The spin-orbit (SO) coupling is conventionally understood to be odd in momentum. Here, through model calculations, symmetry analysis, and the method of invariants, we reveal that, in ordinary semiconductor heterostructures with two subbands, a quadratic Dresselhaus SO term emerges via the intersubband effect while fully respecting time-reversal and spatial symmetries. We further find that this even-in-momentum SO field gives rise to a range of unconventional quantum phenomena, including hybridized swirling textures, anisotropic energy dispersion, avoided crossings, longitudinal Zitterbewegung, and opposite spin evolution between different subbands, in contrast to the effects of linear SO terms. Our results uncover a multisubband mechanism for generating even-order SO fields, establishing an alternative route for engineering unconventional spin behavior in semiconductor heterostructures.

Rich phenomenology emerges at the intersection of non-Hermiticity and many-body dynamics, yet physically realizable implementations remain challenging. In this work, we propose a general formalism that maps non-Hermitian many-body Hamiltonians to the Laplacians of Markov chains, such that wave-function amplitudes are reinterpreted as stochastic many-body configuration probabilities. Despite explicitly preserving all state transition processes and inheriting analogous non-Hermitian localization and state-space fragmentation, our Markov chain processes exhibit distinct steady-state behavior independently of energetic considerations that govern quantum evolution. We demonstrate our framework with two contrasting representative scenarios, one involving asymmetric (biased) propagation with exclusion interactions, and the other involving flipping pairs of adjacent spins (agents). These results reveal robust and distinctive signatures of non-Hermitian phenomena in classical stochastic settings such as ecological and social networks, and provide a versatile framework for studying nonreciprocal many-body dynamics across and beyond physics.

Preparing the thermal density matrix ${\rho }_{\beta }\propto e^{-\beta H}$ corresponding to a given Hamiltonian $H$ is a task of central interest across quantum many-body physics, and is particularly salient when attempting to study it with quantum computers. Although solved in principle by recent constructions of efficiently simulable Lindblad master equations—that provably have ${\rho }_{\beta }$ as a steady state [C.-F. Chen et al., Nature 646, 561 (2025)]—the implementation of these “exact Gibbs samplers” requires large-scale quantum computing resources and is hence challenging in practice on current or even near-term quantum devices. Here, we propose a scheme for approximately simulating an exact Gibbs sampler up to a rigorously bounded error that only requires the (repeated) implementation of three readily available ingredients: (a) analog simulation of $H$; (b) strictly local but time-dependent couplings to ancilla qubits; and (c) reset of the ancillas. We give rigorous guarantees on the difference between the fixed point reached by our protocol and the exact thermal state, which only depend on parameters of the protocol and its mixing time. The procedure is efficiently implementable on near-term devices if $H$ is local and the mixing time scales mildly with both system size and protocol parameters. While guaranteeing the latter for Hamiltonians of interest remains an important problem for future work, here we lay the groundwork for developing fully efficient thermal state preparation protocols on quantum simulators.

Through the study of the Rep($D_8$) non-invertible symmetry, we show how non-invertible symmetries manifest in dynamics. Results are presented for dynamics generated by Hamiltonians as well as Floquet unitaries. For both examples, the role of the non-invertible symmetry is studied through the appearance of non-invertible symmetry protected edge modes. In addition, the role of the non-invertible symmetry for the Hamiltonian is studied through eigenstate order. In particular, by considering the effect of symmetry preserving disorder, the non-invertible symmetry is shown to give rise to degeneracies in the spectra of the Hamiltonian that can only be completely lifted at orders of perturbation that scale with system size. The eigenstates of disordered Hamiltonians, whose ground states correspond to non-trivial symmetry protected topological (SPT) states, are shown to have either trivial or non-trivial SPT order that are detected as non-zero expectation value of string order-parameters. In contrast, non-trivial SPT order is absent in the eigenstates of trivial SPT Hamiltonians with disorder. The interface between two different SPT phases host edge modes whose dynamics is studied numerically and analytically. The edge mode is shown to oscillate at frequencies related to different effective chain lengths that are weighted by the temperature, becoming an exact zero mode in the limit of zero temperature. A Floquet model with the non-invertible symmetry is constructed whose edge mode is shown to exhibit period-doubled dynamics at low effective temperatures. The zero and period-doubled edge modes differ from those in conventional SPTs by being symmetric under the invertible symmetry, while being charged under the non-invertible symmetry.

