global order parameter exhibits accelerated exponential-like growth during the onset stage. Throughout this work, abrupt synchronization refers specifically to this exponential onset behavior rather than to thermodynamic first-order hysteresis. Our results demonstrate that increasing coordination density induces a qualitative reorganization of higher-order topological structure that strongly correlates with synchronization efficiency in regular lattice systems.
Statistical Mechanics (cond-mat.stat-mech), Adaptation and Self-Organizing Systems (nlin.AO)
9 pages, 7 figures
Turing patterns in Matrix-Weighted Networks
New Submission | Statistical Mechanics (cond-mat.stat-mech) | 2026-02-16 20:00 EST
Anna Gallo, Wilfried Segnou, Timoteo Carletti
Diffusion-driven instability is a fundamental mechanism underlying pattern formation in spatially extended systems. In almost all existing works, diffusion across the links of the underlying network is modeled through scalar weights, possibly complemented by cross-diffusion terms that are homogeneous across links. In this work, we investigate the emergence of Turing patterns on Matrix Weighted Networks (MWNs), a recently introduced framework in which each edge is associated with a matrix weight. Focusing on the class of coherent MWNs, we provide a novel characterization of coherence in terms of node-dependent orthonormal matrices, showing that link transformations can be written as relative rotations between nodes. This representation allows us to deal with coherent MWNs of any size and to introduce an orthonormal change of variables capable to reduce diffusion on a coherent MWN to diffusion on a standard weighted network with scalar weights. Building on this, we extend the classical Turing instability analysis to MWNs and derive the conditions under which a homogeneous equilibrium of the local dynamics loses stability due to matrix-weighted diffusion. Our results show how network topology, scalar weights, and inter-node transformations jointly shape pattern formation, and provide a constructive framework to analyze and design Turing patterns on matrix-weighted and higher-order networked systems.
Statistical Mechanics (cond-mat.stat-mech), Dynamical Systems (math.DS), Pattern Formation and Solitons (nlin.PS)
Physics-Informed Glass-Structure Descriptors for Assessing the Intrinsic Reactivity of Mixed Amorphous-Crystalline Precursors in Alkali-Activated Materials
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-02-16 20:00 EST
Zhu Pan, Xinru Li, Yucheng Wang, Samira Hossain, Kai Gong
Rapid and reliable assessment of the intrinsic reactivity of amorphous aluminosilicates is critical for their application in alkali-activated materials (AAMs) and blended cements. Although physics-informed glass-structure descriptors have demonstrated strong structure-reactivity relationships for predominantly amorphous systems, their extension to heterogeneous precursors with mixed crystalline-amorphous phases has been limited. Here, quantitative X-ray diffraction combined with bulk compositional analysis was used to reconstruct the effective amorphous compositions of five fly ashes (FAs) and three ground granulated blast-furnace slags (GGBSs). These compositions served as inputs for molecular dynamics simulations employing a melt-and-quench approach to generate atomic-scale structural models of the glassy phases. Based on these structures, the previously introduced descriptors, i.e., average metal oxygen dissociation energy and average metal oxygen bond strength, were refined to cover a broader compositional space spanning SiO2-Al2O3-TiO2-Fe2O3-CaO-MgO-MnO-Na2O-K2O. The refined descriptors exhibit strong inverse correlations with multiple independent reactivity indicators, including cumulative heat release from isothermal calorimetry, bound water content from thermogravimetric analysis, and compressive strength, for both single precursors and binary FA-GGBS blends activated with NaOH. These results demonstrate that physics-informed glass-structure descriptors can be extended from ideal amorphous systems to heterogeneous mixed-phase precursors and capture relative intrinsic reactivity trends in alkaline solutions. The proposed framework provides a transferable, structure-informed basis for comparative assessment of precursor reactivity that complements experimental testing and may inform precursor screening and mix designs for AAM and blended cement systems.
