CMP Journal 2026-05-25
Statistics
Nature Physics: 1
arXiv: 57
Nature Physics
Reconfigurable and multifunctional circuits using the Stark effect in black phosphorus
Original Paper | Electronic and spintronic devices | 2026-05-24 20:00 EDT
He Tian, Zhan Hou, Fan Wu, Jing-Wen Jiang, Dai-Xuan Wu, Yang Shen, Ting-Yi Xu, Xiao-Yong Xue, Zi-Ming Wang, Hao Guo, Tian-Ling Ren
The bandgap of two-dimensional black phosphorus can be modulated under a vertical electric field due to the Stark effect. However, its circuit applications remain elusive. Here we utilize the Stark effect in black phosphorus for digital and analogue circuit applications. By modulating the bandgap, we can control the current on/off ratio and intrinsic carrier concentration. This enables the effective tuning of amplifier gain and bandwidth, as well as the realization of both binary and ternary logic gates. Using this effect, we build a black phosphorus amplifier with a current-source load, showing a steep gain-tuning slope and more than an order-of-magnitude bandwidth modulation. Furthermore, we demonstrated a stacked black phosphorus transistor array for binary convolutional neural network with better performance compared with silicon- and memristor-based circuits, highlighting its potential for next-generation electronic systems.
Electronic and spintronic devices, Electronic devices, Two-dimensional materials
arXiv
Effects of compocasting process parameters on microstructural characteristics and tensile properties of A356-SiCp composites
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-05-25 20:00 EDT
Hamed Khosravi, Hamed Bakhshi, Erfan Salahinejad
The effects of compocasting process parameters on some structural and tensile characteristics of the A356-10% SiCp (volume fraction) composites were studied. Semisolid stirring was carried out at temperatures of 590, 600 and 610 C with stirring speeds of 200, 400 and 600 r/min for 10, 20 and 30 min. The distribution of the SiC particles within the matrix, porosity content and tensile properties of the obtained samples were examined. The structural evaluations show that by increasing the stirring time and decreasing the stirring temperature, the uniformity in the particle distribution is improved; however, by increasing the stirring speed the homogeneity firstly increases and then declines. It is also found that by increasing all of the processing parameters, the porosity content is enhanced. From the tensile characteristics viewpoint, the optimum values of the speed, temperature and time are found to be 400 r/min, 590 C and 30 min, respectively. The contribution of the reinforcement distribution uniformity prevails over that of the porosity level to the tensile properties.
Materials Science (cond-mat.mtrl-sci), Applied Physics (physics.app-ph)
Transactions of Nonferrous Metals Society of China, 24 (2014) 2482-2488
Genome-Guided Interpretable Screening of Phase-Stable, Lead-Free Double Perovskite Absorbers for All-Inorganic Semiconductors, Sensors, and Photovoltaics with DFT-Validated Design Rules
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-05-25 20:00 EDT
Nafis Ahtasu, Sohanur Rahman Sohan, Md. Mostaq Ahmed Himel, Md. Zahid Hassan, Muhammad Harussani Moklis, Masud Rana Rashel, Hasan Jamil, AKM Kamrul Islam, Mouhaydine Tlemcani
The discovery of stable, lead-free halide perovskites for optoelectronic applications is constrained by vast compositional space and limited interpretability of conventional screening approaches. We present a genome-guided, physics-informed framework that decodes thermodynamic stability and optoelectronic behavior through four physically interpretable descriptor families: packing, bonding, polarization, and electronic identity. Trained on 1,221 DFT-calculated A2BB’X6 compounds, machine-learning surrogates achieve robust predictive performance, with a recall-optimized stability classifier (ROC-AUC = 0.92) and an XGBoost regressor for band-gap prediction (R2 = 0.93 on held-out data). Applying a staged inverse-design constraint stack to 13,088 charge-balanced, lead-free compositions reduces the search space to five DFT-validated, phase-stable semiconductors: Rb2SnMnBr6, Cs2CdSnBr6, Cs2CdSnI6, Cs2KGaI6, and Cs2AgAlBr6. These candidates lie on the convex hull (E_hull <= 0 meV/atom), preserve ordered double-perovskite structures, and exhibit strong optical absorption (alpha peak ~1e5 cm^-1). Genotype-phenotype coupling analysis reveals a hierarchical control mechanism: packing genes define structural formability, bonding genes govern near-edge optical transitions and conductivity, and optoelectronic response genes regulate dielectric response and exciton screening (epsilon0 = 4.6-8.2). This work establishes a generalizable paradigm for interpretable inverse design, linking descriptor-level genomics to experimentally relevant optoelectronic phenotypes and providing design rules for discovering stable, lead-free double perovskites for photovoltaics, sensing, and transparent electronic applications.
Materials Science (cond-mat.mtrl-sci)
Weak wave turbulence as a precursor to universal coarsening in a homogeneous Bose gas
New Submission | Quantum Gases (cond-mat.quant-gas) | 2026-05-25 20:00 EDT
Simon M. Fischer, Martin Gazo, Sebastian J. Morris, Nikolai Maslov, Haoyu Zhang, Jiří Etrych, Gevorg Martirosyan, Christoph Eigen, Zoran Hadzibabic
Relaxation and condensation of an isolated low-energy Bose gas provide an ideal setting for the study of the universal features of far-from-equilibrium many-body dynamics and the emergence of long-range order. Conceptually, the emergence of such order involves two steps: the formation of local coherence, on a system-specific microscopic lengthscale, and the spreading of coherence, over lengthscales much larger than any microscopic scale. The latter is understood in terms of universal phase-ordering kinetics, or coarsening, characterized by an algebraic growth of the coherence length. Here, for a homogeneous Bose gas with tunable interactions, we show that the former also has a universal description, within the framework of weak wave turbulence (WWT). Specifically, the initial transport of particles to low momenta corresponds to an inverse turbulent cascade that is, in agreement with the WWT theory, characterized by a power-law momentum distribution, with exponent $ \gamma = 2.4(1)$ , and transport times $ {\propto} (na)^{-2}$ , where $ n$ is the gas density and $ a$ the $ s$ -wave scattering length.
Quantum Gases (cond-mat.quant-gas), Statistical Mechanics (cond-mat.stat-mech), Atomic Physics (physics.atom-ph), Quantum Physics (quant-ph)
4 pages, 4 figures
Fractionalization, emergent SU($N$) symmetries, and fragmentation in layered quantum spin-orbital models
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2026-05-25 20:00 EDT
Pedro M. Cônsoli, Aayush Vijayvargia, Onur Erten
We propose a family of layered quantum spin-orbital models as a platform to study fractionalization, unconventional forms of symmetry-breaking order, and their possible coexistence. The models are built by stacking $ N$ layers of a square-lattice system in which Kitaev-type interactions promote the formation of a $ \mathbb{Z}_2$ quantum spin-orbital liquid and coupling the different layers via Ising spin interactions. Using a parton construction, we show how, at low energies, these Hamiltonians can be mapped to $ N$ -component Fermi Hubbard models on a $ \pi$ -flux square lattice at half filling. We also demonstrate that the models acquire an emergent SU($ N$ ) symmetry in the limit of equal all-to-all interlayer couplings and argue that, for $ N>2$ , the proximity to this limit offers the potential to realize an array of competing phases. To illustrate this point, we compute the zero-temperature phase diagram of the effective $ N=3$ Hubbard model within mean-field theory and uncover rich phenomena, including intertwined orders and flavor-selective localization. Mapping back to the original degrees of freedom reveals that the ground states realize distinct forms of magnetic fragmentation, wherein the orbitals remain in a quantum liquid state whereas the spins can present conventional long-range order or nonlocal order characterized by a nontrivial string order parameters. We highlight possible extensions of our construction as well as its potential to provide concrete microscopic models for different fractionalized quantum critical points.
Strongly Correlated Electrons (cond-mat.str-el)
11+5 pages, 5 figures
Thickness-Dependent Spintronic Terahertz Emission in MBE-Grown PtTe$_2$: From Semiconductor to Type-II Dirac Semimetal
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-05-25 20:00 EDT
Rahul Sharma, Sylvain Massabeau, Armando Pezo, Ekta Yadav, Viliam Vretenár, Ravi K. Biroju, Fatima Ibrahim, Sukhdeep Dhillon, Alain Marty, Isabelle Gomes de Moraes, Adrien Michon, Jing Li, Mairbek Chshiev, Henri Jaffrès, Jean-Marie George, Matthieu Jamet
Spintronic terahertz (THz) emitters have established themselves as among the most practical broadband THz sources available, yet their performance remains fundamentally limited by the spin Hall conductivity of the nonmagnetic conversion layer - a quantity that is fixed once the material is chosen. Here, we demonstrate that in PtTe$ _2$ , a type-II Dirac semimetal within the transition metal dichalcogenide family, this limitation can be circumvented by exploiting the dramatic thickness-driven electronic phase evolution of the material itself. Using molecular beam epitaxy to grow PtTe$ _2$ films with single-monolayer precision from 1 to 20 ML, we show that the spintronic THz emission tracks the underlying electronic phase diagram directly: it is absent in the single-layer semiconducting phase, turns on sharply at the semimetal transition near 2 ML, and reaches a peak amplitude six times that of an equivalent Pt reference at 10 ML, before declining at larger thicknesses due to THz reabsorption in the increasingly metallic film. This non-monotonic behavior is inconsistent with a bulk inverse spin Hall mechanism and instead reflects a multi-channel spin-to-charge conversion process in which spin-momentum-locked topological surface states and a thickness-dependent interfacial Rashba splitting both contribute and strengthen as the type-II Dirac band structure develops. First-principles calculations of the interfacial spin accumulation reproduce the experimental trend quantitatively, confirming this physical picture. These findings introduce thickness engineering of van der Waals semimetals as a new and accessible route to optimizing spintronic THz emitters and spin-orbit torques in magnetic memories (SOT-MRAMs), with direct implications for the broader class of dimensionally tunable topological materials.
