arXane › Physics › Condensed Matter
Wednesday, 4 November 2026: 28 new papers, 14 cross-lists and 14 replacements in Materials Science (cond-mat.mtrl-sci), in arXiv's order, with full abstracts. The same papers as arXiv's own listing, set as a newspaper; every title links to arXiv.
Long-range interactions in machine-learning interatomic potentials are commonly treated by coupling learned sources through either a prescribed electrostatic kernel or a learned but configuration-independent one. Whether such a kernel suffices depends on the underlying screened interaction. We address this question by using Fourier neural operators (FNOs) to learn how latent source fields, built from the descriptors of a local backbone (here MACE), interact across the simulation cell. For a synthetic ionic system with tunable screening, a prescribed Coulomb kernel underestimates the long-wavelength charge fluctuations by 43% under strong screening, whereas the FNO reproduces them within 3% and recovers 95-99% of the variance of the residual left by the local backbone. A linear FNO, which learns a configuration-independent kernel, performs equally well in the homogeneous case. Under inhomogeneous screening, rearranging the remote medium modulates the coupling between distant ions, a dependence that no configuration-independent kernel can represent. Among the models tested, only the nonlinear FNO responds to this modulation, and its force errors are 27-41% lower than those of configuration-independent models. In first-principles benchmarks of liquid water, lithium lanthanum zirconate, and Au2/MgO(001), MACE-FNO is comparable to a prescribed-kernel model for the bulk systems and more accurate for the interface. It further captures the reversal of the Au2 wetting preference induced by remote Al dopants, with deviations below 5 meV per cell from density functional theory. These results indicate that a configuration-dependent kernel, as learned by FNOs, becomes necessary once the screening medium varies, even though the energy remains quadratic in the charges for a fixed medium.
Lattice-mismatched heteroepitaxy is limited by misfit dislocations, threading defects, and residual strain generated at buried interfaces. Here, we show that current-confined electrochemistry transforms the Ge/Si heterointerface into a laterally continuous nanometric free surface while preserving the Ge epilayer. A low-doped Ge layer on a conductive p-type Si substrate redirects anodization current toward the misfit-dislocation-rich interface. Numerical modelling including charge-transfer kinetics shows that this confinement arises from hole-limited charge transfer and, together with electrochemical calibration, defines a process window that combines interfacial current confinement with controlled Si porosification. STEM reveals an approximately 15 Ang separation, while EDX shows localized interfacial oxygen enrichment. After soft annealing, geometric phase analysis and plan-view TEM show a modified strain-relaxation pathway and strongly suppressed threading-dislocation emergence. Raman spectroscopy indicates a reduction in residual tensile strain from approximately 0.10 % to 0.05 %, whereas spreading resistance profiling confirms preservation of the Ge carrier profile. Current-confined electrochemistry therefore provides a controllable post-epitaxial route for buried-interface decoupling, defect filtering, and strain control in lattice-mismatched semiconductor heterostructures.
Spatially programmed functional materials, from functionally graded alloys and metamaterials to quantum superlattices, use their spatial structure to tailor physical properties. However, translating a desired spatial structure into a practical fabrication recipe remains challenging due to the complex relationship between processing conditions and resulting material structures. Here we show that a large language model (LLM) agent can inverse-design such fabrication recipes by using a physics-based simulator of ion-matter interactions as a tool. Given an arbitrary depth profile of implanted ions or vacancies, the agent selects the ion species, energies, incident angles, and target material layers; writes, runs, and interprets simulations; and iteratively refines the recipe until the simulated profile matches the target, with minimal human input. Our work demonstrates physics-guided agentic inverse design as a practical approach to making the spatial structure of materials a programmable variable, opening new opportunities to explore emergent physical phenomena and functional phases of matter.
Three-dimensional (3D) spin-ice compounds, predominantly based on the pyrochlore or spinel structure, have been attracting considerable interest in the last two decades. A two-dimensional (2D) analogue is the spin-ice consisting of kagome planes. So far, only Ising spin ice has been discovered in any material, and only one 2D material, the kagome compound HoAgGe, has been identified as a spin ice. In this Letter, we show that another rare-earth twisted Kagome magnetic compound, DyAgGe, is in fact a Potts spin ice (or color ice), where at each site not two but four spin directions are allowed. We argue that an 8-state spin ice may also exist in this class of systems. We present a first-principles calculation of magnetic interactions in DyAgGe, and confirm the 4-state Potts structure of this material by matching our model predictions with the available experimental data.
MgO-SiO$_2$ binders are promising low-CO$_2$ alternatives to Portland cement that can permanently store CO$_2$ by incorporating magnesium carbonate phases. Adding a magnesium carbonate such as nesquehonite or hydromagnesite is known to change the initial hydration product from crystalline brucite (Mg(OH)$_2$) to disordered hydrous carbonate-containing brucite (HCB), yet how these binders evolve during the initial hours of reaction remains largely unknown. Here, in situ synchrotron X-ray diffraction (XRD) and pair distribution function (PDF) analysis follows an MgO-SiO$_2$ paste with and without hydromagnesite (HY, Mg$_5$(CO$_3$)$_4$(OH)$_2$$\cdot$4H$_2$O) or dehydrated hydromagnesite (DHY, HY heated at 325 {\deg}C to remove water) over the first 24 h, with ex situ measurements to 42 days. Real space phase quantification reveals that magnesium-silicate-hydrate (M-S-H) is detected in the first scan (~45 min) of every paste, before formation of any brucite or HCB. The PDF results also show that in the neat MgO-SiO$_2$ paste, half of the M-S-H present at 42 days has formed by 24 h, while no M-S-H is detected by XRD at any age due to the intrinsic disorder present in this phase. Both carbonate sources (HY and DHY) are found to increase the extent of MgO dissolution, where no unreacted MgO is detected at 24 h in contrast with >7 days for the neat paste. However, DHY is seen to slow the initial stages of MgO dissolution (prior to ~6 h) compared with the neat paste, a period during which significant DHY rehydration is seen to occur without any HCB formation. Hence, this investigation shows that the onset of HCB precipitation in MgO-SiO$_2$-(D)HY paste is influenced by the hydration state of the DHY phase, where precipitation is delayed while DHY is rehydrating.
