We theoretically study the Josephson diode effect (JDE) in two-dimensional antiferromagnets. The staggered potential and Rashba spin-orbit coupling (SOC) can break both time-reversal and inversion symmetries in this antiferromagnetic Josephson junction, so the JDE is expected. It is demonstrated that the staggered potential can be employed to achieve and modulate the nonreciprocal current. This yields an electrically tunable JDE without applying any external magnetic field. The diode efficiency, which reaches up to $\pm 60\%$, exhibits antisymmetry with respect to the staggered potential and antiferromagnetic field. The proposed JDE provides an electrical operation in designing field-free superconducting devices.

We report a quantum oscillation study in the Dirac nodal-line semimetal candidate ${\mathrm{TaPtTe}}_5$. The Fermi surface is probed via magnetic torque measurements with the magnetic field applied in the crystallographic $a\text{−}b$ and $b\text{−}c$ planes. The experimentally determined de Haas–van Alphen frequencies are consistent with results from band-structure calculations. This study serves as an extension to the scarce quantum oscillation data on ${\mathrm{TaPtTe}}_5$ currently present in the literature.

Momentum-forbidden dark excitons with suppressed radiative recombination and extended lifetimes are promising for optoelectronic applications. However, the relaxation mechanism from bright to dark excitons, as well as the influence of excitonic effects and temperature, remains unclear in van der Waals heterostructures. Here, the bright-dark exciton transitions of As/${\mathrm{SnS}}_2$ heterostructures are investigated through nonadiabatic molecular dynamics combined with the $\mathit{GW}$ plus real-time Bethe-Salpeter equation. We discover that high temperature induces phonon excitation to facilitate exciton relaxation, but the large bright-dark exciton energy difference induced by interfacial interaction limits the phonon scattering efficiency. In contrast, the electron-hole Coulomb interactions from excitonic effects exhibit strong nonadiabatic coupling and provide additional relaxation channels that dominate the ultrafast (∼200 fs) bright-dark exciton transitions at different temperatures and stacking configurations. Neglecting the excitonic effects results in much slower transitions, with the maximum difference in transition time reaching a factor of $17292$. The resulting dark excitons exhibit long nonradiative lifetimes (∼50 ps at room temperature). The proposed physical mechanism is crucial for understanding the formation of dark excitons and for designing optoelectronic devices with long-lived excitonic states in van der Waals heterostructures.

This paper explores the effect of the strong-to-weak fragmentation transition, namely, the freezing transition, and its rich characteristics in a family of one-dimensional spinless fermionic models with facilitated hoppings involving short-to-long-range East constraints. Focusing on this family of models with range-$q$ constraints, our investigation furnishes an exhaustive understanding of the fragmented Hilbert space utilizing the enumerative combinatorics and transfer-matrix methods. This further allows us to get insight into the freezing transition in this family of models with the help of the generalization of Catalan numbers introduced by Frey and Sellers for $q>1$, further revealing that increasing the range of constraints drives the transition to transpire at lower filling fractions as $n_c=1/(q+1)$. This distinct fragmentation structure also yields the emergence of ground states at multiple fillings, which can be explained from the root structure of the largest fragment within the full Hilbert space. Furthermore, the ground state exhibits signatures of criticality with logarithmic scaling of entanglement entropy. Thereafter, our investigation exemplifies that the above transition has a profound impact on the thermalization of bulk and boundary autocorrelators at long times, which includes intricate filling-dependent inhomogeneous long-time autocorrelation profiles across the chain in open boundary conditions (OBCs). Finally, we probe the effect of the strong-to-weak fragmentation transition on the transport at intermediate times in periodic boundary conditions (PBCs), restricting ourselves to models up to range-3 constraints. This investigation discloses a vast range of anomalous transport possibilities, ranging from size-stretched exponential relaxation through superdiffusive to subdiffusive behaviors, akin to the fragmentation structure supported by the filling fraction and range of constraints. In brevity, our paper reveals intriguing possibilities conspired by constraints with varying ranges, and those-induced Hilbert-space fragmentation and freezing transition, thus offering exciting avenues for future explorations.

We study a two-dimensional topological insulator in the presence of a static nonuniform gravitational field, which mimics the variations in the temperature distribution. We derive an effective boundary free energy functional for the gravitational field and show that, in contrast to the case of massive Dirac fermions, the addition of a Newtonian mass term significantly modifies the quantum anomalous behavior of the system. A nonzero bulk thermal current appears, which violates the Wiedemann-Franz law. The systematic approach we develop to calculate the contribution of edge states to thermal Hall conductivity and energy magnetization can easily be extended to other models.

Nontrivial geometry of electronic Bloch states gives rise to topological insulators which are robust against sufficiently weak randomness inevitably present in any quantum material. However, increasing disorder triggers a quantum phase transition into a featureless normal insulator. As the underlying quantum critical point is approached from the topological side, small scattered droplets of normal insulators start to develop in the system and their coherent nucleation causes ultimate condensation into a trivial insulator. Unless disorder is too strong, the normal insulator accommodates disjoint tiny topological puddles. Furthermore, in the close vicinity of such a transition the emergent islands of topological and trivial insulators display spatial fractal structures, a feature that is revealed only by local topological markers. Here, we showcase this (possibly) generic phenomenon that should be apposite to dirty topological crystals of any symmetry class in any dimension from the Bott index and local Chern marker for a square-lattice-based disordered Chern insulator model.

