We locate the phase-transition line for the Ising model on the fuzzy sphere from a finite-size scaling analysis of its ground-state energy. Our strategy is to write the latter as $E_{\mathrm{GS}}\left(N_m\right)/N_m=E_0+E_1/N_m+E_{3/2}/N_m^{3/2}+\cdots$ and to search for a minimum of $\chi :=E_{3/2}/E_0$ as a function of the couplings. Conformal perturbation theory predicts that around a conformal field theory, $\chi ={\chi }_{\min }+{\sum }_i{\lambda }_i^2{N}_m^{-{\omega }_i}+O\left({\lambda }^3\right)$, where ${\lambda }_i$ are the couplings associated with perturbations of operators with dimension ${\mathrm{\Delta }}_i$ and ${\omega }_i=d-{\mathrm{\Delta }}_i$. This procedure finds the critical curve of Zhu et al. [Phys. Rev. X 13, 021009 (2023)] and its sweet spot with good precision. Varying two coupling constants allows us to extract the correction-to-scaling exponent $\omega$ associated with the two leading scalars $\varepsilon$ and ${\varepsilon }^{\prime }$. We find similar results when normalizing by the gap to the stress tensor $T$ or the first parity-odd operator $\sigma$ instead of $E_0$.

The combination of disorder and interactions is known in many systems to produce a feature in the single-particle density of states, the shape and parameter dependence of which act as signatures of the underlying electronic state. Strong Coulomb repulsion gives rise to a host of novel phenomena, among these is a unique zero-bias anomaly. While understanding of the anomaly in bulk materials remains incomplete, a version of this anomaly can be found in an ensemble of two-site systems and hence has been predicted to be observable in parallel-coupled double quantum dots. However, prior work did not include the influence of the leads. Here we show that the presence of the leads results in changes to the projected stability diagrams but that the signature of the strongly correlated zero-bias anomaly nonetheless remains clearly visible.

Nonlocal transport, which goes beyond the Ohm's law, can be a key to understanding systems with topological order or edge states. Here, we report an unusual nonlocal charge transport in the nodal-line semimetal ${\mathrm{ZrTe}}_5$ that occurs in magnetic fields applied along the $a$ axis. Surprisingly, the observed decay length of the nonlocality exceeds $100\mu \mathrm{m}$ and it increases linearly with the sample width. This nonlocal transport is detected not only in the longitudinal configuration, but also in the transverse one as an unusual nonlocal Hall effect. Our findings demonstrate that the nonlocal response can offer interesting insights into topological quantum materials.

A theory is proposed for the component of the Casimir-like force that arises between bodies embedded in a macroscopic quantum damped oscillator. When the oscillator's parameters depend on the distance between the bodies, the oscillator-induced Casimir-like force is generally determined by a broad spectral range extending to high frequencies, limited by the frequency dispersion of the damping function. Here, it is shown that there exists a large class of systems in which the low-frequency range dominates the forces. This allows one to use the Ohmic approximation, which is crucial for extending the theory to a lumped-element description of fluctuation-induced forces in electrical circuits. Estimates of the circuit-induced Casimir-Lifshitz force suggest that under certain conditions it can be identified experimentally due to its dependence on various circuit elements.

By combining angle-resolved photoemission, density functional theory, and variable-angle spectroscopic ellipsometry, we determine the bulk electronic structure and anisotropic optical response of platinum disulfide ($\mathrm{Pt}{\mathrm{S}}_2$). Momentum-resolved maps collected at 60 and 85 eV reveal a single holelike branch that peaks at Γ with an effective mass approximately $1.7{\mathrm{m}}_{\mathrm{e}}$. The measured dispersion along the Γ–M–K direction is reproduced within the experimental resolution by calculations including spin-orbit coupling and recursive Green's function approach in semi-infinite geometry. A photon-energy sweep shows a weak but finite out-of-plane dispersion for the top valence band, establishing its bulk character, while constant-energy maps reveal a ring-shaped extremum approximately 1.5 eV below the valence-band maximum that generates nearly flat segments and a Mexican-hat contour consistent with S-p and Pt-d hybridization and a surface-localized, topologically trivial origin. The same ab initio framework yields an indirect bulk gap of approximately 1.22 eV and a strongly anisotropic dielectric tensor with an in-plane epsilon-near-zero crossing near 3.1 eV. The estimated dielectric tensors indicate the existence of a low-energy anisotropic dielectric region; an intermediate range in which both the real and imaginary parts of the dielectric function are negative and only evanescent, plasmonic modes are supported; and type-I hyperbolic windows where the in-plane and out-of-plane components have opposite signs, including a narrow visible band around 3.14–3.24 eV and a broader range above approximately 3.8 eV. Ellipsometry in the 1.24–3.60 eV range confirms experimentally the same ordering of photonic regimes, with an anisotropic dielectric response at low energy, followed by type-I and type-II intervals, and locates the corresponding zero-crossings at slightly lower photon energies than in theory. These results promote the use of $\mathrm{Pt}{\mathrm{S}}_2$ for anisotropic optoelectronic and nanophotonic architectures.