Triboelectric nanogenerators (TENGs) convert low-frequency mechanical energy into electricity and enable self-powered sensing. Their performance depends on interactions among material properties, surface morphology, contact mechanics, charge generation and external circuits. This review examines these interactions across length scales to assess how material and interface descriptions support predictive device design. Polymeric, inorganic, composite and natural materials are discussed in relation to charge generation and retention, mechanical compliance, durability and application requirements. Modelling approaches span molecular dynamics and first-principles calculations, rough-surface contact mechanics, device-scale electrostatics and equivalent circuits. Their capabilities are assessed through the inputs they require, the quantities they predict and the experimental evidence used for validation. Particular attention is given to prescribed surface charge density, idealised geometries and nominal contact-area assumptions, which constrain predictions under realistic loading conditions. Applications are organised by macroscale, milliscale and microscale device dimensions to examine requirements for materials, architecture and integration. The review identifies evolving real contact area and contact-dependent charge generation and decay as critical links between interfacial behaviour and electrical output. A staged validation strategy is proposed for contact mechanics, electrostatics and circuit response, with independent testing beyond calibration conditions. These priorities guide the development of multiscale models and reliable TENG systems.
Charge-density-wave (CDW) instabilities in two-dimensional materials are governed by strongly anharmonic soft phonons, whose dynamical behavior remains poorly understood beyond the statically renormalized vibrations. Here, using monolayer 1H-NbSe2, we investigate how frequency-dependent three- and four-phonon interactions reshape phonon spectral functions and influence electronic excitations. We find that three-phonon interactions induce substantial dynamical softening of CDW modes, increasing the estimated transition temperature relative to static self-consistent phonon theory. Four-phonon interactions further promote such dynamical softening and enhance spectral broadening, producing non-Lorentzian lineshapes that challenge the quasiparticle picture. Incorporating dynamically renormalized phonon frequencies and electron-phonon coupling into Fan-Migdal electron self-energy calculations reveals enhanced electronic kinks, satellite features, and momentum-dependent quasiparticle decoherence, driven by the strong momentum dependence of the electron-phonon coupling matrix elements. These findings establish dynamical anharmonicity as a critical link between soft-mode lattice fluctuations and electronic spectral signatures, providing insights into coupled lattice-electron dynamics in two-dimensional quantum materials.
The coherent elastic wave in untextured polycrystals, central to ultrasonic and seismic characterization, was recently observed to have two modes per polarization at short wavelengths. However, their physical origin and amplitude partition have remained open. We address both by theory, grain-scale numerical simulations and a grain velocity estimate. The first-order smoothing approximation, simplified by the far-field approximation, predicts three waves, which are the classical effective wave and one for each type of scattered wave (longitudinal and transverse). At long wavelengths, only the effective wave is weakly attenuated. At short wavelengths, one of the other two waves joins it with comparable attenuation, whereas the third stays far more attenuated. A new residue method, which needs no fitting, gives the same pattern for the amplitude partition, with the two waves sharing the coherent field and the third carrying little. The simulations reveal exactly these two modes, for transverse waves in iron and longitudinal waves in strongly anisotropic SrMgSn, and never the third. The wavefields reveal the mechanism, in which the incident wave is extinguished within one grain correlation length and the coherent field is rebuilt by forward multiple scattering. Strikingly, a grain velocity estimate from single-crystal constants provides independent evidence, tracing the two modes to plane waves of the individual grains and closely reproducing their velocities. Observability of multiple waves is thus set by attenuation and amplitude partition together, and short-wavelength measurements in random media must allow for more than one coherent mode.
Heat transport in solids is usually described in a phenomenological way via Fourier's law. However, at small time and length scales in low thermal conductivity materials, a microscopic description is needed. This is traditionally done by invoking the phonon Boltzmann Transport Equation (BTE), which has been successful in describing transport in high thermal conductivity materials. Recently, a generalization of the BTE, the Wigner Transport Equation, was developed to be able to microscopically describe transport in low thermal conductivity materials by taking into account not only phonon scattering processes but also phonon tunneling processes, so-called coherences. We present a Python package that solves the Wigner Transport Equation (WTE) in spatial and temporal Fourier space for arbitrary source terms, thereby enabling the study of heat transport at small space and time scales. This allows one to compute both static and dynamic thermal conductivities from bulk to nanoscale. Beyond that, it can be used to study the response of phonon systems in materials to arbitrary heat sources.
Using the Wannier function approach, we develop a gauge-covariant formalism for the orbital angular momentum (OAM) operator and the orbital Hall conductivity (OHC). The Wannier function formulation resolves the position-operator ambiguity inherent to Bloch states, providing a transparent and rigorous theory of orbital transport. Our formalism is validated through a finite-lattice calculation of the Haldane model, where the OAM operator is evaluated exactly from its real-space definition. Our results are also relevant to other orbital phenomena in solids such as the orbital Edelstein effect, orbital torque generation, and the like, where the OAM plays a crucial role.
Strong coupling between collective excitations provides a route to controlling quantum states of matter, yet its evolution under thermal fluctuations remains poorly understood. In the van der Waals antiferromagnet FePS3, strong magnon-phonon coupling is established at low temperatures. At the same time, recent terahertz experiments revealed the counterintuitive stabilization of a long-lived metastable magnetic state with an exceedingly long lifetime of 5 msec at the antiferromagnetic transition, not at the base temperature. This was attributed to a strongly coupled spin-lattice scenario, challenging the conventional wisdom that increased magnetic and thermal fluctuations near TN should be detrimental to the coherent control of a metastable phase. Thus it requires an independent examination for correct understanding. Using high-field Raman spectroscopy, we systematically investigate the temperature evolution of magnon-phonon coupling in FePS3. We observe a pronounced avoided crossing between magnon and phonon modes across a wide range of temperatures and find that the coupling strength remains remarkably robust with increasing temperatures. The zero-field magnon-phonon detuning decreases progressively with warming, driving the system toward resonance and thereby enhancing their hybridization near the transition temperature. This anomalous thermal evolution provides the crucial key to understanding the unusual terahertz-driven states recently reported in FePS3. More broadly, our results highlight van der Waals magnets as a promising platform for strong coupling among collective excitations and for controlling magnetic states through light-matter interactions.
