Deterministic synthesis of borophene remains challenging because many polymorphs compete during nucleation and growth. Here we combine a reactive machine-learned interatomic potential with grand-canonical Monte Carlo simulations and data-driven structural classification to track borophene formation from early nuclei to extended layers on Ag(111) and Ag(100). We build temperature-pressure substrate growth maps and resolve how vacancy motifs, phase intermixing and seed structure govern polymorph selection. The simulations reproduce key experimental trends, including the prevalence of $β_{12}$/$χ_3$ phases and their temperature-dependent competition, while revealing kinetic pathways that connect metastable nuclei to long-range order. We identify conditions that suppress competing motifs and promote targeted phases, providing actionable synthesis windows. These results establish a predictive framework for directing borophene growth and, more broadly, for controlling polymorphism in low-dimensional materials by coupling atomistic simulation with machine-learning-enabled phase recognition.

We present the results of a resonant X-ray diffraction experiment, resolving both charge and spin textures in the intermetallic topological magnet Eu(Al$_{1-x}$Ga$_{x}$)$_4$, $x$ = 0.1. Below $\approx$ 75 K the system develops a charge density wave (CDW) with propagation vector kCDW ~ (0, 0, 0.18). The CDW order parameter grows monotonically on cooling until ~ 15 K, when a sudden decrease in the CDW amplitude occurs. Pairs of magnetic satellites of the (0, 0, 8) Bragg reflection corresponding to two distinct domains, k = ($\pm δ_\text{m}$, 0, 0), k2 = (0, $\pmδ_\text{m}$, 0), $δ_\text{m} = 0.2002(4)$ were studied at the Eu L3 edge, appearing below TN = 14.8 K. Our measurement of TN is exactly coincident with the sudden drop in the CDW amplitude, which suggests strong coupling between the charge and spin orders, as observed in other compounds of the Eu(Al$_{1-x}$Ga$_{x}$)$_4$ series. Azimuthal measurements revealed a single helical spin arrangement with an elliptical envelope of $μ_\text{Y}/μ_\text{Z}$ = 1.19(6) for the k2 domain, and a tilted helical (helicoidal) spin arrangement for the k1 domain, with $μ_\text{Y}/μ_\text{Z}$ = 1.14(4) and $μ_\text{X}/μ_\text{Z}$ = 0.20(2) that may be hidden for the k2 domain due to multiple subdomains. Temperature evolution of the magnetic satellite intensities in linear and circularly polarised light found the respective ratio to be invariant with temperature, suggesting a single magnetic phase below TN. This behaviour is unlike the x = 0 material, in which a spin density wave forms first, transitioning to a helical ground state on cooling through intermediate phases. Future theoretical work on the Eu electronic ground state, supported by related experiments, will help understand the effects of Ga substitution on the evolution of the magnetic structure.

X-ray photoemission spectroscopy (XPS) is a powerful technique to gain insight into the chemical properties of oxide surfaces. However, the interpretation of XPS spectra is notoriously difficult as realistic surfaces contain different terminations, reconstructions, adsorbates and defects all of which leave (potentially overlapping) spectroscopic fingerprints. To address this challenge, we present a first-principles approach based on the Z+1 method that allows us to predict XPS spectra of oxide surfaces which can directly be compared to experimental measurements. We present results for different SnO$_2$ (110) surfaces: the stoichiometric surface, surfaces with different types of vacancies (one of which is the fully reduced surface) and also the fully reduced surface with adsorbed OH and O$_2$ molecules. For these systems, we calculate the O 1s core-electron binding energies of all oxygen atoms and then use this to predict the XPS spectrum. We find that the fully reduced surface gives rise to a highly symmetric peak shape in agreement with recent XPS measurements. In contrast, the spectrum of the stoichiometric surface exhibits an additional feature at low binding energies caused by the bridging oxygen atoms at the surface. For the reduced surface with OH and O$_2$ adsorbates, the spectrum exhibits additional features at higher binding energies. The predicted spectra are in good agreement with experimental results obtained for reduced surfaces that have been exposed to oxygen gas. The presented method is general and can be straightforwardly applied to other surfaces.

