Dirty superconducting films with magnetic impurities can exhibit nontrivial behavior in a magnetic field that polarizes the impurity spins. As predicted by Kharitonov and Feigelman (KF) [JETP Lett. 82, 421 (2005)], this polarization reduces the exchange scattering rate. Consequently, a parallel magnetic field can enhance the critical temperature $T_c$ when magnetic-field pair breaking is weak, as realized for strong spin-orbit scattering and small film thickness. Recently, Llanos et al. [Nat. Phys. 22, 856 (2026)] observed a pronounced enhancement of $T_c$ consistent with the KF theory. The same experiment also reported an enhancement of the perpendicular upper critical field $H_{c2}^{\perp }$ and a suppression of the London penetration depth ${\lambda }_L$ by a parallel magnetic field. These quantities were not considered in the original KF theory. To address this gap, we develop a theoretical framework based on Gor'kov's diagrammatic technique for dirty superconductors. We extend the KF theory in two experimentally relevant directions: (i) to arbitrary temperatures $T<T_c$ and several superconducting observables and (ii) to arbitrary magnetic-field orientations. As a result, we demonstrate theoretically the suppression of ${\lambda }_L$ and the enhancement of $H_{c2}^{\perp }$ by a parallel magnetic field, in agreement with experiment.

Topological defects play a fundamental role in the investigation of symmetries in quantum field theories. For conformal field theories in two space-time dimensions, it is possible to construct these defects using lattice models allowing ab initio analytical and numerical computations of their characteristics. In this work, topological defects are investigated in nonunitary conformal field theories using appropriate variations of the restricted solid-on-solid models. The relevant impurity models and the corresponding defect operators are constructed for the lattice system. Numerical computations are performed for the energy spectrum, eigenvalues of the defect operators, as well as thermodynamic characteristics and compared with analytical predictions. Finally, renormalization group flows between the different fixed points are analyzed using numerical methods.

Robust states emerging at the boundaries of a system are an important hallmark of topological matter. Here, using the Su-Schrieffer-Heeger model and the Kitaev chain as examples, we study the impact of a type of experimentally realizable bond dissipation on topological systems by calculating the steady-state density matrix, and demonstrate that such dissipation applied near the system boundary can assist in preparing topological edge states of the parent Hamiltonian, irrespective of the initial state or filling. This effect stems from the matching between the phase distribution encoded in the topological edge states and the target state prepared through bond dissipation. This work provides insights into the preparation of topological edge states, particularly in the context of Majorana zero modes.

In this work, we show that the edge dynamics of the composite boson condensate in the weakly nonlinear regime is governed by the Korteweg–de Vries (KdV) equation. Our starting point is the Chern-Simons-Ginzburg-Landau (CSGL) theory in the lower half-plane, where the effective edge dynamics are encoded in anomaly-compatible boundary conditions. The CSGL theory captures several key features of the Laughlin state. The saddle-point bulk dynamics and the corresponding boundary conditions of this action can be reformulated as two-dimensional compressible fluid dynamic equations, subject to a quantum Hall constraint that links the superfluid vorticity to its density fluctuations. The boundary conditions in this hydrodynamic framework consist of no-penetration and no-stress conditions. We then apply the method of multiple scales to this hydrodynamic system and derive the KdV equation for the edge dynamics in the weakly nonlinear regime. By employing the Hamiltonian framework for the KdV equation, we show that we can recover the chiral Luttinger liquid theory in the linearized regime and provide a pathway for canonically quantizing the edge dynamics in the weakly nonlinear limit.

We investigate the topological properties and phase diagrams of a one-dimensional Kitaev chain with spin-orbit coupling, subject to an external magnetic field, and hosting coexisting singlet $s$-wave and triplet $p$-wave pairings. To drive the system out of equilibrium, we introduce a phase in the hopping parameter that accounts for a uniform particle current. Using symmetry analysis, we identify the conditions under which the system belongs to the topological class BDI with a $\mathbb{Z}$ invariant. Breaking chiral symmetry by introducing the particle current reduces the classification to topological class D with a ${\mathbb{Z}}_2$ invariant. We calculate the winding number for class BDI and the Pfaffian invariant for class D to obtain the corresponding phase diagrams. In addition, we compute the energy spectrum for class D to determine the phase boundaries analytically, and employ the real-space formulation to numerically obtain the Majorana number maps and verify the analytical results. Our findings highlight how mixed pairing channels and current-induced symmetry breaking enrich the landscape of one-dimensional topological superconductivity and provide new insights into the stability of Majorana modes under nonequilibrium conditions.

