We demonstrate that nontrivial multiband topological invariants of electronic wave functions can be revealed through orbital magnetization responses to external magnetic fields. We find that decomposing orbital magnetization into energetic and quantum-geometric contributions allows one to deduce nontrivial multiband topology, provided knowledge of the energy spectrum. We showcase our findings in general effective models with multiband Euler topology. We moreover identify such multiband topological invariants in effective models of strontium ruthenate (${\text{Sr}}_2\text{Ru}{\text{O}}_4$), which may in principle be verified in the state-of-the-art doping-dependent magnetization measurements. Our reconstruction scheme for multiband invariants sheds a topological perspective on the multiorbital effects in materials realizing unconventional phenomenologies of orbital currents or multiband superconductivity.

Magnetic kagome materials have emerged as a new platform for exploring exotic topological transport phenomena. The anomalous Hall effect, a phenomenon prevalently observed in various magnetic kagome materials, is commonly explained using Berry-curvature concepts. Here we report that ${\mathrm{MgMn}}_6{\mathrm{Ge}}_6$, a kagome helimagnet exhibiting a spin-flop transition under magnetic field parallel to the kagome plane, displays a large anomalous Hall conductivity (AHC) of 1179 S/cm at 5 K. The intrinsic AHC reaches approximately 377 S/cm, which is consistent with theoretical calculations and ranks among the highest values reported in magnetic R166 systems. We further reveal that the intrinsic AHC originates from the topological nodal rings at the Fermi level, where a large Berry curvature is induced by the spin-flop transition that breaks time-reversal symmetry. In addition, a pronounced topological Hall effect conductivity of up to 900 S/cm is clearly observed under a magnetic field applied along the [001] $c$-axis direction, strongly indicating the existence of topological magnetic textures. Our results suggest that ${\mathrm{MgMn}}_6{\mathrm{Ge}}_6$ serves as a promising platform for investigating large anomalous transport responses and their interplay with magnetic topological textures.

High-harmonic generation (HHG) in strongly correlated Mott insulators is investigated using exact diagonalization and time-dependent density-matrix propagation of a laser-driven one-dimensional Hubbard chain. By projecting onto equilibrium Hubbard bands, we use the doublon population and its dynamics as a diagnostic to analyze intraband (spin-wave-like) and interband (doublon-holon creation) excitation channels. A filling-dependent crossover emerges: Bloch-like intraband response at dilute filling, mixed dynamics at intermediate filling, and interband-dominated HHG with plateau and cutoff near half-filling. In the considered parameter range, increasing interaction strength $U$ strongly suppresses interband contributions through the enlarged Mott gap and correlation-induced localization. Intra- and interband current decomposition reveals opposing flows below the Mott gap (${\mathrm{\Delta }}_{\mathrm{Mott}}$) and selective dephasing suppression of interband coherence, enhancing net doublon accumulation. Time-frequency analysis uncovers the filling-dependent features of quantum trajectories, manifesting in distinct below-${\mathrm{\Delta }}_{\mathrm{Mott}}$ emission. This doublon-based analysis provides a transparent link between equilibrium spin-charge separation and nonequilibrium strong-field response, and clarifies how dephasing modifies interband coherence and doublon accumulation.

Circuits based on superconducting nanostructures are among the most promising platforms for quantum computing. Understanding how device geometry governs nonlinear electrodynamics is crucial for implementing superconducting quantum technologies. However, to date, research has largely been limited to superconducting nanostructures with collinearly aligned static and dynamic applied magnetic fields. Here, we analyze the dynamics of Meissner currents and Abrikosov vortices in a superconducting nanocube exposed to combined static and microwave magnetic fields, extending the analysis to a more general excitation geometry. We demonstrate that, in a noncollinear configuration, the magnetization component parallel to the static field develops a dominant second-harmonic response under the microwave driving. This effect is strongly enhanced when Meissner currents saturate at static fields just below the thresholds for successive vortex nucleation. By numerically solving the time-dependent Ginzburg-Landau equations, we show that the response originates from Meissner-current saturation combined with the nonlinear oscillations of normal-phase indentations, yielding an anisotropic second-harmonic signal that is directionally separated from, and not overshadowed by, the first-harmonic component of the dynamic magnetization. These findings are relevant for superconducting devices that require controllable high-frequency nonlinearity.