The quantitative detection of paramagnetic molecular oxygen (O2) in gas mixtures using optically detected magnetic resonance (ODMR) from negatively charged nitrogen-vacancy (NV-) centers in fluorescent nanodiamonds is described. Fluorescent nanodiamonds approximately 70 nm in diameter were deposited on the glass surface of a microfluidic channel, and the oxygen concentration varied from 0 to 100% (0 to 760 mmHg O2 partial pressure) by mixing O2 and N2 gases at ambient pressure. Continuous-wave (CW) ODMR contrast was measured using a double-modulation (lock-in) detection scheme applied to both optical excitation and microwave drives. The ODMR contrast decreases linearly with oxygen partial pressure, with a sensitivity coefficient k of (-10.1 +/- 0.3) x 10^-4 % mmHg^-1. The oxygen detection limit of the experimental setup was estimated to be approximately 8 mmHg O2 partial pressure (corresponding to about 1% O2 in the gas mixture). Cycling of the content of O2 in the gas mixture in the range of 0-5% revealed slight hysteresis and corresponding repeatability of 0.006 in percent ODMR contrast. The observed fluorescence quenching and relatively slow response (ranging from several to tens of minutes) upon changes in oxygen concentration suggest that physisorption of gas molecules on the nanodiamond surfaces contributes to equilibration dynamics. The applicability of the nanodiamond-based oxygen quantum sensor was further demonstrated by detecting transient bursts of molecular oxygen generated by enzyme-catalyzed decomposition of hydrogen peroxide.

Micromechanical testing enables small-scale fracture energy measurements, but values depend strongly on geometry and specimen preparation. Here, the fracture energy of the single-crystal 6H-SiC {10-10} plane was measured using microscale double cantilever beam (DCB) and single cantilever beam (SCB) geometries. DCBs showed stable crack growth under displacement control and obtained 7.5 +- 0.3 J/m2. In contrast, SCBs notched by a Ga focused ion beam gave fracture energies over twice this value, indicating Ga implantation and near-notch residual stresses. Increasing the final notching current increased the measured fracture energy further. Although near-cryogenic notching limited ion-beam-induced damage, it did not reconcile SCB-derived values with DCB test results. Vacuum annealing substantially lowered the fracture energy and brought SCB results into close agreement with DCB measurements, whereas annealing in argon was less effective. Our findings highlight the importance of careful sample preparation and testing geometry selection for reliable fracture property measurement in ceramic materials.

Raman spectroscopy is one of the most accessible vibrational probes in materials laboratories, but its forward problem (structure to spectrum) is bottlenecked by the cost of density functional perturbation theory, and its inverse problem (spectrum to structure) typically relies on retrieval against curated references. We introduce RamanGPT, a deep-learning framework that addresses both directions for crystalline inorganic materials. The forward model, an Atomistic Line Graph Neural Network (ALIGNN), is trained on the 5{,}099-material Computational Raman Database and predicts 200-bin spectra over 50-1000~cm$^{-1}$ with 42.5\% having a cosine similarity greater than or equal to 0.354 suggesting qualitative features of the target spectrum. The model also shows some qualitative agreement with the approximate features and appearance of similar relative intensity of the modes to an experimental measurement of metallic 1T VSe$_{2}$, a system absent from the training set. The inverse model fine-tunes a large language model via Quantized Low-Rank Adaptation on Raman-plus-formula prompts, recovering lattice parameters with mean absolute errors of 1.14-2.16~Å and reduced-formula consistency of 86.8\% on 508 held-out materials. A cosine-similarity matcher and an inverse$\rightarrow$relax$\rightarrow$forward consistency loop are deployed at https://atomgpt.org/raman.

We analytically derive the continuous limit of the Cellular Potts Model (CPM) for a one-dimensional cell subjected to constant and run-and-tumble driving forces. By coarse-graining the discrete lattice dynamics, we obtain the Fokker-Planck equations governing the cell's size and center-of-mass position. We show that in the low-force regime, the cell dynamics are accurately described by an overdamped Langevin equation. Beyond this regime, we expose intrinsic algorithmic artifacts, including a force-dependent diffusion coefficient, a non-linear force-velocity relationship, and the breakdown of the Einstein relation. We demonstrate that replacing the conventional Metropolis update rule with Glauber dynamics significantly mitigates these artifacts, broadening the physically valid parameter space. Our exact results bridge the gap between lattice-based simulations and continuous active matter models.