Materials Science (cond-mat.mtrl-sci), Disordered Systems and Neural Networks (cond-mat.dis-nn)
52 pages, 12 figures, 9 tables
Hierarchical quasiparticle dynamics in antiferromagnets revealed by time- and momentum-resolved X-ray scattering
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2026-02-16 20:00 EST
Arnau Romaguera, Elizabeth Skoropata, Yun Yen, Biaolong Liu, Abhishek Nag, Shih-Wen Huang, Ludmila Leroy, Katja Sophia Moos, Gian Parusa, Serhane Zerdane, Ritwika Mandal, Celine Mariette, Matteo Levantino, Eugenio Paris, Luc Patthey, Ekaterina Pomjakushina, Urs Staub, Monica Ciomaga Hatnean, Michael Schueler, Elia Razzoli, Hiroki Ueda
Energy flows among coupled subsystems are essential for ultrafast dynamics and high-speed technologies. In magnetic materials, spin fluctuations – magnons – mediate these flows in ultrafast magnetism. Yet momentum-resolved access to low-energy magnons governing the microscopic dynamics has been lacking. Using time-resolved resonant diffuse scattering alongside complementary time-resolved X-ray techniques and quantum-kinetic simulations, we unveil the hierarchical energy pathways among correlated systems in the photoexcited antiferromagnet CuO. Above-bandgap excitation triggers near-instantaneous spin disorder, generating non-thermal magnons throughout reciprocal space within femtoseconds. Real-time momentum-resolved tracking reveals picosecond magnon quasi-thermalization, followed by nanosecond recovery via momentum-selective magnon-phonon scattering. The quasiparticle dispersion mismatch creates recovery bottlenecks that control non-equilibrium lifetimes. This microscopic framework transcends phenomenological models and generalizes across materials, establishing design principles for ultrafast control of material properties.
Strongly Correlated Electrons (cond-mat.str-el)
57 pages, 21 figures
Unveiling the origin of the capacity fade in MnO$_{2}$ zinc-ion battery cathodes through an analysis of the Mn vacancy formation
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-02-16 20:00 EST
Caio Miranda Miliante, Kevin J. Sanders, Liam J. McGoldrick, Nicola Seriani, Brian D. Adams, Gillian R. Goward, Drew Higgins, Oleg Rubel
Currently explored rechargeable aqueous zinc-ion battery (RAZIB) cathode materials, such as $ \alpha$ -MnO$ _{2}$ , suffer from severe capacity fade when cycling at rates appropriate for grid-scale operation. Mn dissolution has been previously identified as the cause of $ \alpha$ -MnO$ _{2}$ cathode degradation during RAZIB cycling, with conflicting evidence being found in support of the proposed Jahn-Teller effect-assisted charge disproportionation reaction as the mechanism behind Mn dissolution. In order to unveil the Mn dissolution mechanism in MnO$ _{2}$ cathode cells under RAZIB operation conditions, the energetic feasibility for Mn vacancy formation was probed in both charged (MnO$ _{2}$ ) and discharged (ZnMn$ _{2}$ O$ _{4}$ ) phases of $ \alpha$ and $ \lambda$ polymorphs of MnO$ {2}$ using density functional theory. The formation of a Mn vacancy, and consequently the dissolution of Mn as Mn$ ^{2+}{(aq)}$ , was found to be thermodynamically feasible for the $ \alpha$ -ZnMn$ _{2}$ O$ _{4}$ phase due to the energetically unfavourable Zn bent coordination formed during the Zn$ ^{2+}$ intercalation process, indicating that Mn dissolution is promoted by an unstable Zn coordination environment. The theoretical calculations were then corroborated by operando $ ^{1}$ H nuclear magnetic resonance experiments which captured the Mn dissolution occurring throughout the RAZIB discharge, with subsequent electrochemical deposition of the Mn atoms on the electrode during charge. The combined computational and experimental analysis reveals the critical role of defect energetics and coordination environment in driving active material dissolution, and consequently capacity fade, with the proposed mechanism also relevant for understanding cathode degradation in other intercalating ion battery chemistries.
Materials Science (cond-mat.mtrl-sci)
44 pages, 6 figures, 2 tables, and supporting information
Valence-free open nanoparticle superlattices
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-02-16 20:00 EST
Binay P. Nayak, Zinnia Mallick, Wenjie Wang, Prapti Kakkar, Shan Zhou, Honghu Zhang, Dmytro Nykypanchuk, Surya K. Mallapragada, Alex Travesset, David Vaknin
A cornerstone of advanced materials design is establishing a framework for assembling nanoparticle superstructures with tailored symmetries. A longstanding challenge has been assembling diamond-like superstructures for photonic devices. Traditionally, such open superstructures require functionalized nanoparticles with directional or anisotropic interactions, reminiscent of valence bonding in a diamond. Here, we present a robust strategy for assembling valence-free nanoparticles into a broad array of cubic superstructures. By grafting nanoparticles with oppositely charged, end-functionalized water-soluble polymers of adjustable molecular weight, we gain control over electrostatic interactions and conformational constraints. This unified approach yields lattices analogous to rock salt, CsCl, zinc-blende, diamond, and the rare simple cubic phase, with tunable lattice constants. Theoretical models and simulations elucidate the underlying interactions, providing a framework for engineering valence-free nanoparticle superlattices.