Altermagnetism, characterized by pronounced momentum-space spin splitting without net magnetization, provides an emerging platform for spintronics. Yet nonvolatile control of its spin states remains a key challenge for device application. Here, we demonstrate that antiferroelastic lattice distortions offer a universal structural mechanism for controlling altermagnetism by directly locking the momentum-space spin texture to the antiferroelastic structural order parameter $\eta$. In contrast to ferroelastic distortions, which involve uniform strain, antiferroelasticity consists of oppositely staggered lattice distortions with zero macroscopic strain, analogous to antiferroelectricity (zero net polarization) or antiferromagneticity (zero net magnetization), thereby introducing a hidden structural degree of freedom. Reversal of $\eta$ ($+\eta \to -\eta$) enforces inversion of the altermagnetic spin splitting without Néel vector reversal or net magnetization, providing a low-energy pathway for nonvolatile control. Guided by this principle, we identify a family of antiferroelastic altermagnets, spanning from two-dimensional monolayers (e.g., $\mathrm{Cr}{\mathrm{S}}_3$) to three-dimensional compounds (e.g., $\mathrm{N}{\mathrm{a}}_3\mathrm{Mn}{\mathrm{S}}_4$). Both $\mathrm{Cr}{\mathrm{S}}_3$ and $\mathrm{N}{\mathrm{a}}_3\mathrm{Mn}{\mathrm{S}}_4$ exhibit robust lattice-spin coupling, where biaxial strain triggers antiferroelastic phase transitions accompanied by an inversion of spin-splitting energy (about 396 meV for $\mathrm{Fe}{\mathrm{S}}_2$). Our results establish antiferroelasticity as a general materials design paradigm for strain-driven switchable altermagnets and open avenues for nonvolatile-control spintronic devices.

The process of spin-transfer torque in an altermagnet (AM) is theoretically investigated from the perspective of disparate effective exchange fields acting on the two sublattices. The momentum dependent, anisotropic spin splitting in the AM band structure can cause this asymmetry, leading ultimately to a net uncompensated torque to the Néel vector through preferential absorption of injected electron spins by one of the sublattices. A theoretical model based on this skewed electron spin angular momentum transfer to sublattice magnetizations is developed to account for the effect phenomenologically in the Néel vector dynamics. A subsequent analysis clearly illustrates that a spin-polarized current injection can induce the Néel vector motion in an AM closely resembling that of the magnetization in a ferromagnet under spin-transfer torque. Numerical calculations in a magnetic tunnel junction geometry establish the conditions for a range of responses including deterministic ${180}^{\circ }$ switching and self-oscillations in terms of the injected spin-polarized current density and characteristic material properties. Clearly, the order parameter in an AM with sufficiently strong spin-dependent anisotropy can be modulated effectively via electrical control just as in a ferromagnet, while retaining at the same time advantages attributed to antiferromagnetic dynamics.

We study the impact of off-resonant tunneling and coherences on the electron pumping through quantum dots. Thereby, we focus on two electron-pump setups where lowest-order tunneling processes are suppressed and the pump is exclusively driven by modulations of the coupling energy. The first setup is driven by switching on and off the couplings between the quantum dot and the leads, while the second setup employs measurements of the dot occupation. We derive exact solutions for arbitrarily strong tunnel couplings in the absence of Coulomb interaction, identify parameter regimes with optimal pumping currents or optimal energy efficiency, and discuss similarities between both pumping mechanisms.

We present a theoretical analysis of interface states emerging at junctions between armchair graphene nanoribbons of varying widths. By exploring diverse width combinations and junction geometries, we demonstrate that predicting the precise number of interface states requires considerations beyond the topological classification alone; specifically, the width differences and bonding configuration at the interface play crucial roles. For junctions involving ribbons with small gaps, we further examine how an applied strain affects their topological properties and, consequently, the interface states formed. The spin states at these junctions are investigated using the mean-field Hubbard model, revealing how the magnetic behavior at the interface depends on the number of localized states present. These results are summarized in a series of “rules of thumb” to predict the number of localized states and the magnetic moment at the junction. Our findings contribute to understanding and engineering localized states in graphene-based devices, providing guidelines for manipulating electronic and magnetic properties through structural design.

