We theoretically investigate spin-dependent transport in altermagnet/triplet-superconductor/altermagnet (AM/TSC/AM) junctions in the presence of interfacial Rashba spin-orbit coupling (RSOC). Within a microscopic Bogoliubov–de Gennes scattering formalism, we compute angle- and energy-resolved conductance, spin polarization, zero-bias response, and tunneling magnetoresistance (TMR) for nodal $p_x$ and chiral $p_x+i{p}_y$ superconductors. Although altermagnets carry no net magnetization, the momentum-dependent spin splitting, combined with RSOC enables a pronounced spin valve effect without ferromagnetic electrodes. We show that conductance, spin polarization, and TMR exhibit distinct and robust fingerprints of the triplet pairing symmetry. For nodal $p_x$ superconductor, sign-change-induced surface Andreev bound states dominate subgap transport, producing strongly anisotropic conductance, giant zero-bias spin polarization, and a monotonic enhancement of TMR with increasing RSOC. In contrast, the chiral $p_x+i{p}_y$ state exhibits smoother conductance and polarization profiles governed by topological edge modes, resulting in broader, lobelike TMR patterns with weaker sensitivity to interface transparency. Moreover, RSOC can acts as an electrically tunable spin-mixing knob, while the barrier strength controls coherence and energy selectivity, together enabling large, symmetry controlled spin filtering and magnetoresistance. Our results establish AM/TSC/AM junctions as a symmetry sensitive transport platform for realizing electrically tunable spin valve functionality and probing triplet pairing without ferromagnetic components.

We present a theoretical study of proximitized planar Josephson junctions (JJs) with Rashba spin-orbit coupling (SOC) subject to an in-plane magnetic field and demonstrate that the magnetocurrent-phase relation (magneto-CPR) provides a powerful and unified probe of their microscopic and topological properties. By analyzing the full phase and Zeeman-field dependence of the supercurrent, we show that magneto-CPR measurements allow one to reconstruct the ground-state phase that minimizes the system's free energy in the absence of phase bias. This reconstructed phase generally displays $0-\pi$-like transitions as a function of the Zeeman energy, and we demonstrate that the magnitudes of the associated phase jumps provide quantitative information about the Rashba SOC. We further show that the mixed phase-field response encoded in the magneto-CPR enables the extraction of the second mixed spin susceptibility, which serves as a sensitive diagnostic of gap closings and can be used to construct a superconducting topological phase diagram in terms of the relative topological gap. In addition, the magneto-CPR yields the field dependence of the forward and reverse critical currents, allowing one to characterize the Josephson diode effect and its connection to the Zeeman field, Rashba SOC, and junction transparency. Our results establish magneto-CPR measurements as a versatile spectroscopic tool that can be used to extract key system parameters and provide evidence of topological superconducting phases in planar JJs.

We investigate self-consistent unconventional superconductivity in a two-dimensional $d$-wave altermagnetic metal. We find that momentum-dependent altermagnetic spin splitting suppresses opposite-spin-singlet pairing and stabilizes highly anisotropic equal-spin triplet order. In the spin-conserving limit, this directional triplet pairing gives rise to nearly dispersionless Majorana boundary states associated with effective one-dimensional topological channels. Rashba spin-orbit coupling mixes spin sectors, activates additional pairing components, and drives the system into a mixed-parity superconducting state with dispersive Majorana boundary states. The spin-resolved boundary spectra further reveal a characteristic locking between boundary orientation and spin polarization, reflecting the underlying altermagnetic symmetry. These results identify altermagnetic spin splitting as an intrinsic mechanism for selecting unconventional pairing and generating spin-resolved Majorana boundary states without external magnetic fields.

We study a one-dimensional quasiperiodic tight-binding model with simultaneous off-diagonal (hopping) and diagonal (on-site) modulations. Using the inverse participation ratio and the wave-function centroid, we construct localization-delocalization phase diagrams for both equilibrium and nonequilibrium steady states. We analyze the robustness of the system's initial properties under dissipation and characterize dissipation-induced localization-delocalization transitions (and their reversals) in detail. Trace-distance dynamics provide evidence for a quantum Mpemba effect: states prepared farther from the steady state can relax faster than states initialized closer to it. We propose a starting-line hypothesis to explain the presence or absence of this effect in different parameter ranges of our selected system. Through the study of wave-packet transport under the same dissipative system, we analyze the applicable conditions of the starting-line hypothesis and summarize a way to design the Mpemba effect based on this. These results advance the understanding of steady-state phase transitions and relaxation dynamics in dissipatively driven quasiperiodic systems.