Materials Science (cond-mat.mtrl-sci)
The article has 15 pages and 5 figures. Supporting Information uploaded as ancillary files. The article is published at Nature Communications, DOI: this http URL
Nat Commun 17, 1611 (2026)
Enhanced Spin Lifetime and Long-Range Spin Transport in p-Silicon using Spin Gapless Semiconductor as Ferromagnetic Injector
New Submission | Other Condensed Matter (cond-mat.other) | 2026-02-16 20:00 EST
Nilay Maji, Subham Mohanty, Pujarani Dehuri, Garima Yadav
Electrical spin injection and transport in silicon are central challenges for realizing semiconductor-based spintronic devices, particularly in p-type Si, where strong spin relaxation and interface effects often suppress detectable spin signals. Here, we report electrical spin injection, accumulation, and transport in lightly doped p-type silicon using the spin-gapless Heusler compound Mn$ _2$ CoAl as a ferromagnetic spin injector, separated from the p-Si channel by a thin MgO tunnel barrier in a lateral device geometry. Spin transport is systematically investigated through three-terminal (3-T) Hanle and four-terminal (4-T) nonlocal (NL) spin-valve and Hanle measurements. Clear Lorentzian Hanle signals are observed in the 3-T configuration from \SI{5}{K} up to room temperature, yielding a spin lifetime of approximately $ \sim$ \SI{0.68}{ns} at \SI{300}{K} that increases to approximately $ \sim$ \SI{4.11}{ns} at \SI{5}{K}. Temperature-dependent analysis reveals a weak power-law dependence of the spin lifetime, indicating a Bir–Aronov–Pikus-type spin relaxation mechanism. To validate genuine spin transport, NL spin-valve and Hanle measurements were performed, revealing well-defined spin-valve switching and controlled spin precession at \SI{5}{K}. From NL Hanle fitting, a spin lifetime of approximately $ \sim$ \SI{5.65}{ns} and a spin diffusion length of approximately $ \sim$ \SI{0.82}{\micro\meter} are extracted, confirming diffusive long-range spin transport in the p-Si channel. Although NL signals diminish at elevated temperatures due to reduced interfacial spin polarization and thermal noise, the combined 3-T and 4-T results establish spin-gapless Mn$ _2$ CoAl as an effective spin injector for p-type silicon. These findings highlight the potential of spin-gapless semiconductors for improving spin injection efficiency and advancing Si-compatible spintronic devices.
Other Condensed Matter (cond-mat.other)
Emergent aperiodicity in Bose-Bose mixtures induced by spin-dependent periodic potentials
New Submission | Quantum Gases (cond-mat.quant-gas) | 2026-02-16 20:00 EST
Abid Ali, Pei Zhang, Hiroki Saito, Yong-Chang Zhang
We study the ground-state and low-lying metastable phases of repulsive binary Bose-Einstein condensates confined in twisted, spin-dependent periodic optical lattices. For balanced mixtures, weak intercomponent interactions yield a fourfold momentum-space symmetry dictated by the lattice geometry. Increasing the coupling strength leads to the emergence of additional momentum peaks that combine with the lattice-induced structure to produce an eightfold rotationally symmetric pattern, signaling quasicrystalline order. At intermediate interactions, global phase separation suppresses this quasicrystalline state; however, at stronger coupling, local phase separation gives rise to a long-lived metastable phase in which the eightfold symmetry is restored. In this regime, a secondary ring of dominant momentum peaks appears at smaller wave vectors, indicating longer-wavelength density modulations and a crossover from lattice-dominated to interaction-driven quasicrystalline order. In contrast, imbalanced mixtures form partially miscible density clusters with eightfold-symmetric aperiodic patterns only at intermediate coupling, while stronger interactions drive global phase separation and permanently destroy quasicrystalline order. Real-time simulations demonstrate that these aperiodic structures are dynamically stable and experimentally accessible. Our results show that quasicrystalline order can emerge in binary condensates without explicitly aperiodic lattices and reveal population balance as a key ingredient for stabilizing quantum quasicrystals.
Quantum Gases (cond-mat.quant-gas)
10 pages, 8 figures
Resonant level model coupled to a Sachdev-Ye-Kitaev bath
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2026-02-16 20:00 EST
Anastasia Enckell, Stefan Kehrein
We investigate the non-equilibrium dynamics of a resonant level model coupled to a strongly interacting electron bath modeled by a Sachdev-Ye-Kitaev (SYK) model. Different from the well-investigated case of a structureless non-interacting Fermi gas bath leading to a temperature-independent exponential decay of the impurity orbital occupation, we find a temperature-dependent oscillatory decay. We attribute this difference to the lack of quasiparticles in the SYK model, which is reflected in its singular density of states at the Fermi level. Our results are exact and can be obtained analytically by mapping to a suitably structured Fermi gas bath as an ancillary model for the SYK bath.
