Polymeric nitrogen frameworks are of interest for high-energy-density materials because their conversion to molecular ${\mathrm{N}}_2$ is associated with substantial energy release, while their experimental synthesis remains challenging. Here we combine particle-swarm structure prediction, first-principles calculations, and laser-heated diamond-anvil-cell experiments to investigate the phase stability and bonding of the In-N system under pressure. Two pressure-stabilized ${\mathrm{InN}}_{10}$ polymorphs were obtained experimentally, with in situ synchrotron x-ray diffraction and Raman spectroscopy supporting their assignment to tetragonal $I4$ at 55 GPa and orthorhombic Ama2 at 80 GPa. The $I4$ phase contains isolated pentazolate ${\mathrm{N}}_5$ rings, whereas the Ama2 structure contains an extended chain-ladder nitrogen framework involving ${\mathrm{N}}_{17}$-based motifs. Electronic-structure and bonding analyses indicate substantial charge transfer from indium to the nitrogen sublattice, with the dominant bonding contributions arising from covalent N-N interactions. The calculated energetic metrics show that Ama2 ${\mathrm{InN}}_{10}$ has a higher volumetric energy density than the other predicted In-N phases, associated with its higher packing density and extended nitrogen connectivity. The results establish two pressure-stabilized ${\mathrm{InN}}_{10}$ polymorphs with distinct ring-based and chain-ladder polynitrogen frameworks and clarify the role of indium in stabilizing different nitrogen connectivities under pressure.

Control of the orientation and size of magnetic domain structures is crucial for the proper functioning of various magneto-optical devices. Here we propose and demonstrate garnet-based heterostructures that allow stabilization of in-plane stripe domain orientation and period under certain conditions. This was achieved using a 5-$\mu \mathrm{m}$-thick epitaxial garnet layer covered with one-dimensional ferromagnetic metal gratings. Using optical polarization microscopy, we show that the interaction between the garnet film and Co/Au or (Co/Pt)${}_{10}$ gratings (with thicknesses on the order of tens of nanometers and periods close to the intrinsic domain width) leads to two key effects: (1) deviation of the stripe domains' orientation from the applied magnetic field direction toward the metal grating and (2) fixation of the stripe domain period within a specific range of external magnetic fields. Second harmonic generation microscopy confirms that this pinning effect is homogeneous throughout the entire thickness of the garnet film. These findings open opportunities for precise control over both domain orientation and width, thereby enhancing the stability of functional magneto-optical heterostructures.

We study the superconducting response induced by a Néel domain wall in a thin superconducting film proximity-coupled to a ferromagnetic layer in the presence of interfacial Rashba spin-orbit coupling. The combined action of the magnetic texture and broken inversion symmetry generates a magnetoelectric coupling that induces spontaneous equilibrium currents. To establish the basic response to a continuously rotating magnetic texture, we first consider a periodic harmonic cycloid as an analytically tractable reference problem. Near $T_c$, this reference problem illustrates how the magnetoelectric coupling modifies the superconducting order parameter, while below $T_c$ it provides a simple setting for describing the phase response, Pearl screening, and the interaction with a vortex. We then turn to the main problem of this work, a single Néel domain wall, and derive analytical expressions for its equilibrium phase profile, spontaneous current, magnetic field, and vortex-wall interaction energy. We show that the Néel wall acts as an extended magnetoelectric source and produces a vorticity-selective pinning landscape controlled by the competition between the wall width and the effective screening length. We further demonstrate that sufficiently strong magnetoelectric coupling can render a bound vortex-antivortex pair energetically favorable relative to the vortex-free state, even in the absence of an applied magnetic field. Our results provide an analytical framework for understanding magnetoelectric vortex pinning and vortex-antivortex nucleation by Néel domain walls in spin-orbit coupled superconducting films.