The fate of quantum entanglement at finite-temperature phase transitions remains an open question, particularly for continuous symmetry breaking where zero-temperature Goldstone modes generate long-range correlations. Using large-scale quantum Monte Carlo simulations, we investigate the third Rényi negativity across the $O\left(3\right)$ transition in the three-dimensional Heisenberg antiferromagnet, studying a thermal critical point with continuous symmetry. We uncover two fundamental results. First, the negativity exhibits a pure area law at the critical point, with the subleading constant term vanishing within statistical uncertainty. This demonstrates that thermal fluctuations completely destroy the long-range entanglement present at zero temperature. The divergent classical correlation length leaves no imprint on such quantum entanglement. Second, despite this absence of singular behavior in the negativity, its temperature derivative follows the exact scaling of the specific heat, yielding critical exponents $-\alpha /\nu \approx 0.190$ and $1/\nu \approx 1.350$ in precise agreement with the $O\left(3\right)$ universality class. Our work establishes that while quantum entanglement is blind to thermal criticality its thermodynamic derivatives encode the full universal scaling, revealing an unexpected connection between entanglement and classical phase transitions.

The Hall effect provides a route for unidirectional manipulations of classical and quantum waves. In optics, the spin Hall effect (SHE) induced by the interaction between intrinsic angular momentum (AM) and material inhomogeneity enables AM-dependent control of light at the subwavelength scale. Despite its significance across various bulk and nanostructured geometries, the effect of non-Hermiticity on the optical Hall effect is generally assumed to be trivial except at the exceptional points in parity-time symmetric systems with tailored gain and loss. Here, we demonstrate the nontrivial Hall effect for light carrying both spin and orbital AM in a general non-Hermitian medium by revealing the emergent Hall shifts which rely solely on loss/gain of the systems. We demonstrate that loss or gain at a simple sharp interface introduce a spectral-selective absorption of light through a complex-valued geometrical phase, leading to AM-related corrections to the usual transverse SHE, including the transverse momentum shift, and the spin-orbit and nonlinear orbital Hall shifts along the longitudinal direction. We also propose to engineer and enhance the Hall effect with non-Hermitian gradient metasurfaces. We generalize the analysis to the propagation of light in inhomogeneous continuous media in the framework of geometrodynamics and identify the anomalous velocities due to non-Hermiticity as the counterparts of the interfacial Hall effect. Our work not only deepens our understanding of the Hall effect but also enables subwavelength light manipulations in non-Hermitian optical systems.

The self-energy encodes the fundamental lifetime of quasiparticle excitations. In one dimension, it is known to display anomalous behavior at zero temperature for interacting fermions, reflecting the breakdown of Fermi-liquid theory. Here we show that the self-energy is also anomalous in the infinite-temperature Hubbard chain, where thermal fluctuations are maximal. Focusing on the second-order ring diagram, we find that the imaginary part of the self-energy diverges nonperturbatively: as a power law with exponent $-1/3$ near half filling, and logarithmically away from it. These divergences are captured numerically by the anomalous temporal relaxation of the Green's function and the composite fermion spectral function. Our results demonstrate that anomalous relaxation and the breakdown of perturbation theory survive even at maximal entropy, which can be observed in cold-atom experiments probing the Hubbard chain at high temperatures.

Using crystal structure prediction and first-principles calculations, we show that the Li-Xe system exhibits diverse structural, electronic, and dynamical behaviors under pressure. Lithium-rich phases display electride character, with interstitial electrons dominating the states at the Fermi level, leading to metallicity and phonon-mediated superconductivity with superconducting transition temperatures of approximately 9–14 K. In contrast, xenon-rich phases transition into a superionic state at elevated temperatures, characterized by Li ions becoming increasingly mobile within a rigid Xe lattice before melting at higher temperatures. These results reveal the dual nature of Li-Xe compounds, combining interstitial electron driven superconductivity at low temperatures with ion diffusion mediated superionicity at high temperatures, providing insights into noble-gas chemistry under extreme conditions and potential implications for planetary interiors.