Moiré superlattices formed in ${\mathrm{WS}}_2/{\mathrm{WSe}}_2$ heterobilayers have emerged as an exciting platform to explore the quantum many-body physics. The key mechanism is the introduction of moiré potentials for the band-edge carriers induced by the lateral modulation of interlayer interactions. This trapping potential results in the formation of flat bands, which enhances the strong correlation effect. However, a full understanding of the origin of this intriguing potential remains elusive. In this paper, we present a comprehensive investigation of the origin of moiré potentials in both R-type and H-type moiré patterns formed in ${\mathrm{WS}}_2/{\mathrm{WSe}}_2$ heterobilayers. We show that both lattice reconstruction and interlayer charge transfer contribute significantly to the formation of moiré potentials. In particular, the lattice reconstruction induces a nonuniform local strain, which creates an energy modulation of $\sim 200\mathrm{meV}$ for the conduction band-edge state located at ${\mathrm{WS}}_2$ layer and $\sim 20\mathrm{meV}$ for the valence band-edge state located at ${\mathrm{WSe}}_2$ layer. In addition, the lattice reconstruction also introduces a piezopotential energy, whose amplitude ranges from $\sim 40$ to $\sim 90\mathrm{meV}$ depending on the stacking and band-edge carrier. The interlayer charge transfer induces a built-in electric field, resulting in an energy modulation of $\sim 80\mathrm{meV}$ for an R-type moiré and $\sim 40\mathrm{meV}$ for an H-type moiré. Taking into account both effects from lattice reconstruction and interlayer charge transfer, the formation of moiré potential is well understood for both R-type and H-type moirés. This trapping potential localizes the wavefunctions of conduction and valence bands around the same moiré site for an R-type moiré, while around different moiré site for an H-type one. Our work not only provides an efficient method to study lattice-mismatch-induced moiré patterns, but also gives help in understanding the intriguing moiré physics in ${\mathrm{WS}}_2/{\mathrm{WSe}}_2$ heterobilayers.

We study the spontaneous chiral surface current circulating in a three-dimensional disk of a chiral superconductor (SC) utilizing quasiclassical Eilenberger theory. We obtain spatial profiles of the chiral current for both a ($d_{zx}+i{d}_{yz}$)-wave and a ($p_x+i{p}_y$)-wave SCs (where the top and bottom surfaces of the disk are perpendicular to the $z$ axis). Whereas the chiral current for a ($p_x+i{p}_y$)-wave SC does not depend on $z$, a reversal of the chiral current takes place at the top and bottom surfaces in the case of a ($d_{zx}+i{d}_{yz}$)-wave SC. In this latter case, flat-band Andreev bound states appear at the top and bottom surfaces in addition to the chiral surface states at the lateral surface. The chiral current reversal is explained in terms of a hybridization between the two types of Andreev bound states. As a result, the magnetic field around the disk differs drastically between the two cases.

Even though thermodynamic stability-oriented crystal structure prediction (CSP) has revolutionized materials discovery, the energy-driven CSP approaches often struggle to identify experimentally realizable metastable materials synthesized through kinetically controlled pathways, creating a critical gap between theoretical predictions and experimental synthesis. Here we propose a synthesizability-driven CSP framework that integrates symmetry-guided structure derivation with a Wyckoff encode-based classification model, allowing for the efficient localization of subspaces likely to yield synthesizable structures. Within the identified promising subspaces, a structure-based synthesizability evaluation model, fine-tuned using recently synthesized structures to enhance predictive accuracy, is employed in conjunction with ab initio calculations to systematically identify synthesizable candidates. The framework successfully reproduces 13 experimentally known $X\mathrm{Se}$ ($X=\mathrm{Sc}$, Ti, Mn, Fe, Ni, Cu, and Zn) structures, demonstrating its effectiveness in predicting synthesizable structures. Notably, 92 310 structures are filtered from the 554 054 candidates predicted by Graph Networks for Materials Exploration, exhibiting promising synthesizability. Additionally, eight thermodynamically favorable $\mathrm{Hf}\text{−}X\text{−}\mathrm{O}$ ($X=\mathrm{Ti}$, V, and Mn) structures have been identified, among which three ${\mathrm{HfV}}_2{\mathrm{O}}_7$ candidates exhibit high synthesizability, presenting viable candidates for experimental realization and potentially associated with experimentally observed temperature-induced phase transitions. This work establishes a symmetry-guided and data-driven framework for machine-learning-assisted prediction of synthesizable inorganic materials, highlighting its potential to bridge the gap between computational predictions and experimental realizations while unlocking new opportunities for the targeted discovery of novel functional materials.