Electric field-induced phase transitions in ferroelectrics provide a reversible and effective strategy for tuning the lattice thermal conductivity. In this study, we systematically investigate phonon thermal transport in bilayer SnSe across its antiferroelectric (AFE) and ferroelectric (FE) phases using accurate neural network potentials combined with the phonon Boltzmann transport equation. Our results reveal that the AFE-to-FE transition dramatically reduces the lattice thermal conductivity, achieving ultralow values of $0.21$ and $0.15\mathrm{W}{\mathrm{m}}^{-1}{\mathrm{K}}^{-1}$ along the $a$ and $b$ axes at $300\mathrm{K}$, respectively. This suppression is primarily attributed to a downward shift of low-frequency optical branches due to weakened interlayer interactions, together with enhanced phonon anharmonicity induced by bonding heterogeneity. Furthermore, the AFE and FE phases of SnSe exhibit marked differences in four-phonon scattering processes and optical phonon transport behavior. While four-phonon processes are negligible in the AFE phase, they become crucial in the FE phase, reducing the lattice thermal conductivity by up to 50%. Moreover, in the FE phase, optical phonons contribute up to 78.0% and 90.7% of the thermal conductivity along the $a$ and $b$ axes, respectively, which deviates from the conventional acoustic phonon-dominated paradigm. Further analysis shows that this phenomenon is driven by the hardening of optical phonons and the enhanced anharmonicity of acoustic phonons. This work not only deepens the understanding of phonon thermal transport in ferroelectric materials but also provides crucial insights for its efficient regulation.

A wide variety of experimental platforms, ranging from semiconductor quantum-dot arrays to moiré materials, have recently emerged as powerful quantum simulators for studying the Hubbard model and its variants. Motivated by these developments, here, we investigate a generalization of the Hubbard model which includes the effects of long-range Coulomb interactions. Working on finite-sized two-dimensional square and triangular lattices, we use exact diagonalization and density-matrix renormalization group calculations to probe the magnetic structure of the ground state in the strong-coupling regime, where $U$ (the on-site repulsion) $\gg t$ (the nearest-neighbor hopping). For small electron dopings above the half-filled antiferromagnet, we numerically uncover a rich variety of magnetically ordered states, and in conjunction with theoretical arguments, infer the phase diagram of the system as a function of doping and interaction strengths. In particular, we find that the inclusion of long-range Coulomb interactions induces an instability of high-spin states—such as the saturated Nagaoka ferromagnet—towards phase separation and stripe ordering. We also present proposals for the observation of some of our key findings in experiments that would shed further light on this paradigmatic strongly correlated system.

The coupling between multiple magnetic sublattices in rare-earth-transition metal compounds provides an ideal materials platform for exploring exotic magnetic orders and transport behaviors. Here, we systematically investigate the magnetic and electrical transport properties of $\mathrm{PrCrG}{\mathrm{e}}_3$ single crystal with dual magnetic sublattices. The significant magnetic anisotropy arises from the distinct ordering of $\mathrm{C}{\mathrm{r}}^{3+}$ ($\sim 90\mathrm{K}$) and $\mathrm{P}{\mathrm{r}}^{3+}$ ($\sim 11\mathrm{K}$) moments, leading to contrasting behaviors for different field directions. Electrical transport exhibits strong anisotropy with clear signatures of both magnetic transitions. Magnetoresistance (MR) and Hall effect measurements reveal complex, field-direction-dependent transport phenomena, including nonmonotonic MR, sign reversal, and linear positive MR, reflecting the competition and coupling between the two magnetic sublattices. Our work elucidates the intricate interplay between dual magnetic sublattices and anisotropic magnetotransport in $\mathrm{PrCrG}{\mathrm{e}}_3$.