We investigate the electronic structure, local orbital coupling, and strain-tunable nonlinear Hall response of two arsenic-substituted borophosphene-derived monolayers, As@MBP and As@AMBP, using first-principles calculations and tight-binding analysis. In the absence of spin--orbit coupling, both systems exhibit a finite Berry-curvature dipole (BCD) and a substantial nonlinear Hall conductivity, demonstrating that the nonlinear response is intrinsically driven by orbital physics and inversion-symmetry breaking. $As$ substitution opens sizable band gaps of $120~\mathrm{meV}$ in As@MBP and $90~\mathrm{meV}$ in As@AMBP, well exceeding room-temperature thermal fluctuations ($k_{\mathrm{B}}T \approx 25.9~\mathrm{meV}$). Tight-binding analysis reveals that $As$ incorporation breaks the equivalence of $B-P$ hoppings in As@MBP and induces sign reversals in key nearest-neighbor hoppings in As@AMBP, reflecting a pronounced electronic reconstruction beyond simple geometric effects. Under mechanical strain, the redistribution of Berry curvature yields a maximum BCD of $22~\mathring{\text{A}}$ in As@MBP, approximately $10$ times larger than that of unstrained structure, and induces a reversal of the BCD sign. These results establish $As$-substituted borophosphene derivatives as promising light-element platforms for mechanically switchable nonlinear transport and quantum-material applications without relying on strong spin-orbit coupling.
The free energy of a crystal is an integral over the positions of all its atoms, in 3N dimensions. We evaluate it without random sampling for the ordered alloys B2 NiAl and gamma-TiAl with embedded-atom potentials, using a self-consistent harmonic approximation (SCHA) corrected to third order in temperature, calculated via thermal averages of tensor-train (TT) integrals built from one atom and its neighbors, which we call TT-SCHA. The result is for an infinite crystal without sampling error; its numerical error is set by the starting pivots of the interpolation (up to 9 MPa in the pressure, reduced by averaging three runs; SM Table S26). Against the molecular dynamics of 65,536 atoms (Frenkel-Ladd free energy at 600 K, integrated energy above), TT-SCHA free energy agrees to 0.13 meV per atom at 600-1000 K, using 420-500 times fewer core-seconds for one run. At zero pressure, results agree with published calculations that use the same embedded-atom potential: the published elastic constants of gamma-TiAl (to 1 GPa, by a static lattice calculation) and its thermal expansion from Monte Carlo sampling (to 0.012 percentage points).
Tantalum pentoxide (Ta2O5) thin films deposited by ion beam sputtering (IBS) are essential components in high-power laser systems, where post-deposition annealing is routinely used to optimize film quality. In this work, we systematically investigate the structural and optical evolution of IBS-deposited Ta2O5 single layers subjected to post-deposition annealing at temperatures from 400 to 800 $^{\circ}\mathrm{C}$. The films undergo an amorphous-to-polycrystalline transition between 600 $^{\circ}\mathrm{C}$ and 700 $^{\circ}\mathrm{C}$, accompanied by a marked increase in surface roughness. Argon bubbles inherently incorporated during IBS serve as structural markers: their size correlates positively with the surface roughness from the as-deposited to 700 $^{\circ}\mathrm{C}$ but decouples at 800 $^{\circ}\mathrm{C}$, revealing a transition from matrix-relaxation-dominated to surface-diffusion-dominated behavior. Transmittance spectra show a red shift at 400 and 600 $^{\circ}\mathrm{C}$ which can be explained by physical thickness increase. Weak absorption decreases from ~6 ppm in as-deposited films to ~2 ppm at 400-600 $^{\circ}\mathrm{C}$ due to annihilation of oxygen vacancies, rises markedly at 700 $^{\circ}\mathrm{C}$ due to grain-boundary defects and then drops again at 800 $^{\circ}\mathrm{C}$ as grain boundaries relax. We identify 400 $^{\circ}\mathrm{C}$ as the optimal annealing window for IBS-deposited Ta2O5 single layers, with the lowest surface roughness and effectively reducing weak absorption while preserving the amorphous phase.
Ionic conduction in solid-state electrolytes is conventionally described by mobile cations migrating through a static host lattice. Yet the fastest conductors are often the most disordered, and how disorder enhances transport remains unresolved at the mesoscale, inaccessible to ensemble-averaged probes. We use Bragg X-ray photon correlation spectroscopy to measure nanoscale structural dynamics of a single ball-milled Na$_3$PS$_4$ particle. We find that the cubic phase behaves as a strain glass: a frustrated configuration of three degenerate tetragonal variants with short-range order. Its domain-wall motion is stress-driven, crossing over irreversibly to thermally activated dynamics on annealing as residual milling stress is depleted. Rearrangements follow scale-free avalanche statistics, matching ferroelastic martensites but without external driving. The tetragonal polymorph shows none of these features and relaxes fifty times more slowly. These dynamics occur on timescales comparable to estimated ionic diffusion across the particle, indicating the host structure cannot be assumed static on transport-relevant timescales.
Simulating microstructure evolution requires tracking many moving grain and phase boundaries coupled to thermodynamic and mechanical fields. We present Gaussian-projected kinetics (GPK), a sharp-interface framework in which every cell stores an integer grain or phase label. Near a boundary, a temporary Gaussian projection of the label map provides the interface normal and curvature and is then discarded. Capillarity, chemistry, stored energy, transport and elasticity move the boundaries through one topology-preserving update. Because the Gaussian measurement length is fixed in physical units, mesh refinement keeps a consistent capillary scale without a diffuse interface. GPK models grain growth, recrystallisation, multiphase evolution and elastic-coupled solidification in two and three dimensions. It is verified on analytical benchmarks and compared grain by grain with phase-field simulations, running 8.5 to 96 times faster at matched accuracy in our tests. An Al-Cu application with CALPHAD thermodynamic data connects it to measured recrystallisation and precipitation data.
Electrochemically formed two-dimensional free surfaces (2DFS) decouple Ge epilayers from the misfit-dislocation network at the Ge/Si interface, but the origin of their selectivity has remained unclear. We combine finite-volume current-distribution modelling, including charge-transfer kinetics, with a one-dimensional Poisson analysis of the p-Ge/p+-Si heterojunction. With realistic conductivities, an ohmic description would drive 77% of the anodic current through Ge, whereas hole-limited charge transfer reduces this fraction to 0.07%, independently of the electrolyte conductivity. The valence-band offset accumulates holes on the Ge side up to ~1019 cm--3 within a self-limited nanometric layer, which localizes dissolution at the interface. The model yields design rules for the doping contrast (NSi/NGe ___ 60) and the mesa width (___ 3.6$\lambda$, with $\lambda$ $\approx$ 1.7 $\mu$m).
