Quasi-two-dimensional (2D) layered structured BiTe, a member of the infinitely adaptive series ${\left({\mathrm{Bi}}_2\right)}_m{\left({\mathrm{Bi}}_2{\mathrm{Te}}_3\right)}_n$, is an efficient thermoelectric material and a dual topological insulator at ambient pressure. This undergoes pressure-induced sequential structural transitions into various 3D network structures (SnTe-type) and superconductivity emerges at elevated pressures. Here, using systematic high-pressure x-ray diffraction, Raman scattering, optical conductivity, and transport measurements, we identify the 2D and 3D BiTe phases with their distinct superconducting and normal state transport properties. Superconductivity emerges with $T_c \sim 2\mathrm{K}$ at 3 GPa within the 2D layered phase, where evidence of enhanced spin polarization of the Rashba surface states are found. This superconductor (SC) phase has been unambiguously identified by its much lower $T_c$, critical field and critical current, as compared to the high-pressure 3D phases. With pressure the 3D BiTe phase evolves from orthorhombic phase into atom-disordered body-centered cubic alloy phase, where a dramatic increase of the electronic phase relaxation rate is noticed within the enhanced metallic character. The observed sharp resistance peak anomaly near SC $T_c$ in the high-pressure 3D crystalline BiTe phases are interpreted as novel metal–bosonic insulator–superconductor transitions and the possible origins of this phenomena are discussed based on the magnetoresistance measurements.

Diamond is a symbolic material in nature due to its extremely high hardness. The Hugoniot-elastic limit (HEL) under shock compression can be used as an alternative method to evaluate the strength of a material. We measured the HELs of three types Ia-, Ib-, and IIa-diamond single crystals using large samples (thickness: 1.12–2.50 mm) in the peak stress range up to 119 GPa by a velocity-interferometer system of any reflector (VISAR). A minimum constant (steady-state) HEL value of $20.5\pm 2.0$ GPa was obtained for the highly pure type IIa-diamond large single crystals (nitrogen content: $<0.1$ ppm, thickness: 1.52–1.92 mm) along the $\langle 100\rangle$ axis, although the values in the range of 35–53 GPa were obtained for type Ia- and type Ib-diamond large single crystals (nitrogen content:10–2000 ppm, thickness: 1.42–2.50 mm). Considering these and previous reported results for thin diamond samples (thickness: 0.08–0.51 mm), we suggested that our steady-state HEL of type IIa-diamond single crystals was inherent for diamond and that the intrinsic strength was $18.4\pm 2.0$ GPa. The slip system was confirmed to be the {111} plane by the transmission electron microscopy observation of the recovered sample. The critical resolved shear stress of the {111}[110] slip system was derived to be $7.5\pm 1.0$ GPa, which can be comparable with the Peierls stress of diamond.

The non-Hermitian skin effect is a crucial feature in non-Hermitian systems, characterized by the pronounced localization of bulk eigenstates. In this work, we investigate an extended non-Hermitian Su-Schrieffer-Heeger model with power-law-decaying long-range complex couplings, revealing a skin transition from unipolar to bipolar. Specifically, we rigorously validate this skin phase transition by combining the energy spectra, spectral winding numbers, and spatial profiles of eigenstates. Meanwhile, the process of dynamical evolution further corroborates this transition, as wave packets are observed to spread toward both boundaries of the system rather than propagating unidirectionally. Remarkably, we reveal that the complex couplings can accelerate the dynamical evolution while suppressing the localization effect. Furthermore, we demonstrate that the couplings between identical sublattices lead to stronger localization and faster dynamic behaviors compared to those between opposite sublattices. In particular, we show that anti-Hermitian complex couplings, realized through dissipative couplings, can also effectively induce the bipolar non-Hermitian skin effect. Finally, we propose a feasible experimental scheme for realizing our model based on an electric circuit system. These findings provide a deeper understanding of both the directionality of the skin effect and non-Hermitian topological dynamics.

The coexistence of current-induced spin-orbit torque (SOT) and thermal effects necessitates their disentanglement for the realization of device applications. The second harmonic Hall voltage is widely used to study electrically driven spin torques and thermoelectric (anomalous Nernst effect) and/or thermomagnetic (spin Seebeck effect) effects in ferromagnet (FM)/heavy metal (HM) heterostructures. On the other hand, the third harmonic voltage has recently been considered for studying nonlinear SOT effects, thermally induced magnetization modulation, and SOT in antiferromagnet (AFM)/HM heterostructures. Here, we studied third harmonic Hall voltage characterization in Pt/CoFe with a higher magnetostriction coefficient for CoFe (Co 66%, Fe 34%). Our experiments demonstrate that the third harmonic voltage reveals two key mechanisms behind thermally driven spin torques: thermal expansion via the magnetoelastic effect and thermally induced magnetization reduction. This highlights the third harmonic voltage as a powerful tool for exploring nonlinear effects in a FM/HM heterostructure.