With first-principles theoretical and symmetry analysis, we establish that (${\mathrm{PbMnO}}_3{)}_1$/(${\mathrm{PbVO}}_3{)}_1$ superlattice is a multiferroic with coexisting ferromagnetism, ferroelectricity, and Berry curvature dipole. Transfer of electronic charge from ${\mathrm{V}}^{4+}$ to ${\mathrm{Mn}}^{4+}$ is shown to drive (a) polar (${\mathrm{\Gamma }}_5^{-}$ symmetry) distortion dominated by ${\mathrm{V}}^{5+}$ ($d^0$) displacements, and (b) Jahn-Teller distortion of ${\mathrm{Mn}}^{3+}{\mathrm{O}}_6$ octahedra to open up a gap. Berry curvature and associated spin-polarized Berry curvature dipole are of magnitude comparable to that of Weyl semimetals composed of heavy elements with strong spin-orbit coupling. Integrating Berry curvature dipole with magnetoelectric multiferroic behavior of the heterostructure ${\mathrm{PbMnO}}_3$:${\mathrm{PbVO}}_3$ gives a combination of magnetoelectric coupling and electrically switchable anomalous Hall effects. The sign and spin-polarization of dc nonlinear transverse Hall voltage, generated by a longitudinal ac electric field, encodes nonvolatile four-state memory in a Hall device, making it useful for oxide electronics and spintronics.

We investigate signatures of quantum chaos in the mixed-field quantum Ising model on finite-size Erdős–Rényi graphs using probes scalable on near-term quantum devices. Upon tuning the graph connectivity, the system exhibits a crossover from a localized regime at low connectivity, through a chaotic regime at intermediate connectivity, to a permutation-symmetric integrable limit near all-to-all connectivity. This crossover has possible implications for the performance and trainability of variational algorithms such as QAOA. We characterize this crossover in finite-size systems using complementary probes. First, deep thermalization of a projected ensemble starting from a product state reveals slow (fast) convergence to the Haar ensemble at extremal (intermediate) connectivities. Second, we analyze eigenstate and eigenvalue correlations using the partial spectral form factor, an experimentally scalable proxy for the spectral form factor with reduced resource overhead, and observe characteristic chaos signatures at intermediate connectivities and distinct deviations at extremal connectivities. Finally, we explore the Krylov complexity of operators, a locality-independent diagnostic that, although not directly experimentally accessible, serves as a tool for quantifying scrambling. We show that it is maximized deep in the chaotic regime, corroborating the signatures observed through the experimentally scalable probes. Our results provide finite-size benchmarks demonstrating robust signatures of chaos in scalable probes and suggest that these diagnostics can be implemented in current quantum platforms to access regimes beyond classical simulation.

We demonstrate that the Kibble-Zurek mechanism holds for open systems transitioning from a disordered phase to a discrete time crystal (DTC). Specifically, we observe the characteristic power-law scaling with quench time of the number of spatial defects and the transition delay measured from the time at which the system crosses the critical point. We show analytically that this universal behavior can be traced back to how systems that can be mapped onto a dissipative linear parametric oscillator (DLPO) satisfy the adiabatic-impulse approximation, evinced by the divergence of the relaxation time of the DLPO near a critical point. We verify our predictions in both the classical and quantum regimes by considering two systems: the sine-Gordon model, which is a paradigmatic system for emulating classical DTCs, and the open Dicke lattice model, an array of spin-boson systems subject to quantum fluctuations. We establish a universality class for DTC formation in systems that can be mapped onto a DLPO, and we show that the classical and quantum models considered here belong to this class.

We propose a semiclassical framework for solving open quantum dynamics in driven-dissipative spin systems. Our method consists of generalized spin-wave approximations tailored to describing quantum trajectories unraveled from the master equation, and it generically applies to regimes beyond the reach of conventional spin-wave theories, including short-range interactions and local quantum jumps, enabling the efficient simulation of large-scale interacting spins. We illustrate the versatility of our framework by studying a variable-range driven-dissipative Ising model on a two-dimensional lattice. When the dissipation acts along the drive axis, we find a continuous phase transition breaking the ${\mathbb{Z}}_2$ symmetry, and we demonstrate that the interaction range, when tuned from fully connected to nearest-neighbor, profoundly alters the universality class of the criticality. With the dissipation along the interaction axis, we show the emergence of a first-order transition. Demonstrated with both state-diffusion and quantum-jump types of trajectory dynamics, our framework provides a powerful toolbox for the efficient semiclassical description of nonequilibrium dynamics and many-body phases in spin systems.