Iron-rhodium (FeRh) has a first-order phase transition near room temperature between antiferromagnetic (AFM) and ferromagnetic (FM) phases, making it a promising material for magnetic memory technologies like heat-assisted magnetic recording (HAMR). It has a comparatively sharper phase transition and lower writing temperature than alternative materials, implying less thermal engineering constraints and an increase in write/read head lifetime. Despite great effort, however, AFM-based magnetic memory using FeRh has not yet been realized. Here, we employ both wide-field and scanning nanoscale quantum diamond microscopes (QDMs) to image directly the magnetic field of a patterned FeRh thin film structure under ambient conditions, demonstrating a magnetic recording technique that is reliable and robust. We experimentally identify coupling between the Néel and magnetization vector directions; and also, that the magnetic orientation of the FM phase uniquely determines the Néel vector in the AFM phase, due to pinned uncompensated magnetic moments (UMMs) in the FeRh structure. Thus, the magnetic orientation is maintained when the system is cycled between AFM and FM phases, providing the foundation for a practical, AFM-based magnetic memory.

The Hubbard model on the honeycomb lattice is a pristine realisation of a semimetal-to-insulator Mott transition belonging to the Gross-Neveu O(3) universality class. We couple this system to a single linearly polarised cavity photon mode. The light-matter coupling is such that the photon number remains an intensive quantity as is the case for an empty cavity. For this interacting light-matter model, we formulate a negative-sign-free fermion quantum Monte Carlo algorithm that allows for bias-free results on finite system sizes. Our numerical results show that the coupling to the cavity is irrelevant at criticality, even at strong electron-photon coupling. On the other hand, we observe, and show analytically, that the photon spectral function couples to the optical conductivity of the electronic system. The cavity photons thereby undergo a Mott transition, and the photon spectral function acts as a contact-free non-invasive probe for Mott criticality.

Mechanical energy accelerates many physicochemical processes, including materials syntheses that are hard to produce with thermal energy alone. However, physical understanding connecting applied mechanical forces with internal stresses and ensuing reaction mechanisms is lacking. Here we demonstrate mechanical force-enabled synthesis and nanoscale patterning to metallize a two-dimensional (2D) material, producing an atomically-thin superconducting material. Localized force applied by atomic force microscope tips to van der Waals (vdW) encapsulated stacks of 2D bilayer MoTe2 and adjacent source Pd guides 2D Pd7MoTe2 growth with 50 nm lateral resolution. Force accelerates reaction kinetics exponentially per Eyring's stress-assisted thermal activation model, reducing synthesis temperatures from ~200 °C to near-room temperature. Finite element simulations, density functional theory, and ab-initio grand canonical Monte Carlo calculations show that tip-induced compression facilitates Pd chemisorption to tensile-strained MoTe2 that converts to uniform Pd7MoTe2. This demonstrates a new, generalizable paradigm for nanoscale synthesis of quantum materials, and high-precision engineering of superconductivity.

Unlocking superconductivity in intrinsically non-superconducting noble metals (Au, Ag, Cu) represents a fundamental challenge in low-dimensional physics. While quantum confinement in the atomically thin limit is known to trigger emergent superconductivity, strategies to amplify this marginal effect to experimentally accessible temperatures remain a key open question. Using first-principles calculations, we establish a unified framework linking intrinsic confinement effects with interface engineering in noble metal films. We reveal that intrinsic superconductivity is element-specific: it is suppressed in Ag by a stiff phonon spectrum, but emerges in trilayer Cu ($T_{\rm C} \approx 0.78$ K) and pentalayer Au ($0.63$ K) driven by confinement-induced density-of-states (DOS) enhancement and phonon softening, respectively. In h-BN/Cu(111) heterostructures, $T_{\rm C}$ is critically dictated by the interfacial stacking configuration. We identify the thermodynamically stable N-bonded interface as a reliable platform for accessible superconductivity ($T_{\rm C} \approx 3.23$ K), whereas manipulating the system into a metastable B-bonded configuration boosts $T_{\rm C}$ to $7.00$ K. This enhancement originates from a B-bonded-induced Lifshitz transition, where the Fermi surface forms a tangential contact with the Brillouin zone boundary at the M point, enhancing electron-phonon coupling beyond DOS effects. Our work unifies the understanding of intrinsic two-dimensional superconductivity with atomistic interface design, offering a blueprint for functionalizing noble metals as emergent superconductors.