Materials Science (cond-mat.mtrl-sci)
23 pages, 4 figures
Emergent heavy-tailed distributions from a Markovian random walk
New Submission | Statistical Mechanics (cond-mat.stat-mech) | 2026-05-25 20:00 EDT
Henrique S. Lima, Evaldo M. F. Curado
The emergence of heavy-tailed statistics in complex systems is conventionally attributed to non-local stochastic jumps or non-Markovian memory. Here, we present a one-dimensional random walk where power-law behaviors arise instead from a strictly local, discrete-time Markovian mechanism. The step length is governed by a deterministic function of the walker’s position, establishing a positive feedback loop that induces strong effective correlations along the trajectories. Through analytical derivations in the continuum limit and extensive numerical simulations, we show that this rule yields a robust, non-Gaussian stationary state. The exact analytical solution is obtained in the closed form of a symmetric, Lorentz-like distribution, $ \rho_{\text{st}}(x) \propto (|x|/l+r\Delta x)^{-2}$ , confirming asymptotic power-law tails that decay as $ |x|^{-2}$ over six decades. Furthermore, by employing the Onsager-Machlup path-integral formalism, we demonstrate that effective velocity and acceleration acquire physical meaning along the shortest fluctuation trajectories. Crucially, we find that a non-zero initial acceleration acts as the fundamental mechanism driving the walker away from the origin, ensuring both the emergence of scale-free statistics and the normalizability of the stationary distribution. This minimal pathway provides a new microscopic foundation for the widespread $ -2$ power law observed across multidisciplinary complex systems.
Statistical Mechanics (cond-mat.stat-mech), Classical Physics (physics.class-ph), Computational Physics (physics.comp-ph), Data Analysis, Statistics and Probability (physics.data-an), Popular Physics (physics.pop-ph)
9 pages and 1 figure
A new method to probe conducting filaments in MoS$_2$-based memristors
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-05-25 20:00 EDT
Pierre Trousset, Lucie Le Van-Jodin, Bruno Reig, Clotilde Ligaud, Thomas Jalabert, Hanako Okuno, Le Van-Hoan, Paul Brunet, Stéphane Cadot, Matthieu Jamet
Two-dimensional (2D) transition metal dichalcogenides (TMDs), such as molybdenum disulfide (MoS$ _2$ ), are emerging as promising materials for next-generation electronic devices. They have proved to be serious candidates for integration with memristors in non-volatile memory and radio frequency (RF) applications. However, the physical mechanisms behind their resistive switching, particularly the formation and resorption of conducting filaments, remain unclear. In this study, we present a novel mechanical exfoliation technique that selectively removes the top metallic electrode from MoS$ _2$ -based memristors by exploiting the weak van der Waals interaction between MoS$ _2$ and the top electrode. This method enables direct and multi-scale characterization of the MoS$ _2$ surface in different states (initial, ON and OFF) using Kelvin Probe Force Microscopy (KPFM) and Raman spectroscopy mapping. To complete this study, cross-sectional Transmission Electron Microscopy (TEM) was also performed in different conductive states. Our results reveal that the conducting filament is formed by metallic atom migration from the top electrode into the MoS$ _2$ layer. Additionally, we demonstrate that the choice of metallic electrodes (gold vs. nickel) significantly impacts the switching behavior due to differences in adsorption and diffusion energies. This work not only clarifies the filament formation mechanism and introduces a reproducible approach for in-operando characterization but also represents a real progress in the understanding and optimization of 2D material-based memristors.
Materials Science (cond-mat.mtrl-sci)
16 pages, 6 figures
Non-reciprocal Coulomb drag in a ballistic quantum wire
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2026-05-25 20:00 EDT
Suyang Cai, Mingyang Zheng, Nathan Rao, Glen Gillia, Rebika Makaju, Sadhvikas J. Addamane, Dominique Laroche
1D-Coulomb drag serves as a platform for probing electron-electron interactions in 1D systems. Under the charge fluctuation formalism, the non-reciprocal component of Coulomb drag signal in mesoscopic devices is predicted to rely on the breaking of translational invariance due to intrinsic disorder. In this work, we report the measurement of a Coulomb drag device with a ballistic drag wire, allowing us to study the drag signal in nearly pristine quantum wires. Surprisingly, a non-reciprocal component with strength comparable to that of the reciprocal component is still detected across the measured regime, despite the drag wire being ballistic. We suggest that the non-reciprocal signal arises from low energy disorder in the device, which is consistent with the evolution of the drag wire’s conductance at low biases voltages and temperatures. Additionally, the non-reciprocal component of the drag signal shows a power-law temperature dependence that coincides with a diffusive model, while the reciprocal component’s temperature dependence cannot be explained under the existing framework. The bias voltage dependence of the drag wire conductance is fitted into three models to extract the interaction parameter and disorder level within the wire, but none of the models provides a fully self-consistent explanation for the data.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
7 pages, 4 figures
Amorphous Radial Frustration and Water-Like Anomalies in a Ramp-Shoulder Fluid
New Submission | Soft Condensed Matter (cond-mat.soft) | 2026-05-25 20:00 EDT
Murilo S. Marques, Lucas Axel R. Santana, Gabriel San R. R. Câmara, José Rafael Bordin
We investigate the thermodynamic, structural, and dynamic behavior of a three-dimensional coarse-grained ramp-shoulder fluid derived from effective interactions between polymer-grafted nanoparticles. The interaction combines a softened repulsive ramp with a shallow attractive shoulder, stabilizing competing local organizations over a broad pressure interval. Molecular dynamics simulations reveal density, diffusion, and structural anomalies together with crystalline, amorphous, and fluid regions in the phase diagram. Unlike conventional isotropic core-softened fluids, the anomalous hierarchy becomes partially decoupled: the density anomaly extends beyond the structural anomaly, while the diffusion anomaly becomes closely connected to amorphization and shell migration processes. Analysis of radial distribution functions, excess entropy, translational and orientational order, and coordination-shell organization shows that the anomalies are not controlled solely by shell competition. Instead, they emerge from cooperative radial restructuring in a regime where radial correlations increase without the development of crystalline orientational order. The results indicate that the detailed shape of the softened interaction region strongly influences the structural pathways explored under compression, leading to a regime of amorphous radial frustration associated with anomalous diffusion and frustrated shell reorganization.
Soft Condensed Matter (cond-mat.soft)
Surface States in Strain-Induced Nodal-Line Topological Semiconductors
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2026-05-25 20:00 EDT
Vitaly N. Golovach, Alexander Khaetskii
This work explores the topological phase diagram of inverted-band-gap semiconductors under strain and spin-orbit coupling. Using a minimalistic Luttinger Hamiltonian model, we follow the transitions between a 3D topological insulator, a Dirac semimetal, a nodal-line semimetal, and a Weyl semimetal. Analytical and exact solutions for surface states are derived for high-symmetry directions as well as in several limiting cases. We demonstrate the continuous evolution of these surface states across phase boundaries, providing a unified picture that synthesizes previous literature. Specifically, we detail the progression from a Dirac to a nodal-line and then to a Weyl semimetal as spin-orbit coupling originating from bulk inversion asymmetry is introduced. A hierarchy of energy scales is established, defining the criteria for realizing these phases. Finally, we reveal a non-analyticity in the surface-state dispersion at the projected nodal line, originating from distinct, terminating patches of surface states with unique spin textures in momentum space.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Materials Science (cond-mat.mtrl-sci)
17 pages, 4 figures, submitted to SciPost Physics
Nonlinear Wave Propagation in 1D Polycatenated Ring Chains
New Submission | Soft Condensed Matter (cond-mat.soft) | 2026-05-25 20:00 EDT
Xiaoxiao Xiong, Reo Yanagi, Tingtao Zhou, Chiara Daraio
We study the nonlinear wave dynamics of one-dimensional chains of polycatenated rings. These interlocked structures support amplitude-dependent nonlinear wave propagation driven by tensile activation and internal structural flexibility, unlike traditional granular crystals. Through dynamic impact experiments, finite-element modeling, and discrete-particle simulations of vertical chains pretensioned by gravity, we observe and explain nonlinear waves characterized by a compact leading wavefront followed by persistent trailing oscillations, which arise from energy partitioning into the rings’ internal bending modes. Further, we demonstrate that the system’s nonlinearity is not a fixed material constant. By altering the rings’ geometric aspect ratio and contact angles, we can tune the effective contact exponent and the amplitude scaling of the wave speed. This work builds upon nonlinear wave propagation in classical granular crystals and establishes polycatenated systems as a highly tunable and designable platform to study and control nonlinear dynamics.
Soft Condensed Matter (cond-mat.soft), Pattern Formation and Solitons (nlin.PS), Applied Physics (physics.app-ph)
9 pages, 4 figures
Mean first passage time of chiral active Brownian particles
New Submission | Soft Condensed Matter (cond-mat.soft) | 2026-05-25 20:00 EDT
Sarafa A. Iyaniwura, Mingfeng Qiu, Zhiwei Peng
Chiral active Brownian particles (CABPs) are self-propelled agents with intrinsic rotational dynamics, giving rise to circular trajectories commonly observed in biological and synthetic microswimmers. Understanding how CABPs explore confined environments and locate targets is crucial for characterizing transport, search efficiency, and reaction processes in physical and biological systems. We study the escape dynamics of CABPs from one- and two-dimensional confined domains. In one dimension, we consider intervals with either two absorbing boundaries or a reflecting boundary on one side and an absorbing boundary on the other, and derive closed-form asymptotic solutions in the high-chirality regime, revealing the quantitative scaling of the mean first passage time (MFPT) as a function of particle rotation speed (chirality). In two dimensions, we analyze escape from a disk containing one absorbing arc or two symmetric absorbing arcs. By numerically solving the governing partial differential equations, we compute the MFPT for CABPs to escape the domains as a function of the particle’s initial orientation, self-propulsion speed, angular velocity, and domain geometry. Our results show that, depending on the parameters and geometry, the MFPT can exhibit non-monotonic behavior as a function of chirality. There exists an optimal chirality at an intermediate value that minimizes the escape time. Our work offers a comprehensive characterization of CABP escape dynamics in canonical confinements and identifies chirality as a key control parameter for transport and search in confined physical and biological systems.
