The presence of different electronic orders other than superconductivity populating the phase diagram of cuprates suggests that they might be the key to disclose the mysteries of this class of materials. In particular charge order in the form of charge density waves (CDW), i.e., the incommensurate modulation of electron density in the CuO2 planes, is ubiquitous across different families and presents

Significant advances in numerical techniques have enabled recent breakthroughs in the study of various properties of the Hubbard model — a seemingly simple, yet complex model of correlated electrons that has been a focus of study for more than half a century. In particular, it captures the essence of strong correlations, and is believed to possess various emergent, low energy states and collective

We study the temperature dependence of the low energy phonons in the \((H,0,L)\) reciprocal plane of the highly ordered ortho-II YBa2Cu3O6.55 cuprate high temperature superconductor by means of high-resolution inelastic x-ray scattering. Anomalies associated with the emergence of long-range charge density wave (CDW) fluctuations are observed, and are qualitatively similar to those previously observed

Unconventional symmetry breaking without spin order, such as the rotational symmetry breaking (= nematic or smectic) orders as well as the spontaneous loop-current orders, have been recently reported in cuprate superconductors and their related materials. They are theoretically represented by symmetry breaking in the correlated hopping integrals, which we call the form factor fk,q. In this paper, we

Studies on the interplay between the charge order and the d-wave superconductivity in the copper-oxide high Tc superconductors are reviewed with a special emphasis on the exploration based on the unconventional concept of the electron fractionalization and its consequences supported by solutions of high-accuracy quantum many-body solvers. Severe competitions between the superconducting states and the

The discovery of a magnetic-field-induced charge-density-wave (CDW) order in the pseudogap state via nuclear magnetic resonance (NMR) studies has highlighted the importance of “charge” in the physics of high transition-temperature (Tc) superconductivity in copper oxides (cuprates). Herein, after briefly reviewing the progress achieved in the last few years, we report new results of 63,65Cu-NMR measurements

Charge density wave (CDW) in high-TC cuprates has drawn a lot of attention in the field. In this article, we review some of our recent x-ray studies about the ground state and the excitation spectrum of the CDW. Using high magnetic field to suppress the superconductivity, a three-dimensionally-ordered charge stripe state emerges in YBa2Cu3O6+x at low temperatures, which arguably bears the characteristics

Superconductivity in layered cuprates is induced by doping holes into a parent antiferromagnetic insulator. It is now recognized that another common emergent order involves charge stripes, and our understanding of the relationship between charge stripes and superconductivity has been evolving. Here we review studies of 214 cuprate families obtained by doping La2CuO4. Charge-stripe order tends to compete

The presence of charge order in high-transition-temperature copper oxides (high-Tc cuprates) was identified a decade ago. Now it is a universally observed order like the antiferromagnetic and the superconducting orders of the cuprates. The charge order shows up in various forms depending on materials, and it overlaps other orders in the phase diagram. Because of this diversity and complexity it has

We introduce a new extended Heisenberg model that contains orbital-dependent spins together with the retarded effects of spin torque. The model is directly derived from the dynamical linear response functions on the transversal spin fluctuation. Our model allows us to address effects that are not accessible via the usual Heisenberg model. With the model, we can describe not only the relaxation effects

We discuss the Uranium 5f electron states in UPd3 and UAl3 on the basis of the theoretical calculation of the core level photoemission with the use of the impurity Anderson model. In order to suppress the ambiguity in evaluating the relevant physical parameters involved in the model, such as the 5f–5f Coulomb interaction strength and the hybridization strength between the 5f and ligand valence orbitals

The training requirements for machine-learning interatomic potential based on artificial neural networks (ANN) are investigated to reproduce melting and crystallization of sodium. Only when the virial stress tensor, as well as the potential energy and atomic forces, is considered in the training, the constructed ANN potential precisely mimics the temperature dependence of the phase behavior obtained

Machine learning has recently been applied to many problems in condensed matter physics. A common point of many proposals is to save computational cost by training the machine with data from a simple example and then using the machine to make predictions for a more complicated example. Convolutional neural networks (CNN), which are one of the tools of machine learning, have proved to work well for

The transport and thermodynamic properties of β-ReO2 crystallizing in a nonsymmorphic structure were studied using high-quality single crystals. An extremely large magnetoresistance (XMR) of 22,000% was observed in a transverse magnetic field of 10 T at 2 K. However, unlike other topological semimetals that show XMR, β-ReO2 has a high electron carrier density of 1 × 1022 cm−3, as determined by Hall

We theoretically study ferromagnetic (FM) fluctuations in the heavily overdoped region of cuprate superconductors. To explore the origin of FM fluctuations, we evaluate the spin susceptibilities of a single-band Hubbard model within the fluctuation exchange approximation. Model parameters are derived using the Wannierization technique and the constrained random phase approximation method based on the

Growing demand for high-speed Ising-computing-specific hardware has prompted a need for determining how the accuracy depends on a hardware implementation with physically limited resources. For instance, in digital hardware such as field-programmable gate arrays, as the number of bits representing the coupling strength is reduced, the density of integrated Ising spins and the speed of computing can

The non-dimensional prefactor of the Kolmogorov 2/3 law in the inertial range of homogeneous isotropic turbulence (HIT) has been believed to be a universal constant for many years, and then people have continued intensive search for evaluation of the constant by theory, experiment, and direct numerical simulation (DNS). Here a simple consideration is presented on this problem. First, a piecewise analytical

