The magnetization dynamics of two skyrmions with antiparallel vortex rotations on a nanowire substrate were investigated using micromagnetic simulations. When positioned in proximity, the skyrmions exhibit attractive interactions that decrease their separation distance. This interaction leads to a magnetic energy transition, resulting in the fusion of the two skyrmions into a single connected entity

Janus transition metal-dichalcogenide materials have attracted a great deal of attention due to their remarkable physical properties arising from the two-dimensional geometry and the breakdown of the out-of-plane symmetry. Using first-principles density functional theory, we investigated the phase stability, strain-enhanced phase stability, and superconductivity of Janus WSeH and WSH. In addition,

The control of the spin degree of freedom is at the heart of spintronics, which can potentially be achieved by spin-orbit coupling or band topological effects. In this paper, we explore another potential controlled mechanism under debate: the spin-deformation coupling (SDC)—the coupling between intrinsic or extrinsic geometrical deformations and the spin degree of freedom. We focus on polar-deformed

We investigate the energy band structure and energy levels of graphene with staggered intrinsic spin-orbit coupling and in-plane Zeeman fields. Our study demonstrates that staggered intrinsic spin-orbit coupling induces bulk band crossover at the 𝐾 and 𝐾′ valleys and generates antihelical edge states at the zigzag boundaries, resulting in topological metallic phases. Quantized transport coefficients

We studied the absorption of microwave electromagnetic radiation incident normal to a two-dimensional electron system on a dielectric substrate with a metallic back reflector. We have shown that the presence of a back gate strongly modifies the spectrum of plasmon polaritons in such a structure. We observe a transverse plasmon mode which starts from zero frequency at zero magnetic field and follows

The high-pressure temperature phase diagram and transport properties of materials are of broad interest to planetary sciences and high-energy-density sciences and applications. Alumina (Al2⁢O3) or its various forms (e.g., solutions with other oxides or silicates) are important constituents in Earth's and super-Earths' mantles, common window materials in dynamic compression experiments, and standard

Alloying stands out as a pivotal technological method employed across various compounds, be they metallic, magnetic, or semiconducting, serving to fine-tune their properties to meet specific requirements. Ternary semiconductors represent a prominent example of such alloys. They offer fine-tuning of electronic bands, the band gap in particular, thus granting the technology of semiconductor heterostructures

Exceptional points with coalescence of eigenvalues and eigenvectors are spectral singularities in the parameter space, achieving which often needs fine-tuning of parameters in quantum systems. We predict a persistent realization of nodal magnon-photon polariton, i.e., a polariton of long wavelength without any gap splitting in a thin ferromagnetic insulator film sandwiched by two normal metals, which

We report the growth and physical properties of high-quality needle-shaped R⁢e3⁢G⁢e7 single crystal with various characterizations. It exhibits a gapped metal-insulator (MI)-like phase transition with evident Shubnikov–de Haas oscillation of low-𝑇 electrical resistivity. The superconducting phase diagram was revisited by measuring the electrical resistivity in a cubic anvil cell (CAC) under various

A mechanism to deterministically prepare a nanowire Josephson junction in an odd parity state is proposed. The mechanism involves population of two Andreev levels by a resonant microwave drive breaking a Cooper pair, and a subsequent ionization of one of the levels by the same drive. Robust preparation of the odd state is allowed by a residual Coulomb repulsion in the junction. A similar resonant process

By utilizing a multiorbital periodic Anderson model with parameters obtained from ab initio band structure calculations, combined with degenerate perturbation theory, we derive effective Kondo-Heisenberg and spin Hamiltonians that capture the interaction among the effective magnetic moments. This derivation encompasses fluctuations via both nonmagnetic 4⁢𝑓0 and magnetic 4⁢𝑓2 virtual states, and its

Structural defects are important for both solid-state chemistry and physics, as they can have a significant impact on chemical stability and physical properties. Here, we identify a vacancy-induced pseudogap formation in antiferromagnetic C⁢r0.86⁢ZnSb. C⁢r1−𝑥⁢ZnSb alloys were studied combining efforts of density functional theory (DFT) calculations and experimental methods to elucidate the effect

The reflection point is different from the incident point on the interface between two Weyl semimetals, and a spatial shift happens during the reflection. The reflection shift vector as a function of in-plane wave vector shows vortex structures in the incident pocket (the projection of the isoenergy surface on the junction interface) and on the pocket edge. We propose a topological quantity, which

Fano resonance is believed to arise when a direct path interferes with a resonant path. We demonstrate that this is not true for chiral electronic transmission without additional direct paths. To address the Fano effect in chiral electronic transport, we suggest an electronic Mach-Zehnder-Fano interferometer, which integrates a quantum dot into an electronic Mach-Zehnder interferometer. Due to the

