When magnon propagates through a magnetic texture, the Hall effect arises as a prominent feature to characterize the underlying nontrivial magnetic topology, due to the action of the emergent pseudomagnetic field. Here, we propose a complementary framework based on the angular momentum conservation, which offers an intuitive yet quantitative toolkit to analyze the magnon deflection. Specifically, the spin and orbital components of the angular momentum carried by the magnon, as well as its redistribution along magnon trajectories are anatomized. Guided by the intrinsic constraint of angular momentum conservation, the magnon Hall angle is evaluated through the associated geometric features of the magnon trajectories.

The origin of stripe-domain (SD) formation in soft magnetic thick films remains unresolved, particularly in NiFe-based systems where SDs are often associated with columnar microstructure. Here, by combining fixed-thickness processing control, decisive reference samples, quantitative structural and magnetic analysis, and micromagnetic validation, we show that the experimentally determined effective anisotropy is the key controlling factor for SD formation. Columnar, microstructure in NiFe films is identified as an important, but nonunique, structural route for generating or enhancing this anisotropy. A pressure-tuned 350-nm NiFe series traverses labyrinth-SD, SD, and in-plane-domain states at fixed thickness, whereas an annealed 200-nm NiFe series exhibits systematic stripe broadening without a change in thickness. These data are complemented by an amorphous FeCoHf SD film and a 130-nm-thick columnar NiFe film without SDs. These two reference samples demonstrate that columnar microstructure is neither necessary nor sufficient for SD formation. Stripe-bearing and stripe-free states are separated more clearly by the experimentally determined effective anisotropy scale than by the mere presence of columnar geometry. Within the columnar NiFe family, the aspect ratio $h/w$ provides a useful structural proxy for stripe stabilization, and stripe broadening is quantitatively associated with reduced effective anisotropy. Minimal micromagnetic simulations reproduce both the shift of the SD-IP phase boundary and the increase in stripe period under reduced perpendicular anisotropy. We conclude that SD formation is governed by a processing-defined effective anisotropy landscape, within which columnar microstructure is an important structural route but not a universal prerequisite for stabilization.

Polar antiferromagnetic metals have recently attracted increasing interest due to their combined traits of both ferromagnets (with spin polarization) and antiferromagnets (absence of net magnetization) for spintronic applications. However, the inherently incompatible nature of antiferromagnetism, metallicity, and polarity pose a significant challenge in designing these materials. Herein we propose that charge disproportionation can lead to this novel state in the negative charge transfer gap regime in molecular orbital crystals. As a proof of concept, this proposal is demonstrated by molecular orbital analyses of first-principles density functional theory plus $U$ electronic band structures for the representative Ruddlesden-Popper bilayer perovskite oxide ${\mathrm{Sr}}_3{\mathrm{Co}}_2{\mathrm{O}}_7$, corroborated by density matrix renormalization group calculations. Due to the negative charge transfer nature of ${\mathrm{Co}}^{4+}$ and strong interlayer coupling, localized molecular orbitals stemming from the hybridization of Co $d_{z^2}$ and $d_{xz/yz}$ orbitals through the apical oxygen $p$ orbitals preferentially emerge within each bilayer unit and develop antiferromagnetic ordering by invoking Hubbard repulsion. Charge disproportionation driven by Hund's physics causes an occupation imbalance (with broken inversion symmetry) in the remaining $d_{xy}$ and $d_{x^2-y^2}$ orbitals from distinct Co atoms within the bilayer unit, resulting in the polar metallicity. Meanwhile, this charge disproportionation scenario allows consequent conducting carriers to couple with interlayer local spins via Hund's coupling, giving rise to in-plane double-exchange ferromagnetism. Our molecular orbital formulation further provides a guide towards an effective Hamiltonian for modeling the unconventional synergy of metallicity, polarity, and antiferromagnetism in ${\mathrm{Sr}}_3{\mathrm{Co}}_2{\mathrm{O}}_7$, which may be a unified framework widely applicable to double-layer Ruddlesden-Popper perovskite oxides.

