The magnetization dynamics of nonuniform magnetic structures induce the spin-dependent force acting on the conduction electrons via the s–d coupling. This emergent electric field, the so-called spin-motive force (SMF), is observed in a variety of magnetic structures such as magnetic domain walls, magnetic vortices, and staggered ferrimagnetic structures. The magnitude and direction of the SMF depend

We demonstrate observation of the angular momentum compensation temperature TA, at which the net angular momentum is quenched in ferrimagnets. Using the Barnett effect, in which an object is magnetized by mechanical rotation owing to spin–rotation coupling, we measure TA in the Ho3−xDyxFe5O12 system. We determine TA to be 240 K in Ho3Fe5O12 (HoIG). We find that TA increases with Dy content and show

Spin waves and their quanta magnons are collective excitation of electron spins in magnetic materials which can serve as information carriers for future low-power-consumption computing systems. Ferrimagnetic thin-film iron garnets are considered as an ideal platform for spin waves due to the low Gilbert damping. Here, we review the recent progress of magnonics based on thin-film iron garnets, including

The rare-earth-free ferrimagnet Mn4N has attractive features for spintronics applications, because it possesses a perpendicular magnetization, due to a relatively large magnetic anisotropy constant of ∼105 J m−3 and a small spontaneous magnetization of ∼100 kA m−1, and a large spin polarization (P = 0.8). More crucially, it is possible to reach the magnetic compensation at room temperature, by tuning

The research into insulating ferrimagnetic garnets has gained enormous momentum in the past decade. This is partly due to the improvement in the techniques to grow high-quality ultrathin films with desirable properties and the advances in understanding the spin transport within the ferrimagnetic garnets and through their interfaces with conducting materials. In recent years, we have seen remarkable

Conventional spintronics exploit predominately the properties of ferromagnets (FM). The functionalities of the related devices suffer from two detrimental aspects including the stray fields and the gigahertz (GHz) spin dynamics. These intrinsic limits of FMs can be overcome in antiferromagnets (AFMs), resulting from their vanished stray field, and the faster dynamics in the terahertz (THz) range. On

This article reviews the past works on topological Hall effects of magnons in insulating magnets with a particular focus on ferrimagnets. First, we discuss the magnonic quantum Hall effect in ferromagnets induced by the Aharonov–Casher effect. Specifically, starting from the classical Hall effect of magnons proposed by Meier and Loss [Phys. Rev. Lett. 90, 167204 (2003)], we establish the Landau quantization

In this review we introduce computer modelling and simulation techniques which are used for ferrimagnetic materials. We focus on models where thermal effects are accounted for, atomistic spin dynamics and finite temperature macrospin approaches. We survey the literature of two of the most commonly modelled ferrimagnets in the field of spintronics — the amorphous alloy GdFeCo and the magnetic insulator

Using inelastic neutron scattering, we investigate the spin wave excitations on the antiferromagnetic MnTiO3 (TN = 65 K), which has the stacked honeycomb structure. At T = 2 K, the spin wave energy extends up to 10.7 meV with the zone-center anisotropy gap of 0.8 meV. Whereas the dispersion is also strong along the direction perpendicular to the honeycomb planes, the exchange cancellation causes the

The magnetic properties of a mixed spin-\((1/2,5/2)\) chain produced in a charge-transfer salt (4-Cl-o-MePy-V)FeCl4 were investigated. The formation of a mixed spin-\((1/2,5/2)\) chain with a slight bond alternation was confirmed by molecular orbital calculations. An entire magnetization curve was observed until the point of saturation, which included a clear Leib–Mattis (LM) magnetization plateau

Determining the origin and consequences of novel phase transitions is a key task in condensed matter physics research. Recently, Lu(Pt1−xPdx)2In was discovered to present a very rare case of strongly enhanced superconductivity at a charge density wave (CDW) quantum critical point (QCP). Unlike in most other systems, the CDW transition here is of second-order. By tuning it continuously to absolute zero

The crystal structure of the magnetoelectric metal UNi4B was determined from high-resolution synchrotron X-ray diffraction experiments using single-crystalline samples. The direct method and the least-square refinement indicate a structural model with the space group Cmcm (no. 63, \(D_{2h}^{17}\)), where U atoms form a pseudo-triangular lattice in the U–Ni–B layers stacking along the a-axis alternately