We employ terahertz Faraday magneto-optical spectroscopy to probe the relaxation dynamics of quantized helical Caroli-de Gennes-Matricon (CdGM) states in epitaxial FeTe$_{1-x}$Se$_x$ thin films, nodeless multiband superconductors with short coherence lengths in the moderately clean limit. By exploiting polarization-selective optical transitions, we directly resolve the helicity and band origin of vortex-core quasiparticles. We observe long-lived CdGM resonances with opposite circular polarizations for electron- and hole-like bands. This enables independent, band-resolved determination of quasiparticle lifetimes, vortex masses, coherence lengths, and upper critical fields, and reveals their systematic evolution with isovalent substitution. The results establish terahertz magneto-optics as a direct probe of helical vortex-core excitations and provide dynamical evidence for multiband CdGM states in iron-based superconductors.

Collective dynamics is an important out-of-equilibrium feature of quantum coherent states and usually reflects the intrinsic properties of the state. Collapse and revival (CR) dynamics of phase coherence is a well-known example for bosonic coherent states, which is usually induced by applying a quench. Previous studies have shown that the CR frequency is governed solely by interactions, even in the presence of a tilt quench. However, whether such interaction-dominated oscillation is a universal feature remains unknown. In this work, we show that an ensemble of one-dimensional bosons can undergo two-mode CR, with frequencies set by both the interaction and the tilt, particularly when the tilt is weaker than the interaction. The newly discovered tilt mode is enabled by tunneling between lattice sites. When the two modes coexist, the amplitudes of both modes exhibit universal linear scaling for various tilts. These findings clarify the general features of CR dynamics in tilted lattice models and the underlying mechanism, and provide deeper insight into collective dynamics in correlated systems.

Neutron spectroscopy is a powerful technique for determining the vibrational states of matter. Instruments with fixed geometry may measure inelastic scattering at a limited set of angles, producing a 1-D spectrum $S(ω)$. Such measurements are usually simulated in a DOS-like semi-analytic incoherent approximation, well-established for study of bending/stretching modes in molecular crystals. In this work we empirically test the simulation method for two ceramics with industrial electronic applications that act as "worst-case" systems. The phonon scattering from $α$-SiC and $β$-Ga$_2$O$_3$ is coherent, depends on momentum transfer $Q$ and sits in frequencies below the typical "fingerprint" range of molecular spectroscopy. Inelastic neutron-scattering measurements of powders were performed with two contrasting spectrometers at cryogenic and elevated temperatures, and simulations performed using a variety of density-functional approximations. We find that for 1-D powder spectra from a compact instrument, the approximate simulations are easily comparable with experimental spectra and give similar results to a more computationally-intensive numerical sampling of the coherent spectrum. Given the success with these systems, the approximate method appears to be suitable for modelling inelastic neutron scattering by harmonic phonons of almost any powder sample with this technique. When a $Q$-resolved instrument is used to collect the 2-D dynamical structure factor $S(Q,ω)$, numerical averaging is still required to capture phonon features. Our simulations of inelastic scattering from $α$-SiC in the 6H polytype using the PBEsol functional gave good agreement with the experiments. By contrast, the RSCAN functional gave the best agreement with the measured spectra of $β$-Ga$_2$O$_3$ and is recommended for future work on the lattice dynamics of this material.