Soft Condensed Matter (cond-mat.soft)
16 pages, 13 figures
Tuning J$_1$-J$_2$ in Quasi-2D Triangular Lattice Antiferromagnet $α$-SrCr$_2$O$_4$ via Uniaxial Pressure
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2026-05-25 20:00 EDT
Jazzmin Victorin, Shreenanda Ghosh, Seyed Koohpayeh, Chris Lygouras, Natalia Drichko
Triangular lattice antiferromagnets first attracted attention as a frustrated magnetic lattice which can serve as a platform to realize the resonating valence bond state. While the triangular lattice itself was shown to support classical 120 degree order, many theoretical phase diagrams suggest a quantum spin liquid state within a small range of parameters. One possible avenue to achieve such a state is to tune the anisotropy of the triangular lattice antiferromagnet by applying uniaxial pressure. This motivated our Raman scattering study of quasi-two-dimensional antiferromagnet $ \alpha$ -SrCr$ _2$ O$ _4$ under applied uniaxial pressure. Under ambient conditions, $ \alpha$ -SrCr$ _2$ O$ _4$ develops long-range helical magnetic order below T$ _N$ = 43 K. We identify two-magnon excitations associated with this long-range antiferromagnetic order below T$ _N$ at 15.5 meV and 40 meV by comparison with spin wave calculations. We observe the two features from the two-magnon excitation shift away from (towards) each other under applied tensile (compressive) pressure, indicating a decrease (increase) in anisotropy. Raman active phonons show a shift to higher (lower) frequencies under applied compressive (tensile) pressure, indicating efficient transmission of pressure and tuning of the lattice. We show spin wave and two-magnon density of states calculations under uniaxial pressure are consistent with our experimental results.
Strongly Correlated Electrons (cond-mat.str-el)
9 page manuscript plus 3 page SI, 8 figures and 1 table
Pulsed thermal annealing enables switching of chiral antiferromagnetic order with a sub-millitesla field in Mn$_3$Sn
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-05-25 20:00 EDT
Xiaokang Li, Jing Zhang, Xiaodong Guo, Zengwei Zhu
The manipulation of antiferromagnetic (AFM) order is a central theme in modern spintronics. In this work, we achieve reliable switching of the chiral AFM state in the Weyl antiferromagnet Mn$ _3$ Sn using a heat pulse combined with a very small magnetic field as small as 0.1 mT. By systematically measuring the anomalous Hall effect (AHE) in high-quality single crystals, we show that the field needed for switching decreases as the temperature approaches the Néel temperature $ T_N$ , and vanishes at $ T_N$ . Pulsed thermal annealing above $ T_N$ followed by cooling in a tiny external field enables full and reproducible switching of the magnetic octupole order. Our results show that thermal softening (heating above $ T_N$ to temporarily remove the magnetic anisotropy) is a key step that lowers the energy barrier to nearly zero. This allows an extremely weak directional field (like the effective field from spin-orbit torque in thin-film devices) to set the final magnetic state during cooling. We also provide a simple model to estimate the temperature rise in nanoscale devices under current pulses, giving practical guidance for device design. This work highlights that thermal effects are not a side issue but an important partner to spin torques, and suggests that future work should take both into account.
Materials Science (cond-mat.mtrl-sci), Strongly Correlated Electrons (cond-mat.str-el), Applied Physics (physics.app-ph)
7 pages, 3 figures
Optical Transmission of 2D Material with Quantum Anomalous Hall Effect
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2026-05-25 20:00 EDT
Nathan Pravda, Oleg L. Berman, Klaus Ziegler
We study the optical properties of gapped two-dimensional materials which are subject to the quantum anomalous Hall effect. At sufficiently low temperatures the transmission, reflection and absorption coefficients are found to have a universal behavior that depends only on the ratio of the photonic energy and the gap energy. There is a singular behavior with total reflection when these energies are equal. In the limit of a vanishing gap we recover results for graphene, where the optical coefficients depend only on the fine-structure constant. The observed optical properties provide an accurate measurement of the bandgap.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Materials Science (cond-mat.mtrl-sci)
7 pages, 3 figures
Non-adiabatic phonon renormalization in metallic versus insulating rutile oxides
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-05-25 20:00 EDT
Reshma Kumawat, Shubham Farswan, Simranjeet Kaur, Kaushik Sen
We present a comparative Raman scattering study of metallic rutile oxides (RuO$ _2$ and IrO$ _2$ ) and insulating rutiles (TiO$ _2$ and SnO$ _2$ ). Temperature-dependent Raman spectra reveal that the metallic compounds exhibit pronounced phonon frequency hardening, $ \omega(11\mathrm{K})-\omega(300\mathrm{K})=\Delta\omega \approx 6$ -$ 10\mathrm{cm}^{-1}$ , whereas the insulating rutiles show only modest hardening, $ \Delta\omega \approx 1$ -$ 3\mathrm{cm}^{-1}$ . In contrast, the linewidth changes, $ \Delta\Gamma \approx 1$ –$ 7~\mathrm{cm}^{-1}$ , do not display a systematic metallic-insulating classification. Fits with the conventional Klemens anharmonic decay model reproduce the overall temperature trends but yield inconsistent anharmonic parameters for the metallic compounds when benchmarked against insulating rutile analogues. A modified Klemens framework, incorporating an additional $ T^{2}$ correction to the phonon frequency arising from the electronic contribution to the phonon self-energy, quantitatively accounts for the enhanced renormalization observed in metallic systems. These results establish finite non-adiabatic electron-phonon coupling in metallic rutiles and demonstrate that phonon renormalization can be identified even in the absence of observable Fano asymmetry in the phonon line shapes.
Materials Science (cond-mat.mtrl-sci)
Accepted in Phys. Rev. B as a regular article (this https URL)
Exact solution of generalized gauge-invariant Ising chains with multi-spin interactions
New Submission | Statistical Mechanics (cond-mat.stat-mech) | 2026-05-25 20:00 EDT
Pavel Khrapov, Stepan Shchurenkov
In this work, exact solutions are obtained for a class of generalized gauge-invariant $ n$ -chain Ising models ($ n=1,2,3,4$ ) with arbitrary multi-spin interactions that are invariant under the local $ \mathbb{Z}_2$ gauge group. On a strip lattice of finite length $ L$ and width $ n$ with periodic or free boundary conditions, an explicit expression for the partition function is derived using the transfer-matrix method. Two successive transformations are developed: elimination of gauge redundancy and reduction of the original model to an effective $ n$ -chain Ising model with all possible interactions between neighboring vertical layers. On the basis of the spectral decomposition of the $ 2^n\times 2^n$ transfer matrix, general formulas are obtained for gauge-invariant correlation functions and Wilson loops of arbitrary width. For $ n \le 3$ , explicit expressions are derived in terms of eigenvalues and eigenvectors. A detailed analysis of the behavior of the Wilson loop is performed, which allows us to identify regimes exhibiting area-law (confinement-like) and perimeter-law (deconfinement-like) dependence. For specific Hamiltonians, the string tension is computed and the corresponding phase diagrams are constructed. The results generalize and substantially extend the classical works on the gauge-invariant Ising model.
Statistical Mechanics (cond-mat.stat-mech)
19 pages, 8 figures
Quantum fluctuations in quartet superfluid of two-dimensional Fermi mixture
New Submission | Quantum Gases (cond-mat.quant-gas) | 2026-05-25 20:00 EDT
Wei Wang, Yupeng Wang, Xiaoling Cui
We study quantum fluctuations in quartet superfluid (QSF) of two-dimensional (2D) fermion mixtures with mass imbalance. Here QSF is a high-order superfluid that corresponds to the condensation of ($ 1+3$ ) clusters, each consisting of a light fermion and three heavy ones. By incorporating the Gaussian fluctuations respecting dominant four-body correlations in this system, our theory successfully produces the logarithmic dependence of the 2D equation of state in the deep binding regime, thereby offering a correct physical picture of quartet clusters behaving as composite bosons. By extending the Gaussian fluctuation theory from pairing to quartet superfluids, our results shed light on quantum fluctuations in general fermion superfluids with arbitrarily high-order correlations.
Quantum Gases (cond-mat.quant-gas), Superconductivity (cond-mat.supr-con)
12 pages, 3 figures
In situ estimation of local acoustic pressure amplitude by force balancing with a ferrofluid droplet probe
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-05-25 20:00 EDT
Seiya Usui, Yoshiaki Uchida, Akira Nagakubo, Norikazu Nishiyama
Acoustic tweezers enable non-contact manipulation of microscale objects, but quantitative in situ evaluation of the peak local pressure amplitude remains difficult in confined devices. Conventional hydrophone-based measurements are often limited at the microscale by probe size and installation constraints. Here, we present a force-balance method in which a trapped ferrofluid droplet serves as a local probe in a standing-wave acoustic field and an externally applied magnetic-field gradient is tuned so that the magnetic force balances the maximum primary acoustic radiation force on the droplet. From the magnetic force on the ferrofluid droplet, determined at the balance point, we estimate a peak local pressure amplitude of $ 2.6\times10^{5}$ Pa for 7.2MHz operation at 10~V$ _{\mathrm{pp}}$ . This approach provides a practical route for quantitative in situ characterization of microscale acoustic fields and for setting operating conditions in compact acoustofluidic devices.
Materials Science (cond-mat.mtrl-sci)
4 pages, 4 figures
Thermodynamic stability of twisted domains in AgCrSe$_{2}$ thin films grown on lattice-matched YSZ(111) substrate
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-05-25 20:00 EDT
Haruto Sato, Kota Mihara, Kenshin Inamura, Yusuke Tajima, Kazutaka Kudo, Jobu Matsuno, Junichi Shiogai
Control of structural domains in epitaxial thin films of functional materials is a fundamental technique to utilize their intrinsic physical and chemical properties in solid-state devices. In this study, we report on suppression of twisted-domain formation in thin-film growth of polar magnetic semiconductor AgCrSe$ {2}$ using pulsed-laser deposition. In exploring concomitant optimized growth temperature and Ag/Cr composition ratio of supply, we find the critical growth temperature ($ T\mathrm{{sub}}$ ) for obtaining single 60$ ^{\circ}$ domain in c-axis oriented AgCrSe$ {2}$ thin film on a lattice-matched (111) plane of the yttria-stabilized zirconia substrate. At temperatures below and above the critical $ T\mathrm{{sub}}$ , metastable 0$ ^{\circ}$ domain in addition to the 60$ ^{\circ}$ domain emerges, indicating delicate energy balance of thermodynamic stability for obtaining the single-domain structure. Surface structural analysis using time-of-flight low-energy atom scattering spectroscopy reveals the presence of two polar orientations along $ +Z$ and $ -Z$ directions. These findings provide valuable insights into the thin-film growth mechanisms for a family of two-dimensional compounds with rhombohedral lattices.