Temperature-pressure ($T-P$) phase diagrams of ${\mathrm{FeSe}}_{1-\mathrm{x}}{\mathrm{S}}_{\mathrm{x}}$ were investigated by the measurements of dc magnetization ($M$) and electrical resistivity ($\rho$) under pressure, using single crystal specimens with $x$ = 0.04, 0.08, and 0.13. For all specimens, the $M(T$) curves under pressure near the end point of the antiferromagnetic (AFM) phase are found to show a two-step diamagnetic response, which can be described as the sum of two diamagnetic components $M_1(T$) and $M_2(T$), indicating that two superconducting (SC) phases with different $T_{\mathrm{c}}$ values coexist within a pressure range of $\mathrm{\Delta }P\sim 1\mathrm{GPa}$. Moreover, the pressure dependence of the amplitudes of $M_1(T$) and $M_2(T$) indicates a continuous transfer of the volume fraction between the two SC phases. These behaviors suggest that a crossover of superconductivity occurs in conjunction with the emergence of AFM phase and imply that the SC phases inside and outside the AFM phase could have different origins.

The title paper [Phys. Rev. B 110, 064104 (2024)] examines the negative thermal expansion and phase transitions in ${\mathrm{ScF}}_3$ and related materials through density functional theory calculations. The calculations of negative thermal expansion in the noncubic materials are in error for two important reasons. First, these calculations use a formulation of Grüneisen theory that is only applicable to isotropic systems. Not only is this formulation wrong, but the choice of volume change in the derivatives of phonon frequencies is automatically arbitrary. A second error is the neglect of LO/TO splitting of the phonon frequencies at zero wave vector, which in the software chosen by the authors leads to an error that spreads across the Brillouin zone. These are both common errors in the literature, which we wish to highlight so that future authors can perform these calculations correctly. We further make two comments on the interpretation of these results. First, in systems that show phase transitions, the thermal expansion is likely dominated by spontaneous strains associated with the phase transition and not through a tension-effect mechanism. Finally, we point out that negative thermal expansion in ${\mathrm{ScF}}_3$ is much better understood than acknowledged in the title paper. Indeed, on the basis of recent work, we can easily and automatically understand why the negative thermal expansion would be much reduced, should the thermal expansion be associated with a tension effect, in related materials that are distorted as a result of a displacive phase transition.

We calculate the renewed phonon bands and mode-Grüneisen parameters for the $Pm\overline{3}m$ phases of $B{\mathrm{F}}_3$ ($B=\mathrm{Sc}$, Y, La, Al, Ga, In) including the nonanalytical term correction, as well as the mode-Grüneisen parameters for the $R\overline{3}c$ phase of $\mathrm{Sc}{\mathrm{F}}_3$ under hydrostatic pressure derived from the six different types of strains, all of which are based on the comments by Dove and Phillips [Phys. Rev. B (2025)]. As a result, we show that there is no significant change in the discussion given in our original publication [Phys. Rev. B 110, 064104 (2024)]. However, we acknowledge that the disappearance of the negative thermal expansion (NTE) behavior in the $R\overline{3}c$ phase of $\mathrm{Sc}{\mathrm{F}}_3$ cannot be solely explained by the less negative Grüneisen parameters of the $Pm\overline{3}m$ phase of $\mathrm{Sc}{\mathrm{F}}_3$. We denote that we did not claim that the NTE behavior of $\mathrm{Sc}{\mathrm{F}}_3$ is not well understood, and the most important point of our original paper is that we have explained the dynamical stability of the cubic $\mathrm{Sc}{\mathrm{F}}_3$ by the group theoretical analyses of the electronic and phonon band structures.