The interplay of non-Hermiticity, nonreciprocal hopping, and interparticle interactions provides new possibilities for tuning localization and emergent phase transitions in quasiperiodic systems. Here we investigate, within the two-body Fock space, the effects of nearest-neighbor dipolar interaction on the spectral structure and localization behavior of two bosons in a nonreciprocal non-Hermitian quasiperiodic extended Bose-Hubbard model. The analysis is restricted to the two-body sector, while higher-occupancy sectors are not considered. We find that dipolar interaction replaces the single transition point of the noninteracting system by an intermediate mobility-edge phase. This intermediate phase can be understood as a consequence of the successive localization of doublon states and nearest-neighbor states. It originates from the distinct spectral and Fock-space localization thresholds of different two-particle eigenstates induced by dipolar interaction. Under open boundary conditions, both doublon and nearest-neighbor states exhibit non-Hermitian skin effects, leading to distinct boundary accumulation and relaxation dynamics in different phases. Our results deepen the understanding of two-body Fock-space localization transitions and skin effects in non-Hermitian quasiperiodic systems, and may provide new insight into non-Hermitian few-body physics in quasiperiodic lattices.

Altermagnets exhibit spin-split electronic structure without requiring spin-orbit coupling, but transport measurements generally mix intrinsic spin splitting with extrinsic scattering. We examine this identifiability problem for a two-dimensional $d$-wave altermagnet within a unified semiclassical framework spanning ballistic to diffusive transport. The spin-dependent Fermi-surface anisotropy produces a pronounced size effect, where vastly different longitudinal velocities cause the two spin channels to exhibit markedly different effective relaxation lengths within the same device geometry. However, the altermagnetic coupling $\alpha$ and the momentum relaxation time ${\tau }_0$ strongly compensate each other in longitudinal conductance, producing strong parameter correlation. To address this inverse problem, we formulate a physics-informed neural network (PINN) as a differentiable Boltzmann solver with contact-injection and current-continuity losses and a particle-conserving local distribution. Driven by sparse synthetic conductance spectra, this solver uses the Fermi-level dependence of transport to recover the coupled parameters under the tested conditions, including joint inversion at 1% Gaussian noise and single-parameter extraction at noise levels up to 10%. These results demonstrate parameter recovery by combining Fermi-level-dependent transport data with a physically constrained numerical solver within the model and parameter range studied.

The crystal structure of high-pressure solid hydrogen remains a fundamental open problem. Although the research frontier has mostly shifted toward ultra-high pressure phases above 400 GPa, we show that even the broken symmetry phase observed around 130 GPa requires revisiting due to its intricate coupling of electronic and nuclear degrees of freedom. Here, we develop a first principle quantum Monte Carlo framework based on a deep neural network wave function that treats both electrons and nuclei quantum mechanically within the constant pressure ensemble. Our calculations reveal an unreported ground-state structure candidate for the broken symmetry phase with $Cmcm$ space group symmetry, and we test its stability up to 96 atoms. The predicted structure quantitatively matches the experimental equation of state and gives the closest x-ray diffraction peak-position match among the tested candidates. Furthermore, our group-theoretical analysis provides a symmetry-counting compatibility check between the $Cmcm$ structure and existing Raman and infrared spectroscopic data. Crucially, static density functional theory calculation reveals the $Cmcm$ structure as a dynamically unstable saddle point on the Born-Oppenheimer potential energy surface, demonstrating that a full quantum many-body treatment of the problem is necessary. These results shed new light on the phase diagram of high-pressure hydrogen and call for further experimental verifications.