Strongly Correlated Electrons (cond-mat.str-el)
Non-chiral ephemeral edge states and cascading of exceptional points in the non-reciprocal Haldane model
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2026-02-16 20:00 EST
Aditi A. Prabhudesai, H. S. Chhabra, Suraj S. Hegde
We study a variant of the Haldane honeycomb model that has non-reciprocal hoppings between the next-nearest neighbours. The system on a torus hosts time-reversal symmetry protected exceptional rings(ER) in the spectrum. The ERs act as Berry-curvature flux tubes i.e the Berry curvature is non-zero only inside the ERs. The system on a cylinder having zig-zag boundaries (and transverse momentum $ k_x$ ) hosts edge-states that have zero group velocity at $ k_x=\pi$ and are therefore non-chiral'. The edge states undergo a bifurcation transition at an exceptional point(EP)in the BZ and delocalise into the bulk. As the non-reciprocity is increased, the bulk states that are approaching each other are converted into pairs of EPs due to non-Hermiticity. As the non-reciprocity is further increased, there is a Russian doll’-like nested proliferation of pairs of EPs, leading to an EP-cascade. The proliferation of EPs takes place only at specific values of the non-hermiticity parameter, leading to a step-like structure in the EP-pair density when plotted as a function of non-Hermiticity. Further, using wave packet dynamics, we find a tunable regime where the non-chiral edge states can be dynamically stabilised for large timescales. The self-acceleration' term in the equations of motion tends to diffuse the wave packets into the bulk, thus making them ephemeral edge states’. But we find that for small non-hermiticity, the edge localisation is stabilised until late times for sufficiently wider wave packets. Thus, we have brought forth an intriguing phenomenology of the exceptional phase of the non-reciprocal Haldane model, which may bear direct relevance for systems such as disordered Kitaev honeycomb model, wherein such ERs have been predicted.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Quantum Physics (quant-ph)
12 pages, 10 figures
Accuracy Comes at a Cost: Optimal Localisation Against a Flow
New Submission | Statistical Mechanics (cond-mat.stat-mech) | 2026-02-16 20:00 EST
Till Welker, Patrick Pietzonka
How much work does it cost for a propelled particle to stay localised near a stationary target, defying both thermal noise and a constant flow that would carry it away? We study the control of such a particle in finite time and find optimal protocols for time-dependent swim velocity and diffusivity, without feedback. Accuracy, quantified via the mean squared deviation from the target, and energetic cost turn out to be related by a trade-off, which complements the one between precision and cost known in stochastic thermodynamics. We show that accuracy better than a certain threshold requires active driving, which comes at a cost that increases with accuracy. The optimal protocols have discontinuous swim velocity and diffusivity, switching between a passive drift state with vanishing diffusivity and an active propulsion state. This study highlights how a time-dependent diffusivity enhances optimal control and sets benchmarks for cost and accuracy of artificial self-propelled particles navigating noisy environments.
Statistical Mechanics (cond-mat.stat-mech)
8 pages, 5 figures
Absorption imaging of quantum gases near surfaces using incoherent light
New Submission | Quantum Gases (cond-mat.quant-gas) | 2026-02-16 20:00 EST
Julia Fekete (1), Poppy Joshi (1), Peter Krüger (1 and 2), Fedja Oručević (1) ((1) University of Sussex, (2) Physikalisch-Technische Bundesanstalt)
We introduce an absorption imaging technique for ultracold gases that suppresses interference fringes and coherence-induced artifacts by reducing the transverse spatial coherence of the imaging light. The method preserves the narrow spectral bandwidth required for resonant absorption imaging and is implemented as a modular extension to standard imaging setups using a rotating diffuser. We demonstrate tunability of the illumination light’s coherence without modifying the imaging optics. Using this approach, we achieve reliable imaging of ultracold atomic clouds in micron-scale proximity to complex surfaces, where standing waves, edge diffraction, and speckle severely limit conventional absorption imaging.