Nonrelativistic spin splitting in collinear compensated magnets is constrained by spin-group symmetry, with distinct alternating and Zeeman-type splitting typically associated with altermagnets and fully compensated ferrimagnets, respectively. From a spin-density perspective, we propose a class of hybrid compensated magnets in which alternating-like and Zeeman-type spin splitting coexist within a single collinear compensated state. Using a minimal two-sector model, we demonstrate that this coexistence arises from competition between directional sublattice dispersion and the sector-dependent energy biases arising from the same structural inequivalence. First-principles calculations provide a proof of concept in a crossed bilayer of unequal-width Janus graphene nanoribbons, where the structurally inequivalent ribbons retain approximately symmetry-related spin-density distributions. The valence and conduction sectors support direction-selective spin transport and energy-selective spin-polarized states, respectively. These results connect the spatial organization of spin density with the electronic response to structural inequivalence, providing a design principle for hybrid spin splitting in compensated magnets.
We investigate the effects of ionic hydrogen (H$^+$) intake on the occupied and unoccupied states of MnSb$_2$Te$_4$, a van der Waals magnetic material. Using angle-resolved photoemission spectroscopy (ARPES) and time-resolved ARPES, combined with resonant and core level photoemission, we reveal that hydrogen binds near specific lattice sites, locally redistributing charge density and reshaping the valence band spectral weight. While the band gap and picosecond carrier dynamics show only minor changes upon hydrogenation, the conduction band exhibits a striking stoichiometry-dependent response. These findings indicate that hydrogen interacts strongly with the intrinsic defects in the lattice, acting as a selective dopant in MnSb$_2$Te$_4$. Our work provides a spectroscopic basis for using hydrogen as a tool for the control of the electronic and magnetic properties in layered 2D materials.
Intrinsic electron localization in amorphous silica (a-SiO2) contributes to charge trapping and defect generation in silica-based electronic materials - a phenomenon that degrades logic-device performance but can be exploited for memory applications. However, the structural distribution of one- and two-electron traps remains incompletely characterized, largely because the disordered covalent network of a-SiO2 spans a vast configurational space. To address this, we perform statistical sampling to select a representative 200-model subset of defect-free bulk a-SiO2 structures from a structurally converged parent set of 2512 models, generated via classical melt-quench molecular dynamics simulations. We then characterize the intrinsic one- and two-electron traps in this subset using HSE06 density functional theory calculations. Analysis of neutral precursor sites shows that trapping propensity is not determined by a universal O-Si-O angle or Si-O bond length; it is controlled by the accessibility of the relaxed trap geometry, requiring both local strain and medium-range network flexibility. Single electrons predominantly form edge-centred polarons on distorted SiO4 tetrahedra, with occupied states 3.1-4.3 eV below the conduction band minimum. Injection of a second electron drives stronger lattice relaxation, most commonly Si-O bond elongation leading to rupture, thereby forming threefold-coordinated-Si (Si3) bipolarons and, in some cases, Si-Si-bonded bipolaron configurations. The calculated bipolaron energy ranges are consistent with optical absorption features at 3.7, 4.7, and 6.4 eV associated with intrinsic electron localization.
The real mechanism of ferromagnetism in III-V diluted magnetic semiconductors such as Ga$_{1-x}$Mn$_x$As is still debated. The experimental results point out the realization of appreciable ferromagnetism at filling of the impurity band close to one-half that can be expressed in terms of compensation degree. Based on our recent results on the existence of two competing mechanisms of pair indirect exchange (with ferro- and antiferro alignment of Mn $d$ shells), a theory of magnetic ordering in (Ga,Mn)As is presented. The molecular-field-like equation is derived in which the effective exchange constant contains all necessary information about material, including the Mn content, the compensation degree, the crystal coordination, and the parameters of two competing pair exchange interactions. The Curie temperature depends crucially on the compensation degree. Depending on Mn content and compensation degree, three possible magnetic phases (paramagnetic, ferromagnetic, and spin-glass-like) are predicted. However, the spin-glass-like phase in (Ga,Mn)As is apparently not realized due to the additional inevitable compensation caused by As antisites. The phase transition into the ferromagnetic state occurs not only with Mn content variation but through the change of the compensation degree as well. The new mechanism of photoferromagnetic effect is predicted and discussed in the context of possible clarification of the magnetic ordering mechanism. It is assumed that the main obstacle to a possible increase in the Curie temperature is the increasing contribution of the antiferromagnetic superexchange between the nearest-neighbor Mn's, rather than compensatory (electric or magnetic) effects from Mn interstitials, as was previously stated. The comparison of our predictions with available experimental data is presented.
Defect states directly influence not only functional properties, but also oxynitride formation during ammonolysis. Along with structural stability and charge balance, these defects can cause non-uniform nitrogen incorporation. To address this, the recently proposed Fermi Level Engineering concept provides a powerful alternative of rationalising oxynitride synthesis. By using the electron chemical potential, i.e., the Fermi level, as a unique descriptor, this approach can predict, understand, and manipulate defect formation enthalpies and charge transition levels, subsequently allowing to incorporate defect-property correlations to the concept. This work combines theoretical modelling and experimental characterisation of barium titanium oxynitrides to explain an intrinsic, self-limiting nitridation process. Progressive nitrogen incorporation causes a Fermi level downward shift, leaving further nitrogen substitution on oxygen sites energetically unfavourable, up to 0.03 N per unit formula. We demonstrate that A-site cation substitution in Eu$_{1-x}$Ba$_x$TiO$_3$- and Eu$_{1-x}$Ca$_x$TiO$_3$-derived oxynitrides can be applied to control compensation of the additional negative charge from N$^{3-}$ and keep the Fermi level high. The Eu$^{2+/3+}$ redox couple enables substitution of oxygen by nitrogen through pinning of the Fermi level at the europium charge transition level, at $\sim$ 2.9 eV above the VBM. This allows for higher nitrogen uptake of up to 0.65 per formula unit (taken from hot gas extraction) through a more controlled process. Further incorporation is then limited by an intra-Ti(O,N)$_6$ octahedra distortion due to internal bond-angle variance. These findings demonstrate that Fermi Level Engineering provides a pathway to predict and overcome intrinsic synthetic and thermodynamic limitations in oxynitride synthesis.