Coherent information quantifies the transmittable quantum information through a channel and is directly linked to the channel's quantum capacity. In a monitored quantum circuit, regarded as a quantum channel, extensive and positive coherent information is sustained at low measurement rates, protected by the scrambling dynamics. However, noise suppresses coherent information, driving it to zero or negative values. Here, we show that incorporating quantum-enhanced operations facilitates reliable quantum information transmission even in the presence of noise, as evidenced by a phase transition in coherent information from a recoverable phase with positive values to an irrecoverable phase with negative values. We provide both analytical understanding and numerical evidence demonstrating this transition, which is modulated by the relative frequencies of noise and quantum-enhanced operations. Additionally, we propose a resource-efficient protocol to characterize this phase transition in experiments, effectively avoiding postselection by utilizing every run of the quantum circuit. This approach bridges the gap between theoretical insights and practical implementation, making the phase transition feasible to demonstrate on realistic noisy intermediate-scale quantum devices.

We study quantum circuits with gates composed randomly of identity operators, projectors, or a kind of $R$ matrices which satisfy the Yang-Baxter equation and are unitary and dual unitary. This enables us to translate the quantum circuit into a topological object with distinguished overcrossings and undercrossings. The circuit corresponds to a classical loop model and is postselection free when an overcrossing and an undercrossing coincide. The entanglement entropy between the final state and initial state is given by the spanning number of the classical model, and they share the same phase diagram. Whenever an overcrossing and undercrossing differ, the circuit extends beyond the classical model. Considering a specific case with $R$ matrices randomly replaced by swap gates, we demonstrate that the topological effect originating from worldline braiding dominates, and only the area-law phase remains in the thermodynamic limit, regardless of how small is the replacement probability. We also find evidence of an altered phase diagram for non-Clifford cases.

Classical Landau theory considers structural phase transitions and crystallization as a condensation of several critical density waves whose wave vectors are symmetrically equivalent. Analyzing the simplest nonequilibrium Landau potentials obtained for decagonal and dodecagonal cases, we derive constraints on the phases of the critical waves and deduce two pairs of flat tilings that are the simplest from the viewpoint of our theory. Each pair corresponds to the same irreducible interference pattern: the vertices of the first and second tilings are located at its minima and maxima, respectively. The first decagonal pair consists of the Penrose P1 tiling and the Tie and Navette one. The second pair is represented by dodecagonal tiling of squares, triangles, and shields, and previously unidentified one formed by regular dodecagons and identical deformed pentagons. Surprisingly, the proposed method for finding extrema of interference patterns provides a straightforward way to generate the Penrose tiling P3 and its more complicated analogs with 2n-fold symmetries. Within Landau theory, we discuss the assembly of the square-triangular tiling and its relationship with the dodecagonal tiling that includes shields. Then we develop a nonequilibrium assembly approach that is based on Landau theory and allows us to produce tilings with random phason strain characteristic of quasicrystals. Interestingly, the approach can generate tilings without or with a minimum number of defective tiles. Examples of real systems rationalized within Landau theory are considered as well. Finally, the derivation of other tilings arising from the reducible interference patterns is discussed, and the relative complexity of nonphenomenological interactions required for the assembly of decagonal and dodecagonal structures is analyzed.

The chain disordering transition, often observed in incommensurate host-guest (HG) systems, has never been observed in antimony, and the underlying mechanism remains poorly understood. Here, the x-ray diffraction results show that, upon decompression from 12 GPa to ambient pressure at 90 K, the incommensurate HG structure of Sb-II transforms into a new incommensurate structure with chain disorder, while the host framework maintains its tetrahedral structure. This is distinct from the structural evolution observed at room temperature. The density functional theory calculation reveals the structural modulation of the guest chains evolving from the uniform distribution with metallic bonds at high pressure (>15 GPa) to the atomic pairing with enhanced host-guest bonding polarity at ambient pressure. The atomic pairing and bonding polarized behaviors at low pressure are likely the driving force for the chain disordering during decompression. Moreover, the phonon calculation shows that there are two low-frequency quasiacoustic modes associated with pressure-induced chain disordering and intraphase transitions. This study advances the understanding of the HG structural evolution through host-guest interactions, offering insights into pressure modulation in the incommensurate phases.