We uncover four coupled spin-charge ground states in the strong coupling limit of the Kondo lattice model at various electronic fillings on a frustrated decorated honeycomb lattice, where each regular honeycomb sublattice point is occupied by three-site triangular units. We employ a hybrid Markov Chain Monte Carlo (hMCMC) simulation method which combines classical MCMC for localized spins and exact diagonalization of the electronic Hamiltonian. Two of the spin-charge ground states, respectively, consists of three-site and six-site ferromagnetic (FM) clusters arranged in antiFM and ${120}^{\circ }$ Yafet-Kittel (YK) phase which we label as S-AF (super-antiferromagnet) and S-YK (super-YK), respectively. Two even more interesting coupled spin-charge states, respectively accommodate FM dimers and trimers (as three-site line segment), which we label as FM-D and FM-T. In both cases, the antiFM aligned dimers and trimers in respective phases, are arranged in stripes along one of three lattice directions: the spontaneously symmetry broken phases giving rise to nontrivial macroscopic degeneracy. These underlying magnetic textures (except S-YK state) restrict electrons in fragmented small regions (e.g., triangular units, two-site dimers, three-site line segments, respectively, in S-AF, FM-D and FM-T), resulting in flat bands by opening large gaps in electronic density of states, which in turn stabilize these coupled spin-charge states: a “band effect”. These exotic spin-charge ground states could be relevant to electron-doped spin systems resulting from various metal-organic frameworks, which have attracted significant attention to condensed matter physics.

Efficient generation of DC spin-polarized currents via light is a promising route toward ultrafast spintronics, yet remains challenging. Here, we show that altermagnets, a class of antiferromagnets with symmetry-driven spin splitting, can generate DC spin currents via the nonlinear spin Hall effect. Using a three-dimensional Hubbard model, we identify the Berry curvature dipole as the dominant source of the nonlinear response, while the first-order quantum-metric-like term yields only ac spin currents. The contribution from the Berry connection polarizability is found to vanish in the absence of spin-orbit coupling. A comprehensive symmetry analysis of all noncentrosymmetric spin point groups, supported by first-principles calculations for ${\mathrm{CuFeS}}_2$, establishes altermagnets as a robust platform for pure spin-current generation. The predicted second-order spin-current conductivity reaches the ${\mathrm{mA}/\mathrm{V}}^2$ range, demonstrating experimental feasibility and highlighting the promise of altermagnets for ultrafast spintronics, including terahertz applications.

The Heisenberg antiferromagnet with an easy-plane anisotropy is discussed in which a magnetic spiral is induced by Dzyaloshinskii-Moriya interaction and/or frustration of the exchange coupling. The distortion of the spiral by small in-plane magnetic field is described analytically. It is found that the field can gradually change the vector of the magnetic structure ${\mathbf{k}}_0$ and can produce transitions between phases with incommensurate and commensurate magnetic orderings when ${\mathbf{k}}_0$ is close to $\mathbf{g}/n$, where $\mathbf{g}$ is a reciprocal-lattice vector and $n$ is integer. Analytical expressions for critical fields are derived for $n=2$, 3, and 4. Application of the theory to the triangular-lattice compound $\mathrm{RbFe}{\left({\mathrm{MoO}}_4\right)}_2$ is discussed alongside its potential applicability to other materials. As a by-product of the main consideration, model parameters are found which describe more accurately the full set of available experimental data suggested before for $\mathrm{RbFe}{\left({\mathrm{MoO}}_4\right)}_2$.