We propose a simple scaling of anomalous Hall conductivity ${\sigma }_{\mathrm{xy}}$ with sign by considering the contributions of the Fermi surface and Fermi sea. For the four ferromagnetic metals studied, polycrystalline Co, Ni, $\mathrm{C}{\mathrm{o}}_{27}\mathrm{N}{\mathrm{i}}_{73}$, and amorphous $\mathrm{C}{\mathrm{o}}_{40}\mathrm{F}{\mathrm{e}}_{40}{\mathrm{B}}_{20}, {\sigma }_{\mathrm{xy}}$ is dominated by the linear term in the conductivity ${\sigma }_{\mathrm{xx}}$, mainly attributed to the Fermi surface by skew scattering. Notably, the quadratic term (square of ${\sigma }_{\mathrm{xx}}$), attributed mainly to the Fermi sea, is of opposite sign to the linear term from the Fermi surface. The sum of the quadratic (Fermi-sea) term and the constant term can be larger than the linear (Fermi-surface) term for $\mathrm{C}{\mathrm{o}}_{27}\mathrm{N}{\mathrm{i}}_{73}$. Our scaling of the anomalous Hall effect is applicable to various materials, even largely deviating from conventional scaling.

Collinear antiferromagnets with nonrelativistically spin-split bands and no net magnetization, called altermagnets, show interesting transport properties due to their unique band structure. We compute the linear response optical conductivity of thin films of such materials in the presence of phonon scattering. Using a tight-binding lattice model for altermagnets and the Holstein model for the phonon sector, we find that the electron-phonon scatterings can strongly increase the spin conductivity at finite frequencies. This occurs despite the fact that the self-energy describing the electron-phonon interactions is spin independent. Interestingly, we show that electron-phonon scattering also enhances the spin-splitter effect at finite frequencies. These results suggest that altermagnets with strong electron-phonon coupling are favorable with regard to AC spin-polarized transport.

Forces on atoms are both fundamental and crucial physical quantities that give rise to the infinite diversity of matter and its properties. How do atomic forces arise? That is the origin of atomic force is therefore crucial for a comprehensive understanding of a rich variety of structural, mechanical, and dynamic properties as well as physical and chemical phenomena. In particular, the influence of electronic states on atomic forces via chemical bonding and crystal structures, however, remains elusive. Here we develop a computational method for calculating the quantum electronic force, which is decomposed into atomic orbitals and/or spins, implemented in first-principles calculations based on a linear-combination-of-pseudoatomic-orbital (LCPAO) method. We demonstrate this methodology for simple diatomic molecules and extend its application to hydrogen diffusion on a platinum catalyst and the nitrogen-vacancy center in diamond. We clarify that specific orbitals dominate the driving forces for hydrogen diffusion, while spin-dependent forces determine the stable nitrogen-vacancy center configuration in diamond by monitoring quantum electronic forces. Our approach provides electronic insight into structural and dynamic phenomena by visualizing how each electron induces atomic forces.

We investigated the structural and magnetic properties of single-crystalline ${\mathrm{SmCuAs}}_2$ using high-resolution synchrotron x-ray diffraction and x-ray resonant magnetic scattering (XRMS) at the Sm $L_2$ and $L_3$ edges. Temperature-dependent diffraction measurements confirm that ${\mathrm{SmCuAs}}_2$ maintains its tetragonal symmetry from room temperature down to 8 K, with lattice parameters showing anomalous behavior below the resistivity minimum ($T\approx 30\mathrm{K}$). Notably, the c-axis lattice parameter exhibits a plateau and subsequent increase near the Néel temperature, indicating magnetoelastic coupling. XRMS measurements reveal a commensurate antiferromagnetic structure with a propagation vector $\mathit{q}=(0,0,0.5)$. Our measurement shows that the Sm moments are aligned within the $\mathit{ab}$ plane and arranged in a $++--$ stacking along the $\mathit{c}$ axis. Comparison with related $RE{\mathrm{CuAs}}_2$ compounds (RE = Pr, Nd, and Gd) suggests that in-plane moment orientation and associated magnetic frustration play a key role in the emergence of the resistivity minimum. Differences in spin-orbit and magnetoelastic coupling across the series highlight their importance in governing low-temperature transport behavior.