Understanding lithium (Li) ordering and dynamics is foundational in energy storage. X-ray based experimental methods do not simultaneously provide atomic structure information together with chemical composition and local bonding information for lithium in solids. Here we employ scanning transmission electron microscopy (STEM) and combine imaging, spectroscopy, and diffraction within a single experiment, to observe, in situ, an all-solid-state electrochemical cell. By integrating multimodal STEM with other complementary techniques, we report a complete mapping of lithium intercalation in a layered system, LaTe3. We identify three ordered phases of LixLaTe3 with x ranging from 1/3 to 3 with in-plane strain of up to 5%. At a very high lithium concentration of Li3LaTe3, we discover an unexpected three-layer, superdense lithium phase with tetragonal symmetry occupying the van der Waals gap. This represents a new Li phase that is reversible. Our multimodal approach thus enables complete tracking of lithium ordering and dynamics, important for next-generation energy storage applications.

We investigate the kinetics of wetting ridge growth and droplet cloaking on lubricant-infused polymer brushes using a combination of experiments, molecular dynamics simulations, and theoretical modeling. We focus on three representative systems: DMSO-water on hexadecane-swollen PLMA (D-H), water on hexadecane-swollen PLMA (W-H), and water on PDMS (W-S). The dynamics are governed by the interplay between interfacial thermodynamics, brush elasticity, and transport of lubricant within the brush. Ridge growth is accompanied by the formation of depletion zones both beneath and outside the drop. This leads to a progressive slowdown governed by the need to transport lubricant through the brush. At sufficiently high swelling, we observe local separation of oil from the brush within the ridge, providing an additional mechanism for lubricant depletion. To rationalize these observations, we develop a continuum diffusion model based on the free energy of the brush and its coupling to the contact line. The model quantitatively captures the growth of the wetting ridge at intermediate and late times, demonstrating that the kinetics are largely controlled by diffusive transport within the brush.

Sliding ferroelectricity in van der Waals materials shows great potential for designing robust memory devices. However, its thermodynamic behaviors and the coupling with certain quantum effects remain largely unexplored. Here, we demonstrate ferroelectric control over quantum nonlinear transport in a hexagonal boron nitride (hBN) encapsulated twisted double-bilayer graphene moiré heterostructure. The ferroelectricity is attributed to the presence of rhombohedral stacking in the top hBN, confirmed by both electrical transport and optical second harmonic generation (SHG) measurements. Remarkably, the polarization magnitude remains temperature-independent across 1.7-200 K, while nucleation time exhibits thermally activated behavior, decreasing with increasing temperature. Furthermore, we demonstrate a ferroelectric-switchable nonlinear Hall effect, attributed to the chiral scattering induced by Berry curvature, with outstanding fatigue-resistant and nonvolatility, demonstrating direct coupling between sliding ferroelectricity and quantum geometric properties. Our results establish sliding ferroelectrics as a platform for exploring electrically programmable Berry curvature physics.

Nonreciprocal interactions in active matter provide interesting structure and dynamics. Here we investigate chemophoretic systems in which nonreciprocity arises from the asymmetric coupling between agents: first species produces certain chemicals and the other phoretically responds to it. This leads to phase separation at varying scales. Our study uncovers a re-entrant steady-state phase diagram as the nature of the coupling changes from chemoattractive to chemorepulsive character. Chemoattraction provides sustained domain growth, leading to macrophase separation via cluster coalescence. Aggregation in the chemorepulsive case, on the other hand, leads to a steady-state situation that displays phase separation only at a microscale, owing to strong caging effect and frequent fragmentation. The overall far-from-steady-state dynamics is quantified via calculations of growth exponents, cluster transition matrices, and mean-squared displacements.

Twisted carbon nanotubes support phonons involving not only torsion, naturally associated with microrotation, but also radial breathing, which requires a scalar stretch degree of freedom. We derive an effective microstretch theory for these modes starting from nonlinear elasticity on a cylindrical surface. By linearizing the equation of motion around a uniformly twisted equilibrium configuration, we obtain the dynamical matrix for the twisting, longitudinal, and radial-breathing modes. This matrix coincides with that of a one-dimensional microstretch theory, and the corresponding elastic constants are expressed in terms of the Lamé constants, the nanotube radius, and the twist rate. The twist generates chiral couplings in the effective theory, which hybridize the three modes and open an anticrossing in the phonon dispersion. These results provide a microscopic basis for the microstretch description of phonons in twisted carbon nanotubes and clarify how structural chirality enters the effective couplings.