Basal plane dislocations (BPDs) in the epitaxial layer in 4H-SiC is one of the remarkable manufacturing issues because they degrade device performance. Although most BPDs are converted to threading edge dislocations (TEDs), some remain. Therefore, elucidating the mechanism of BPD-TED conversion is crucial for the enhancement of this process. In this study, we addressed this gap by analytically clarifying the contraction mechanism of partial BPDs, which is one of the main processes in BPD-TED conversion. We employed the dislocation dynamics method based on dislocation theories, which can precisely describe interactions between dislocations. Our method incorporates surface effects such as image force in addition to the elastic interaction between dislocations and stacking faults by calculating the stress derived from the surface. Using this method, we focused on the effect of a terrace and step riser comprising steps on the epitaxial surface. The results revealed that the depth of the BPD pair from the surface as well as the direction of the Burgers vectors relative to the step riser significantly influence the contraction of BPDs. In addition, we investigated a model with an off-angle to determine its effect on BPD contraction, which showed that the BPD width decreases for small off-angles and closed Burgers vectors. Therefore, a small off-angle can result in a high BPD-TED conversion rate, which is consistent with the experimental results. These findings were clearly explained by the forces exerted on dislocations by the surface-induced stress. Our computational model clarifies the mechanism of BPD-TED conversion and is expected to be applicable to other SiC epitaxy conditions.

Altermagnets combine compensated magnetic order with unconventional symmetry-dependent responses, offering a promising platform for spintronic applications. Here, we show that a voltage-controlled magnetic-anisotropy gradient drives altermagnetic (ATM) skyrmions in a rectilinear, Hall-free motion in the absence of thermal fluctuations, owing to their strongly compensated gyrotropic response. Thermal magnons qualitatively modify this behavior by increasing the longitudinal drag through magnon-skyrmion scattering and generating a transverse reaction force through handedness-dependent skew scattering. Owing to the anisotropic altermagnetic magnon band structure, the relative transport weights of the two magnon handednesses are interchanged between propagation along the $x$ and $y$ directions, resulting in opposite signs of the Hall angle for driving along the $x$ and $y$ directions. By contrast, along the high-symmetry direction, the two magnon handednesses remain degenerate and their transverse contributions cancel, preserving Hall-free motion even at finite temperature. We thus uncover a thermally emergent anisotropic skyrmion Hall effect whose direction-dependent magnitude and sign originate from the intrinsic symmetry-dependent magnon spectrum, making it a generic finite-temperature dynamical feature of ATM skyrmions. Our results establish a low-power route toward electrically controlled and thermally tunable ATM skyrmion transport.

Establishing a versatile, fast, and reliable magnetic memory technology is a giant bottleneck for cryogenic computing since present-day room-temperature solutions either cease to work or consume too much power. The long-term goal of superconducting spintronics has been to overcome this bottleneck by creating magnetic memories with equal-spin triplet supercurrent driven through them to control their magnetization direction. This path has been hampered by the short spin relaxation length and strong anisotropy in ferromagnets. Here we show how the supercurrent driven generation of spin accumulation in a superconductor/magnetic insulator bilayer together with Gilbert damping of magnetization lead to a motion of magnetic domain walls. This manifests as a local voltage across the wall, which allows its position to be identified. Associated with this voltage and the current is Joule power, which is dissipated via the Gilbert damping. The power required to maintain domain wall motion is orders of magnitude smaller than in the normal state, where most of the power is wasted in maintaining the current.

Accurate models of planetary formation and evolution rely on equation-of-state (EOS) models for their constituent materials across wide ranges of pressure, temperature, and density. Currently, estimates of thermoelastic properties along Earth-like pressure and temperature adiabats (the geotherm) require extrapolation of laboratory data, which confounds clear interpretation of the physical and chemical states of planetary interiors. We designed experiments on the Z Machine at Sandia National Laboratories to directly measure the EOS and sound speeds in dense oxides along quasi-isentropes close to the geotherm using shock-ramp compression. Here we demonstrate the method on magnesium oxide, representing the major nonsilicate mineral in the mantle, to pressures exceeding Earth's core. Our observations up to 400 GPa are confirmed by independent density functional theory and quantum Monte Carlo predictions and indicate the experimental compression path is close to a 1900 K geotherm. The results show excellent agreement with the preliminary reference Earth model (PREM), suggesting the technique can produce highly accurate thermoelastic data useful for interpreting the internal structure of terrestrial planets.

It is well established that the high-pressure $\beta$-Sn silicon phase converts to the low-pressure BC8 phase during decompression, however the transformation mechanism linking them is less clear with the differing energy barriers and intermediates reported in the literature. In this work, we use density functional theory to find a thermally activated process consistent with experiments when the decompression rate is low. Nudged elastic band calculations identify the mechanistic transformations and show that the displacive reaction involves multiple changes of coordination, from six to eight to five to four. Close to the minimum energy path is a highly symmetric pentavalent structure which resembles molecular ${\mathrm{SiH}}_5^{-}$, and we name Si-220 after its space group. Although the structure is only stable at pressures above 10 GPa, it appears as a saddle point at lower pressures and can directly transform into all three low-pressure phases BT8, R8, and BC8. Although we do not expect Si-220 to be observable in the laboratory, knowledge of its presence helps to resolve the conflicting pathways and the multitude of BC8-like structures seen in experiments.