Three-dimensional (3D) curvilinear nanomagnetism is an emerging field that has gained attention owing to modern advances in material engineering. Current experimental techniques now enable the fabrication of intricate ferromagnetic systems with 3D geometries, where curvature can induce asymmetry in magnon propagation and ultrafast chiral domain-wall dynamics. This paper reports on the formation and stability of conical-helix magnetic textures in thin ferromagnetic cylindrical nanotubes with interfacial Dzyaloshinskii-Moriya interaction (DMI) and radial magnetic anisotropy. It is found that geometry imposes a natural quantization of the helix wavelength along the azimuthal direction. The sign of the DMI strength ($D$) dictates the preferred handedness of the magnetization around the tube's circumference, leading to a notable asymmetry in the nucleation modes with respect to $D=0$, a curvature effect particularly pronounced at smaller radii. Finite-element micromagnetic simulations support the analytical predictions, showing how the magnon instability of the saturated state, in which the frequency of a particular mode vanishes at a critical field, correlates to the nucleation of the predicted magnetic textures at those fields. These findings provide guidelines for tailoring helical textures in ferromagnetic nanotubes with defined chirality, offering experimentally testable predictions for applications in spintronics, and a framework that can be extended to more complex curved three-dimensional magnetic nanostructures.

Interfacial magnetism in complex oxide heterostructures underlies both fundamental many-body physics and advanced spintronic applications. Here we report a pronounced stacking-order dependence of magnetic coupling in $\text{L}{\text{a}}_{0.78}\text{C}{\text{a}}_{0.22}\text{Mn}{\text{O}}_3/\mathrm{SrRu}{\mathrm{O}}_3$ (LCMO/SRO) bilayers. While Ru–O–Mn superexchange drives antiparallel spin alignment between interfacial Ru and Mn moments, macroscopic antiferromagnetic correlations emerge only within a proper thickness ratio range, consistent with first-principles calculations. Ferromagnetic enhancement—manifested as a significant increase in Curie temperature ($T_{\mathrm{C}}$)—occurs exclusively when LCMO is grown atop SRO, vanishing in the inverse stack. Atomically resolved structural analysis attributes this unidirectional phenomenon to suppressed Jahn-Teller distortions and preferential in-plane orientation of the LCMO crystallographic $c$ axis in the LCMO grown on SRO configuration, which together strengthen double-exchange interactions. Control experiments rule out interfacial charge transfer and Sr interdiffusion as primary mechanisms. These findings establish that stacking-sequence–induced structural asymmetry serves as a dominant control parameter for interfacial ferromagnetism, offering a deterministic route to engineer correlated oxide heterostructures.

We study theoretical models for charge reflectometry and capacitive readout of the Majorana parity degree of freedom in Majorana box qubits, considering decoherence channels within the framework of the Lindblad master equation. Noting that a parity-dependent dynamical susceptibility ${\chi }_z\left(\omega \right)$ governs both readout schemes, we provide a general expression for ${\chi }_z\left(\omega \right)$ which covers the full crossover from the resonant regime to the off-resonant dispersive regime. In addition, we reexamine previous results which were obtained under a semiclassical factorization assumption. Using three different error measures, we show that this approximation is quantitatively justified in the dispersive regime. In the resonant regime, however, we find deviations from exact reference data, obtained by numerical solution for the steady state of the full Lindblad equation. These deviations are typically of the order of a few percent in the considered error measures.