The three-dimensional cubic conformal field theory governs the critical behavior of Heisenberg magnets with cubic anisotropy. Studying this theory nonperturbatively is challenging because its most easily accessible observables are numerically very close to those of the more symmetric $O\left(3\right)$ model. In this work, we overcome this difficulty using the fuzzy sphere regularization method. By adding a cubic-invariant two-body interaction to the quantum rotor Hamiltonian used for the $O\left(3\right)$ model, we break the continuous rotational symmetry by construction and unambiguously isolate the cubic critical point. Using exact diagonalization and the density matrix renormalization group, we calculate the scaling dimensions of several key operators, including the leading scalar singlets, and resolve the splitting of the $O\left(3\right)$ rank-two traceless symmetric tensor into the $E_g$ and $T_{2g}$ representations of the cubic group. Our results are consistent with existing Monte Carlo, conformal perturbation theory, and $\varepsilon$ expansion benchmarks, demonstrating the power of the fuzzy sphere in resolving closely spaced universality classes.

The plethora of possible ground states of spinor bosons placed in an external lattice and a cavity are revisited. We discuss the simplest configuration when the external lattice nodes coincide with the antinodes of the cavity field. We analyze the problem within the grand-canonical mean-field approach, considering both the homogeneous system and the nonhomogeneous case with a harmonic trapping potential. Due to the spin degree of freedom, in the homogeneous case, we treat the system in a twofold manner: We impose the physically relevant total-magnetization constraint while also discussing the minimization landscape for the full unconstrained problem. In the latter, by combining analytical arguments with numerical calculations based on the Gutzwiller ansatz, we show that the system exhibits two types of magnetic phases: an antiferromagnetic Mott insulator and a ferromagnetic density wave (FDW). In addition, two distinct supersolid phases emerge, characterized by different patterns of spin and density imbalances. In the case of zero total magnetization, the FDW phases are replaced by charge density waves that lack net magnetic ordering. Finally, we establish the phase diagram of the trapped system, providing direct guidance for future experiments.

We develop a projector-based formulation of the coherent potential approximation (CPA) within a pseudopotential Hamiltonian in the framework of density functional theory. In the pseudoatomic-sphere scheme, the projectors are constructed from corelike orbitals localized near each pseudoatomic site, which enables a systematic treatment of element-dependent site scattering in pseudized Hamiltonians without relying on explicit atomic-sphere boundaries or intermediate effective model Hamiltonians. In the unit-cell scheme, by contrast, the projectors are defined by window functions that extract the potential contribution at individual mesh points over a unit cell. This generalizes the single-site scattering picture to a unit-cell scattering picture that incorporates the full potential within each unit cell, and fits naturally into a plane-wave-based framework. We assess both schemes by computing the density of states for a one-dimensional Gaussian-well chain with the orthogonalized plane wave method. Because the pseudized potential has a small contribution inside the pseudoatomic sphere, the pseudoatomic-sphere scheme yields results almost indistinguishable from the virtual crystal approximation. In contrast, the unit-cell scheme successfully reproduces the split-band feature characteristic of CPA in strongly disordered alloys. The present work paves the way for extending plane-wave-based ab initio methods to chemically disordered alloy systems.

The atomic-layer dependence of friction is a fundamental characteristic of two-dimensional (2D) materials, yet the impact of atomic defects on it remains largely unexplored. Here, we report the reversal of frictional layer-number dependence in chemical vapor deposition grown ${\mathrm{MoSe}}_2$ by tuning the selenium vacancy concentration. While stoichiometric triangular ${\mathrm{MoSe}}_2$ follows the conventional trend where bilayer friction is lower than that of the monolayer, Se-deficient hexagonal ${\mathrm{MoSe}}_2$ exhibits an anomalous behavior with bilayer friction exceeding the monolayer. A similar defect-dependent reversal is further observed in ${\mathrm{WSe}}_2$, while triangular ${\mathrm{WSe}}_2$, ${\mathrm{MoS}}_2$, and ${\mathrm{WS}}_2$ exhibit the conventional layer dependence consistent with the proposed mechanism. Density functional theory calculations and experiments reveal that Se vacancies impede interlayer charge redistribution and weaken van der Waals coupling, reducing adhesion energy from 0.538 to 0.498 J/${\mathrm{m}}^2$. The consequent reduction in effective film stiffness amplifies the out-of-plane puckering effect, enhancing energy dissipation. These findings demonstrate that defect engineering provides an effective strategy for modulating the nanotribological properties of 2D lubricating interfaces.