It is of great interest to develop methods to rapidly and effectively control the magnetic configurations in artificial spin ices, which are arrangements of dipolar coupled nanomagnets that have a variety of fascinating collective magnetic phenomena associated with them. This is not only valuable in terms of acquiring fundamental understanding but is also important for future high-performance applications. Here, we demonstrate ultrafast control of magnetic relaxation in artificial square ice through femtosecond laser pulsed excitation, enabling rapid access to low-energy states via dipolar interactions. Time-resolved magneto-optical Kerr effect measurements reveal that, after laser-induced demagnetization, the magnetization recovers 60% of its original value within 40 picoseconds. During this brief time window, dipolar coupling drives a collective magnetic ordering. Ex situ magnetic force microscopy confirms the emergence of extended domains with the lowest-energy vertex configuration, characteristic of ground-state ordering, thus establishing ultrafast laser-driven relaxation as a route to attain the low-energy states. Through complementary energy barrier calculations and micromagnetic simulations incorporating Landau-Lifshitz-Bloch dynamics, we elucidate the underlying mechanism: transient ultrafast demagnetization followed by rapid remagnetization that enables a dipolar-driven collective rearrangement. Moreover, a tailored decreasing-fluence laser excitation protocol is shown to enhance ground-state ordering, consistently achieving over 92% ground-state vertex populations. This work opens the way to ultrafast and spatially selective control of magnetic states in artificial spin ice for spin-based computation and memory technologies, and highlights the critical interplay of thermal fluctuations, magnetostatic coupling, and transient magnetization dynamics.

Spin-momentum locking plays a fundamental role in spintronics and, more broadly, is an important concept in condensed matter physics. In 2D and 3D, spin-momentum locking typically does not allow spin conservation because the spin-1/2 operators of electrons anticommute. Instead, here we study spin-momentum locking terms with conserved, commuting pseudospins built from a combination of spin and orbitals. We find that 2D spin-momentum locking terms with conserved pseudospins generally lead to linearly dispersing modes at low-energy with anomalous charge and pseudospin currents. To cure the anomaly, we show that such anomalous modes can be realized on the surface of a 3D Weyl semimetal (or an associated weak topological insulator) with a nonzero mixed spin-momentum quadrupole moment, which is determined by the momentum location and pseudospin eigenvalues of Weyl points at the Fermi level. Crucially, this mixed quadrupole moment captures a mixed pseudospin-charge bulk response that cancels the anomaly of surface modes, and can generate a giant 3D spin Hall effect, among other phenomena.

Hall conductivities are important characterizations of phases of matter. It is known that nonzero Hall conductivities are difficult to realize in local commuting projector lattice models due to no-go theorems in $(2+1)\mathrm{D}$. In this work we construct local commuting projector models in $(2+1)\mathrm{D}$ and $(3+1)\mathrm{D}$ with nonzero generalized Hall conductivities for ordinary and higher-form continuous symmetries on tensor product Hilbert space of finite local dimension. The model is given by a standard ${\mathbb{Z}}_N$ toric code, but the symmetries do not admit expression in terms of on-site charge operators. The symmetry do not have local charges or currents on the lattice in the absence of boundaries, but there is still a notion of Hall conductivities that coincide with the continuum field theories. We construct protected gapless boundaries of the lattice models using modified Villain formalism. The generalized Hall conductivities are computed by surface currents as well as bulk flux insertion and many-body Chern number.