Three metastable $\beta$ titanium alloys with different molybdenum contents, Ti-12Mo, Ti-15Mo and Ti-18Mo (wt.%), were investigated to determine the influence of $\beta$-phase stability on phase transformations during continuous heating. Electrical resistance measurement, dilatometry and differential scanning calorimetry were performed during linear heating at 5 {\deg}C/min up to 750 {\deg}C. The in-situ experiments were complemented by electron microscopy observations of specimens heated to selected temperatures and subsequently water-quenched. All alloys exhibited a sequence involving partial dissolution of athermal $\omega$ phase, stabilization and growth of isothermal $\omega$ phase, subsequent $\omega$ dissolution and precipitation of $\alpha$ phase. Increasing molybdenum content progressively suppressed $\omega$ phase evolution and subsequent $\alpha$ precipitation and narrowed the temperature interval associated with $\omega$-related transformations. The excellent agreement between electrical resistance measurements, DSC, dilatometry and electron microscopy enabled a consistent description of phase evolution during heating and demonstrated the benefits of combining complementary experimental techniques for investigation of complex transformation pathways in metastable $\beta$ titanium alloys.
Polypyrrole NH$_3$ chemiresistors in nanotube (NT) and planar film (PF) morphologies are compared on response magnitude, limit of detection (LOD), sensitivity, and response/recovery kinetics, including the performance of the same sensors tracked over 60 days of ambient storage and repeated NH$_{3}$ exposure. In the case of fresh sensors, the time constants for the fast process ($\tau_1$) is shorter in the NT than in the PF at every concentration. NT is 38 \% faster on average than PF. The slow process ($\tau_2$) overlaps between two morphologies and shows no concentration dependence. The two time constants differentiate the two morphologies through aging: NT $\tau_1$ and $\tau_2$ decrease substantially and monotonically over 60 days, while the time constants of PF show no consistent trend. All measured sensing parameters, LOD, sensor response and sensitivity improve or at least remain stable with aging in the case of NT, while all parameters degrade in the PF case. These improved sensor performance and aging identify the nanotube morphology as the more robust and manufacturable choice for long-term NH$_3$ sensing applications.
Simulating quantum many-body systems classically encounters exponential bottlenecks, which quantum devices circumvent by natively encoding wavefunctions. In the Noisy Intermediate-Scale Quantum (NISQ) era, however, hardware noise constrains simulation accuracy. As a stepping stone toward strongly correlated materials, we compute the band structure of 2D monolayer graphene and 1D nanoribbons (zigzag and armchair) using a single variational workflow in the $p_z$ tight-binding approximation. Non-interacting ground states also provide essential initial reference states for subspace and warm-started variational methods to solve interacting spectra. By mapping the Bloch Hamiltonian to Pauli operators, we extract the ground band via the Variational Quantum Eigensolver (VQE) and excited subbands via Variational Quantum Deflation (VQD), validating our approach from ideal simulations to execution on physical IBM Quantum processors. In ideal simulations, the workflow reproduces exact diagonalization results with high precision, whereas hardware noise introduces energy deviations of a few hundredths of the hopping parameter. While qubit counts scale logarithmically with ribbon width, fixed-depth ansatz accuracy degrades with Hilbert space dimension. Crucially, deepening the ansatz improves ideal simulation accuracy by over three orders of magnitude but worsens energy estimates under noise, proving that practical circuit depth is bounded by hardware noise rather than expressivity. Finally, we complement energy evaluations with a wavefunction-level diagnostic measuring subspace containment. This diagnostic captures degenerate manifolds and exposes optimization failure modes disguised by energy agreement alone. Operating directly on NISQ hardware, this validated workflow establishes a controlled baseline for studying topological and strongly correlated phases in realistic materials.
Ferrons are elementary excitations of ferroelectric order that can propagate and transport polarization when excited with light. Here, we show theoretically that ferron polaritons exhibit a Hall effect: an applied magnetic field generates polarization transport perpendicular to the propagation direction of a ferron polariton excited by an incident terahertz pulse. We demonstrate this effect for the example of ferroelectric SnTe using first-principles calculations and a microscopic theory of the phonon-polariton current. The direction and magnitude of the transverse polarization transport can be controlled by the polarization of the terahertz pulse and the applied magnetic field. Our results establish a route toward light-controlled directional transport of electric polarization in ferroelectrics.
Minimal model and its linear stability analysis (LSA) for Plateau-Rayleigh (PR) instability of an intermixed, solid binary alloy nanowire is presented. Model accounts only for the surface diffusions of the alloy components without anisotropies of a surface energies, and for a classical thermodynamic surface segregation. Model allows to assess a deviation of a longwave instability cutoff wavelength $\lambda_c$ from the classical value $2\pi r_0$ (a wire circumference) as a function of a surface composition deviation from its equilibrium value, a wire radius, and a bulk concentration of a minority component. Results of LSA are presented for AuNi, PtNi, and CoNi nanowires, where an important distinction is that a surface segregation curve for CoNi is qualitatively different from the one for AuNi and PtNi. For each nanowire there is a sizable region of a parameter space where $\lambda_c<2\pi r_0$ and correspondingly, a fastest growing perturbation wavelength $\lambda_{max}$ is also less than a wire circumference. This is in stark contrast to PR instability of a single-component nanowire transporting mass by surface diffusion - in this case $\lambda_c$ and $\lambda_{max}$ are larger than a wire circumference. Strong surface segregation is primarily responsible for unusually small $\lambda_c$ and $\lambda_{max}$. Results suggest that a large number of small and closely spaced nanoparticles may emerge upon disintegration via annealing of a binary alloy nanowire.
Pauling's electrostatic valence rule assigns to each bond of a cation of charge $z$ with $n$ anion neighbors the strength $z/n$. Bond-valence theory replaces the equal split of valence among bonds by $s=\exp[(R_0-d)/B]$ in the bond length $d$ and takes the sum rule, that the valences at each atom add to its formal charge, as its first axiom. Here the bond valence is defined in the electron density. Atomic basins of a first-principles density are bounded by faces, one per bond critical point, and the electric flux of that density through a face is a charge associated with the bond. The fluxes leaving a cation sum to its basin charge by Gauss's law, so on this surface the sum rule is a theorem. Across 3680 oxides, halides, chalcogenides and pnictides the flux follows the bond-valence law site by site, with a median deviation of ten percent. The softness $B$ varies nearly an order of magnitude from stiff sulfides to softer arsenides. In all cases it is set by the electrostatic flux at atomic basin faces. $R_0$ then follows from the bond lengths and their differences. Anion valences equal those of bonded cations to within 5\% for most of the oxide, fluoride, sulfide and nitride sites. Transferability of $(R_0,B)$ between compounds fails in 96 of 106 families, suggesting that the softness is a local site property defined by the basin charge rather than a transferable constant of a given cation--anion pair. Eliminating $B$ by the sum rule gives $s=(z/n)^{(R_0-d)/(R_0-d_B)}$, Pauling's strength raised to a distance exponent at the softness-weighted mean bond length $d_B$. Thus, bond-valence theory is Pauling's rule with a distance exponent, and the electron density supplies the surface on which the two are equivalent.