Materials Science (cond-mat.mtrl-sci), Strongly Correlated Electrons (cond-mat.str-el)
31 pages, 5 figures, and supplementary materials
Memory-driven topological ordering during the transition from dormant to migrating epithelia
New Submission | Soft Condensed Matter (cond-mat.soft) | 2026-05-25 20:00 EDT
Richard Ho, Anna Lång, Emma Lång, Stig Ove Bøe, Luiza Angheluta
Transitions from quiescence to collective migration in epithelia underlie wound healing and cancer invasion, yet their physical origin remains poorly understood. Here we show that quiescent epithelial monolayers store spatially contractile stresses that function as a form of mechanical memory. Upon serum-induced reactivation, these pre-stressed regions nucleate extensile asters that emit propagating polarity domain walls. Along these interfaces, topological defects are created, advected and annihilated, leading to defect coarsening with faster kinetics than by elastic interactions. An active elastic model quantitatively reproduces the observed dynamics and identifies stored stress as the origin of rapid topological reorganization. Our results establish a mechanism in which mechanical memory in quiescent epithelia triggers active stress release, driving collective migration via rapid topological ordering, distinct from conventional unjamming and flocking transitions.
Soft Condensed Matter (cond-mat.soft)
Orientational frustration drives enhanced diffusion of anisotropic particles in a liquid labyrinth
New Submission | Soft Condensed Matter (cond-mat.soft) | 2026-05-25 20:00 EDT
Rohit Mangalwedhekar, Limeng Ruan, Somen Nandi, Quentin Gresil, Marc Tondusson, Stephane Bancelin, Lea-Laetitia Pontani, Laurent Cognet
Transport of nanoscale objects in complex, structured environments plays a key role in a wide range of processes, from biomolecular dynamics in extracellular spaces to transport in porous materials such as filters and catalysts. While anomalous diffusion is well established, how particle anisotropy governs transport under geometric constraints remains unclear. Here we use 3D single-particle tracking to investigate the diffusion of stiff one-dimensional carbon nanotubes in a continuous soft matter network of interconnected chambers and constrictions. Transport is anomalous and antipersistent, with strong length dependent confinement and trapping, consistent with obstructed diffusion. Unexpectedly, however, escape from confinement is poorly sensitive to nanotube length as opposed to what would be expected of pore mediated transport. Despite a tenfold length increase and significantly enhanced trapping, escape time increased by only ~1.4. Single-particle orientational tracking reveals the origin of this weak scaling. Indeed, long nanotube, i.e. those with length comparable to the chamber dimensions, dynamically align with constrictions enabling efficient, geometry-assisted escape that offsets increased confinement while shorter nanotubes need to screen the volume to find their escape path. These results uncover an alignment-mediated transport mechanism that decouples confinement strength from escape kinetics, distinct from pore-mediated transport mechanisms, establishing a quantitative framework for anisotropic diffusion in complex environments.
Soft Condensed Matter (cond-mat.soft), Biological Physics (physics.bio-ph)
21 pages, 5 figures, 4 supplementary figures
Studying Creep-Fatigue interaction of Nickel-Based Superalloys using Crystal Plasticity and Entropy-Based life prediction model
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-05-25 20:00 EDT
Santosh Kumar Shaw, Sabyasachi Chatterjee, Alankar Alankar, Ayan Bhowmik
Creep-fatigue interaction in single-crystal nickel superalloys is difficult to predict because the response depends on the combined effects of loading parameters, hold time, temperature, and the underlying deformation mechanisms. This is important for turbine blade applications, where components experience both fatigue and creep during service. In the present work, a crystal plasticity finite element (CPFE) framework is used to study the creep-fatigue response of a single-crystal nickel superalloy under a range of practically relevant thermo-mechanical loading conditions. In particular, the effects of strain amplitude, R-ratio, hold duration, and temperature on cyclic deformation, stress relaxation, damage evolution, and creep-fatigue life are examined. Particular attention is given to separate the roles of fatigue and creep damage, understanding their interaction, and identify the creep-dominated and fatigue-dominated regimes as a function of strain amplitude and hold time. The study brings together these effects within a single framework and shows that the predicted trends in cyclic response and life are in good agreement with experimental observations reported in the literature.
Materials Science (cond-mat.mtrl-sci)
Cathodoluminescence Analysis of Defects and Grain Boundaries in Zn3P2 Thin Films Grown on Graphene by MOVPE and MBE
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-05-25 20:00 EDT
Thomas Hagger, Mohammadreza Hassanzadeh, Aidas Urbonavicius, Ahmed El Alouani, Victor Boureau, Gulnaz Ganeeva, Nico Kawashima, Raphael Lemerle, Kamil Arthur Wodzislawski, Sebastian Lehmann, Kimberly A. Dick, Silvana Botti, Adrien Michon, Anna Fontcuberta i Morral, Simon Escobar Steinvall
Zn3P2 is a promising earth-abundant absorber for thin-film photovoltaics, yet its development is hindered by the lack of lattice-matched substrates, its incompatible thermal expansion coefficient, and a complex defect landscape. Here, we demonstrate the quasi-van der Waals epitaxy of Zn3P2 on graphene by metal-organic vapour phase epitaxy (MOVPE) and directly link the density of antiphase boundaries to optical emission modulation using correlative electron microscopy and cathodoluminescence (CL). Moreover, it is observed through CL that grain boundaries act as non-radiative sinks for excited charge carriers. The effect extends several micrometres into the grains, making grain boundaries detrimental to the applicability of Zn3P2 in read devices. Further comparison with molecular beam epitaxy grown films reveals the suppression of strain-related sub-bandgap emission in MOVPE-grown material. Overall, quasi-van der Waals epitaxy of Zn3P2 by MOVPE resulted in larger grains and improved material quality. In addition, these results directly link extended defects to recombination pathways in Zn3P2 and highlight grain-size control as a key strategy for improving earth-abundant photovoltaic absorbers.
Materials Science (cond-mat.mtrl-sci)
A Metadynamics-Based Framework for Free Energy Surface Mapping of Multiparticle Diffusion in Crystals
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-05-25 20:00 EDT
Shunya Yamada, Kazuaki Toyoura
We propose two metadynamics (MetaD)-based methodologies for efficiently mapping free energy surfaces (FESs) of multiple interacting carriers diffusing in crystalline solids. Our approaches circumvent the challenges of high-dimensional collective variables (CVs) by employing replica state exchange MetaD and parallel bias MetaD, both of which decompose the high-dimensional CVs into multiple lower-dimensional ones. As a benchmark, we investigate two-dimensional lithium (Li) diffusion in LixTiS2 across a wide range of Li concentrations. The Li jump frequencies estimated from the obtained FESs exhibit concentration- and temperature-dependent trends consistent with previous kinetic Monte Carlo simulations and nuclear magnetic resonance measurements. Our approaches provide a promising framework for capturing the slow dynamics of diffusive carriers that are typically inaccessible to conventional molecular dynamics simulations.
Materials Science (cond-mat.mtrl-sci)
Field evolution of the magnetic structure and spin Hamiltonian in Cs$_2$RuO$_4$
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2026-05-25 20:00 EDT
S.D. Nabi, E. Ressouche, D. G. Mazzone, J. Lass, R. Sibille, Z. Yan, S. Gvasaliya, A. Zheludev
We report neutron diffraction under applied magnetic fields and complementary zero-field neutron spectroscopy measurements on Cs$ _2$ RuO$ _4$ . Previous work [Phys. Rev. B. 112, 134436 (2025)] identified a spin-flop-like transition accompanied by a quantum critical point within the ordered phase, attributed to strong frustration between alternating single-ion anisotropy planes. Here, we quantitatively confirm the predicted field evolution of the magnetic structure using neutron diffraction. Furthermore, analysis of the excitation spectrum within an SU(3) spin-wave framework resolves previously undetermined parameters of the minimal spin Hamiltonian and lifts the associated degeneracies.
Strongly Correlated Electrons (cond-mat.str-el)
9 pages, 8 figures
Inviscid scaling in the Kuramoto-Sivashinsky equation from functional renormalization group and direct numerical simulations
New Submission | Statistical Mechanics (cond-mat.stat-mech) | 2026-05-25 20:00 EDT
Liubov Gosteva, Dipankar Roy, Nicolás Wschebor, Léonie Canet
We show that the one-dimensional Kuramoto-Sivashinsky (KS) equation features a scaling regime characterized by the dynamical exponent $ z=1$ at intermediate scales between the large-scale Kardar-Parisi-Zhang (KPZ) scaling with $ z=3/2$ and the small-scale non-universal behavior. This scaling regime is intrinsic to the KS dynamics since it arises from the vanishing of the effective viscosity when evolving from its microscopic negative KS value, to its macroscopic effective positive KPZ value. This vanishing of the viscosity deeply imprints the behavior of correlations at intermediate scales, which exhibit a universal $ z=1$ scaling. This behavior pertains to the inviscid-Burgers universality class, which corresponds to the zero-viscosity fixed point of the KPZ equation. We evidence and characterize this so-far-overlooked scaling regime using both functional renormalization group and direct numerical simulations.