Superconductivity is intrinsically linked to the crystal structure of materials, and structural heterogeneity under high pressure often yields broadened or mixed superconducting transitions. Here instead we report multiple superconducting phases in compressed ${\mathrm{PbSnSe}}_2$: two well-separated superconducting transitions that coexist over a broad pressure range and are associated with two crystallographically distinct phases as established by in situ high-pressure x-ray diffraction. Electrical transport and DC magnetization measurements, reproduced across independent samples, consistently resolve both transitions and their evolution under compression. First-principles calculations show that the two structures possess distinct electron-phonon coupling, dominated in both cases by Se-related phonon modes, providing a direct link between the structural symmetry and the superconducting pairing strength. These results illuminate the microscopic connection between phase transitions and superconductivity in layered chalcogenides, and provide a clean platform for exploring the intricacy of the underlying physics.

We investigate nonequilibrium dynamics of a triad of fermionic superfluids connected via Josephson junctions, following sudden switch-on of two-body loss in one of the three superfluids. By formulating the dissipative BCS theory for the Lindblad equation, we find that the superfluid order parameter exhibits a phase rotation, thereby giving rise to three types of dc Josephson currents corresponding to different junctions. We demonstrate that, when the tunneling amplitude $V_{31}$ between superfluids without two-body loss is weak, a two-step nonequilibrium phase transition characterized by the vanishing dc Josephson currents occurs: dissipation first induces the nonequilibrium phase transition by making one dc Josephson current finite, while further increasing dissipation makes this remaining dc Josephson current vanish. By contrast, when $V_{31}$ is strong, dissipation induces the nonequilibrium phase transition in which all dc Josephson currents simultaneously vanish. An analytical study based on a simplified model further supports this observation.

We develop variational continuous unitary transformations (VCUTs), which integrate Wegner-Wilson flow equations with tensor network techniques to approximately diagonalize many-body localized (MBL) Hamiltonians. The diagonalizing unitary is represented as a matrix product operator whose bond dimension controls the accuracy. For the disordered Heisenberg chain, VCUTs accurately reproduce the full spectrum across the ergodic-to-MBL crossover at small system sizes and scale to $L=48$ sites. Beyond eigenenergies, the method can track the spatial entanglement structure of the diagonalizing unitary $U\left(l\right)$ at each flow step, enabling identification of local integrals of motion deep in the MBL phase.

There has been considerable recent interest in the phenomenology of high harmonic generation (HHG) in topological insulators. We study HHG in the Qi-Wu-Zhang (QWZ) model for a Chern insulator, which satisfies spatial inversion symmetry but breaks time-reversal symmetry. The QWZ model is particularly interesting because it combines rich physics with unique simplicity. Our theoretical approach is based on the semiconductor Bloch equations, and we present two distinct numerical methods for simulating HHG which are immune to topological obstruction of the Bloch phase. We obtain highly converged HHG spectra in both trivial and topological phases of the QWZ model, and we use these results to investigate spectral characteristics which have been proposed as signatures of band topology. We derive a simple relationship between harmonic ellipticity and material Berry curvature for two-band systems, and we show that this can be used for accurate prediction of the helicity of emitted harmonics. While this clarifies the relationship between ellipticity and Berry curvature, it also uncovers limitations that restrict the scope of ellipticity as an indicator of topological phase. More generally, our findings contribute to the important discussion surrounding topological signatures in HHG spectra. Beyond that, we also observe a dual plateau structure of the HH spectrum in the topological phase which is absent in the trivial phase, but the origin of this phenomenon is not topological. Rather, the multiple plateaus are clearly attributed to the interference of HHG originating from different regions of the full two-dimensional Brillouin zone (BZ). As a consequence, our study reinforces the importance of including the entire BZ for accurate modeling of HHG in solids.

Ce-based intermetallics often display a delicate interplay between magnetism, electron correlations, and lattice geometry, making them highly sensitive to external pressure. We report the evolution of the Ce valence in the frustrated Shastry-Sutherland compound ${\mathrm{Ce}}_2{\mathrm{Pd}}_2\mathrm{In}$ under high pressure using Ce $L_3$-edge x-ray absorption spectroscopy. Although long-range magnetic order collapses around $\sim 4\mathrm{GPa}$, the spectra remain dominated by the the Ce $4f^1$ configuration across this region, pointing to its remarkable stability. Tiny signs of a valence increase appear only above $\sim 8\mathrm{GPa}$, well beyond the pressure at which magnetism is suppressed. These observations demonstrate that the collapse of magnetic order is not driven by a valence instability but arises primarily from enhanced geometrical frustration within the Shastry-Sutherland lattice of Ce ions. ${\mathrm{Ce}}_2{\mathrm{Pd}}_2\mathrm{In}$ thus represents a rare realization of a Ce-based intermetallic in which frustration, rather than valence fluctuations, governs the suppression of long-range magnetic order, providing a clean platform to explore exotic ground states in frustrated rare-earth systems.