In cuprate superconductors, superconductivity appears below the CDW transition temperature TCDW. However, many-body electronic states under the CDW order are still far from understood. Here, we study the development of the spin fluctuations under the presence of d-wave bond order (BO) with wavevector \(\boldsymbol{q} = (\pi /2,0),(0,\pi /2)\), which is derived from the paramagnon interference mechanism

We have measured and analyzed the in-plane thermal diffusivity of the Mott insulator Ca2RuO4 around room temperature under external currents with an infrared camera as a contactless thermometer. We find that the thermal diffusivity decreases by 40% for an external current density of 14 A/cm2. This large impact on lattice properties highly nontrivial in the sense that the external current primarily

We study linear responses to metric perturbation in two-dimensional topological systems based on the Dirac fermion formalism. We introduce a novel quantity, Hall viscosity to particle density ratio, which is analogous to the viscosity to entropy ratio suggested by AdS/CFT correspondence. This quantity corresponds to the filling fraction which characterizes the quantum Hall states, and hence it could

Multiple transition phenomena in divalent Eu compound EuAl4 with the tetragonal structure were investigated via the single-crystal time-of-flight neutron Laue technique. At 30.0 K below a charge-density-wave (CDW) transition temperature of TCDW = 140 K, superlattice peaks emerge near nuclear Bragg peaks described by an ordering vector \(\boldsymbol{q}_{\text{CDW}} = (0,0,\delta _{c})\) with δc ∼ 0

Complex oxides with 4d and 5d transition-metal ions recently emerged as a new paradigm in correlated electron physics, due to the interplay between spin–orbit coupling and electron interactions. For 4d and 5d ions, the spin–orbit coupling, ζ, can be as large as 0.2–0.4 eV, which is comparable with and often exceeds other relevant parameters such as Hund’s coupling JH, noncubic crystal field splitting

In this paper, the effect of the dust particles on the decay of blast waves is studied in a two-phase, unsteady flow of an inviscid gas with small dust particles. Asymptotic analysis is used to derive the zeroth and the first order solutions and it is generalised to all geometries, i.e., planar, cylindrical and spherical. The forms of drag force and the heat transfer rate experienced by the particles

We numerically and theoretically investigate how the softness of particles affects the rheology of sheared dilute granular gases. We find that the kinetic theory predicts the deviation of the flow curve from the Bagnold scaling, and it works well below a certain shear rate when we compare with the simulation results. It is also found that there is no theoretical solution above this shear rate, which

A non-equilibrium isolated macroscopic system spontaneously changes into an equilibrium one. The origin of such a well-known thermodynamic phenomenon has been left unclear since the 19th century. This paper shows that irreversible thermodynamic laws can be directly deduced from quantum mechanics if we investigate an isolated system from a new standpoint of looking at it from the inside. This result

A dependable description of the frontier orbitals around the highest occupied molecular orbital (HOMO) and the lowest unoccupied molecular orbital (LUMO) is essential for the theoretical elucidation of exciton and charge-transfer dynamics in molecular systems. In this study, an efficient scheme for constructing molecular orbitals (MOs) of large molecular systems is proposed within the framework of

In solving optimization problems, objective functions generally need to be minimized or maximized. However, objective functions cannot always be formulated explicitly in a mathematical form for complicated problem settings. Although several regression techniques infer the approximate forms of objective functions, they are at times expensive to evaluate. Optimal points of “black-box” objective functions

We have employed a magnetic field angle as a tuning parameter in a comprehensive measurement of the specific heat, magnetocaloric effect, and magnetization for the quasi-kagome Kondo lattice CeRhSn, which is considered to exhibit zero-field quantum criticality driven by geometrical frustration. By constructing the field-angle-resolved landscape of the entropy, we unexpectedly revealed that the non-Fermi-liquid

The Fe2+/Fe3+ charge order (CO) in LuFe2O4 has been examined by Mössbauer quadrupole effect. The stoichiometric single crystal of LuFe2O4 was used to measure the paramagnetic spectrum at 282 K. The spectrum was analyzed by assuming the CO monoclinic structure (space group C2/m) with four inequivalent Fe sites, among which two are occupied by Fe3+ and other two are occupied by Fe2+. The obtained quadrupole