Statistical Mechanics (cond-mat.stat-mech), Chaotic Dynamics (nlin.CD)
4 pages, 4 figures
Selective Fermi-Level Pinning: A Design Strategy for Giant Rectification in Molecular Junctions
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2026-05-25 20:00 EDT
Junnan Guo, Wenhui Fang, Jian Huang, Weikang Wu, Hui Li, Lishu Zhang
Molecular rectifiers are key functional components of molecular-scale integrated circuits, yet achieving high rectification ratios remains a longstanding challenge due to the intrinsic symmetry of resonant tunneling and the complexity of interfacial energy-level alignment. Here, we propose a rectifier design strategy based on selective Fermi-level pinning that breaks transport symmetry via pinning interactions between molecular frontier orbitals and electrodes. This framework enforces tunneling transport to be predominantly governed by unoccupied molecular orbitals, while substantially suppressing contributions from occupied states, thereby establishing a simplified and highly controllable rectification mechanism. The resulting cyclo[n]carbon-based molecular junctions exhibit giant rectification ratios exceeding 103, while retaining exceptional structural robustness against variations in both donor chain length and carbon ring size. This work reveals the critical role of selective Fermi-level pinning in molecular junctions and provides a general design principle for engineering functional single-molecule electronic devices.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Materials Science (cond-mat.mtrl-sci), Quantum Physics (quant-ph)
Localized Excitonic Emission in Wafer-Scale MOCVD-Grown GaSe 2D Nanosheets for Classical and Non-Classical Light Sources
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2026-05-25 20:00 EDT
Bhabani Sankar Sahoo, Nils Fritjof Langlotz, Shachi Machchhar, Kartik Gaur, Robin Günkel, Max Bergmann, Naghmeh Ghadghooni, Aris Koulas-Simos, Jürgen Belz, Chirag Chandrakant Palekar, Maximilian Ries, Kerstin Volz, Stephan Reitzenstein, Imad Limame
Wafer-scale growth of two-dimensional semiconductors remains a key challenge for their integration into photonic technologies. While most studies of two-dimensional semiconductors have focused on transition metal dichalcogenides and their scalable fabrication, comparatively little attention has been given to III-VI monochalcogenides. Here, we report wafer-scale growth of gallium selenide (GaSe) by metal-organic chemical vapor deposition (MOCVD) and investigate its structural and optical properties for visible-range classical and quantum light emission. Two samples with thicknesses ranging from a few monolayers to several micrometers, controlled via the growth time, were investigated. The 30-minute grown sample yields intense, broad photoluminescence spanning 1.7–2.0$ ,$ eV, whereas the thinner 3-minute sample exhibits discrete narrow emission lines and single-photon emission with $ (g^{(2)}(0) = 0.15 \pm 0.10)$ . Remarkably, cathodoluminescence mapping reveals pronounced spatial localization of both spectrally narrow and broad emission centers. Together with temperature-dependent power-law analysis and Raman mapping, our results indicate defect-induced emission rather than intrinsic excitonic recombination. These findings establish wafer-scale MOCVD grown 2D GaSe as a platform for classical and non-classical light sources and highlight defect-engineered localization as a route toward scalable quantum photonics.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
Nonreciprocal surface tension: anisotropy-induced defect motility and organization
New Submission | Soft Condensed Matter (cond-mat.soft) | 2026-05-25 20:00 EDT
Laya Parkavousi, Suropriya Saha
We show that interfacial nonreciprocity transforms defect dynamics in conserved scalar fields within the framework of the Nonreciprocal Cahn-Hilliard model. Nonreciprocal surface tension alone produces intermittently stable defects: system-spanning target patterns form, lose stability, self-destruct, and nucleate again from a defect-chaotic state. When bulk and interfacial contributions interplay in a particular way, the system forms a distinct mosaic-wave state: traveling waves remain coherent within finite domains demarcated by linear arrangements of motile dislocations, which act as lines of phase slip. Mosaic-waves exhibit scale-free fluctuations at length scales much larger than the average wavelength of the traveling patterns. To explain the wide range of emergent dynamics, we construct the dynamics of the Goldstone-mode. The nonlinearities governing its large-scale fluctuations belong to the anisotropic Kardar-Parisi-Zhang universality class, with the sign of the nonlinear anisotropy controlling the nature of the out-of-equilibrium dynamics.
Soft Condensed Matter (cond-mat.soft)
Generalized Shift Vector as the Intrinsic Dipole of Many-Body Correlated Electronic States
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2026-05-25 20:00 EDT
Jiaming Hu, Sudipta Kundu, Zhichao Guo, Joshua J.P. Thompson, Wenbin Li, Hua Wang, Bartomeu Monserrat
Shift vectors play a central role in nonlinear optics and transport phenomena, where they are usually understood as charge-center shifts associated with transitions between quantum states. Here we show that the same geometric structure can be more fundamentally understood as the intrinsic dipole moment of a single correlated state. Our derivation clarifies the local and global aspects of gauge invariance, the origin of the phase-gradient term, and its connection to the internal coherence structure of many-body correlations. The single-state shift character appears both as a displacement of the real-space joint probability density and as a linear electric-field modification in energy space. Applying this framework to optically induced correlations, electron-phonon-mediated processes, and excitonic electron-hole states, we recover previously proposed shift vectors and the standard expression for the shift current as special cases. Our results establish a common physical foundation for shift vectors as intrinsic dipolar properties of correlated electronic states.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Quantum Physics (quant-ph)
17 pages, 2 figures
Analysis of spin avalanches due to interplay of disorder and temperature
New Submission | Disordered Systems and Neural Networks (cond-mat.dis-nn) | 2026-05-25 20:00 EDT
Niharika Bhuyan, Diana Thongjaomayum
The nonequilibrium zero-temperature Random Field Ising Model (RFIM) has been extensively studied to understand critical response and avalanches in disordered driven systems. The emergence of power-law behaviour is observed over a wide region around the critical point. These studies however, are confined to zero-temperature dynamics. We study the role of temperature, which is inevitable in real experiments, in the context of RFIM on triangular lattices. We explore the interplay of different parameters: temperature, random field strength, and relaxation time which affect the prevalence of power-law behaviour on the lattice. The results indicate that power-law survives only in the regime of low temperature or small and intermediate disorder. Variations in temperature and disorder have similar affects on the avalanche-size distribution, indicating their strong correspondence. We also discuss the process of blurring out of the power law on increasing temperature or disorder.
Disordered Systems and Neural Networks (cond-mat.dis-nn)
6 pages, 8 figures
Symmetry-protected nodal planes and accidental nodal surfaces in mixed odd-even wave spin-momentum locking of relativistic altermagnets
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-05-25 20:00 EDT
Xujia Gong, Amar Fakhredine, Sahar Izadi Vishkayi, Carmine Autieri
Non-relativistic spin–momentum locking in altermagnets exhibits an even number of nodal planes. In the relativistic limit, the number of nodal planes can be lowered by symmetry reduction due to the Néel vector and spin–orbit coupling in noncentrosymmetric systems. Therefore, an analysis of the evolution of the nodal planes in relativistic altermagnets is required. While $ g$ -wave spin–momentum locking is straightforward to realize in non-relativistic altermagnets, this $ g$ -wave does not necessarily survive in the relativistic case. In this work, we investigate the relativistic spin–momentum locking of the centrosymmetric CrSb and the noncentrosymmetric wurtzite MnTe. As a first result, we show that in both systems the dominant spin component retains its $ g$ -wave character in the relativistic regime only when the Néel vector is oriented along the $ z$ -axis, while the subdominant components exhibit $ d$ -wave symmetry in CrSb and $ p$ -wave symmetry in ferroelectric wurtzite MnTe. More generally, the $ g$ -wave character is preserved in the relativistic limit only when both the Néel vector and the electric field associated with inversion-symmetry breaking are oriented along the $ z$ -axis. As a second result, we show that relativistic spin–momentum locking of ferroelectric altermagnets can exhibit $ p$ -wave magnetism with one symmetry-protected nodal plane and an accidental nodal surface not protected by symmetry, or can have two accidental nodal surfaces. With the Néel vector aligned along the $ x$ -axis, selected bands of ferroelectric altermagnet wurtzite MnTe exhibit $ p$ -wave magnetism. Our results establish that altermagnets can host distinct spin components that realize a mixture of angular-momentum wave symmetries in momentum space in the relativistic limit.
Materials Science (cond-mat.mtrl-sci)
Self-organized formation of step-terrace structure in SrRuO3 thin films grown on mixed-terminated SrTiO3 (100) substrates
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-05-25 20:00 EDT
Ryotaro Arakawa, Sachio Komori, Kotaro Tomita, Shunsei Komori, Masaaki A. Tanaka, Tomoyasu Taniyama
Surface morphology of the substrate and bottom layers plays a critical role in the epitaxial growth of oxide thin films. Here, we report on the self-organized formation of a step-terrace structure in SrRuO3 (SRO) thin films grown using pulsed laser deposition on mixed-terminated SrTiO3 (100) substrates without any prior surface treatment. Atomic force microscopy observations reveal that SRO films initially grow in a three-dimensional island mode and subsequently undergo a transition to a step-flow growth mode through island coalescence as the film thickness increases, resulting in a well-defined step-terrace morphology with a step height consistent with the SRO unit-cell parameter. The average terrace width of the self-organized structure can be systematically tuned by varying the substrate temperature and the target-substrate distance, which we attribute to changes in the critical island radius that governs the nucleation behavior. To demonstrate the utility of this self-organized morphology, we show that BiFeO3 thin films grown on SRO films with such a step-terrace structure exhibit improved surface flatness and crystalline quality compared to those grown directly on bare SrTiO3 substrates. These findings provide a clear understanding of the mechanism of thickness-driven growth-mode transitions in perovskite oxide thin films under various growth conditions.
Materials Science (cond-mat.mtrl-sci), Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
Intrinsic Point Defects and Frenkel Pair Formation in Photovoltaic Absorber Zn$_3$P$_2$: Regulating $p$-type Conductivity through Growth and Annealing Conditions
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-05-25 20:00 EDT
This study investigates the ground-state energetics and thermodynamics of intrinsic point defects in zinc phosphide Zn$ _3$ P$ 2$ using \emph{ab initio} density functional theory combined with an extensive potential energy landscape search. Our analysis reveals that the defect chemistry is dominated by zinc vacancies $ V\mathrm{Zn}$ and zinc interstitials Zn$ _i$ , with equilibrium concentrations significantly surpassing those of other intrinsic species. Notably, we find that phosphorus interstitials P$ _i$ , previously suggested to be significant, possess high formation energies and likely exist only in negligible quantities. The characteristic $ p$ -type conductivity of undoped Zn$ _3$ P$ 2$ is shown to be a direct consequence of zinc vacancies, which act as shallow acceptors and pull the Fermi level toward the valence band. Furthermore, we identify a positive binding energy between $ V\mathrm{Zn}$ and Zn$ _i$ , leading to the formation of electrically benign Frenkel pairs that partially compensate the intrinsic p-type conductivity. Our results suggest that achieving $ n$ -type conductivity is fundamentally limited by these thermodynamic constraints. We conclude that hole densities can be optimized through phosphorus-rich growth conditions and high-temperature annealing, and suggest that future photovoltaic strategies should prioritize interface engineering over bulk $ n$ -type doping.