We report the growth and physical properties of single-crystalline $\mathrm{B}{\mathrm{i}}_2\mathrm{T}{\mathrm{a}}_3{\mathrm{S}}_6$ crystallizing in the $P{6}_3/mcm$ space group, which comprises alternating Ta-S layers and Bi layers with each Bi atom connected to adjacent S atoms. Temperature-dependent electrical resistivity measurements reveal a superconducting transition at 0.84 K, with an upper critical field of 231 Oe under an out-of-plane magnetic field. Magnetization measurements confirm its nature as a type-II superconductor, with anisotropic Ginzburg-Landau parameters ${\kappa }_{ab}=7.67$ and ${\kappa }_c=4.50$. Hall measurements reveal holes as the dominant species of charge carriers at room temperature. Hydrostatic pressure is applied, under which both the superconducting transition temperature and upper critical field increase sharply under low pressure before undergoing slight suppression under higher pressure. DFT calculations reveal nontrivial topological surface states on the (100) surface in $\mathrm{B}{\mathrm{i}}_2\mathrm{T}{\mathrm{a}}_3{\mathrm{S}}_6$, which may offer a new avenue for exploring potential topological superconductivity in layered transition metal dichalcogenides.

Iron chalcogenides exhibit rich phenomena which are governed by orbital-dependent electronic interactions and strong electronic correlation. In particular, many studies have explored orbital selectivity in FeTe through Se doping. Here, applying tensile strain to thin films allows us to precisely control the system without other impurities that may arise from chemical doping to investigate the emergent behaviors in FeTe. Using angle-resolved photoemission spectroscopy, we observe a spectral weight transfer between $d_{\mathrm{xy}}$ and $d_{{\mathrm{z}}^2}$ orbitals, evidence of an orbital-selective Mott phase (OSMP). Beyond OSMP, we reveal an unobserved strain-induced effects, distinct from chemical doping. The evolution of $d_{\mathrm{xz}}$ orbital demonstrates how electron hopping mechanism plays an important role in defining the electronic properties of the system. Our findings highlight a direct correlation between epitaxial strain and the evolution of electronic structures in FeTe.

We develop a general theoretical framework showing that Berry curvature of electronic bands can produce intrinsic optical bistability under circularly polarized illumination. The bistability arises directly from Maxwell's boundary conditions, which couple the transmitted circular field to a transverse current generated by the imaginary component of the incident field. This transverse response is governed by anomalous Hall conductivities originating from the Berry curvature. By combining these components, we obtain a self-consistent nonlinear input-output equation that has multiple stable transmission states, demonstrating that bistability can emerge solely from the material's Berry curvature, without relying on cavities, interference paths, or external feedback mechanisms.

The discovery of higher-order topological phases hosting boundary modes at hinges or corners has revolutionized our understanding of quantum materials. While axion insulators (AXIs) characterized by symmetry indicator ${\mathbb{Z}}_4=2$ are known to host chiral hinge states, the topological landscape of magnetic crystals with a trivial indicator ${\mathbb{Z}}_4=0$ remains largely unexplored. In this work, we demonstrate that a trivial symmetry indicator can mask a rich variety of topological phases, including Weyl semimetals with even pairs of Weyl points, trivial insulators, and weak second-order topological insulators (WSOTIs). We find that these WSOTIs are rooted in fragile topology and support robust chiral hinge states that mimic the signatures of AXIs, despite their distinct topological invariants and contrasting spin-polarization patterns. Through Wilson loops analysis and symmetry-compatible orbital coupling, we establish a generalized bulk-hinge correspondence for WSOTIs and demonstrate that external magnetic fields and surface engineering can precisely control the propagation of their hinge states. Finally, we propose a WSOTI-AXI heterostructure that functions as a tunable topological spin splitter. Our results provide a general framework for uncovering higher-order topology in fragile phases and suggest a platform for topological transport of spin polarization.