Charge equilibration assigns atomic charges by equalizing an atomic chemical potential built from electronegativity, hardness and the Coulomb interaction. Under one global constraint it lets charge flow without limit between molecules, which fluctuating-charge models prevent with one neutrality constraint per molecule. A metal needs the opposite: a global constraint and a hardness near zero, and there the charge operator becomes indefinite unless it includes each charge's own self-energy. Here, we present samQEq (solids-and-molecules QEq), a unified charge-equilibration package for LAMMPS that combines the two constructions in one energy functional and one matrix-free solve. An orthogonal projector imposes one neutrality constraint per molecule, and the finite-width self-energy of a Gaussian charge on designated conductor types, narrower than the conductor's own Gaussian, keeps the conductor's part of the operator positive definite at any hardness. On a gold slab carrying a water film, the operator stays definite down to the conductor limit of the model, the metal screens a point charge by a constant amount at every height beyond 4 {\AA}, and the film's charges stay bounded under dynamics. Reciprocal-space electrostatics is evaluated inside the matrix-vector product, and three distinct shielding kernels are run-time settings. We verify the implementation by reproducing a published fluctuating-charge water model without refitting, and the native ReaxFF charge-equilibration step to approximately $10^{-9}\,e$. On a single four-V100 node the largest tested systems run at approximately twice the throughput of a 128-core CPU node. samQEq thus provides one charge-equilibration layer for molecules, conductors and the interfaces between them.
Level-set simulators of etching and deposition move the surface with a velocity that depends on adsorbate coverages. These coverages are usually computed from balances solved and coded by hand for each chemistry, whereas voxel-based Monte Carlo profile simulators read the reaction mechanism as data. For the open-source level-set simulator ViennaPS, this work presents a surface model whose rate laws, Jacobian and velocity are derived from a reaction file and evaluated with ray-traced fluxes. Steady-state coverages are obtained with Newton's method and transient coverages with a conservative integrator. One compiled model is applied to eight chemistries for chemical vapour deposition, selective epitaxy, plasma etching, sputtering and atomic layer deposition. It reproduces a hand-written silicon etch model to seven significant digits at a single point and within the Monte Carlo noise in a masked trench. In a high-aspect-ratio cavity, alumina conformality is determined by a trimethylaluminium reaction probability within the measured range.
As general-purpose Large Language Models (LLMs), such as Gemini and DeepSeek, exhibit increasingly advanced reasoning capabilities, a critical question arises: how do their property prediction abilities compare to those of domain-specific pretrained materials models? In this study, we evaluate predictions for Ti, steels, high-entropy alloy (HEA) and Al, demonstrating that general-purpose LLMs surprisingly outperform SteelBERT, MatSciBERT, and SciBERT. To further enhance performance, we introduce a hybrid approach that utilizes numerical priors from a prior model, such as CatBoost or SteelBERT, to guide the general LLMs (Deepseek V3.1, Gemini-2.5-Flash). By inputting these initial estimates from a prior model as prompts, the LLM acts as a reasoning corrector, achieving accuracy superior to the prior model and "unguided mode". Furthermore, we investigate the impact of data strategy using a similarity-based metric, revealing that data quality dominates quantity; using merely 5% of high-similarity reference data of training set as input yields performance similar to the results of using 100% of training set. Additionally, the LLMs demonstrate excellent uncertainty calibration, where self-reported "high" confidence strongly correlates with minimal deviation from ground truth. Our findings suggest that synergizing general-purpose LLMs with prior model numerical baselines and high-quality data curation creates a cost-effective and accurate paradigm for materials discovery, reducing the need for expensive domain-specific pretraining.
Strong electron correlations and topology offer complementary routes to controlling electrical conduction, as correlations can make electrons heavy (e.g. Kondo lattices) whereas topology can make them behave as massless particles (e.g. Dirac or Weyl systems), and having both in one material is rare. In Kondo lattice systems, Kondo hybridization between localized 4$f$ and conduction electrons strongly enhances the quasiparticle mass, where in Weyl-Kondo systems these Kondo-renormalized bands form Weyl states, and simultaneous signs of both Kondo and Weyl states in one material have not been observed in transport. Here we report signs of both in the kagome metal \ce{Yb_yCo3Ge_{3-x}Sn_x} by combining magnetotransport, heat capacity, magnetization, angle-resolved and X-ray photoemission spectroscopy, and DFT+U calculations to reveal Yb-dependent Kondo scattering developing into lattice coherence, with extrapolated Sommerfeld coefficient of approximately 2 ~Jmol$_{\mathrm{Yb}}^{-1}$K$^{-2}$. Transverse magnetoresistance (MR) follows single-ion Kondo scaling, whereas longitudinal transport contains an additional negative response proportional to B$^2$ and remains unsaturated up to 32 T, consistent with a chiral anomaly. These findings support a picture of Kondo and Weyl-like conduction arising from distinct electronic states without external Fermi-level tuning, suggesting a possible route to combining correlated and topological functionality in a bulk material.
The Landau transformation xi = x/s(t) is the usual way to hold a moving boundary in place. It fails for fractional time derivatives because they have no chain rule: the transformed operator gains a nonlocal integral with a closed form only for self-similar fronts. We develop a sharp-interface finite-difference scheme for the conservation-consistent memory-flux fractional Stefan problem on a fixed grid, storing the memory limit h(x) = s^-1(x) as the time each node melts. The front is advanced using an integrated energy balance, with the singular source timed to the sub-step crossing instant. Against a known self-similar solution, the front constant is accurate to 0.02 to 0.11%, whereas competing formulations differ by 17 to 27% at alpha = 0.6. A remaining positivity violation follows from dt/t0 ~ s0^(1 - 2/alpha) and disappears on a front-locked time grid. We also derive two exact solutions with non-power-law fronts: a source-dominated solution and a Mittag-Leffler traveling wave, and verify the scheme against both. Neural-network solvers for moving boundaries are often trained in normalized coordinates; for alpha < 1, this silently changes the problem, while the change vanishes at alpha = 1, where checks are commonly performed. In the classical limit, our scheme is more accurate in 12 ms than a reimplemented moving-boundary network in 177 s.