Materials Science (cond-mat.mtrl-sci), Computational Physics (physics.comp-ph)
11 pages, 12 figures
Nonequilibrium dynamics of high energy transitions in monolayer WSe$_{2}$
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-05-25 20:00 EDT
Oleg Dogadov, Jorge Cervantes-Villanueva, Nicholas Olsen, Chiara Trovatello, Xiaoyang Zhu, Giulio Cerullo, Alejandro Molina-Sánchez, Davide Sangalli, Stefano Dal Conte
High-energy optical transitions in monolayer transition-metal dichalcogenides exhibit characteristics that are markedly distinct from those of lower-lying band-edge excitons. These differences arise from the involvement of electronic states located at regions of the Brillouin zone that are displaced from the $ K$ valleys. In this work, we investigate the ultrafast dynamics of these high-energy excitations by employing broadband ultrafast transient absorption spectroscopy spanning the visible to ultraviolet spectral range. We observe that the formation and relaxation dynamics of one of the high energy transitions display a distinct behavior compared to the lower-energy excitonic resonances, developing on a significantly slower timescale. First-principles calculations of the excitonic landscape allow us to account for this delayed response and attribute it to the phonon-mediated formation of momentum-dark excitons.
Materials Science (cond-mat.mtrl-sci)
9 pages, 4 figures
Commensuration torques in double-moiré twisted trilayer hexagonal boron nitride and graphene heterostructures
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2026-05-25 20:00 EDT
Youngju Park, Nicolas Leconte, Prathap Kumar Jharapla, Md Shaifullah, E. H. Hwang, Jeil Jung
We study commensuration-driven torques and angle locking in double-moiré trilayer hexagonal boron nitride (hBN) and graphene heterostructures using large-scale atomistic relaxations. In twisted trilayer hBN (t3BN) homostructures, double-moiré commensuration ($ \theta_{12} = -\theta_{23}$ ) give rise to local energy minima accompanied by torque sign reversals, signaling a restoring tendency toward the commensurate configuration. The corresponding binding energies are $ \sim$ 0.2-0.3 meV/atom, originating from enhanced overlap of low-energy stacking domains, although the system is globally stable at zero twist. In contrast, in graphene/hBN heterolayers systems the global energy minimum can coincide with the double-moiré commensuration angle, particularly near $ \sim$ 0.6$ ^{\circ}$ , reflecting competition between lattice mismatch and interfacial relaxation. Incommensurate atomic structures have reduced stabilization due to suppressed overlap of low-energy stacking and have enhanced superlubricity due to spatial averaging of interfacial energies. These results establish double-moiré commensuration as a general, system-dependent mechanism for twist-angle stabilization, whose angular stability is characterized by the torque magnitude and binding energy. Coulomb electrostatic interactions further enhance the stabilization energy without changing the underlying physics.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
15 pages, 5 figures
Ambiguity in B-Site cation ordering: A Case study of the double perovskite Ca$_2$CoNbO$_6$
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-05-25 20:00 EDT
Svetlana A. Artiukova, Ivan V. Yatsyk, Ruslan G. Batulin, Yulia A. Deeva, Tatiana I. Chupakhina, Vladislav V. Bazhal, Alexandr I. Balitskiy, Rushana M. Eremina, Dina I. Fazlizhanova
The ordering of cations in the B sublattice remains a challenging issue in double perovskites. In this work, a combined experimental and theoretical approach was employed to investigate the Co/Nb distribution in Ca$ _2$ CoNbO$ _6$ and its influence on magnetic and transport properties. The density functional theory, supported by magnetic susceptibility measurements, indicates that Co adopts a high-spin Co$ ^{3+}$ state. No long-range magnetic ordering was observed down to low temperatures; however, the presence of short-range correlations points to the partial disorder in the Co/Nb sublattice. This interpretation is further supported by electron paramagnetic resonance, which also reveals slight oxygen nonstoichiometry. Electrical transport follows a small-polaron hopping mechanism with an activation energy of 0.25 eV. The Seebeck coefficient reaches 0.4 mV/K at 600 K.
Materials Science (cond-mat.mtrl-sci)
18 pages, 12 figures
Phase diagram of the vortex state in an amorphous Re6Zr thin film exhibiting inverse melting
New Submission | Superconductivity (cond-mat.supr-con) | 2026-05-25 20:00 EDT
Pritam Das, Subhamita Sengupta, Anjan Jana, Rishabh Duhan, Sulagna Dutta, Arghya Dutta, John Jesudasan, Vivas Bagwe, Pratap Raychaudhuri
In Type II superconductors, the vortex lattice can exhibit “inverse melting,” transitioning from a liquid to a crystalline solid as temperature increases. While recently observed via scanning tunneling microscopy in a 20 nm thick amorphous Re6Zr thin film, this work investigates the corresponding d.c. transport and low-frequency magnetic screening responses. By identifying distinct signatures of these transitions and integrating scanning tunneling spectroscopy imaging, we construct a comprehensive vortex-state phase diagram in the magnetic field-temperature parameter space. Furthermore, we demonstrate that inverse melting is thickness-dependent: a 5 nm film retains an inhomogeneous liquid state, while a 50 nm film maintains a crystalline solid structure except near the upper critical field.
Superconductivity (cond-mat.supr-con), Statistical Mechanics (cond-mat.stat-mech)
Momentum-Resolved Tunneling Modulation Induced Giant Multistate Resistance in Antiferroelectric Multiferroic Junction
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2026-05-25 20:00 EDT
Wei Yang, Yibo Xu, Shen Li, Jiangchao Han, Jiayou Chen, Juan-Carlos Rojas-Sánchez, Stéphane Mangin, Xiaoyang Lin, Weisheng Zhao
Multiferroic tunnel junctions (MFTJs), integrating ferroelectric and ferromagnetic functionalities within a single nanoscale device, hold significant promise for non-volatile, multi-state memory and innovative computing paradigms. In conventional MFTJs, tunneling resistance modulation relies primarily on ferroelectric (FE) polarization switching, which alters interfacial electric fields and shifts the Fermi level of adjacent ferromagnetic electrodes. However, achieving high tunnelelectroresistance (TER) through this approach demands strong built-in electric fields, which simultaneously hinder FE polarization switching, creating an intrinsic trade-off between reliable data reading and efficient writing. Here, we propose a dual mechanism that combines antiferroelectric (AFE) phase-transition modulation of the evanescent decay states with interfacial spin filtering based on $ Fe_3GaTe_2$ /bilayer-$ In_2Se_3$ /$ Fe_3GaTe_2$ heterostructure. Beyond altering the electrostatic potential as in AFE-FE switching, the transitions between head-type and tail-type AFE states preserve the centrosymmetric potential profile yet fundamentally modulate the momentum-resolved distribution of evanescent decay rates across the Brillouin zone. When integrated with perfect spin filtering at the $ Fe_3GaTe_2$ /$ \alpha$ -$ In_2Se_3$ interface, this mechanism yields a giant TER (~$ 7.6\times10^3%$ ), over 4 times that of conventional FE-based MFTJs, and a TMR exceeding $ 6.8\times10^5%$ , enhanced by two orders of magnitude over typical MFTJs. These mechanisms resolve the performance trade-off in MFTJs, enabling six distinct non-volatile resistance states at room temperature.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Materials Science (cond-mat.mtrl-sci)
26 pages, 5 figures
ACS Nano 19 (2025) 38573-38582
Disorder-Induced Phase Transitions in Altermagnetic Josephson Junctions
New Submission | Superconductivity (cond-mat.supr-con) | 2026-05-25 20:00 EDT
Altermagnetic Josephson junctions (AMJJs) can host unconventional $ \pi$ phase and $ \varphi$ phase despite vanishing net magnetizations. Whether these phases are stable against disorder existing in real materials remains an open question. Here, we investigate impact of disorder on exotic phases in two-dimensional d-wave AMJJs. We show that disorder is able to induce phase transitions between the exotic $ \pi$ and conventional 0 phases, accompanied by a strong suppression of critical current. This behavior is attributed to modifications of the tunneling Cooper-pair phase shift and superconducting decoherence. Remarkably, the anomalous $ \varphi$ phase is highly fragile in presence of disorder and can be driven to either a $ \pi$ phase or 0 phase in a nonreciprocal manner. Across such transitions, the first harmonic of current-phase relation changes sign, while the higher-order harmonics are rapidly suppressed. Our findings reveal the crucial role of disorder in tailoring distinct phases of AMJJs and shed new light on their potential functionalities.
Superconductivity (cond-mat.supr-con)
11pages, 9 figures
First-principles transition-state tensorial cluster expansion of vacancy diffusion in Ta-W beyond the kinetically-resolved activation approximation
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-05-25 20:00 EDT
Jacob Jeffries, Brianna Sebastian-Olazabal, Enrique Martinez
Predicting diffusion in chemically complex alloys remains challenging due to the strong dependence of migration barriers on local atomic environments. Here, we develop a first-principles-informed framework that directly learns environment-dependent migration barriers without relying on reduced kinetic approximations such as the kinetically resolved activation (KRA) model. Migration barriers computed using density functional theory and nudged elastic band calculations are represented via a tensorial cluster expansion including transition states and deployed in on-lattice kinetic Monte Carlo simulations. Applied to the Ta-W system, the framework captures nontrivial composition-dependent diffusion behavior arising from a crossover between solute trapping and percolated low-barrier transport pathways, yielding a maximum in the apparent activation energy near intermediate compositions. This approach establishes a general and scalable route for integrating first-principles transition-state energetics into mesoscale kinetic simulations, enabling predictive multiscale modeling of diffusion in chemically complex materials and providing a pathway for uncovering emergent transport phenomena.
Materials Science (cond-mat.mtrl-sci)
17 pages, 11 figures
Close correlation between giant magnetostriction and the microstructure in Fe-Ga melt-spun ribbons
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-05-25 20:00 EDT
Likun Chen, Mitsutaka Sato, Jiahao Han, Rie Y. Umetsu
Magnetoelastic anisotropy and <100> texture are crucial for promoting magnetostriction in Galfenol (Fe-Ga). Given that single-crystal Fe-Ga remains technically demanding and low magnetostriction of polycrystal, we explore melt-spun as an alternative, where rare-earth (RE) doping and cooling rates optimizing enable controllable <100> textured with required magnetoelastic anisotropy. Fe81Ga19 binary ribbons and RE-doped ribbons (0.2 at.% Pr, 1 at.% Pr and 1 at.% Ce) were fabricated at various cooling rates. Microstructural analyses reveal that RE elements preferentially dissolve into the matrix, while second-phase formation is suppressed at higher cooling rates. RE substitution increases the magnetostriction by enhancing magnetocrystalline distortion energy, while cooling rates act as an effective tuning knob to maximize the <100> texture. Notably, the decreased melting temperature associated with 1 at.% RE doping shifts the optimum texture to lower cooling rate compared with the binary alloy and 0.2 at.% RE doping sample. The magnetostriction as high as 688 ppm is achieved for the 1 at.% Ce doped ribbon fabricated at the speed of 1000 rotation per minute. These results demonstrate that RE-doped melt-spun ribbons are promising candidates for giant magnetostriction and establish a practical processing-texture-property guideline for designing highly magnetostrictive alloys.