Valley, as an emerging degree of freedom of electron, has attracted extensive attention on account of its huge potential in electronic component technology. Two-dimensional (2D) materials provide an ideal platform for the research of valleytronics. Here, we study the sliding and twist effects on valley of bilayer NiI2 by the first-principles calculations. For a monolayer, spatial inversion symmetry

Motivated by exploring correlated multiorbital altermagnets (A⁢ℓ⁢Ms) we study minimal 𝑡−𝐽 models on the square-octagon lattice, which favors such a collinear magnetic order. While antiferromagnetic order breaks translational and time-reversal symmetries, the A⁢ℓ⁢M state (equivalently, a “𝑑-wave ferromagnet”) features multipolar order, which separately breaks time-reversal and crystal rotation symmetries

We propose a nonlinear ac Hall effect in two-dimensional BCS single-band superconductors. Namely, a nonlinear ac transverse Hall current emerges in the superconductor interacting with an incident polarized light if a built-in dc supercurrent is present in the system. Applying the nonequilibrium Keldysh diagram technique, we calculate an ac Hall current density oscillating at double the electromagnetic

In this study we revisit the properties of the (″8.88×8.88″)⁢R⁢30∘ surface reconstruction obtained by evaporation of Cu on Ge(111), motivated by the predictions of Dirac nodal lines in two-dimensional Cu2⁢Ge monolayer. After providing an updated version of the band structure of Ge(111) by angle-resolved photoemission (ARPES), we present the band structure of the Cu/Ge⁡(111)−(8.88×8.88)⁢R⁢30∘ surface

The advances of machine-learned force fields have opened up molecular dynamics (MD) simulations for compounds for which ab initio MD is too resource intensive and phenomena for which classical force fields are insufficient. Here we describe a neural-network force field parametrized to reproduce the r2⁢SCAN potential energy landscape of HfO2. Based on an automatic differentiable implementation of the

The conductive properties and defect structure of Sn-doped 𝛽−Ga2⁢O3 bulk materials with different Sn concentrations are studied in this work. The calculations and experiments of positron annihilation spectroscopy clarify the existence of Ga monovacancies of high concentrations in these semiconductors. The temperature dependencies of positron annihilation parameters and the linear relationship between

We present the microscopic theory of the spin Nernst effect, which is a transverse spin current directly induced by a temperature gradient, employing the linear response theory with Luttinger's gravitational potential method. We consider a generic, noninteracting electron system with randomly distributed impurities and evaluate the spin current response to the gravitational potential. Our theory takes

YMn6⁢Sn6 consists of two types of Mn-based kagome planes stacked along the 𝑐-axis having a complex magnetic interaction. We report a spin reconstruction in YMn6⁢Sn6 from ferromagnetic (FM) into a combination of two incommensurate spin spirals (SSs) originating from two different types of Mn kagome planes driven by frustrated magnetic exchanges along the 𝑐-axis with the inclusion of the Hubbard 𝑈

This paper reports an experimental demonstration of efficient excitation of fundamental dark spin wave solitons on a magnonic active ring below self-oscillation threshold by means of a biharmonic technique. This technique is shown to be especially appropriate for implementing multisoliton regimes otherwise unattainable. Theoretical analysis has revealed a very important role played by the phase relations

The ternary chalcogenide Bi2⁢Rh3⁢Se2 was found to be a charge density wave (CDW) superconductor with a 2×2 periodicity. The key questions regarding the underlying mechanism of CDW state and its interplay with lattice and electronic properties remain to be explored. Here, based on the systematic Raman scattering investigations on single-crystalline Bi2⁢Rh3⁢Se2, we observed the fingerprinting feature

We have studied the Co layer thickness dependences of magnetocrystalline anisotropy (MCA), Dzyaloshinskii-Moriya interaction (DMI), and orbital moment anisotropy (OMA) in W/Co/Pt trilayers, in order to clarify their correlations with each other. We find that the MCA favors magnetization along the film normal and monotonically increases with decreasing effective magnetic layer thickness (𝑡eff). The

Quantum magnets based on honeycomb lattices with a low coordination number offer a viable ground to realize exotic emergent quantum excitations and phenomena arising from the interplay between competing magnetic interactions, spin correlations, and spatial anisotropy. However, unlike their low-spin analogs, high-spin honeycomb lattice antiferromagnets have remained comparatively less explored in the

This paper investigates the superconducting properties of a two-dimensional 𝑠-wave superconductor on a kagome lattice subjected to correlated disorder. Using the Bogoliubov–de Gennes theory, we analyze the impact of disorder correlations on superconducting behavior. Additionally, we derive the stiffness formula for the kagome lattice and calculate its superfluid stiffness. An intriguing finding of