Carbonic acid (H2CO3) is connected with the dissolved CO2 and bicarbonate (HCO3-) equilibria in aqueous solutions. Its two elementary reactions in water, acid dissociation and dehydration to CO2, are difficult to resolve because both are coupled to proton transfer through hydrogen-bonded networks. In this work, we combine 0.5 ns of unbiased PBE-D3 molecular dynamics of 1 molar solution of H2CO3 with metadynamics on the O - H coordination (H2CO3 = HCO3- + H+) and the C - O distance of the leaving hydroxyl (H2CO3 <=> CO2 + H2O). These unbiased trajectories show frequent cis-cis <=> cis-trans interconversion through long-lived bicarbonate (well separated from solvated proton, H3O+, and also mediated by a short-lived three-water [H2O...H3O+...H2O] ring that acts as a solvent-shared ion pair (SSIP); only 16-23% of deprotonation events reach a solvent-separated ion pair (SShIP). Resolving ion-pairs as SSIP for proper reaction leads to an improved estimate of pKa1 from 1.1 to 2.4, toward the experimental 3.45-3.59 (measured at supposedly infinite dilution). Further, metadynamics simulations provide a dehydration barrier of 17.8 (1D) and 15.3 kcal/mol (2D), suggesting that the final product CO2 + H2O is 2.8 kcal/mol below H2CO3. Our two-dimensional free energy surface also shows that C--O cleavage proceeds through the CO2 + OH- which further goes down by 9.9 kcal/mol to product CO2 + H2O.
The Yb delafossites NaYbSe$_2$, KYbSe$_2$, CsYbSe$_2$ and NaYbO$_2$ are candidates for the U(1) Dirac spin liquid (DSL) of the triangular lattice. Strong spin-orbit coupling gives their exchange an XXZ anisotropy $\Delta$ and bond-dependent couplings $J_{\pm\pm}$, $J_{z\pm}$ that lock the spin frame to the lattice. We show that, within a single layer of a stable Heisenberg DSL, these couplings generate no relevant Lorentz-scalar operator of their own. Inversion at the bond centers removes the Dzyaloshinskii-Moriya channel that gaps the kagome DSL, so the locked symmetry forbids a mass, density or current at any order and, assuming continuity, any new monopole term through charge three. Every Lorentz-scalar four-fermion operator induced by spin-orbit coupling shares an SU(4) multiplet, and hence its scaling dimension, with a Heisenberg-allowed one, and the nine non-scalar quartics without such a partner arise only at second order and are irrelevant at large $N$. The Heisenberg DSL itself allows a Lorentz-vector quartic of large-$N$ dimension 2.92, which a stable phase must also render irrelevant. Beyond a single layer, spin-orbit coupling opens an interlayer monopole channel in rhombohedral stacking. If the Heisenberg DSL is instead multicritical, an anisotropy as small as that of KYbSe$_2$ matters only below tens of mK. At the transition to 120$^\circ$ order the anisotropy is relevant, and exact diagonalization indicates that easy-plane anisotropy selects the chiral-Ising class. Existing KYbSe$_2$ neutron data below $J$ do not yet fix the K-point exponent, and gapless out-of-plane spin fluctuations at the K point would test the chiral-Ising selection.
The Yb delafossites NaYbSe$_2$, KYbSe$_2$, CsYbSe$_2$ and NaYbO$_2$ are candidates for the triangular U(1) Dirac spin liquid, QED$_3$ with $N_f=4$, but their exchange is spin-orbit coupled. Under their spin-orbit-locked space group we determine which operators the XXZ anisotropy and the bond-dependent couplings $J_{\pm\pm}$, $J_{z\pm}$ induce, and at what order. Symmetry forbids every Dirac mass, density and current at any order and, assuming adiabatic continuity, any new monopole term through charge three. At linear order the couplings reach only spin-2 members of the quartic multiplets $\mathbf{20}'$ and $\mathbf{84}$, which share their dimensions with Heisenberg-allowed operators. At second order $J_{\pm\pm}$ and $J_{z\pm}$ renormalize the anisotropy through $J_{z\pm}^2-2J_{\pm\pm}^2$, and nine spin-1 quartics without Heisenberg partners appear, irrelevant at $O(1/N)$. A single layer of a stable Heisenberg spin liquid thus acquires no relevant Lorentz-scalar operator from spin-orbit coupling. The Heisenberg liquid itself allows a Lorentz-vector $\mathbf{20}'$ quartic of large-$N$ dimension 2.92, with two-loop $\epsilon$-expansion estimates 2.9-3.5. Rhombohedral stacking adds triplet-monopole tunneling between layers at first order. At the transition to 120$^\circ$ order the anisotropy is relevant, with crossover exponent $y_T\simeq0.74$-1, and exact diagonalization shows that easy-plane anisotropy selects the chiral-Ising class. The out-of-plane spectrum at the K point then stays gapless, and the spin-flip to non-spin-flip ratio grows as $\omega^{-0.56}$ at leading order. Existing KYbSe$_2$ neutron data below $J$ do not fix the K-point exponent. In-plane fields induce a chiral mass and an out-of-plane moment proportional to $\sin3\varphi$, zero along the bonds and canceling between CsYbSe$_2$ layers, which the planar thermal Hall effect can test.
Phase-field models resolve microstructural evolution during rapid alloy solidification, but their computational cost limits long trajectories, stochastic ensembles, and studies across process conditions. We present a variance-preserving denoising diffusion bridge model (VP-DDBM) for state-conditioned prediction of two-dimensional Al-Cu solidification. Given the current phase, concentration, and prescribed temperature fields, the model predicts the subsequent state and is applied autoregressively. Across two held-out thermal gradients, VP-DDBM produces lower long-horizon errors than deterministic U-Net and SI-ConvNeXt baselines in domain-mean phase, domain-mean Cu concentration, and leading-tip position. It also retains fine dendritic structure over long rollouts, whereas the deterministic U-Net progressively smooths the morphology. VP-DDBM predicts the phase and concentration evolution approximately $73\times$ faster than the phase-field solver, showing potential for faster process-condition screening and ensemble-based microstructure studies.