Materials Science (cond-mat.mtrl-sci)
Graphene-based Photodetector with Engineered Hot Carrier Cooling Dynamics
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2026-05-25 20:00 EDT
Yishu Huang, Anand Nivedan, Florian Ludwig, Bohai Liu, Michiel Debaets, Steven Brems, Hai I. Wang, Alessandro Principi, Dries Van Thourhout, Christian Haffner, Aron W. Cummings, Klaas-Jan Tielrooij
Graphene has emerged as a promising material for integration into silicon photonics, owing to its ultrafast and broadband photoresponse without the need for an external bias voltage. This photoresponse relies on the photo-thermoelectric effect created by hot carriers. A key factor underlying the performance of graphene photodetectors is the cooling dynamics of these hot carriers. In this work, we engineer these dynamics in a WSe2-graphene-WSe2 waveguide-integrated photodetector. In particular, by introducing proximity screening by a nearby graphite layer to this structure, we prolong the hot-carrier cooling time, leading to an enhanced photoresponse. We characterize the cooling dynamics under continuous-wave laser excitation by employing a photomixing technique, revealing an increase in the cooling time by up to a factor of four. Direct photoresponse measurements show that the internal photoresponsivity improves by approximately 50%. Together, these results demonstrate the potential of proximity screening to enhance the performance of graphene-based photodetectors on an integrated photonics platform.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Applied Physics (physics.app-ph), Optics (physics.optics)
24 pages, 13 figures
Nonreciprocal conductance in uniformly dissipative devices
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2026-05-25 20:00 EDT
Oliver Solow, Emil J. Bergholtz, Karsten Flensberg
When studying non-Hermitian electronic systems, an obvious question is how various non-Hermitian effects affect measurable quantities like the conductance. Here, we show that uniformly dissipative circuits can exhibit nonreciprocal conductance, meaning that the two nonlocal conductances are different. We describe how this happens through a difference in transmission times between left-moving and right-moving electrons. We consider a specific case of a dissipative Rashba nanowire with a skewed magnetic field, and show how this difference in transmission times comes about through interference inside the circuit, and how this is modified as the dissipation strength changes.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
6 pages
Kondo singlet from ferromagnetic coupling: an analog of Anderson-Morel superconductivity in the magnetic channel
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2026-05-25 20:00 EDT
Ewan Scott, Yaqi Chen, Michael Turaev, Tarkan Yzeiri, Chris Hooley, Krzysztof P. Wójcik, Michał P. Kwasigroch
We consider magnetic impurities coupled to a conduction sea via a fully isotropic ferromagnetic spin-exchange term, the strength of which depends on the conduction-electron modes involved in the scattering. In the single-impurity case we show both analytically and numerically that there exists a parameter regime in which the conventional Kondo effect develops at low temperatures, leading to a singlet ground state. In the case of a lattice of impurities, we show that this leads to a heavy Fermi liquid state that is energetically favored over magnetic ordering in a broad parameter range. We argue that these effects are analogs of Anderson-Morel superconductivity, and discuss routes to their experimental realization.
Strongly Correlated Electrons (cond-mat.str-el), Superconductivity (cond-mat.supr-con)
Order-Disorder Tricriticality in $\mathrm{A}_n \mathrm{B}_n$ Star Polymer Melts
New Submission | Statistical Mechanics (cond-mat.stat-mech) | 2026-05-25 20:00 EDT
Minhoon Kim, Wonjun Kang, Daeseong Yong, Junhan Cho, Jaeup U. Kim
Tricriticality usually requires tuning an additional thermodynamic parameter. Here we show that, in symmetric $ \mathrm{A}n\mathrm{B}n$ star-polymer melts, the arm number $ n$ itself plays this role and drives the order–disorder transition (ODT) from second order to first order. By developing a sixth-order free-energy expansion within the random phase approximation and comparing it with self-consistent field theory (SCFT) calculations, we analytically identify a tricritical arm number, $ n{\mathrm{tc}}\approx 5.4475$ . For $ n<n_{\mathrm{tc}}$ , the lamellar ordering transition remains continuous and occurs at the spinodal point, $ (\chi N)_{\mathrm{s}}\approx 10.495$ . For $ n>n{\mathrm{tc}}$ , the transition becomes first order, and $ (\chi N){\mathrm{ODT}}$ shifts below $ (\chi N){\mathrm{s}}$ with a quadratic dependence near the tricritical point. SCFT calculations confirm the predicted transition character and phase-boundary shift. The origin of this behavior is traced to inter-arm correlations generated by the common junction. We further show that the noninteger tricritical arm number can be effectively realized in binary mixtures of star polymers. This provides a rare analytically tractable example of architecture-induced tricriticality in a microphase-separating polymer system.
Statistical Mechanics (cond-mat.stat-mech), Soft Condensed Matter (cond-mat.soft)
Evidence of a Hybridized Topological State in Weyl Semimetal/Topological Insulator Mn${3+x}$Sn${1-x}$/Bi${0.85}$Sb${0.15}$ Heterostructures
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-05-25 20:00 EDT
Ryan T. Van Haren, Gillian P Boyce, Gregory M. Stephen, Vinay Sharma, Don Heiman, Aubrey T. Hanbicki, Adam L. Friedman
We report magnetotransport evidence of a hybridized Weyl semimetal (WSM) Fermi arc/topological insulator (TI) surface state at the interface of a ferromagnetic Mn$ _{3+x}$ Sn$ _{1-x}$ /Bi$ _{0.85}$ Sb$ _{0.15}$ heterostructure. High target utilization sputtering (HiTUS) was used to grow polycrystalline Mn$ _{3+x}$ Sn$ _{1-x}$ films and Mn$ _{3+x}$ Sn$ _{1-x}$ /Bi$ _{0.85}$ Sb$ _{0.15}$ heterostructures on thermally oxidized Si/SiO$ _2$ (100) substrates that exhibit the negative coefficient anomalous Hall effect (AHE) resulting from topological Weyl node transport. When various defects and impurities are introduced into these Mn$ _{3+x}$ Sn$ _{1-x}$ films, a ferromagnetic (FM) phase develops that practically eliminates the topological Weyl node conduction. These FM Mn$ _{3+x}$ Sn$ _{1-x}$ films exhibit large exchange bias effects below T=200 K that we attribute to the coexistence of a FM phase and the triangular antiferromagnetic (AFM) WSM phase. When Bi$ _{0.85}$ Sb$ _{0.15}$ overlayers are grown on the FM Mn$ _{3+x}$ Sn$ _{1-x}$ , the magnetotransport signal of Weyl node topological transport is restored, an effect we do not observe when replacing the Bi$ _{0.85}$ Sb$ _{0.15}$ TI with heavy metal overlayers. We attribute the restoration of the Weyl node topological transport to the formation of a hybridized topological state at the WSM/TI interface.
Materials Science (cond-mat.mtrl-sci)
Interaction-Split Edge Spectral Flow and Neutral Triplet Boundary Modes in a C = 2 Hubbard Pump
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2026-05-25 20:00 EDT
Yong-Feng Yang, Zhao-Rui Tian, Chen Cheng, Hong-Gang Luo
We show that a sliding spatial modulation of the on-site Hubbard interaction realizes a many-body Thouless pump whose boundary spectral flow is reconstructed by correlations. For a period-three Hubbard chain at filling $ \rho=2/3$ , density-matrix renormalization group (DMRG) calculations identify a correlated insulator with many-body Chern number $ C=+2$ , corresponding to two units of charge pumped per cycle. Its excitation spectrum separates the charge gap from the lowest neutral spin gap, revealing an interacting bulk response beyond a simple spin-degenerate band pump. Under open boundary conditions, this contrast becomes even more pronounced. A spin-degenerate Hartree/Aubry-André-Harper reference pump exhibits simultaneous edge flow in the two spin channels, whereas the full modulated Hubbard model suppresses the boundary doublon channel and splits the spectral flow into two distinct edge events. Between these events, the boundary charge is neutralized while a neutral, spinful triplet-like excitation is localized at the edge. The global $ \mu-U$ phase diagram reveals filling-dependent topology: the $ \rho=2/3$ regime remains in the $ C=+2$ sector, while $ \rho=4/3$ regime undergoes a spin-gap-closing transition from a $ C=-2$ pump to a distinct $ C=+1$ topological Mott pump.
Strongly Correlated Electrons (cond-mat.str-el)
7 pages, 4 figures, plus Supplemental Material (4 pages, 6 figures)
Multi-field Return Point Memory
New Submission | Statistical Mechanics (cond-mat.stat-mech) | 2026-05-25 20:00 EDT
Nathaniel Croce, Hossein Salahshoor, D. Zeb Rocklin
Non-equilibrium systems display memory, a dependence not merely on their present environment but on previously applied fields. Multistable systems such as spin glasses, martensites and granular matter have exponentially many microstates consistent with an applied field, making their rich dynamics difficult to control. Control and order can be achieved through the concept of partial ordering, which we here generalize to systems subject to multiple control fields. We demonstrate, within the model system of the zero-temperature Ising model, that this leads to return-point memory, in which an applied sequence of fields restores the hysteretic system not only to a previous magnetization, but to a previous exact microstate. The multiplicity of fields grants more precise and complex control of the system, with different classes of operations displaying commutative and noncommutative behavior. This grants new insight into how physical systems can remember, learn, and be trained.