Quantum Gases (cond-mat.quant-gas), Applied Physics (physics.app-ph), Optics (physics.optics)
6 pages, 5 figures
Diamond-to-graphite transformation under hypersonic impact
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-02-16 20:00 EST
Abhijit Biswas, Aniket Mote, Rajib Sahu, Marcelo Lopes Pereira Junior, Shuo Yang, Sudaice Kazibwe, Jishnu Murukeshan, Raphael Benjamin de Oliveira, Guilherme da Silva Lopes Fabris, Shreyasi Chattopadhyay, Gelu Costin, Jianhua Li, Robert Vajtai, Ching-Wu Chu, Lizhong Lang, Yu Zou, Liangzi Deng, Tobin Filleter, Douglas Soares Galvão, Christian Kübel, Thomas E Lacy Jr, Pulickel M. Ajayan
Diamond to graphite transformation is a complex kinetically driven process which has been studied under various conditions for its fundamental importance. We report the transformation of diamond embedded ceramic matrix composites during hypersonic impact. Diamond particles embedded in cubic boron nitride matrix provide a superhard composite that was subjected to high impact collisions of metal projectiles travelling at speeds reaching Mach 8.45. Our observations suggest that the energy absorption and fracture of the composite is primarily enabled via the phase change of diamond into graphite. Characterization of the impact-fractured composite shows transformed diamond particles and provides details of the shock-induced phase transformation and the nature of diamond-graphite interfaces formed during rapid phase change. The study provides new understanding of phase transformation of diamond under extreme conditions.
Materials Science (cond-mat.mtrl-sci)
58 pages, 4 main figures, 28 supporting figures, authors verison, comments are welcome
Disorder viscosity correction approach to calculate spinodal temperature and wavelength
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-02-16 20:00 EST
Simon Divilov, Hagen Eckert, Nico Hotz, Xiomara Campilongo, Stefano Curtarolo
Spinodal decomposition, a key mechanism to microstructure formation in materials, has long posed challenges for predictive modeling, due to the need for parameter-free approaches that accurately capture local energy landscapes. In this work, we propose an approach to predict spinodal behavior by introducing a disorder viscosity correction to bulk free energies computed from finite, small, representative cells. We approximate the energy penalty required to transition into a disordered state to enable the stabilization of locally concave bulk free energy regions - essential for interface formation - while suppressing long-range concentration fluctuations. This approximation circumvents the complexity of full ab initio parameterization of interfacial properties and is well-suited for high-throughput and machine-learning frameworks. Our approach captures the necessary physics underpinning spinodal kinetics, offering a scalable route to predict spinodal regions in compositionally complex and high-entropy materials.
Materials Science (cond-mat.mtrl-sci)
16 pages, 6 pictures
Acta Mater. (2026) 10.1016/j.actamat.2026.121983
Matter-induced plaquette terms in a $\mathbb{Z}_2$ lattice gauge theory
New Submission | Quantum Gases (cond-mat.quant-gas) | 2026-02-16 20:00 EST
Matjaž Kebrič, Fabian Döschl, Umberto Borla, Jad C. Halimeh, Ulrich Schollwöck, Annabelle Bohrdt, Fabian Grusdt
Lattice gauge theories (LGTs) provide a powerful framework for studying confinement, topological order, and exotic quantum matter. In particular, the paradigmatic phenomenon of confinement, where dynamical matter is coupled to gauge fields and forms bound states, remains an open problem. In addition, LGTs can provide low-energy descriptions of quantum spin liquids, which is the focus of ongoing experimental research. However, the study of LGTs is often limited theoretically by their numerical complexity and experimentally in implementing challenging multi-body interactions, such as the plaquette terms crucial for the realization of many exotic phases of matter. Here we investigate a $ (2+1)$ D $ \mathbb{Z}_2$ LGT coupled to hard-core bosonic matter featuring a global U(1) symmetry, and show that dynamical matter naturally induces sizable plaquette interactions even in the absence of explicit plaquette terms in the Hamiltonian. Using a combination of density matrix renormalization group simulations and neural quantum state calculations up to a system size of $ 20 \times 20$ , we analyze the model across different fillings and electric field strengths. At small coupling strength, we find a large plaquette expectation value, independent of system size, for a wide range of fillings, which decreases in the presence of stronger electric fields. Furthermore, we observe signatures of a confinement-deconfinement transition at weak coupling strengths. Our results demonstrate that dynamical U(1) matter can induce complex multi-body interactions, suggesting a natural route to the realization of strong plaquette terms and paving the way for realizing a topological quantum spin liquid protected by a large gap.
Quantum Gases (cond-mat.quant-gas), Strongly Correlated Electrons (cond-mat.str-el), High Energy Physics - Lattice (hep-lat), Quantum Physics (quant-ph)
8 + 8 pages, 3 + 6 figures