The microscopic dynamics of metallic glasses are fundamentally governed by their out-of-equilibrium state. In this study, we combine synchrotron x-ray photon correlation spectroscopy with atomistic simulations to track the evolution of structural dynamics from the out-of-equilibrium glassy solid into the metaequilibrium state. The experiments reveal a clear transition from compressed- to stretched-exponential dynamics driven by physical aging. In contrast, the simulations consistently exhibit stretched-exponential behavior across all tested conditions, including zero pressure and applied hydrostatic stress. Despite these qualitatively different initial responses, we demonstrate here that both experimental and computational approaches converge toward a common metaequilibrium stretched relaxation shape with $\beta \approx 0.8$. Further, in this regime both experiment and simulation exhibit de Gennes narrowing in the relaxation timescale and shape parameter, a behavior that emerges in the experiments even before the metaequilibrium state is reached. Ultimately, the absence of compressed-exponential dynamics in simulated quenched-in and pressurized states indicates that the experimental as-cast state possesses a distinct dynamical fingerprint whose exact structural origin continues to remain unresolved.

Discovering antiferromagnetic materials with a sizable colossal magnetoresistance (CMR) effect and precisely tuning their responses remain significant challenges in materials science. This work reports the synthesis, phase transitions, and magnetotransport properties of the narrow-gap Zintl arsenide ${\mathrm{Eu}}_2{\mathrm{CdAs}}_2$. The compound undergoes antiferromagnetic ordering at $T_{\mathrm{N}}=9\mathrm{K}$ and exhibits semiconducting behavior with a low-temperature activation energy of 3.2 meV, achieving a large CMR effect of $-{10}^4\%$ at 9 T. Below $T_{\mathrm{N}}$, a distinct butterfly shaped magnetoresistance hysteresis emerges without any macroscopic ferromagnetic order, revealing a transport anomaly likely dictated by AFM domain dynamics and/or the formation and percolation of localized magnetic polarons. Furthermore, a systematic survey of reported Eu-based Zintl phases uncovers a nearly exponential scaling trend between the maximum CMR magnitude and the low-temperature activation energy. This correlation demonstrates that band-gap engineering serves as an effective strategy for tailoring magnetotransport, establishing Eu-containing Zintl phases as a versatile platform for exploring and manipulating CMR effects.

A generalized expression for the relaxation time of dipolar-interacting magnetic nanoparticles is derived by extending the Kramers-Brown escape-rate theory within the Tsallis statistical framework. A coarse-grained microscopic motivation is developed for the fluctuation-dominated superdiffusive regime, whereas the subdiffusive regime is treated as an effective phenomenological description of configurationally confined relaxation in strongly interacting assemblies. The resulting relaxation law describes both slower and faster dynamics relative to the Néel-Brown limit. The experimental systems considered here primarily probe the subdiffusive regime, while the quantitative validation of the microscopic relation proposed for the superdiffusive regime remains an open question. The theory yields a natural kinetic interpretation of the $T_{\mathrm{cutoff}}$ temperature as a characteristic freezing scale associated with configurational confinement, collective slowing down, and glasslike dynamics within the nonextensive framework and Néel-Brown relaxation theory, thereby contributing to ongoing discussions regarding collective slowing down phenomena in interacting nanoparticle systems.

We develop a symmetry-controlled theory of anisotropic thermomagnonic torques in insulating altermagnets. Starting from the stochastic Landau-Lifshitz-Gilbert equations, we identify a spin-splitter magnonic torque associated with thermally generated, sublattice-odd spin currents and an anisotropic entropic torque dictated by crystal symmetry. These torques produce anisotropic magnetic-texture responses to temperature gradients. In particular, thermally generated spin currents induce domain-wall precession, which reduces domain-wall velocities for selected gradient directions. We also predict an anisotropic skyrmion Hall response, with symmetry-selected directions enabling fast skyrmion motion with strongly suppressed transverse deflection. Our results reveal experimentally testable symmetry fingerprints of insulating altermagnets and extend more broadly to anisotropic magnets with exchange-driven magnon spin splitting.