Statistical Mechanics (cond-mat.stat-mech)
Orientable Surfactants on Thin Liquid Films: A Dynamic Density-Functional Theory Approach
New Submission | Statistical Mechanics (cond-mat.stat-mech) | 2026-05-25 20:00 EDT
Thin liquid films are ubiquitous across many natural and engineering systems, including films which are laden with surface active molecules, i.e. surfactants. The presence of surfactants may have a destabilising effect on the film owing to their influence on surface tension, the so-called Marangoni effect, which in turn can induce flows in the film. Classical thin-film models for surfactant-laden films lead to paradigmatic gradient dynamics equations governing the film height and surfactant concentration and have been widely studied. However, in all these works, which are based on fluid dynamics or nonequilibrium thermodynamics, the shape of surfactants is neglected, and they have been treated as symmetric point-like particles. In general, this is a drastic oversimplification, as surfactants are amphiphilic with a polar head-tail structure. To account for this effect we use elements from the statistical mechanics of classical fluids, namely density-functional theory (DFT), and its dynamic extension (DDFT). Starting from DDFT and under the long-wave approximation, we derive the pertinent thin-film equations with the surfactants treated as polar uniaxial particles. These are equations which govern the film height, as well as the surfactant concentration and polarisation field. They preserve the gradient dynamics form by appropriately defining the free energy, which contains the usual interfacial contributions, as well as further contributions from the polarisation field. In doing so, we uncover a novel form of a generalised surface tension that is dependent on the surfactant polarisation as well as concentration, and show that it arises in a thermodynamically consistent way.
Statistical Mechanics (cond-mat.stat-mech)
16 pages, 1 figure
Chirality-sensitive mobility and dissipation of Brownian motion on a helical landscape
New Submission | Statistical Mechanics (cond-mat.stat-mech) | 2026-05-25 20:00 EDT
Debankur Bhattacharyya, Abraham Nitzan
We study the Brownian dynamics and linear response of a particle with inertia moving in a 2-dimensional helical landscape imprinted on a cylindrical surface. In the harmonic well approximation, the deterministic motion separates into free propagation along the screw direction and harmonic motion in the transverse screw-normal direction. We show that for isotropic damping this simplification survives in the Langevin description, whereas anisotropic damping along the axial and angular directions couples the stochastic dynamics and destroys separability. The resulting anisotropic model is formulated as a linear Ornstein-Uhlenbeck process in phase space with a zero mode associated with diffusion along the screw coordinate, so that in an infinite system the full phase-space dynamics does not relax to a stationary distribution. To treat transport in this setting, we construct the stationary dynamics in the stable subspace obtained after projecting out the zero mode. This leads to a linear response theory for this system and yields closed analytical expressions for stationary time-correlation functions and the dynamical mobility tensor in both the time and frequency domains. The off-diagonal elements of the mobility tensor describe cross-response between axial forcing and angular motion, and between applied torque and axial transport. Consistent with time reversal symmetry, these cross mobilities are equal and provide a direct dynamical signature of the helical geometry. In addition, a simultaneous application of driving in both the axial and angular direction reveals asymmetry in energy dissipation rate due the helical landscape.
Statistical Mechanics (cond-mat.stat-mech), Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Mathematical Physics (math-ph), Chemical Physics (physics.chem-ph)
Orbital Selective Dirac-like States in EuAgAs Revealed by Polarization Dependent ARPES and DFT
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2026-05-25 20:00 EDT
Mohit Mudgal, Suman Nandi, Mohamed El Gazzah, Masashi Arita, Shin-ichiro Ideta, Nirmal J. Ghimire, Kenya Shimada, Anup Pradhan Sakhya
Magnetic topological semimetals provide a promising platform for emergent quantum phenomena driven by the interplay between magnetism and relativistic fermions, including anomalous transport effects and tunable topological phases. Here, we investigate the electronic structure and orbital character of EuAgAs, a magnetic topological Dirac semimetal candidate, using density functional theory (DFT) and polarization dependent angle resolved photoemission spectroscopy (ARPES). Fermi surface mapping and constant energy contours measured at 9 eV reveal ring like features that systematically expand with increasing binding energy, consistent with nearly linear low energy Dirac like dispersion. ARPES measurements at different photon energies hint at the presence of a van Hove singularity predicted by DFT calculations. Furthermore, this indicates that the photoemission matrix elements are highly sensitive to the excitation energy, allowing different photon energies to selectively probe distinct orbital characters. Polarization dependent ARPES measurements performed in s- and p-polarized geometries exhibit pronounced variations in spectral intensity, indicating symmetry selective orbital contributions to electronic states. These matrix element driven intensity modulations are well reproduced by DFT calculations. Furthermore, the observed Dirac like states remain nearly unchanged over the temperature range from 9 K to 30 K, suggesting that the magnetic ordering has minimal influence on the electronic structure. Our combined experimental and theoretical results provide detailed insight into the orbital selective electronic structure of EuAgAs and its implications for magnetic topological quantum states.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
Quantum critical collapse of a pinned vortex glass
New Submission | Superconductivity (cond-mat.supr-con) | 2026-05-25 20:00 EDT
David Perconte, Thibault Charpentier, Nikolaos Koutsopoulos, Kalpajit Roy, Nadjib Benchabane, Xiaoli Peng, Florent Blondelle, Frédéric Gay, Mikhail Feigel’man, Viktor Kabanov, Benjamin Sacépé
The interplay between disorder and vortex–vortex interactions in strongly disordered superconductors in a magnetic field can stabilize a vortex-glass state, characterized by strong pinning and the absence of positional order. Yet its role in the destruction of superconductivity at the field-driven superconductor–insulator transition has remained unresolved. Here we use plasmonic microwave spectroscopy of superconducting resonators patterned from amorphous indium oxide thin films to directly track the superfluid density up to the critical field $ B_c$ . We find an unexpected resilience of the superfluid density, which decreases only logarithmically over nearly three orders of magnitude in field, in stark contrast to the rapid power-law suppression expected for vortex lattices. We attribute this anomalously slow decay to a collective vortex-pinning mechanism counterintuitively enhanced by vortex–vortex interactions. The superfluid density then vanishes linearly at $ B_c$ , where independent magnetoresistance measurements identify a continuous quantum critical point, unlike the abrupt transition observed at zero field. We further uncover an exceptionally large nonlinear electromagnetic response of the vortex glass, manifested as a pronounced positive-Kerr effect with potential for quantum sensing. These results show how disorder controls the critical magnetic field and identify the vortex glass as the key intermediate state governing the magnetic-field-induced superconductor–insulator transition.
Superconductivity (cond-mat.supr-con), Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
Maintext and SI
Phase-dependent electronic structure of two-dimensional Ag layers at the graphene/SiC interface
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-05-25 20:00 EDT
Sawani Datta, Boyang Zheng, Arpit Jain, Kathrin Küster, Joshua A. Robinson, Vincent H. Crespi, Ulrich Starke
Intercalation at the graphene/SiC interface provides a controlled route to stabilize atomically thin layers with properties distinct from their bulk counterparts. In this platform, the structure and stability of the intercalated phase depend sensitively on the defect landscape of the starting substrate. For intercalated two-dimensional silver at the graphene/SiC interface, two phases have been observed: a phase epitaxial to the SiC lattice, Ag$ _{(1)}$ , readily obtained following the conventional intercalation method under ultra-high-vacuum conditions and extensively characterized, and a more densely packed phase, called Ag$ _{(2)}$ , which has remained largely unexplored. Here we report an in situ ultra-high-vacuum preparation method of the second phase intercalated at the graphene/SiC interface; this phase previously was prepared via high-pressure confinement heteroepitaxy. Low-energy electron diffraction shows that Ag$ _{(2)}$ is rotated by 30 degree relative to the SiC lattice and forms supercells, in contrast to the $ (1\times 1)$ epitaxial relation of Ag$ _{(1)}$ with SiC. High-resolution angle-resolved photoemission spectroscopy reveals a more rich Ag$ _{(2)}$ band dispersion compared to the Ag$ _{(1)}$ . In density functional theory calculations, by defining the unfolding entropy which, in a quantified way, finds that the band structure of Ag$ _{(2)}$ is more suitable to be unfolded to the SiC primitive cell, and the resulting unfolded band dispersion is in great agreement with the experimental data. We further show that the different intercalated Ag phases tune the electronic properties of the overlying quasi-free-standing graphene layer differently: compared with Ag$ _{(1)}$ , Ag$ _{(2)}$ yields an $ \sim$ 1.75 times higher charge carrier density and modifies the charge-plasmon interaction of the graphene layer, indicating a change in effective screening at the interface.
Materials Science (cond-mat.mtrl-sci)
13 pages, 7 figures, Supplementary information is in the ancillary file
Photoluminescent Tetragonal Tb-doped Pb2P2O7
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-05-25 20:00 EDT
Yong Liu, Wenhua Bi, Alla Arakcheeva, Arnaud Magrez
In this study, we report the synthesis and characterization of a novel tetragonal polymorph of Tb-doped Pb2P2O7. Single-crystal X-ray diffraction confirms the stabilization of the P41 and P43 enantiomorphs at room temperature due to the incorporation of Tb3+ ions. Optical investigations reveal green photoluminescence from the characteristic 5D4 -> 7Fj (J = 1-5) transitions of Tb3+, with each emission split due to the crystal field effect, indicating the presence of Tb3+ in multiple coordination environments. The power dependence of the PL intensity follows a linear power-law behavior, suggesting a one-photon excitation process. Temperature-dependent PL measurements show an initial increase in intensity up to 125C, attributed to energy transfer from structural defects, followed by thermal quenching above this temperature. Structural stability at elevated temperatures is confirmed via high-temperature X-ray diffraction (XRD), showing no phase transitions before melting at approximately 800C. These findings highlight the potential of tetragonal Tb-doped Pb2P2O7 as a new class of photoluminescent material.
Materials Science (cond-mat.mtrl-sci)
Time crystals in cavity-BEC systems
New Submission | Quantum Gases (cond-mat.quant-gas) | 2026-05-25 20:00 EDT
Jayson G. Cosme, Ludwig Mathey
The understanding of light-induced dynamical states continues to be a challenging and fruitful pursuit of science. This pursuit is supported by quantum simulation of dynamical phenomena, e.g., in ultracold atom systems. Typically, ultracold atom dynamics are read out destructively, via time-of-flight imaging, limiting a detailed analysis. However, atom-cavity systems provide a real-time readout of the photonic state via photon emission from the cavity, making the system ideally suited for the simulation of dynamical phenomena. Here, we review three distinct time crystalline states, predicted and realized in a cavity-BEC system. We give an example for each of them, based on minimal few-mode models. We characterize the time crystalline states via correlation functions of the cavity mode, and characteristic momentum modes of the condensate. This supports a clear distinction between these time crystals. More generally, the sequence of studies reviewed here, serves as a blueprint for setting up minimal models and their characterization, for dynamical phenomena.
Quantum Gases (cond-mat.quant-gas), Quantum Physics (quant-ph)
14 pages, 13 figures