In altermagnets and fully compensated ferrimagnets, not only the electron band but also the magnon band exhibits spin splitting without net magnetization, which enables thermal activation of the magnon spin current. Here, we theoretically investigate magnetic field effects on the magnon properties of these antiferromagnets in the presence of a weak easy-axis anisotropy which makes the collinear states robust against the magnetic field. For the altermagnet and compensated ferrimagnet, we analyze a 2 sublattice order in the $J_1$-$J_2$-$J_2^\prime$ model on the square lattice and a triple-${\bf Q}$ 12-sublattice order in the $J_1$-$J_3$ model on the kagome lattice, respectively, each accompanied by $d$-wave and $s$-wave spin splitting at zero field. It is shown that for positive (negative) magnetic field $H$ whose energy scale is smaller than the anisotropy gap, the up- and down-spin magnon bands are shifted to lower (higher) and higher (lower) energies, respectively, similarly to the Zeeman coupling in electron systems. In the altermagnet, with increasing field, the $d$-wave splitting tends to be deformed into the $s$-wave one, which is reflected as the change in the direction of the spin current generated by thermal gradient. In the compensated ferrimagnet, the $s$-wave nature, i.e., the population imbalance between the up- and down-spin magnons at $H=0$, results in an asymmetric field dependence of the longitudinal spin and thermal conductivities.

The Mpemba effect, a counterintuitive phenomenon where a hotter system relaxes faster than a colder one, has been widely observed in various nonequilibrium systems. Despite this progress, the fundamental structural features of the energy landscape required for its emergence remain a subject of debate. In this study, we investigate the conditions for the Mpemba effect within one-dimensional overdamped Langevin dynamics. We classify the potential landscapes based on the presence of single or double wells, their symmetry properties, and the existence of walls. We establish that the existence of the effect is primarily driven by the presence of boundaries, either hard or soft, rather than the specific internal structure of the potential landscape, such as metastability or the number of minima. By employing a spectral decomposition of the Fokker-Planck operator, we analyze the behavior of the first nontrivial eigenmode and demonstrate that its derivative acts as a Dirac delta peak in the low-temperature regime. This helps us elucidate the mechanism underlying the Mpemba effect: it appears as the interplay between this behavior and the initial population dynamics in a non-trivial way induced by the presence of the wall. Our analysis provides a unified classification across single- and double-well potentials, highlighting the crucial role of boundary conditions and asymmetry. Furthermore, we demonstrate that this framework allows for the engineering of potential landscapes capable of producing multistage Mpemba transitions.

Two-dimensional Chern insulators support topologically protected, chiral edge currents, and these can be detected in experiments with ultracold atoms in optical lattices. It has previously been shown that one can populate a selected group of edge states of a Chern insulator by transferring particles from a reservoir. Here, we numerically investigate the effect of performing an instantaneous, projective measurement on the reservoir before the reservoir is discarded. In this way, the final state of the system is pure and described by a wavefunction. We also show that quite likely measurement outcomes can help to increase the final number or percentage of particles in the chiral edge states through postselection. Without the measurement step, the physics can be described in terms of single-particle physics. The measurement significantly complicates the description. By appropriately rewriting the analytical expressions, we show that measurement probabilities, expectation values, averages of expectation values, and purity can nevertheless be computed from the state before the measurement in a way that scales only linearly with the number of lattice sites for a fixed number of particles. This enables us to investigate a setup with, for instance, 14 particles and 198 lattice sites numerically. The approach applies generally to noninteracting, fermionic models that conserve the number of particles.

We study the critical properties of the topological Anderson phase transition in a strongly disordered Chern insulator, separating the topological phase from a trivial Anderson insulator. We show that the transition is characterized by a non-zero electrical conductance and by the emergence of a critical length scale in the real-space profile of the local Chern marker. From this, we extract the correlation-length and the dynamical critical exponents, which are consistent with those of non-interacting models of the integer quantum Hall effect. We then ramp the disorder strength across the transition and study the ensuing dynamics. In contrast to clean topological systems, we find that the excitation density does not follow the Kibble-Zurek scaling. The non-equilibrium length scale associated with the local Chern marker is decoupled from the generation of excitations. For studied system sizes, we find it to be close to the Kibble-Zurek prediction for the topological-to-trivial quench, while it deviates from it for the reverse direction.