In ultraclean 2D materials, electron viscosity is as important as Ohmic dissipation, and electron transport exhibits hydrodynamic features. Using a simple framework of Brinkman equations, we find that hydrodynamic electron flows give rise to a geometric skin effect: sharp obstacles locally enhance the current, suppressing it far from the edges where the flow is unobstructed. This effect arises within hydrodynamic transport with finite momentum relaxation and does not rely on ballistic dynamics. Our results provide a natural hydrodynamic interpretation of edge-enhanced and double-bump current profiles observed in constricted geometries. By comparing with recent scanning NV magnetometry experiments on gated graphene, we demonstrate that such flow patterns are consistent with viscous hydrodynamics shaped by geometry, clarifying the role of geometric effects in the interpretation of electronic flow experiments.

An identity term in the Hamiltonian is conventionally regarded as spectrally inert; it shifts energies but does not alter eigenstate topology. We show that under non-Hermitian skin pumping, this paradigm fails: a momentum-dependent identity term actively deforms the generalized Brillouin zone, thereby challenging established topological criteria that rely on fixed complex contours. Here, by introducing spin-orbit coupling into a Hatano-Nelson chain, we present an exact analytical solution for the entire non-Hermitian eigensystem under open boundary conditions. Our solution reveals how intercell spin-orbit coupling, synergizing with this nontrivial identity term, induces topological edge states and robust zero modes in the complete absence of chiral symmetry. This work establishes an exactly solvable paradigm for non-Hermitian topology beyond symmetry protection, and provides a rigorous benchmark for testing topological invariants in systems with momentum-dependent identity terms.

We analytically describe the dynamically separated ${\mathbb{Z}}_2$ skin channels (wave-packet evolutions) under a periodic boundary condition in non-Hermitian systems with anomalous time-reversal symmetry by combining the semiclassical worldline perspective with an enhanced understanding of skin effects. These channels, tied to the initial state and relevant symmetries, exhibit individually exponential-dominated time evolution in momentum space, where their amplitude maxima evolve toward the dominant momenta. In real space, their centers of mass circulate around the one-dimensional chain, tracing semiclassical worldlines. Such circulations imply quantum revivals and effective Loschmidt cusps, with the latter showing scale-dependent behavior, a feature distinct from conventional dynamical quantum phase transitions. This work extends our previous findings on worldline windings and the winding-control mechanism to the ${\mathbb{Z}}_2$ skin effects, confirming that the core physics is shared with the ordinary skin effect.

Dimensional extension by adiabatic phase evolution connects one-dimensional (1D) Peierls chains to two-dimensional (2D) Chern insulators and identifies chiral solitons as the 1D analogs of quantum Hall edge states. Here, we show that this framework cannot generate the 1D counterparts of quantum spin-Hall edge states, which we call helical solitons, within the class of time-reversal (TR)-invariant extensions built from real-valued order parameters. For $s_z$-conserving models, the spin-Chern numbers of the dimensionally extended 2D system satisfy $C_{\uparrow }=C_{\downarrow }$, ruling out the $C_{\uparrow }=-C_{\downarrow }$ structure required for quantum spin-Hall topology. For spin-mixing Rashba coupling, the same obstruction holds for the projected spin-Chern numbers provided the spin-spectrum gap remains open. The origin is that the adiabatic parameter is not a physical momentum and therefore does not flip under time reversal, removing one sign factor from the Berry curvature transformation. The result constrains topological pumping in TR-invariant Peierls systems and has direct implications for indium atomic wires and related surface systems.