While the conducting CuO2 planes in cuprate superconductors have been widely recognized as a crucial component in producing high superconducting 𝑇c, recent experimental and theoretical studies on Ba2−𝑥⁢Sr𝑥⁢CuO3+𝛿 have also drawn much attention to the importance of Cu-O chains in one-dimensional (1D) cuprates. To better understand the cuprates containing Cu-O chains, here we have studied the electronic

Motivated by the recent proposal that the Monte Carlo sign problem might be used as an indicator of quantum phase transitions, we simulate the periodic Anderson model at half-filling with a staggered ionic potential using the determinant quantum Monte Carlo (DQMC) approach. We observe a phase transition from a band insulator to a Kondo insulator as the hybridization increases. At finite temperature

Perovskite rare-earth nickelates are a prototypical class of quantum materials that exhibit rich phase-transition physics with promising applications in neuromorphic computing. Although there is existing experimental evidence demonstrating that strain may strongly influence the phase transitions of nickelate thin films, it would be extremely challenging to experimentally construct temperature-strain

An electronic topological transition (ETT) in cadmium below 1 GPa is investigated in situ with experimental x-ray absorption spectroscopy and projecting calculated core-valence excitons onto the band structure. These projections are a useful application of the Bethe-Salpeter equation approach that considers many-body effects. The method described herein can be used for systems that are otherwise difficult

Previous studies of metal nanoparticle plasmonic properties yielded various nontrivial effects beyond the simple dipole response to light, such as the higher-order plasmon modes and dark and bright localized surface plasmons. Another intriguing plasmonic effect is the reduction of bulk plasmon (BP) resonances strength due to the Begrenzung effect, a phenomenon of the BP resonance modifications at the

The graphenelike form of carbon nitride is known as 𝑔−C3⁢N4, a single sheet of which may be composed of an 𝑠-triazine (𝑆-type) or tri-𝑠-triazine (𝑇-type) periodic lattice with a different size of hole. By employing the first-principles calculation, we find that the difference in the out of plane polarization caused by the symmetry breaking of the 𝑆-type or 𝑇-type structure of bilayer 𝑔−C3⁢N4

Hexagon-boat-star (HBS) pentagonal tilings often appear in the description of decagonal quasicrystals and their periodic approximants. Being related to the Penrose tiling, they differ from the latter by a significantly higher packing density of vertices, which, in turn, depends on the relative frequency of appearance of the H, B and S tiles. Since boats (also known as “ivy leaves”) have the lowest

In this paper, we propose a concept of bilayer stacking 𝐴-type altermagnet (BSAA), in which two identical ferromagnetic monolayers are stacked with antiferromagnetic coupling to form a two-dimensional (2D) 𝐴-type altermagnet. By solving the stacking model, we derive all BSAAs for all layer groups and draw three key conclusions: (i) Only 17 layer groups can realize intrinsic 𝐴-type altermagnetism

Resonant modes within phononic crystals exhibit remarkable capabilities for the effective control of acoustic waves. In this study, we examine an underwater system comprising bilayer periodic polymethyl methacrylate rods and investigate the behaviors of Fabry-Perot bound states in the continuum (BICs) by adjusting the interlayer spacing parameter and the side length of rectangular rods. Additionally

Mosaic lattice models have been recently introduced as a special class of disordered systems displaying resonance energies, multiple mobility edges, and anomalous transport properties. In such systems on-site potential disorder, either uncorrelated or incommensurate, is introduced solely at every equally spaced site within the lattice, with a spacing 𝑀≥2. A remarkable property of disordered mosaic

We explore the consequences of disorder on phase coherence in the Mott insulator phases in an optical lattice. Few bosons with contact interaction in small optical lattice can feature varieties of insulating phases—weakly interacting Mott in deep lattice, maximally fragmented and strongly interacting Mott in intermediate lattice, weak Mott with double filling and intrawell coherence, fermionized Mott

We study the algebraic structure of electron density operators in gapless Weyl fermion systems in 𝑑=3,5,7,⋯ spatial dimensions and in topological insulators (without any protecting symmetry) in 𝑑=4,6,8,⋯ spatial dimensions. These systems are closely related by the celebrated bulk-boundary correspondence. Specifically, we study the higher bracket—a generalization of commutator for more than two operators—of

We investigate the quantum Hall effect in a single Landau level in the presence of a square superlattice of 𝛿-function potentials. The interplay between the superlattice spacing 𝑎𝑠 and the magnetic length ℓ𝐵 in a clean system leads to three interesting characteristic regimes corresponding to 𝑎𝑠<ℓ𝐵, 𝑎𝑠≫ℓ𝐵, and the intermediate one where 𝑎𝑠∼ℓ𝐵. In the intermediate regime, the continuous

“Half moons,” distinctive crescent patterns in the dynamical structure factor, have been identified in inelastic neutron scattering experiments for a wide range of frustrated magnets. In an earlier paper [H. Yan et al., Phys. Rev. B 98, 140402(R) (2018)] we have shown how these features are linked to the local constraints realized in classical spin liquids. Here, we explore their implication for the

Recently, a first-order phase transition associated with charge density wave (CDW) has been observed at low temperatures in intermetallic compound BaFe2⁢Al9. However, this transition is absent in its isostructural sister compound BaCo2⁢Al9. Consequently, an intriguing question arises as to the underlying factors that differentiate BaFe2⁢Al9 from BaCo2⁢Al9 and drive the CDW transition in BaFe2⁢Al9.