Finding the global minimum of a potential energy surface is a fundamental challenge in materials science, with applications ranging from protein folding to cluster physics and, more broadly, to systems in which the number of (meta)stable configurations grows prohibitively large. In recent decades, quantum annealing (QA) has emerged as a promising global optimization strategy, exploiting quantum fluctuations in contrast to the thermal fluctuations that drive its classical counterpart. Here, we introduce a novel implementation of QA based on path-integral molecular dynamics, an efficient and well-established framework for sampling the quantum nuclear density without the need to manipulate many-body wavefunctions explicitly. While retaining the flexibility and simplicity of molecular dynamics simulations, this quantum-annealing protocol delivers strong performance across a wide range of atomic systems, simulated by either empirical force fields or machine-learning interatomic potentials. The method can be used either as a global optimizer of the potential-energy surface, or as a quantum-informed structure-search strategy in which nuclear quantum effects are included directly in the optimization workflow -- a feature particularly relevant for materials such as high-pressure hydrides.

The non-Hermitian skin effect (NHSE) represents one of the most distinctive phenomena in non-Hermitian physics. Here, we uncover a new drag-induced NHSE mechanism in interacting Bose--Fermi mixtures where only bosons and not fermions experience asymmetric hoppings. %While bosons exhibit intrinsic skin localization due to asymmetric hopping, fermions remain Hermitian in isolation and do not independently support NHSE. We show that strong Bose--Fermi interactions enable fermions to inherit boundary accumulation through correlated bound states. %In the few-body regime, The interplay of interactions, quantum statistics, and non-Hermitian dynamics gives rise to an interaction-induced blockade mechanism, leading to highly asymmetric fermionic transport. We demonstrate that the drag-induced NHSE is dynamically stable and propose a feasible realization in ultracold Bose--Fermi mixtures with Floquet-engineered asymmetric tunneling. Our results establish a general interaction-mediated mechanism for emergent non-Hermitian localization in hybrid quantum matter.

A controllable phase shifter is a key component for spin-wave-based logic and information processing devices. Here, we propose a domain-wall-position-controlled spin-wave phase shifter that exploits dipolar coupling between two closely spaced waveguides to enable continuous phase tuning over a range approaching 360degrees while keeping the spin-wave amplitude constant. Using micromagnetic simulations, we model a bias-free hybrid structure composed of a nanoscale waveguide magnetostatically coupled to a half-ring-shaped structure both made from bismuth-doped yttrium iron garnet with strong perpendicular magnetic anisotropy. Displacing a domain wall in the half-ring modulates the dispersion relation in the adjacent straight waveguide due to the changed magnetostatic interaction, providing a compact and dynamically reconfigurable phase-shifting mechanism. This approach offers precise and non-volatile control over spin-wave propagation and is compatible with energy-efficient magnonic logic architectures.

The evolution of interfacial atomic structures critically influences the friction and wear behavior of carbon-based materials. However, how the characteristic length scale of friction-induced sp\textsuperscript{2} reconstruction governs macroscopic wear remains poorly understood, particularly for diamond and amorphous carbon where the interfacial graphitization modes differ fundamentally. In this work, we develop a machine learning potential for these carbon systems and investigate the structural evolution at interfaces in both diamond/diamond and amorphous/amorphous carbon systems using molecular dynamics simulations. Our results reveal distinct atomic-scale characteristics of graphitization at the two interfaces. Diamond interfaces develop a laterally continuous sp\textsuperscript{2} reconstruction layer with a characteristic length of 30--45~Å, while amorphous carbon interfaces form only fully isolated sp\textsuperscript{2} patches of 8--12~Å. This disparity in characteristic length scale determines the density of weakly bonded interfacial atoms left outside the reconstruction layer, thereby directly dictating the macroscopic wear rate. Based on these insights, we propose a strategy to regulate friction-induced graphitization in diamond coatings by protecting specific crystallographic orientations, such as the (111) close-packed planes. This work bridges the gap between atomic-scale interfacial structure and macroscopic tribological performance, offering mechanistic guidelines for the rational design of wear-resistant carbon-based coatings.