Fast-ion conductors such as $\mathrm{BaSn}{\mathrm{F}}_4$ are of significant interest for next-generation solid-state battery technologies due to their high ionic conductivity and chemical stability. However, the behavior of these materials under extreme conditions remains poorly understood, despite the relevance of pressure-induced modifications for tuning functional properties. In this study, we combine density functional theory (DFT) calculations with high-pressure experiments to investigate the structural evolution of $\mathrm{BaSn}{\mathrm{F}}_4$ up to 40 GPa. DFT predicts two pressure-induced phase transitions: from the ambient-pressure tetragonal $P4$/nmm phase to a monoclinic $P{2}_1/m$-I structure at 10 GPa, and subsequently to a denser monoclinic $P{2}_1$/m-II phase at 32 GPa. The first transition is experimentally confirmed via angle-dispersive X-ray diffraction, Raman spectroscopy, and electrical resistivity measurements, all performed at ambient temperature. The second transition is supported by distinct changes in high-pressure Raman modes and resistivity behavior, consistent with a further structural reorganization. These findings not only clarify the high-pressure phase diagram of $\mathrm{BaSn}{\mathrm{F}}_4$, but also shed light on the potential for pressure-tuned ionic transport in fluorostannate-based solid electrolytes.

Topological valley-Hall phononic crystals offer robust platforms for broadband, backscattering-immune acoustic waveguiding. Here, we introduce a silicon-based phononic heterostructure that supports an extended valley-locked Lamb wave state (EVLS)—a topologically protected guided mode confined within a quasi-two-dimensional Dirac semimetal channel between two valley-Hall domains. A key innovation is the introduction of a geometric tuning parameter—the pillar height difference $dh$ —which enables precise control of the EVLS dispersion. By increasing $dh$, we systematically flatten the band and reduce the group velocity, achieving slow-wave transport while preserving topological immunity. The EVLS arises from hybridization of valley-polarized edge modes at the opposite interfaces and inherits their topological character, consistent with previously studied quantum valley Hall systems. Full three-dimensional simulations confirm that the EVLS supports broadband, slow wave propagation with suppressed backscattering under moderate disorders and bends. The guided Lamb wave operates in the gigahertz regime, and the frequency-scalable design enables large signal delay within a compact footprint while remaining compatible with complementary metal-oxide semiconductor/micro-electromechanical systems fabrication. This work establishes a general design strategy that unifies dispersion engineering and topological robustness, offering a scalable route toward GHz-frequency, dispersion-engineered, robust wave transport in chip-scale phononic systems.

Spin-orbit torque in synthetic antiferromagnets (SyAFs) has been studied extensively as a promising pathway for energy-efficient spintronic devices, but, to date, most studies have focused on the interaction of the SyAF with externally generated spin currents, such as those from the spin Hall effect in heavy metals. Here, we investigate internally generated spin torque in CoFeB/Ru/Ni SyAFs and its interaction with the magnetizations through harmonic resistance measurements. Through combined macrospin modeling and experimental investigations, we demonstrate that the second and third harmonic resistances are predominantly influenced by an unexpected effective field along the current direction, in a sharp contrast to conventional systems involving heavy metals. We attribute this abnormal effective field along the current direction to nonequilibrium spins with longitudinal polarization, induced either by a vertical component of magnetization at the Ni/Ru interface or by the reorientation of nonequilibrium spins through interfacial exchange coupling. Our findings offer insights into spin dynamics in SyAF structures and pave the way for advanced spintronic applications.

Kagome materials have attracted much attention recently due to the emergence of various exotic physical phenomena. A typical type of structural distortion in the kagome lattice is the trimerization of cations, known as the breathing mode, which may have a significant impact on the electronic and magnetic properties of kagome magnets. Here, we reveal the role of the breathing mode in the band topology based on the tight-binding model, and then investigate the influence of the breathing mode on the electronic property, ferroelectricity, and magnetism in a selected material family with a breathing kagome lattice ${\mathrm{Zr}}_3{X}_8$ ($X=\text{Cl}$, Br, I), using first-principles calculations. Although the breathing mode can only open a topologically trivial band gap at the Dirac point, its gradual enhancement can induce a topological phase transition from a nontrivial to a trivial insulator due to the competitive effect between the breathing mode and spin-orbit coupling in modulating the band gap. The breathing mode induces out-of-plane ferroelectric polarization through a linear coupling effect with the polar displacement mode, and the ferroelectric switching is accomplished by the simultaneous reversal of the two modes. The magnetic ground states change from a stripe antiferromagnetic to ferromagnetic phase with increasing anion radius. This work facilitates the exploration of physical phenomena driven by the breathing mode in the kagome lattice.

We report computational uncertainties in Boltzmann transport equation (BTE) based lattice thermal conductivity predictions of 50 diverse semiconductors from the use of different BTE solvers (ShengBTE, Phono3Py, and in-house code) and interatomic forces. The interatomic forces are obtained either using the density functional theory (DFT) as implemented in packages Quantum Espresso and VASP employing commonly used exchange correlation functionals (PBE, LDA, PBEsol, and rSCAN) or using the pretrained foundational machine learning (ML) force fields trained on two different material datasets. We find that the considered BTE solvers introduce minimal uncertainties and, using the same interatomic force constants, all solvers result in an excellent agreement with each other, with a mean absolute percentage error (MAPE) of only 1%. While this error increases to around 10% with the use of different DFT packages, the error is still small and can be reduced further with the use of stringent plane-wave energy cutoffs. On the other hand, the differences in thermal conductivity due to the use of different exchange correlation functionals are large, with a MAPE of more than 20%. The currently available pretrained foundational ML models predict the right trend for thermal conductivity, but the associated errors are high, limiting their applications for coarse screening of materials.