In this study, we measure the magnetic field and temperature variations of the magnetization \(M(H,T)\) of the cubic chiral compound EuPtSi and extensively investigate the magnetic phase transitions in a wide temperature range down to 60 mK. The incommensurate–commensurate transition at \(T_{\text{N}}^{*} \simeq 2.5\) K in the helical state, which has not been observed in transport or thermodynamic

The anomalous Hall effect is caused by magnetic textures such as skyrmions. We derive an analytical formula of the Hall conductivity on the surface of a topological insulator up to third order in magnetization, M(x), based on a perturbative approach. We identify the magnetic textures that contribute to the Hall conductivity up to third order in magnetization and second order in spatial differentiation

We report the inelastic X-ray scattering (IXS) experimental results of iridium oxide Ca5Ir3O12 with a strong spin–orbit interaction, showing the hidden order at 105 K where no superlattice reflections were observed so far. We measured the IXS spectra of Ca5Ir3O12 along Γ–A, Γ–M, Γ–K–M, M–L, and K–H directions in the Brillouin zone of a hexagonal lattice down to 20 K. The obtained phonon spectra show

On the basis of the point charge model, we formulate the crystalline electronic field (CEF) Hamiltonian HCEF in rare-earth based quasicrystal (QC) and approximant crystal (AC) with ligand ions located at pseudo 5-fold configurations by using the operator equivalent method. By setting the total angular momentum J = 7/2, the CEF in the quantum critical QC Au51Al34Yb15 and the 1/1 AC Au51Al35Yb14 is analyzed

We investigated the material parameters of several single-layer cuprates, including those with fluorinated buffer layers, with the aim of identifying possible high-temperature superconductors. To evaluate the material parameters, we use the Wannierization techniques and the constrained random phase approximation. The obtained single-band Hubbard models are studied using the fluctuation–exchange approximation

In Bose–Einstein condensates, quantum phenomena appear in a macroscopic scale. The Gross–Pitaevskii (GP) equation describes the dynamics of weakly interacting Bose–Einstein condensates. The GP equation has a form of the Schrödinger equation with self-interaction. A localized solution called soliton appears when the dispersion effect and attractive interaction are balanced. The coupled GP equations

We have investigated the electronic structure of protect annealed Pr1.3−xLa0.7CexCuO4 (x = 0.05) with small superconducting volume fraction by means of angle-resolved photoemission spectroscopy (ARPES) and scanning photoemission spectromicroscopy (SPEM). The ARPES result exhibits an electron pocket around the \((0,\pi )\) point whose area is consistent with doping level of 0.09 electron per Cu. In

We investigate the anion arrangement effect on the electronic states of various bis(ethylenedithio)tetrathiafulvalene (BEDT-TTF) compounds composed of BEDT-TTF layers and counter-anion networks via Raman scattering measurements. The anion vibrational modes and charge-sensitive BEDT-TTF vibrational modes of disordered-anion compounds κ-(BEDT-TTF)2Cu2(CN)3, κ-(BEDT-TTF)2Ag2(CN)3, and (BEDT-TTF)Ag4(CN)5

Ambipolar transport is a commonly occurring theme in semimetals and semiconductors. Here we present an analytical formulation of the conductivity for a two-band system. Electron and hole carrier densities and their respective conductivities are mapped into a two-dimensional unit-less phase space. Provided that one of the carrier densities is known, the dimensionless phase space can be probed through

We propose a novel current-induced thermoelectric phenomenon, the nonlinear anomalous Ettingshausen effect (AEE), at zero magnetic field in inversion-asymmetric conductors. As an example, we discuss the weak charge ordering state in a layered organic conductor α-(BEDT-TTF)2I3, which is a two-dimensional massive Dirac fermion system with a pair of tilted Dirac cones. The nonlinear AEE is a thermoelectric

A great success in detecting the phase transition in a two-dimensional Ising model using a neural network prompts us to apply the idea of nonequilibrium relaxation to the detection. In fact, convolutional neural networks can afford to predict the transition point at an early learning stage. We also mention the limitations of the machine learning approach.