Isotopic substitution modifies nuclear masses without altering the electronic potential-energy surface to first order and is therefore often interpreted as a simple rescaling of vibrational frequencies. In solids with dense phonon manifolds, however, mass substitution acts as a parametric Hermitian deformation of the mass-weighted dynamical matrix, generating a continuous family of eigenproblems whose eigenvectors can undergo substantial rotation within coupled subspaces. Here, we investigate hydrogenated and deuterated ZIF-8 using inelastic neutron scattering and density-functional theory lattice-dynamics calculations. While many vibrational modes exhibit near-ideal mass scaling and preserve their character across isotopic endpoints, modes embedded in spectrally congested regions display pronounced redistribution of vibrational character that cannot be inferred from frequency shifts alone. Because inelastic neutron-scattering intensity is directly weighted by hydrogen displacement amplitude, spectral sparsity and congestion provide experimental indicators of predictable frequency renormalization or susceptibility to qualitative eigenvector reorganization under deuteration. To establish physically meaningful mode correspondence, we develop an adiabatic eigenvector-continuation framework with overlap-based tracking and explicit stability diagnostics. These results show that vibrational identity in complex framework materials is best understood as a continuous trajectory in eigenvector space and provide a general framework for analyzing isotope-induced spectral flow in dense phonon systems.

Two-dimensional unconventional magnetism has recently attracted growing interest due to its intriguing physical properties and promising applications in spintronics. However, existing studies on stacking-induced unconventional magnetism mainly focus on specific materials and stacking configurations. Here, we develop a general symmetry-based stacking theory for two-dimensional magnets. We first introduce spin layer groups as the fundamental symmetry framework, providing the essential magnetic symmetry information for the stacking theory. Based on this framework, we construct the complete set of 448 collinear spin layer groups for describing two-dimensional collinear magnets. Subsequently, we develop a general magnetic stacking theory applicable to arbitrary magnetic systems and derive its general solutions. Using ${\mathrm{CrF}}_3$ as an illustrative example, we show how this theory enables designs of two-dimensional unconventional magnetism, as validated by first-principles calculations. We realize two-dimensional fully compensated ferrimagnetism through our stacking theory. Our work provides a general symmetry-guided platform for discovering and designing stacking-induced unconventional magnetism.

We show here using atomistic simulations that NiO stripes can be used as waveguides for antiferromagnetic spin waves or domain walls. We numerically demonstrate some of their salient features including their fast velocity over 40 km/s and their interesting propagation properties enabling them to cross ${90}^{\circ }$ corners unscathed, their possible conversion into one another when changing the stripes widths, and their self-interaction. Their exotic behavior offers promising opportunities for building resilient, low-power, and ultrafast logic gates.

We investigate the ground-state magnetic structure of the spin-$1/2$ XXZ antiferromagnet on the triangular lattice in the easy-axis regime using the density-matrix renormalization group. By applying spiral boundary conditions, we exactly map finite $L\times L$ clusters onto one-dimensional chains while avoiding the spatial anisotropy inherent in cylindrical geometries. From symmetry-broken local magnetization profiles, we extract the three-sublattice moments and track their evolution with anisotropy. At the isotropic point, we obtain a positive sublattice moment of 0.217(3), consistent with previous numerical estimates. In the easy-axis regime ($\mathrm{\Delta }=J_z/J_{\perp }>1$), the ordered moments remain close to a Y-like zero-magnetization three-sublattice state, whose $z$-component pattern is of the form $(2m,-m,-m)$, over a broad range of $\mathrm{\Delta }$. Extrapolation in $1/\mathrm{\Delta }$ shows that the positive sublattice moment stays well below the classical saturation value $1/2$, approaching 0.419(7) as $\mathrm{\Delta }\to \infty$, while the magnitude of the negative sublattice moment approaches 0.209(4). We further compare the energies of the Y state and the up-down-down state and find that the Y state is favored at zero field. Independent thermodynamic-limit energy calculations, performed without assuming any particular ordered pattern, yield an energy consistent with the Y-state solution. These results show that the easy-axis ground state does not simply cross over to a trivially saturated collinear Ising state, but instead remains a nontrivial three-sublattice ordered state selected from the macroscopically degenerate Ising manifold by quantum fluctuations.