We theoretically study ambient-pressure superconductivity in thin films of ${\mathrm{La}}_3{\mathrm{Ni}}_2{\mathrm{O}}_7$. We construct model Hamiltonians adopting the crystal structure theoretically determined by fixing the in-plane lattice constant to those substrates examined in the experiment. We also construct a model based on the experimentally determined lattice structure. To the models obtained we apply the fluctuation exchange approximation, which takes into account the full momentum and frequency dependencies of the Green function and the pairing interaction. We find that the electronic structure, including the presence/absence of the so-called $\gamma$ pocket (the Fermi surface originating from the top of the $d_{3z^2-r^2}$ bonding band), depends on the crystal structure adopted and/or the presence/absence of $+U$ correction in the band structure calculation. Nonetheless, $s^{\pm }$-wave pairing symmetry remains robust regardless of these details in the band structure. The robustness of the $s^{\pm }$-wave pairing is mainly due to the fact that it is mediated by finite-energy spin fluctuations, which are insensitive to the details of the Fermi surface topology and give rise to a nearly momentum-independent gap function for the interlayer $d_{3z^2-r^2}$ pairing in the orbital representation. On the other hand, $T_c$ being halved from that of the pressurized bulk can only be understood by adopting the model with small $|t_{\perp }|$ derived from the experimentally determined crystal structure, at least within the present FLEX approach, although there may remain some other possibilities beyond this approach for the origin of the reduced $T_c$.

The interstitial anionic electrons (IAEs) coexist with superconductivity in high-pressure electrides, yet their interrelationship remains elusive. Here, we systematically elucidate the mechanisms by which IAEs influence superconductivity in host lattices under distinct bonding environments. Through crystal-structure prediction and first-principles calculations, we identified two high-pressure electrides, $I4/mmm-\mathrm{L}{\mathrm{i}}_4\mathrm{Pd}$ and $P{2}_1/m-\mathrm{L}{\mathrm{i}}_6\mathrm{Pd}$. Their superconducting transition temperatures ($T_{\mathrm{c}}\mathrm{s}$) are 21 K at 130 GPa and 43 K at 150 GPa, respectively. Our calculations reveal that the electrons in the p-p hybrid orbitals formed by Li and Pd exhibit pronounced electron-phonon coupling, which is the key factor responsible for superconductivity in both electrides. Strikingly, in $I4/mmm-\mathrm{L}{\mathrm{i}}_4\mathrm{Pd}$, IAEs occupy these hybrid orbitals. Increasing pressure enhances their localization, which reduces the electronic density of states at $E_{\mathrm{F}}$ and thereby weakens the EPC. In contrast, IAEs in $P{2}_1/m-\mathrm{L}{\mathrm{i}}_6\mathrm{Pd}$ do not occupy p-p hybrid orbitals at the Fermi level. Instead, its superconductivity originates solely from delocalized electrons residing in the p-p hybrid orbitals, leading to a higher $T_{\mathrm{c}}$. Our results highlight the critical role of p-p hybridization in governing the superconductivity in Li-transition-metal compounds and demonstrate, from the perspective of orbital occupation, that IAEs occupying hybrid orbitals at the Fermi level are detrimental to superconductivity.

Phonons, the quantized collective excitations of crystal lattice vibrations, require long-range periodic order for momentum to be a well-defined quantum number—a condition that breaks down in disordered systems. However, many systems exhibit a complex interplay between ordered and disordered components. A prime example is superionic ice, a novel phase of ice at high temperatures and pressures, where hydrogen ions (protons) diffuse like a liquid while oxygen ions maintain a solidlike vibrational framework. Previous research has mainly focused on the diffusive aspect of the superionic phase, leaving the rich physics of its vibrational lattice dynamics relatively unexplored. Here, we investigate the phonon properties of superionic ices with both body-centered-cubic (bcc) and face-centered-cubic (fcc) oxygen sublattice. Despite the fully disordered protons, the oxygen sublattice exhibits similar phonon dispersion with typical bcc/fcc solids. This similarity is not a trivial regression, but direct evidence of the emergence of higher symmetry and effective interaction degeneracy resulting from hydrogen-bond dissociation, accompanied by strong damping and anharmonicity. Notably, we identify that specific softened phonon modes drive the mechanical instability of the bcc oxygen sublattice, providing a key kinetic mechanism for phase transitions between superionic ices. By extending the phonon concept to a hybrid ordered-disordered system, our work provides a powerful framework for characterizing lattice dynamics in superionic and related complex materials.