Excitation mechanisms in K+–Ar and Cs+–Ar collisions at moderate laboratory energies Elab = 0.05–2 keV are investigated by calculating repulsive potentials V(R) = 0.01–1 keV at distances R = 0.8–10 au. To discuss electronic transitions through radial couplings, the potential crossing distances RC and potential heights V(RC) at the crossings are evaluated using a charge-overlap model. The crossing parameters

The skin effect, which is the extreme sensitivity of the spectrum and eigenstates to the boundary condition, is a remarkable phenomenon of non-Hermitian systems and is currently being actively studied. In particular, the mirror skin effect, which is the protection of the skin effect by mirror symmetry, has recently been discovered. In this paper, we clarify the robustness of the mirror skin effect

We present a study of the thermoelectric (Seebeck and Nernst) response in heavily overdoped, non-superconducting La1.67Sr0.33CuO4. In spite of the electron-like curvature of the Fermi surface, the Seebeck coefficient is positive at low temperatures. Such a feature, previously observed in copper, silver, gold and lithium, is caused by a non-trivial energy dependence of the scattering time. We argue

Polarity memory often commonly stabilizes a polarity order in eukaryotic cells and self-propelled disks. This seemingly does not hold for dense cases: the polarity memory of dense cells stabilizes the order whereas that of dense self-propelled disks destabilizes their order. As the origin of this difference in the stabilization of the order from the aspect of eukaryotic cells, we consider the inhibition

Quantum annealing (QA) is one of the ways of finding ground states of problem Hamiltonians. We initially apply transverse fields corresponding to a driver Hamiltonian and adiabatically change the Hamiltonian to the problem Hamiltonian to obtain the target ground state. However, for some purposes such as quantum chemistry, both ground and excited states are needed to understand the properties of the

The ground-state phases of mixed diamond chains with \((S,\tau ^{(1)},\tau ^{(2)}) = (1/2,1/2,1)\), where S is the magnitude of vertex spins, and τ(1) and τ(2) are those of apical spins, are investigated. The apical spins τ(1) and τ(2) are connected with each other by an exchange coupling λ. Other exchange couplings are set equal to unity. This model has an infinite number of local conservation laws

To analyze the many-body problem based on differential forms, we apply the Heisenberg equation of motion to the Hamiltonian including the many-body term, focusing on the simplest electron–phonon interaction. Simultaneous differential equations are obtained after applying the Heisenberg equation of motion. To confirm our proposed method, we compare the numerical solutions to the simultaneous differential

We present singular value decomposition of the spin correlation matrix defined from the ground state of the one-dimensional antiferromagnetic quantum Heisenberg model. The decomposition creates a data set that coincides with various domain excitations from classical antiferromagnetic state. We determine the scaling relation for the singular values as a function of the domain size. The singular values

Dirac fermions display a singular response against magnetic and electric fields. A distinct manifestation is the large diamagnetism originating in the interband effect of Bloch bands, as observed in bismuth alloys. Through 209Bi NMR spectroscopy, we extract diamagnetic orbital susceptibility inherent to Dirac fermions in the semiconducting bismuth alloys Bi1−xSbx (x = 0.08–0.16). The 209Bi hyperfine

The magnetic properties of the S = 1/2 distorted kagome antiferromagnet CdCu3(OH)6Cl2 have been studied by magnetic susceptibility, heat capacity, and high-field magnetization measurements. The magnetic susceptibility and heat capacity measurements indicated the absence of a magnetic long-range order down to 0.7 K, and the magnetization exhibited spin polarization of one-third of the total spins in

We discuss the mechanism and the conditions for the appearance of synchronized charge oscillations which have been observed experimentally and theoretically after strong photoexcitation of dimerized systems. In the Hubbard model with on-site repulsion, the Bloch equations for a wave-number-dependent pseudospin — whose components describe the charge-density difference, current density, and bond density

The magnetoresistance in weak magnetic fields is calculated in graphene containing “short-range” scatterers causing isotropic intra- and inter-valley scattering and “long-range” scatterers characterized by absence of backscattering within a self-consistent Born approximation. When “short-range” scatterers are dominant, the magnetoresistance is negative and has a double-dip structure in the vicinity

The weak-field magnetoresistance is calculated in tellurene and related two-dimensional systems, characterized by interacting two bands having parabolic dispersion with their centers displaced from each other. Scatterers with short-range potential are assumed. In a Boltzmann theory, positive magnetoresistance appears in the direction of the band displacement near the bottom of the band gap with saddle-point