Altermagnets represent a newly identified third class of collinear magnets and have recently emerged as a focal point in condensed matter physics. In this work, through first-principles calculations and theoretical analysis, we identify monolayer ${\mathrm{Fe}}_2\mathrm{Mo}{X}_4$ ($X$ = S, Se, Te) and ${\mathrm{Fe}}_2{\mathrm{WTe}}_4$, a class of iron-based transition metal chalcogenides, as promising altermagnetic materials. These systems are found to be semiconductors exhibiting spin splitting in their nonrelativistic band structures, indicative of intrinsic altermagnetic ordering. Remarkably, their valence bands feature a pair of valleys at the time-reversal-invariant momenta $X$ and $Y$ points. Unlike conventional valley systems, these valleys are related by crystal symmetries rather than time-reversal symmetry. We investigate valley-dependent physical phenomena in these materials, including Berry curvature and optical circular dichroism, revealing strong valley-contrasting behavior. Furthermore, we investigate the effect of uniaxial strain and show that it effectively lifts the valley degeneracy, resulting in pronounced valley polarization. Under hole doping, this strain-induced asymmetry gives rise to a piezomagnetic response. We also explore the generation of anisotropic noncollinear spin currents in these systems, expanding the scope of their spin-related functionalities. Our findings unveil rich valley physics in monolayer ${\mathrm{Fe}}_2\mathrm{Mo}{X}_4$ ($X$ = S, Se, Te) and ${\mathrm{Fe}}_2{\mathrm{WTe}}_4$, highlighting their significant potential for applications in valleytronics, spintronics, and multifunctional nanoelectronic devices.

Analysis of the thermal and baric evolution of resistance in ${\mathrm{LaBa}}_2{\mathrm{Fe}}_3{\mathrm{O}}_{8+\delta }$ enabled the construction of its pressure-temperature (P-T) phase diagram, which prominently displays a critical boundary, $P_c^{\mathrm{MIT}}\left(T\right)$, marking the transition from localized to hole-type extended states. The relatively low critical pressures $[P_c^{\mathrm{MIT}}\left(T\right)\approx 3–8\text{GPa}]$ suggest that, as $P\to P_c$ in this narrow-gap, strongly correlated charge-transfer system, both the hybridization strength and the charge-transfer character are progressively enhanced, ultimately leading to the emergence of metallicity. Emphasizing the electronic nature of this transition, pressure-dependent structural analyses at room temperature reveal no associated structural phase transition at $P_c^{\mathrm{MIT}}\left(T\right)$; the system retains a (weakly tetragonally distorted) quasicubic perovskite structure with Murnaghan-type compressibility up to 30 GPa. The emergence of hole delocalization and metallic conduction, coupled with suppressed antiferromagnetism, suggests proximity to quantum criticality.

We synthesized high-quality single crystals of $T_3\mathrm{I}{\mathrm{n}}_7, T=\mathrm{Ni},\mathrm{Pd},\mathrm{Pt}$, which crystallize in a body-centered-cubic $I$m-3m space group with $T$-metal-based dumbbells. The systematic study of electrical resistivity exhibits metallic behavior with extremely large nonsaturating magnetoresistance reaching 1500% at 14 T with profound Shubnikov–de Hass quantum oscillations. The fast Fourier transformation analysis shows multiple frequencies pointing to a complex structure of the Fermi surfaces. The large magnetoresistance is attributed to the presence of small, closed Fermi surfaces with light cyclotron masses with good agreement with theoretical calculations. We present the first experimental and theoretical study of the Fermi surface in the $T_3\mathrm{I}{\mathrm{n}}_7$ family.

There has been significant recent interest in the potential exotic properties of multichannel Kondo lattices and their connection to quantum materials, but the strongly coupled nature of these models has posed challenges to theoretical investigations. We study the emergence of topological order in a two-dimensional two-channel Kondo lattice (2CKL) in a time-reversal symmetry-broken channel symmetric phase using a coupled-wire construction from one-dimensional (1D) 2CKLs. Through bosonization and symmetry analysis, we show that away from particle-hole symmetry, the 1D 2CKL model flows to an infrared fixed point with an emergent $\mathrm{SO}(3,1)\times \mathrm{SU}\left(2\right)$ symmetry and a ${\mathbb{Z}}_2$ gauge structure. Interwire couplings induce a transition to a topologically ordered metallic state characterized by fractionalized excitations and eightfold ground state degeneracy on a torus. Our findings connect impurity-based non-Fermi-liquid behavior to lattice topological order, with potential implications for quantum materials and topological quantum computation.