We present a semilocal parametrization of the kinetic-energy density enhancement factor and the associated Pauli potential derived from jellium-slab calculations, within the context of orbital-free density functional theory (OF-DFT). The parametrization is constructed directly from analytical results for slab model systems and exact-exchange Kohn-Sham calculations and is designed to simultaneously satisfy a set of exact constraints, including the correct behavior in both the three-dimensional ($3D$) bulk limit and the two-dimensional ($2D$) extreme quantum limit. In particular, our parametrization reproduces the exact constant value of the Pauli contribution to the noninteracting kinetic energy when only a single slab discrete level is occupied and successfully describes the full dimensional crossover of the noninteracting kinetic energy from the $3D$ bulk limit to the $2D$ extreme quantum limit. The associated orbital-free Pauli potential accurately captures the evolution of surface-induced Friedel oscillations near the bulk-vacuum interface. To our knowledge, this represents the first semilocal kinetic-energy functional and Pauli potential parametrized on the basis of explicit first-principles calculations, with the kinetic-energy density properly capturing the challenging $3D\to 2D$ dimensional crossover.

Superionic crystal possesses a crystalline sublattice and diffusive ions, which is therefore assumed to be a thermal insulator while an electrical conductor, i.e., an ideal thermoelectric. Indeed, some of them, such as ${\mathrm{Cu}}_2\mathrm{Se}$, show excellent thermoelectric performance, while some superionic crystals, such as ${\mathrm{Ag}}_2\mathrm{Te}$, only possess a modest thermoelectric performance. In this work, we demonstrate that the thermoelectric performance of superionic crystals is significantly affected by the Soret effect, which originates from the local enthalpy mismatch between cations and anions. Our results show that the negative Soret effect transport coefficient, characterized by antialigned heat and enthalpy currents as shown in ${\mathrm{Cu}}_2\mathrm{Se}$, hinders the energy transfer channels of both conduction and mass diffusion, while the positive Soret effect transport coefficient with aligned heat and enthalpy currents as observed in ${\mathrm{Ag}}_2\mathrm{Te}$, promotes both these energy transfer channels. Meanwhile, the Soret effect in superionic crystals generates the ionic Seebeck effect. The ionic Seebeck coefficient stemming from the Soret effect can be considerable. The thermoelectric performance of a material is inversely (directly) proportional to the energy transfer coefficient (the Seebeck coefficient). Therefore, while superionic crystals possess the same crystalline structures, their thermoelectric performance may vary significantly, e.g., the figure of merit of ${\mathrm{Cu}}_2\mathrm{Se}$ and ${\mathrm{Ag}}_2\mathrm{Te}$ is $\sim 3.0$ and $\sim 0.2$ at 900 K, respectively.

Lieb and kagome lattices exhibit two-dimensional topological insulator behavior with ${\mathbb{Z}}_2$ topological classification when considering spin-orbit coupling. In this study, we used a general tight-binding Hamiltonian with a morphological control parameter $\theta$ to describe the Lieb ($\theta =\pi /2$), kagome ($\theta =2\pi /3$), and transition lattices ($\pi /2<\theta <2\pi /3$) while considering intrinsic spin-orbit (ISO) coupling. We systematically investigated the effects of shear and uniaxial strains, applied along different crystallographic directions, on the electronic spectrum of these structures. Our findings reveal that these deformations can induce topological phase transitions by modifying the structural lattice angle associated with the interconversibility process between Lieb and kagome, the amplitude of the strain, and the magnitude of the ISO coupling. These transitions are confirmed by the evolution of Berry curvature and by changes in the Chern number when the gap closes. Additionally, by analyzing hypothetical strain scenarios in which the hopping and ISO coupling parameters remain intentionally unchanged, our results demonstrate that the strain-induced phase transitions arise from changes in the hopping and ISO coupling parameters.

We investigate the topological and nonlinear transport properties of uniaxially strained gapped graphene driven by polarized optical fields. We demonstrate that the interplay between optical polarization and lattice strain fundamentally reshapes the Berry curvature distribution, leading to a valley-dependent sign reversal of both the Chern number and the Berry curvature dipole (BCD). Specifically, circularly polarized light drives a valley-selective topological phase transition, which is explicitly manifested by the directional reversal of the nonlinear anomalous Hall current. Moreover, linearly polarized light breaks the residual mirror symmetry of the strained lattice, thereby activating a transverse BCD component that is strictly forbidden in the static limit. Our results uncover a valley-dependent photocontrol mechanism for topological order and Berry curvature distribution, paving the way for designing optovalleytronic devices based on light-matter interaction.