The generation of quantum correlations in hybrid quantum systems remains a central challenge due to the intrinsic limitations of linear interactions. In cavity magnomechanical platforms, the cavity-magnon coupling gives rise to hybridized cavity-magnon polaritons (CMPs). However, as a beam-splitter-type interaction, it does not by itself generate entanglement between the polariton modes in the absence of additional nonlinear or parametric processes. Here, we propose a mechanism based on multimode phonon mediation, in which multiple vibrational modes act as parallel scattering channels that couple the polaritons through Stokes and anti-Stokes processes. We show that, in the parameter regime explored here, the presence of multiple phonon modes leads to a monotonic enhancement of steady-state entanglement, thereby going beyond the limitations of conventional single-mode schemes. Furthermore, we demonstrate that quantum synchronization between the polariton modes originates from the same underlying scattering processes responsible for entanglement generation, yet exhibits an opposite scaling behavior with an increasing number of phonon modes for the phase quadrature, while the amplitude synchronization reveals collective squeezing that grows with the number of phonon channels. Our results provide new insights into the role of multimode interactions in shaping quantum correlations and establish a viable pathway for controlling entanglement and collective dynamics in hybrid magnomechanical platforms.

Atomistic spin simulations have been used to provide insights into the internal structures of twin (T) and spin (S) domain walls (DWs) in antiferromagnetic NiO. While S DWs imply simple continuous spin rotations, T DWs are composed of a combination of rotations and canting. The hybrid nature of these walls stems from geometrical constraints inducing strong frustrations of atomic neighbors' exchange interactions at the twin boundaries, with large spin noncollinearities. The effective DW widths for rotations conventionally depend on the ratio of exchange over anisotropy, but canting regions are mainly set by the ratio of the exchange energies for first and second neighbors. Our calculations provide a strong basis to reinterpret some published experimental observations.

The planar Hall effect (PHE) is typically symmetric under magnetic field reversal, as required by the Onsager reciprocity relations. Recent advances have identified the antisymmetric PHE as an intriguing extension in magnetic systems. While new mechanisms have been proposed, the role of conventional anisotropic magnetoresistance (AMR) in this phenomenon remains unclear. Here, we report the experimental discovery of an antisymmetric PHE and magnetoresistance, with respect to both magnetic field and magnetization, in single-crystal ${\mathrm{Co}}_{30}{\mathrm{Pt}}_{70}$(111) thin films with $C_3$ rotational symmetry and perpendicular magnetic anisotropy (PMA). We demonstrate that both antisymmetric effects arise naturally from the intrinsic fourth-rank AMR tensor inherent to $C_3$-symmetric planes, assisted by PMA. Our findings link conventional AMR to antisymmetric galvanomagnetic responses, offering insights into symmetry-governed transport in crystalline ferromagnets.

Experimental evidence of spontaneous time-reversal (TR) symmetry breaking have been reported for the superconducting ground state in the transition metal dichalcogenide (TMD) superconductor $4{\mathrm{H}}_b\text{−}{\mathrm{TaS}}_2$ or chiral molecule intercalated ${\mathrm{TaS}}_2$ hybrid superlattices, and is regarded as evidence of the emergent chiral superconductivity. However, the $T_c$ of these TMD superconductors is at the same order as pristine 1H or 2H-${\mathrm{TaS}}_2$ that does not show any signature of TR breaking and is believed to be conventional Bardeen-Cooper-Schrieffer superconductors. To resolve this puzzle, we proposed a type of pair-mixing states that mix the dominant conventional s-wave pairing channel with the subdominant chiral p-wave pairing channel via the finite Cooper pair momentum based on the symmetry analysis of the Ginzburg-Landau theory. Our analysis shows the fourth-order terms in the chiral p-wave channel can lead to a variety of pair-mixing states with spontaneous TR breaking. These TR-breaking superconducting states also reveal zero-field junction-free superconducting diode effect that is observed in chiral molecule intercalated ${\mathrm{TaS}}_2$ superlattices.