The Ge-Sb-Te (GST) superlattice phase-change material is a promising candidate for overcoming the high power-consumption of phase-change memory (PCM). However, the working mechanism of the superlattice PCM remains controversial. Partial amorphization, which is currently considered the most plausible mechanism, remains hotly debated: how does the partially amorphized GST recrystallize into its superlattice phase instead of the conventionally expected cubic phase? Here, we address this issue using large-scale molecular dynamics simulations enabled by a machine-learning interatomic potential. Starting from a partially melted GST superlattice, we demonstrate that the residual crystalline regions serve as nuclei, enabling the amorphous GST to recrystallize directly into the superlattice phase without passing through the intermediate cubic phase. Moreover, the recrystallized phase is not an ideal superlattice, but rather a structurally ordered and chemically disordered defective superlattice characterized by anti-site defects and stacking faults. The defective superlattice region is also more susceptible to melting than the defect-free superlattice, and thereby can act as the active region of the PCM device. These results help to clarify the longstanding debates concerning the mechanism of superlattice-based PCM.

Within the full replica-symmetry-breaking (fullRSB) solution of dense hard spheres in infinite dimension, Charbonneau, Kurchan, Parisi, Urbani, and Zamponi (CKPUZ; J.Stat.Mech.P10009, 2014) introduced three critical exponents $a$, $b$, $c$ governing the matching region of the fullRSB profile near the jamming transition. These exponents satisfy two scaling relations. The first, $b=(1+c)/2$, was established analytically by the diffusion-drift balance in the scaling ansatz. The second, $a+b=1$, was observed numerically to arbitrary precision but could not be proven. The exponents $a,b,c$ of the scaling fullRSB ansatz are related to the physical exponents $α, θ, κ$ that control the gap, force, and overlap distributions by the relations $α=a/b$, $θ=(c-a)/(b-c)$, $κ=c+1$. Crucially, the relation $a+b=1$ yields the scaling relations $α=1/(2+θ)$ and $κ=2-2/(3+θ)$ predicted on independent grounds by the mechanical-marginal-stability arguments of Wyart and collaborators. Here, we give an analytic proof of the identity $a+b=1$ from the scaling fullRSB equations. The proof was obtained through interaction with Claude (Sonnet 4.6 and Opus 4.7) and verified by us.

Strained epitaxial films of the antiferromagnetic orthoferrite LaFeO3 offer a promising platform for antiferromagnetic spintronics, yet their magnetic switching behavior and domain structure have remained largely unexplored due to the small magnitude of the weak ferromagnetic moment. Here, we demonstrate that longitudinal magneto-optical Kerr effect (MOKE) measurements provide a sensitive and direct probe of magnetic switching and domain processes in coherently strained LaFeO3 thin films grown on orthorhombic substrates. By employing DyScO3(110), GdScO3(110), and NdGaO3(110) substrates, we achieve straincontrolled, largely twin-free growth and identify the orientation of the orthorhombic c-axis through the presence or absence of a longitudinal MOKE signal. Compressively strained films exhibit large Kerr signals, rectangular hysteresis loops, and magnetic single-domain remanence over macroscopic areas. Tensile strain on orthorhombic substrates is associated with two competing structural effects on thin film orientation; in-plane magnetization has been identified in some films on GdScO3(110) by MOKE. Angle-dependent MOKE hysteresis follows the Kondorsky model, indicating domain-wall-controlled switching analogous to bulk single crystals. Kerr microscopy reveals abrupt domain nucleation and rapid domain-wall motion, with defects acting as pinning centers and governing the coercive field. Our results establish MOKE as an efficient optical tool for identifying orthorhombic orientation, probing magnetic switching of coupled weak magnetization and Neel vectors, and accessing domain dynamics in LaFeO3 films. This provides a foundation for strain-engineered orthoferrite thin films in antiferromagnetic spintronics and magnonics.