Electrostatically defined quantum dots (QDs) with layer-antisymmetric gating in Bernal-stacked bilayer graphene (BLG) open a local gap and generate a masslike term with opposite sign in the two valleys, producing strongly valley-dependent scattering without magnetic fields, strain, or spin-orbit coupling. Building on this mechanism, we propose a tunable platform based on such QDs for valley-dependent electron optics in BLG. Using a four-band continuum model and a generalized multiple-scattering formalism, we analyze the scattering of Gaussian electron beams from single-dot and multidot architectures and compute valley-resolved currents and angular profiles. A single dot produces distinct valley-dependent deflection, while multidot configurations enable enhanced control: identical-dot arrays act as valley splitters, whereas oppositely gated pairs function as valley filters. Combining these elements yields tunable generation, steering, and filtering of highly valley-polarized currents with strong suppression of forward transmission. The required energy scales, gate asymmetries, and device dimensions are within experimentally accessible regimes for dual-gated BLG, establishing quantum-dot arrays as a realistic platform for controllable valley-resolved electron optics.

Functional properties of ferroelectric thin films are governed by domains that can be engineered by epitaxial strain. Soft x-ray microscopy can image domain structures with elemental and electronic sensitivity, but hitherto its application to strain-stabilized domains has been hindered by the absorption of soft x-rays in epitaxial substrates. Here, it is demonstrated how this limitation can be overcome by locally back-thinning the (110) ${\mathrm{TbScO}}_3$ substrate of epitaxial ${\mathrm{K}}_{0.6}{\mathrm{Na}}_{0.4}{\mathrm{NbO}}_3$ ferroelectric thin films to achieve soft x-ray transparency at the O K-edge around 530 eV. Strain-induced ferroelectric stripe domains with periods down to 44 nm were resolved by scanning transmission x-ray microscopy and coherent diffractive imaging by exploiting the x-ray linear dichroism of hybridized O $2p$–Nb $4d$ states, providing sensitivity to in-plane polarization components under normal incidence. The results establish soft x-ray microscopy for nanoscale imaging of epitaxial ferroelectric domain structures and open perspectives for time-resolved studies thereof.

We study a one-dimensional non-Hermitian Stark chain with nonreciprocal, linearly graded hopping. A diagonal similarity transformation eliminates the bond asymmetry and changes the usual exponential skin factor into an algebraic accumulation, $d_j\sim j^{\eta }$, with $\eta =\gamma /F_2$. At fixed spectral energy, the characteristic roots of the transformed recurrence become nonunimodular at $|F_1|=2|F_2|$. The next order in $1/j$ supplies an energy-dependent factor $j^{s(E,r)}$ for nondegenerate roots. At root coalescence, the generic fixed-energy envelope is of Bessel or modified-Bessel type, while a fine-tuned energy gives a separate algebraic branch. The edge polarization turns over near the root threshold, and the selective inverse participation ratio rises on the Stark-localized side. For a charge-density-wave quench at nonzero nonreciprocity, the normalized right-state half-chain entropy, averaged over $t\in [6,8]$, is largest at $F_1/F_2=2$ among the representative ratios 1, 2, and 3. For this site-diagonal quench, the biorthogonal spectrum removes the explicit diagonal skin factor and follows the transformed symmetric dynamics. The model therefore separates the exact gauge dressing, the controlled large-position asymptotics, and the finite-size dynamical signatures of Stark localization.

Josephson junction (JJ) chains combine the coherence of superconductivity with the controllability of microwave-frequency circuits, making them a powerful platform for circuit quantum electrodynamics. In this work, we consider a long JJ chain that effectively realizes a multimode cavity with nonlinear dispersion and additional multimode interactions. Individual modes appearing due to the finite size of the chain can be experimentally probed via microwave spectroscopy, both in equilibrium and in driven far-from-equilibrium settings. We study the role of multimode interactions in degrading internal coherence—observable as excess linewidth—in both equilibrium and driven regimes. Focusing on two-into-two mode scattering as the leading relaxation process, we classify the relevant scattering processes and derive their expected temperature- and frequency-scaling under equilibrium conditions. For experimentally relevant parameters, we show that the equilibrium decay rate is dominated by nonresonant processes, however, weakly driving a particular set of modes out of equilibrium enhances resonant scattering, leading to observable signatures in the distribution function and linewidth. Finally, in the strong nonequilibrium regime, we report a crossover to a qualitatively different nonequilibrium steady state.