Experiments on twisted double bilayer tungsten diselenide have demonstrated that moiré semiconductors can realize a relativistic Mott transition, i.e., a quantum phase transition from a Dirac semimetal to a correlated insulating state, by twist-angle tuning. In addition, signatures of van Hove singularities were observed in the material's moiré valence bands, suggesting further potential for the emergence of strongly correlated states. Based on a continuum model, we provide a detailed analysis of the twist-angle dependence of the system's band structure, focusing on the evolution of the Dirac excitations and the Fermi-surface structure with its Lifshitz transitions across the van Hove fillings. We exhibit that the twist angle can be used to band engineer a high-order van Hove singularity, which can be accessed by gate tuning. We then study the magnetic phase diagram of an effective Hubbard model for twisted double bilayer tungsten diselenide on the effective honeycomb superlattice with tight-binding parameters fitted to the two topmost bands of the continuum model. To that end, we employ a self-consistent Hartree-Fock mean-field approach in real space. Fixing the angle-dependent Hubbard interaction based on the experimental findings, we explore a broad parameter range of twist angle, filling, and temperature. We find a rich variety of magnetic states that we expect to be accessible in future experiments, including, e.g., a noncoplanar spin-density wave with nonzero spin chirality and a half-metallic uniaxial spin-density wave. Finally, we employ a functional renormalization group approach to also study the competition between density-wave and superconducting instabilities. For twist angles of $\theta =2.0^{\circ },2.5^{\circ }$, as well as $\theta \approx 3.5^{\circ }$—where the high-order van Hove-singularity is found—we find clear indications for unconventional superconductivity.

We perform Low-energy Ion Scattering with He ions ranging in energy from 1 keV to 3 keV on ${\mathrm{CaSiO}}_3$ using a commercial electrostatic detector system and determine the charge fraction of scattered ions from comparison with binary collision approximation simulations. The simulations take composition changes due to surface cleaning Xe sputtering into account. Scattered He particles are separated in the simulation into single, dual, and multiple scattering trajectories. We find that the charge fraction of single and dual scattered He is about ten times higher than the one for multiple collisions. Our results show that the charge fraction of scattered He can be reliably extracted for different scattering regimes and that for a given He incidence energy, the entire scattered He spectrum can be modeled with only few constant parameters.

We show that unconventional relaxation dynamics of special initial states in one-dimensional arrays of Rydberg atoms produce nongeneric decay of the initial-state survival probability (SP) at very early times. Using the PXP Hamiltonian as a minimal model of the Rydberg blockade, we prove that the early-time SP for states exhibiting quantum many-body scarring (QMBS) decays at a characteristic rate, whose finite-size scaling is determined solely by scars. We numerically investigate the effects of both revival-enhancing and ergodicity-restoring deformations of the PXP Hamiltonian and find results consistent with the limiting cases of integrable and ergodic dynamics, respectively. We moreover argue that such unconventional early relaxation of scarred initial states is characteristic of a whole class of QMBS models. Since the SP can be easily measured experimentally, our findings enable us to probe the presence of scars at time scales much shorter than that of thermalization.

The origin of the insulating state in $1T-{\mathrm{TaS}}_2$ has long been a subject of debate. A short current pulse transforms this insulating state into a metastable metallic phase. Using micro–angle-resolved photoemission spectroscopy, we investigate the electronic structure of this phase and uncover spatially dependent modifications caused by the current pulse. In some regions of the sample, a Fermi surface emerges, while others remain gapped. Detailed band structure analysis reveals that the metallic regions exhibit an electronic structure similar to that observed in the high-temperature phase of $1T-{\mathrm{TaS}}_2$, characterized by suppressed energy gaps and bands crossing the Fermi level. Furthermore, the metallic and insulating regions display distinct out of plane dispersions, consistent with the current pulse influencing the Star of David dimers that characterize the insulating phase.

The quantum geometric tensor (QGT) embodies the geometry of the eigenstates of a system's Hamiltonian, and its full characterization across diverse quantum systems is essential. However, it is challenging to characterize the QGT of solid-state systems. Here we present an electric scheme to measure the complete QGT of two-dimensional solid-state systems by using spin-polarized scanning tunneling microscopy (STM), in which the spin texture is extracted from geometric amplitudes of Friedel oscillations induced by the intentionally introduced magnetic impurity, and then the QGT is derived from the momentum differential of spin texture. As a canonical spin model, the surface states of a topological insulator offer a promising way to demonstrate the scheme. In a slab of topological insulator, the gapped surface states host complete QGT, i.e., nonvanishing quantum metric and Berry curvature as its symmetric real part and the antisymmetric imaginary part. Thus, a detailed derivation guides the use of the developed scheme to measure the QGT of gapped surface states, even with an external magnetic field. This study opens a new avenue to directly measure the complete QGT of two-dimensional solid-state systems by using spin-polarized STM.