Recent theoretical work has shown that higher-order moments of the Berry curvature, e.g., Berry curvature quadrupole and hexapole moments, can produce the leading order nonlinear anomalous Hall response (NLAH) in systems with special magnetic point group symmetry. Recent experimental work has reported the observation of the Berry curvature quadrupole-induced third-order NLAH (i.e., Hall voltage proportional

We analyze the quasiparticle interaction function (the fully dressed and antisymmetrized interaction between fermions) for a two-dimensional Fermi liquid at zero temperature close to a q=0 charge quantum critical point (QCP) in the 𝑠−wave channel (the one leading to phase separation). By the Ward identities, this vertex function must be related to quasiparticle residue 𝑍, which can be obtained independently

Here we show that, in contrast to the observed surface states in well studied pnictogen chalcogenide van der Waals (vdW) topological insulators with quintuple layer (QL) or septuple layer (SL) structure, in superlattices, comprising the alternating QL and SL vdW blocks, the Dirac state becomes accompanied by emergent spin-polarized states of the Rashba type. This specific feature is caused by an inequivalence

We investigate the Friedel oscillations of the local density of states (LDOS) induced by a single impurity with both a spin-independent potential and an exchange coupling to the electrons in altermagnets and unconventional 𝑝-wave magnets. We identify features that make the Friedel oscillations and magnetization distinct from other materials with nontrivial spin texture such as Rashba metals. Because

We construct a broad class of frustration-free quantum vertex models in 3+1 dimensions (3+1⁢D) whose ground states are weighted superpositions of classical 3D vertex model configurations. Our results are illustrated for diamond, cubic, and BCC lattices, but hold in general for 3D lattices with even coordination number. The corresponding classical vertex models have a ℤ2 gauge constraint enriched with

Recently, a new exciton species of quadrupole exciton (QX) has been discovered in two-dimensional (2D) transition-metal dichalcogenide (TMD) heterotrilayers, which has attracted increasing attention for its fascinating properties. Theoretically, it is predicted that QXs will be squeezed into energetically favored staggered dipole excitons (Stg-DXs) as the exciton density increases. Here, we report

The phase transitions of ferroelectric ceramics under dynamic compressions are of importance for materials and applications design. However, there are very few effective methods for describing the shock-induced phase transition process in ferroelectric ceramics, due to the tiny structural volume change during compression. Here the phase transition behaviors of KNb⁢O3 ceramics under compression are

Considerable attention has been devoted to CaA⁢l2⁢S⁢i2-type Zintl-phase compounds for their intriguing physical properties, particularly the complex interplay between band structures and magnetism. Herein we grow high-quality single crystals of nonmagnetic YbA⁢l2⁢S⁢i2 and examine the physical properties, including resistivity, magnetoresistance, angular magnetoresistance, Hall resistivity, and band

Superconductivity in two dimensions has attracted renewed interest in the context of two-dimensional (2D) van der Waals materials. Key questions remain regarding the nature and manifestations of the superconductivity in these materials. One open question is whether superconducting fluctuations in such 2D systems can be described by the classic Aslamazov-Larkin (A-L) equation. While the A-L model has

FeSe1−𝑥⁢S𝑥 superconductors are commonly considered layered van der Waals materials with negligible interlayer coupling. Here, using inelastic neutron scattering to study spin excitations in single-crystal samples, we reveal that the magnetic coupling between adjacent Fe layers is ferromagnetic in nature, making the system different from most unconventional superconductors including iron pnictides

A recent experiment by P. F. Shan et al. (arXiv:2304.09011) found that rhenium trioxide ReO3, a simple metal at ambient pressure, becomes superconducting with a transition temperature as high as 17 K at 30 GPa. In this paper, we analyze the electron-phonon origin of superconductivity in rhombohedral ReO3 in detail. In addition, we also conduct a high-throughput screening of isostructural transition

Machine-learning models can be trained to predict the converged electron charge density of a density functional theory (DFT) calculation. In general, the value of the density at a given point in space is invariant under global translations and rotations having that point as a center. Hence, one can construct locally invariant machine-learning density predictors. However, the widely used projector augmented