Instrumented indentation enables assessment of local mechanical properties in heterogeneous polymer systems, but specimen preparation and the selected indentation protocol significantly influence the quantitative interpretation of the measured response. This study develops and evaluates an experimental methodology for spatially resolved mesoscale characterization of both unreinforced and short fiber-reinforced composites. An unreinforced material system is used as a reference material to systematically examine the effects of indentation spacing, surface preparation, maximum indentation load, temporal loading parameters, and unloading evaluation. Indentation loads of 500, 1000, and 1750 mN are investigated in complementary experimental campaigns. The apparent indentation modulus exhibits moderate sensitivity to indentation load and loading time within the studied ranges. In contrast, indentation depth and the creep-related depth increment display greater sensitivity to the applied load history. Surface polishing minimizes topographical disturbances and enables reliable identification of residual indentation profiles and pile-up. Based on these methodological findings, a final load-hold-unload protocol with an indentation load of 1750 mN, a loading time of 6 s, a holding period of 300 s, and an unloading time of 4 s is applied to both unreinforced material and short fiber-reinforced composites. The mean apparent indentation modulus increases from 2.91 GPa for unreinforced material to 6.65 GPa for short fiber-reinforced composites, while the mean depth of indentation creep decreases from 2.36 to 1.91 microns. The coefficient of variation also increases for both quantities, indicating that short-fiber reinforcement enhances mean local stiffness and introduces pronounced spatial heterogeneity in both stiffness-related and time-dependent mesoscale indentation responses.
We theoretically investigate the transport properties of a topological insulator (TI) connected to two-dimensional altermagnetic (AM) leads in the absence of an external magnetic field. Exploiting the intrinsic time-reversal symmetry breaking of altermagnets, we report the emergence of a field-free transverse differential conductivity in the resulting AM-TI-AM heterostructure. Our analysis reveals that this transverse response is highly sensitive to the orientation of the N\'eel vector: a finite transverse conductivity manifests when the N\'eel vector possesses an out-of-plane component, whereas it strictly vanishes for in-plane orientations ($\theta = \pi/2$) under symmetric chemical potentials ($\mu_t = \mu_b$) due to the restoration of symmetry between the $k_y$ and $-k_y$ momentum channels. Conversely, when asymmetric chemical potentials are applied ($\mu_t \neq \mu_b$), this symmetry is broken, yielding a finite transverse response even for an in-plane N\'eel vector. Furthermore, we demonstrate that while the longitudinal differential conductivity exhibits Fabry-P\'erot-type oscillations as a function of the TI's chemical potential, the transverse conductivity displays a distinct antisymmetric dependence. Notably, the oscillatory behavior of the longitudinal conductivity persists even at finite temperatures. Spatially, the transverse current contribution decays exponentially with position inside the TI region. We also find that both the longitudinal and transverse differential conductivity exhibit periodic oscillations with the junction parameter $\chi_t=\chi_b$. These findings provide a fundamental understanding of field-free transverse responses in spin-momentum locked boundary states, highlighting the potential of AM-TI heterojunctions for next-generation spintronic applications.
We investigate the geometric phase acquired by low-energy quasiparticles encircling defects in graphene. Following Anandan, this phase is the holonomy of the Poincare connection; its translational part couples momentum to torsion, giving $P_a\int T^a$. In the Katanaev-Volovich theory, dislocation torsion is confined to the defect core. For graphene, the relevant momentum is $\hbar(\tau_3\KK+\mathbf q)$. We show that an isolated dislocation yields a topological valley factor $e^{\mp2\pi i/3}$ when its Burgers vector $\bb$ lies outside the $\sqrt3\times\sqrt3$ superlattice, together with a dispersive factor $e^{-i\mathbf q\cdot\bb}$ for every nonzero $\bb$. The topological factor recovers the lattice result of Mesaros et al. as a torsion-flux phase; 4-8 dislocations retain only the dispersive contribution. Composing Volterra elements gives the holonomy of defect complexes. At zero net Frank angle, it depends only on the net Burgers vector. The valley flux obeys a three-coloring rule: pentagons and heptagons contribute according to their Kekule site color, whereas squares and octagons do not. Atomic models confirm that ring content alone does not fix the phase: a 5-8-5 core is invisible as a divacancy or as a dislocation with $|\bb|=\sqrt3a$, but carries flux $\pm1/3$ for $\bb=2\mathbf a_1$. The torsion trace produces no geometric phase: its vector coupling violates time-reversal symmetry, while the allowed axial coupling causes only anisotropic short-range scattering.
In this work, we have presented S-I-S Josephson junctions with $\rm\alpha$-Ta electrodes and a ${\rm TaO}_x$ barrier. We grew base and top ${\alpha}$-Ta electrodes using seed layer engineering, showing both Nb and ${\rm TaN}_x$ are viable seed layer choices, and particularly emphasize that at room temperature a re-seed layer is required to nucleate $\rm\alpha$-Ta for the top electrode. However, we note that the choice of seed layer can have subtle implications on the electrical tunneling behavior of the junctions. We used room-temperature probing of variable junction areas, combined with Ambegaokar-Baratoff physics, to characterize the wafer scale critical current densities. For 0.4 $\mu$m$^2$ junctions, we found junction spreads as low as 2.0% across the 20 x 20 mm chip relevant for device performance. The entire process was carried out using standard industry foundry processing using 150 mm wafer tooling, which is an important step towards proving that Ta-based junctions can be implemented at scale. We have successfully fabricated and tested junctions with $\rm\alpha$-Ta electrodes and a ${\rm TaO}_x$ insulating tunnel barrier, demonstrating that this is a material platform which merits further investigation and studies for potential application in classical and quantum superconducting technologies.
Particle-resolved colloid simulations are often limited by the fastest microscopic time scale retained in the model, which can be many orders of magnitude shorter than the collective process of interest. This is especially restrictive for aggregating colloids, where explicit near-contact potentials force the time integration to resolve the rapid positional relaxation of bonded pairs within narrow attractive wells. Here we introduce an overdamped constraint-based Brownian dynamics method that replaces the time-resolved integration of stiff near-contact forces by a geometric projection step. After each free Brownian update, hard-sphere exclusion, sticky bonds, and hard-wall interactions are enforced by projecting the particle positions onto the constrained configuration set. The method preserves hard-sphere structure and diffusion, recovers the aggregation kinetics of sticky hard spheres, and extends the physical time reached at fixed computational cost by one to two orders of magnitude relative to the explicit-potential simulations tested here. This acceleration makes Brownian-dominated, low-P\'eclet electrophoretic deposition accessible to particle-scale simulations, revealing a pathway in which the suspension first densifies and only subsequently develops a bonded network. Implemented as a LAMMPS fix, the framework provides a modular route to long-time Brownian simulations of dense constrained colloidal systems.