We demonstrate that topological insulators exhibit an intrinsic interfacial instability that amplifies small interface fluctuations, resulting in chaotic behavior during interface growth. This mechanism is different from conventional interfacial instabilities in crystal growth that are driven by external nonuniformities such as surface diffusion and instead arises from intrinsic electronic properties of topological materials. We find that the boundary states of topological insulators have a pronounced impact on the surface stiffness, which quantifies how strongly a surface resists changes in its shape or orientation. While trivial insulators possess positive stiffness that smooths out surface roughness, topological insulators exhibit negative stiffness that amplifies small shape fluctuations. We derive an effective equation of the interface growth with this negative stiffness and demonstrate that the interface dynamics is governed by the Kuramoto-Sivashinsky equation, a prototypical nonlinear equation exhibiting spatiotemporal chaos.

We investigate analytically and numerically the lateral optical binding force in non-Hermitian nanoparticle dimers with gain-assisted active response. In comparison with conventional plasmonic or dielectric nanostructures with passive behavior, the lateral binding force in an active dimer can be dynamically controlled by the external pumping level. Within a linear-response gain model, we show that in close proximity to a critical point the gain-assisted system can exhibit strong enhancement of the lateral binding force, switching between attractive and repulsive regimes, and the emergence of a pronounced transverse driving force. A variety of configurations are analyzed and discussed, including homo-/heterodimers made from multiple material components, different size parameters in geometry, and varying plane-wave illumination. The forces between the dimer structure are calculated using the Lorentz-force approach in the coupled dipole approximation, as well as rigorous numerical simulation using Maxwell stress tensor formalism, combined with the multiple-multipole scattering theory or a finite-element solver. The results provide a theoretical framework for gain-assisted control of optical forces at the nanoscale and clarify the physical scope of the predicted enhancement for future studies of optically bound matter.

Spin-orbit coupling (SOC) is incorporated into the phaseless plane-wave-based auxiliary-field quantum Monte Carlo (pw-AFQMC) method. This integration is implemented using optimized multiple-projector norm-conserving pseudopotentials, which are derived from the fully relativistic (FR) atomic all-electron Dirac-like equation. The inclusion of SOC enables accurate phaseless pw-AFQMC calculations that capture both electronic correlation and SOC effects concurrently, greatly improving the applicability of the method to studying systems containing heavy atoms. We discuss the form of FR pseudopotentials and detail the corresponding formulations of phaseless pw-AFQMC with a two-component Hamiltonian in the spinor basis. The accuracy of our approach is demonstrated by computing the dissociation energy of molecule ${\mathrm{I}}_2$ and the cohesive energy of bulk Pb, highlighting the large influence of SOC in both. Subsequently, we determine the transition pressure of the III-V compound InP from its zinc-blende to rock-salt phase by constructing and analyzing their respective equations of state.

This work systematically investigates the non-Hermitian chiral skin effect (NCSE) for topological edge states in a square-lattice Haldane model with staggered potential. We clarify two physically distinct mechanisms underlying NCSE: (i) boundary on-site gain/loss that introduces a complex momentum, and (ii) boundary nonreciprocal hopping that endows edge states with a complex Fermi velocity, a new mechanism unexplored in previous work. We show that the complex-Fermi-velocity mechanism yields three unique features absent in the gain/loss NCSE: a linear complex energy spectrum, particle-hole symmetry, and energy-dependent spatial separation of edge modes. We further provide a unified comparative framework for both mechanisms and propose a feasible LC circuit scheme to experimentally realize the NCSE via nonreciprocal hopping. Our results establish that the NCSE is a family of effects arising from distinct non-Hermitian perturbations, greatly extending the understanding and controllability of chiral skin phenomena in open topological systems.