Entanglement asymmetry, used here as a direct probe of symmetry restoration, provides a sharp diagnostic of postquench dynamics. We test this idea in the complex Sachdev-Ye-Kitaev (cSYK) model with a conserved U(1) charge. We numerically track the joint evolution of entanglement entropy and entanglement asymmetry after quenches from charge asymmetric product states. We find rapid volume law entanglement growth and late time subsystem equilibration in the cSYK dynamics, accompanied by a concurrent decay of entanglement asymmetry to a late time plateau set by finite-size effects: Small subsystems display near complete restoration, while residual cross sector weight yields a finite plateau. For the system sizes, initial states, and parameters studied, the cSYK model exhibits faster entanglement growth and subsystem symmetry restoration than the XXZ model and a spin-polarized one-dimensional fermion chain after a common energy scale normalization. In the disorder averaged cSYK dynamics, tilted ferromagnetic states with larger initial asymmetry can relax faster and reach lower late time asymmetry plateaus, exhibiting the quantum Mpemba effect. No crossing of the entanglement asymmetry curves is observed for tilted Néel states within the same parameter window. We further derive a Pinsker-type lower bound relating entanglement asymmetry to the purity difference between the reduced density matrix and its U(1) dephased counterpart. These results highlight entanglement asymmetry as a probe of subsystem symmetry restoration and characterize the residual asymmetry at finite sizes in the cSYK model.

Bilayer metasurfaces offer abundant degrees of freedom and remarkable design flexibility for tailoring bound states in the continuum (BICs) through both interlayer and intralayer coupling compared with a single-layer metasurface. In this work, we present a comprehensive investigation of topological dynamics of BICs in bilayer metasurfaces. By appropriately adjusting the interlayer spacing, Fabry-Pérot BICs (FP-BICs) are successfully constructed at the $\mathrm{\Gamma }$ point in momentum space, which correspond to merging BICs carrying different topological charges whose quality factors ($Q$ factors) follow the scaling law $Q\propto k^{-4}$ or $Q\propto k^{-6}$. We investigate topological charge evolution of BICs for bonding and antibonding modes under both transverse electric (TE) and transverse magnetic (TM) polarizations in bilayer metagratings. A viable approach of achieving customized BICs at prescribed $k_x$ and $k_y$ in momentum space is proposed by simply tuning the interlayer distance. Furthermore, we show that bilayer metasurfaces and photonic crystal slabs serve as powerful platforms for exploiting rich topological dynamics of BICs. In particular, degenerate merging FP-BICs are demonstrated in bilayer metasurfaces with $C_{4v}$ symmetry, where distinct merging dynamics are strongly dependent on the eigenfield distributions. When reducing the $C_{4v}$ symmetry to $C_{2v}$, the degeneracy of BICs can be removed. In addition, we also show that an in-plane displacement between the two layers provides a convenient route for tailoring circularly polarized points in momentum space. Our results provide general guidance for designing BICs with unique topological dynamics in momentum space, and hold great promise for developing applications in nanophotonics.

Computational discovery of magnetic materials remains challenging because magnetism arises from the competition between kinetic energy and Coulomb interaction that is often beyond the reach of standard electronic-structure methods. Here we tackle this challenge by directly solving the many-electron Schrödinger equation with a neural-network variational Monte Carlo technique, which provides a highly expressive variational wave function for strongly correlated systems. Applying this technique to transition metal dichalcogenide moiré semicondutors, we predict itinerant ferromagnetism in ${\mathrm{WSe}}_2$/${\mathrm{WS}}_2$ and an antiferromagnetic insulator in twisted $\mathrm{\Gamma }$-valley homobilayer, using the same neural network without any physics input beyond the microscopic Hamiltonian. Crucially, both types of magnetic states are obtained from a single calculation within the $S_z=0$ sector, removing the need to compute and compare multiple $S_z$ sectors. This significantly reduces computational cost and paves the way for faster and more reliable magnetic material design.

We show that the gate-to-channel capacitance in magnetically doped topological insulators allows access to information on bulk conductivity. We found that unlike resistivity, capacitance directly reveals the presence of two different types of bulk insulators. Furthermore, the capacitance captures the different topology of the two insulators. We also found that deep on a quantized plateau, changes in the low value conductivity of the bulk remain detectable via capacitance. We conclude that the combination of capacitance and transport in Hall bars enables a comprehensive investigation of the interplay of bulk and edge effects in magnetically doped topological insulators.