With a stochastic model based on self-avoiding walk of multi walkers, free radical polymerization in a confined system is numerically investigated. As a reaction field, we consider not a confined lattice but a graph to represent interactions between polymerizable molecules and possible networks. The result of calculation visualized how the individual polymer chains should grow from moment to moment

The electronic structure of newly synthesized marcasite-type cobalt pernitride (CoN2) is investigated using X-ray absorption and photoelectron spectroscopy (XAS and XPS), in combination with the electronic band structure calculation within the scheme of the density functional theory under a generalized gradient approximation. N K-edge XAS spectra and unoccupied electronic structures of the marcasite-type

To clarify the process underpinning the apparently counterintuitive phenomena observed in the freefall experiments conducted by Hamm and Géminard [Am. J. Phys. 78, 828 (2010)], a simple dynamical model of a vertically falling train of one-dimensional rigid segments impinging onto an inelastic horizontal plate in three-dimensional space was developed. The nonlinear governing equations were numerically

The Q(0) branch for molecular ions of N2+ with I = 0 (I: nuclear spin) brings advantages if measurements having uncertainties of 10−18 order are desired. The molecular N2+ ions are prepared in the N = 0 state (N: rotational state) by resonance enhanced multi-photon ionization. For molecular 14N2+ ions with N = 0, I is either 0 or 2 having an abundance ratio of \(1:5\) (for 15N2+, I = 0 only occurs)

To simulate the cell dynamics within mouse and human colonic crypts, many computational models have been developed. While real colonic crypts are shaped like test tubes, crypts were assumed as cylinders in several such models. However, possible drawbacks by modeling the crypt as a cylinder have not been investigated. Here we constructed a model considering a test-tube-like-shaped crypt in three-dimensional

The electric conductivity of Dirac electrons in the organic conductor α-(BEDT-TTF)2I3 [BEDT-TTF = bis(ethylenedithio)tetrathiafulvalene] under pressure has been examined using a two-dimensional tight-binding (TB) model with both impurity and electron–phonon (e–p) scatterings. We study an anomalous temperature dependence of the conductivity, which shows a crossover from σx < σy at low temperatures [region

We calculated the structure of liquid BaTiO3 by first-principles molecular dynamics (FPMD) simulations. Good agreements were obtained if we compare the structure factors [S(Q)s] and the total correlation functions [T(r)s] by the FPMD method with those by X-ray and neutron diffraction experiments. Comparing our partial radial distribution functions [gij(r)s] with those of the empirical potential structure

λ-type molecular π–d systems are coupled systems consisting of π electron systems with strong magnetic interactions and 3d electron systems with weak magnetic interactions. They exhibit an unconventional antiferromagnetic ground state in which the 3d spins behave as if they remain paramagnetic even below TN. In this study, we investigated the anion substitution effects of λ-(BEDT-STF)2FexGa1−xCl4 by

Markov Random Field (MRF) models have become increasingly necessary especially in data-driven science. There are two kinds of MRF model applicable to image segmentation: edge-based and region-based. The region-based model is more easily implemented and is more robust to noise than the edge-based model. However, the region-based model often becomes trapped in a local minimum, which is sensitive to initial

We fabricated and validated a coupled waveguide composed of striplines configured with a pair of closely aligned one-dimensional photonic crystals to develop a microwave component such as a demultiplexer with multiports. The system became opaque inside the photonic band gap region because of the absence of electromagnetic modes. Outside the photonic band gap region, the wave entered from the incident

The mechanism of a quasicrystal (QC) growth, that is, the mechanism by which long-range quasicrystalline order (LRQO) is generated via growth, is investigated using Engel’s model and molecular dynamics simulations. At high temperatures, LRQO is generated, while at low temperatures it is not. During growth at high temperatures, the QC structure near the growth front is highly phason-disordered, and

New superconductors, Lix(C2H8N2)yMoTe2 with 0 < x(Li) ≤ 1, have been synthesized via the co-intercalation of Li and ethylenediamine (EDA) into MoTe2. It has been found that the maximum \(T_{\text{c}}^{\text{onset}} = 5.6\) K is observed at x(Li) = 0.5–0.75 and is higher than 3.8 K for Lix(C2H8N2)yWTe2 with the same structure. On the other hand, only Li-intercalated LixMoTe2 with x ≤ 0.5 exhibits no