Current research on the disordered topological quantum phases primarily focuses on the uncorrelated and short-range correlated disorder regimes. These topological Anderson insulators are typically self-averaging. However, topological quantum systems with long-range correlated disorder have received limited attention due to the absence of tractable analytical methods. In fact, the long-range correlated disorder introduces more complex effects on topological quantum states. Here, we demonstrate that the long-range correlated disorder could induce anomalously statistical features where the topological Anderson states become non-self-averaging, and the phase diagram is strongly dependent on individual disorder configurations. We term this statistical phase the non-self-averaging topological Anderson insulator. The non-self-averaging property is identified by the nonvanishing finite values of the relative variance of the Lyapunov exponent in the thermodynamic limit, alongside the non-Gaussian distributions of the Lyapunov exponent. Consequently, the topological properties of a single disordered sample deviate from the ensemble average, causing a breakdown of the central limit theorem. The non-self-averaging topological Anderson insulator provides insights into the interplay between correlated disorder and topology.

We study localization properties in a system of non-Hermitian quasiperiodic chains coupled to a clean chain by interchain hopping. We find that in the limit of weak interchain coupling, such a coupled system exhibits transitions from delocalized to intermediate phase with increase in the non-Hermiticity parameter. However, for stronger interchain coupling strengths, the delocalized phase undergoes a transition to localized phase and then to an intermediate phase. Interestingly, the intermediate phase in this case exhibits the non-Hermitian comb effect (NHCE), i.e., the coexistence of localized and extended states rather than being well separated from each other by any mobility edge, which is conventional in any intermediate phase. We further show that such a NHCE originates from the isolated site limit of the quasiperiodic chain and provide an analytical explanation supporting the numerical signatures.

We study information propagation in Clifford quantum circuits on trees through the lens of measurement-induced entanglement and purification transitions. We uncover a phase diagram that characterizes the ability of a tree quantum circuit to retain quantum or classical information in the presence of both measurements and decoherence. By mapping the information dynamics to a classical Markov process defined on the tree, we obtain exact solutions for the distinct phases that emerge at different measurement and noise strengths. Our approach thus provides a concrete and intuitive framework for understanding generic features of noisy quantum circuit ensembles on tree geometries.

Quantum many-body scars represent a form of weak ergodicity breaking that highlights the unusual physics of thermalization in quantum systems. Understanding scar formation promises insight into the connection between classical statistical mechanics and the quantum world. The existence of quantum many-body scars calls into question how the macroscopic world can arise from the Schrödinger equation. In this work, we demonstrate the existence of quantum many-body scars in the density difference dependent Hamiltonian. This Hamiltonian has a particular manifestation of chiral symmetry due to its interaction being neither attractive nor repulsive a priori, but depending on the configuration. As a result of this symmetry and peculiar interaction, we find that this system hosts two different classes of quantum scars: a charge density wave ordered scar and an edge-mode scar. We establish the existence of these scars by examining the entanglement entropy of the system as well as demonstrating robust thermalization breaking time dynamics. For each, we propose simple mechanisms that give rise to these scars which may be applicable to other systems.

We investigate an antiferromagnetic quantum Heisenberg model on a square lattice with high-spin magnetic impurities to clarify how random and stealthy hyperuniform impurity configurations influence the bulk magnetic properties. Stealthy hyperuniform configurations are generated using generalized cost functions that interpolate between square-lattice-like and triangular-lattice-like arrangements. Using linear spin-wave theory for the mixed-spin model, we demonstrate that triangular-lattice-like arrangements yield a larger average staggered magnetization than both random and square-lattice-like cases. This enhancement originates from sublattice effects: while the square-lattice-like configuration enforces nearest-neighbor impurities to occupy opposite sublattices due to its bipartite structure, the triangular-lattice-like arrangement allows same-sublattice nearest-neighbor pairs, thereby strengthening cooperative magnetic enhancement.