Superconductors with A15 structure have been studied for decades, with recent research focusing on their potential topological band structures and spin Hall effects. However, direct electronic structure studies are still lacking. Here, we have investigated the electronic structure of ${\mathrm{Nb}}_3\mathrm{Sb}$ and ${\mathrm{V}}_3\mathrm{Si}$ using angle-resolved photoemission spectroscopy. The band structure reveals pronounced three-dimensional features, which are overall consistent with the results of our density-functional theory calculations. Notably, a band renormalization factor of 1.44 is required for ${\mathrm{V}}_3\mathrm{Si}$, whereas no such renormalization is needed for ${\mathrm{Nb}}_3\mathrm{Sb}$, indicating stronger correlation effect in ${\mathrm{V}}_3\mathrm{Si}$. Flat bands are present in both samples, located at −0.28 eV below the Fermi level in ${\mathrm{Nb}}_3\mathrm{Sb}$ and nearly touching Fermi level in ${\mathrm{V}}_3\mathrm{Si}$, thereby enhancing the density of states near Fermi level and thus responsible for the higher superconducting critical temperature of ${\mathrm{V}}_3\mathrm{Si}$. Both ${\mathrm{Nb}}_3\mathrm{Sb}$ and ${\mathrm{V}}_3\mathrm{Si}$ feature four- and eightfold degenerate fermions at the $R$ point. Moreover, ${\mathrm{Nb}}_3\mathrm{Sb}$ is also characterized by a topological invariant of $Z_2$ = 1, confirming it as a strong topological material, which might be responsible for its nonsaturating magnetoresistance. Our results give fundamental understanding of the electronic structure and band topology of the A15 superconductors, fill the long-standing gap of the experimental electronic structure study of these materials.

We investigate the topological properties of modified Dirac Hamiltonians with an altermagnetic mass term and reveal a mechanism for realizing altermagnetic Weyl semimetals. Unlike the conventional Wilson mass, the altermagnetic mass drives direct transitions between nontrivial Chern phases of opposite signs and fundamentally reshapes the band inversion surface. By extending this framework to three dimensions, we construct a minimal lattice model that hosts pairs of Weyl nodes as well as coexisting helical Fermi arcs with opposite chirality on the same surface, which is a phenomenon not found in conventional magnetic Weyl semimetals. We further propose a practical scheme to realize these phases in multilayer structures of two-dimensional Rashba metal with engineered $d$-wave altermagnetic order. Our results deepen the theoretical understanding of mass terms in Dirac systems and provide concrete guidelines for the experimental detection and realization of altermagnetic Weyl semimetals.

We present a comprehensive Floquet-Nambu theory to describe the time-dependent quantum transport in mesoscopic circuits involving superconductors. The central object of our framework is the first-order correlation function, which accounts for the excitations that are generated by a time-dependent voltage and their coherent scattering off the interface with a superconductor. We analyze the time-dependent current generated by periodic voltage pulses and how it depends on the excitation energies of the voltage drive compared to the gap of the superconductor. Our general formalism allows us to identify the conditions for the excitations that are scattered off the superconductor to become coherent electron-hole superpositions. To this end, we consider the purity of the outgoing states, which characterizes their ability to carry quantum information. To illustrate our formalism, we apply it to a system composed of chiral quantum Hall edge states connected to a superconductor, and we calculate the current in the outgoing lead and the purity of the outgoing states for Lorentzian and harmonic voltage drives. Our framework paves the way for systematic investigations of time-dependent scattering problems involving superconductivity, and it may help interpret future experiments in electron quantum optics with superconductors.

Sliding ferroelectricity (FE) in two-dimensional (2D) materials offers a promising route to ultrathin, low-power, nonvolatile devices, yet in pristine homobilayers it is typically weak and confined to a small subset of known 2D materials. This limitation prompts a central question: Can sliding FE be reliably induced and substantially enhanced in otherwise nonferroelectric homobilayers through a controllable, experimentally feasible intervention? Here, we combine high-throughput first-principles calculations with machine learning to establish atomic intercalation as a versatile strategy for activating and amplifying sliding FE. Notably, we identify pristine InP and GaP as record performers, exhibiting out-of-plane polarizations up to 21.0 pC/m, approximately ten times greater than experimentally synthesized BN and over 45 times higher than $\mathrm{Mo}{\mathrm{S}}_2$, while maintaining moderate switching barriers of just 13.6 and 32.0 meV/f.u. Intercalation with Cu, Ag, and Au expands the pool from 106 pristine sliding FE systems to 591, including 212 activated from initially nonferroelectric states. To accelerate exploration of this enlarged configurational space, we develop a descriptor-free graph neural network incorporating message passing and global attention, enabling direct polarization prediction from atomic configurations. This integrated computational–machine learning framework delivers a robust and tunable pathway for designing high-performance sliding ferroelectrics and a blueprint for targeted discovery of functional 2D materials.