In Type II superconductors, the vortex lattice can exhibit inverse melting, transitioning from a liquid to a crystalline solid as temperature increases. While recently observed via scanning tunneling microscopy in a 20 nm thick amorphous ${\mathrm{Re}}_6\mathrm{Zr}$ thin film, this work investigates the corresponding dc transport and low-frequency magnetic screening responses. By identifying distinct signatures of these transitions and integrating scanning tunneling spectroscopy imaging, we construct a comprehensive vortex-state phase diagram in the magnetic field-temperature parameter space. Furthermore, we demonstrate that inverse melting is thickness dependent: a 5 nm film retains an inhomogeneous vortex liquid state, while a 50 nm film maintains a crystalline vortex solid structure except near the upper critical field.

We analytically study the orbital response of alternating-twist multilayer graphene to an in-plane magnetic field using the unitary transformation introduced by Khalaf et al. [Phys. Rev. B 100, 085109 (2019)]. This transformation maps an alternating-twist $N$-layer system onto $N/2$ decoupled twisted bilayer graphene (TBG) systems with distinct effective twist angles, together with a single decoupled layer for odd $N$, thereby generating a hierarchy of effective magic angles. For systems with an odd number of layers, we find that the orbital in-plane magnetic response is negligibly small. For even systems, we express the in-plane orbital susceptibility in terms of the corresponding TBG responses in the flat-band regime, which are large compared to the spin susceptibility and even diverge in the clean limit at charge neutrality near the magic angle. For the finite even-layer systems considered in this work, the in-plane magnetic response strongly depends on the effective magic angle within the hierarchy: the larger the twist angle, the smaller the total response. Moreover, we find a general relation between the outermost interlayer and total susceptibilities of the system when the corresponding effective TBG subsystem is in the flat-band regime. We finally introduce the in-plane Maki parameter as the ratio of the difference in orbital susceptibility between the normal and superconducting states to the paramagnetic Pauli susceptibility. For TBG, we find values up to 2 near the magic angle. Our analysis shows that for certain magic angles, the interpretation of Pauli-limit violation in alternating-twist multilayers requires taking into account the orbital contribution to the in-plane magnetic response.

Antichiral surface states, which exhibit unidirectional propagation along parallel surfaces, hold significant promise for classical wave manipulation. However, their physical realization typically relies on complex implementations of a two-dimensional modified Haldane model, limiting practical applications. We propose a simplified approach to achieve such states within the nodal-line semimetal phase of a single-layer honeycomb lattice, where an additional layer degree of freedom emulates the essential physics of the modified Haldane model. We further demonstrate that asymmetric vertical interlayer couplings give rise to valley higher-order topological partial band gaps, which simultaneously support one-dimensional hinge states and gapped antichiral surface states. These results establish a versatile platform in which antichiral surface states coexist with higher-order hinge states, enabling robust topological wave transport.

Quantum groups have a long and fruitful history of applications in integrable systems. Can quantum group symmetries exist in the absence of integrability? We provide an explicit example of a chaotic system with a quantum group global symmetry. The example is a spin chain with a next-to-nearest interaction term. We show the chaotic behavior of the system by studying the Eigenvalue statistics. The spin chain is nonunitary but PT symmetric and, in addition to exhibiting chaos, exhibits an interesting transition after which the eigenvalues become complex.

Recent work [M. Z. Ansari and K. Damle, Phys. Rev. Lett. 132, 226504 (2024)] that analyzed the effect of vacancy disorder on a short-range resonating valence bond spin liquid state of kagome-lattice antiferromagnets argued that such spin liquids are stable to vacancy disorder. The argument relied crucially on a numerical study that identified the following property of the site-diluted kagome lattice: maximum-density dimer packings (maximum matchings) of any connected component of such site-diluted kagome lattices have at most one unmatched vertex that hosts a monomer. Here, we provide an inductive proof of a stronger result that implies this property: If a connected cluster of such a lattice has an odd number of vertices, its Gallai-Edmonds decomposition [L. Lovasz and M. D. Plummer, Matching Theory (North-Holland, Amsterdam, 1986)] has exactly one $\mathcal{R}$-type region that spans the entire connected cluster and hosts a single monomer of any maximum-density dimer packing. If, on the other hand, it has an even number of sites, it admits perfect matchings (fully packed dimer coverings with no monomers) and its Gallai-Edmonds decomposition consists of a single $\mathcal{P}$-type region that spans the entire cluster. Our proof also applies to the site-diluted Archimedean star lattice, the site-diluted pyrochlore lattice (corner-sharing tetrahedra), the site-diluted hyperkagome lattice, and, more generally, to any lattice satisfying a certain local connectivity property. It does not apply to bond-diluted versions of such lattices.