Majorana zero modes are well studied in the gapped phases of topological systems. We investigate Majorana zero modes at the topological quantum criticality in one dimensional topological superconducting model with longer range interaction. We identify stable localized Majorana zero modes appearing at criticality under certain conditions. Topological invariant number for these non-trivial criticalities

Nuclear quadrupole resonance (NQR) is an indispensable experimental technique, which can elucidate microscopic electronic state of materials. NQR frequency, νQ, of material is important information which reflects the properties of the material. In the present study, a supervised machine learning (ML) technique is applied to predict νQ of 35Cl NQR in organic molecules. The input data of the ML is feature

Accurate evaluation of atomic modulation is essential for the elucidation of structural problems such as stability and structure-related properties of modulated materials. In this study, atomic modulation in two-dimensional (2D) misfit-layered (SnS)1.17NbS2 has been determined by accurate modeling of incommensurate composite crystal structure using the Information Criterion (IC). With use of single

We detect the quantum phase transition of the ground state from the excited state by using the cluster density matrix embedding theory to calculate the excited state of the J1 − J2 model. By analyzing the excitation energy gap of the transformation in the system, we detect that the critical point of the intermediate phase of ground state is J2 \( \simeq \) 0.5. With the increase of energy, the new

A variety of resonances have been observed experimentally in a linear Paul trap. They are excited by weak nonlinear fields that exist within the trap aperture depending on the mechanical design and misalignments of the electrodes. Those inevitable nonlinear terms in the ion confinement potential couple the axial and transverse degrees of freedom, making the resonance feature quite complicated. High-order

We introduce a long-period generic spatial modulation into a typical model of the Thouless pump, namely, the Rice–Mele (RM) model, to examine the lattice analog of the fermion charge in quantum field theory. We derive a Diophantine equation relating the fermion charge and the pumped charge, which leads to the one-dimensional (1D) analog of the Streda formula in the quantum Hall effect (QHE). This formula

9Be-NMR measurements were performed using single crystalline SmBe13 in order to investigate a magnetic structure of a low-temperature ordering state microscopically. We observed a spectral broadening in the ordered state, and the broadened spectral shape depends on the magnetic field directions. By comparing the experimentally obtained and simulated NMR spectra for magnetic fields along the cubic [001]

In order to clarify electronic states and energy dissipations due to a motion of a vortex core in pure FeSe, which is a candidate superconductor possessing a super-clean core, we measured the microwave surface impedance of pure FeSe single crystals under finite magnetic fields. From the magnetic-field dependence of the flux-flow resistivity, we found that a barometer of electronic states inside the

The differential cross sections of the elastic 12C–12C scattering are analyzed in terms of the optical model at refractive energies ranging Elab/A = 20 to 200 MeV/nucleon. The real part of the optical model potential is generated using three different potentials, the full cluster α–α effective interaction (DFC1), the CDM3Y6 effective NN interaction, and phenomenological Woods–Saxon (WS). For the imaginary

Co/Cu(001) multilayers were prepared by sputtering and the depth-dependent spin polarization induced in the conduction electrons of the Cu layers was investigated by resonant X-ray magnetic scattering (RXMS) technique at the Cu K absorption edge. The analysis of the RXMS patterns indicates that only the first Cu atomic layers at the Co–Cu interfaces have induced spin polarization. The induced magnetic

While nodal-line semimetals with magnetism have been theoretically predicted and experimentally observed in a few compounds, idea on the relation between the magnetic order and the electronic structure is still limited. We theoretically explore the electronic structure in bulk and boundary of such a magnetic nodal-line state by introducing magnetism in topological Dirac semimetal (TDSM). TDSMs, such

A new simulation method is developed for the feedback instability in a magnetosphere-ionosphere coupling system. It solves a gyrokinetic model of the magnetosphere as an initial value problem and properly treats the magnetosphere-ionosphere boundary condition. Linear simulation results confirm that the developed method gives growth rates and frequencies of the feedback instability almost consistent

The magnetic properties of the two-dimensional triangular-lattice compound HoZn3P3 synthesized under high pressure are reported. We have performed magnetization, electrical resistivity, and specific heat measurements of the compound. The magnetic susceptibility shows an anomaly at around 5 K attributed to a magnetic ordering. The resistivity reveals metallic behavior and a minimum at around 17 K (Tmin);

We investigate the presence of an acoustic-quasi-elastic interaction contribution in the IXS spectra of liquid water at 301 K using inelastic x-ray scattering with sub-meV energy resolution at momentum transfers 0.77 ≦ Q ≦ 4.20 nm−1. The contribution appears due to the overlap the acoustic mode with the tail the quasi-elastic mode and is fully consistent with hydrodynamic theory. Incorporating this

Impurity-induced antiferromagnetism was observed in the S = 1/2 alternating chain compound NaCu2VP2O10 when a few nonmagnetic ions were substituted at the Cu sites. NaCu2VP2O10 showed a nonmagnetic spin-singlet ground state at low temperatures. The temperature dependence of the magnetic susceptibility and the specific heat of the Mg-doped compounds, Na(Cu1−xMgx)2VP2O10 \((x = 0.03,0.05)\), showed anomalies

Total reflection γ-ray resonant spectra of a Cr/Fe/Cr/MgO thin film in which a 57Fe monolayer was embedded at a depth of 6 nm below the surface were studied using a synchrotron Mössbauer source. Due to an interference between electron and nuclear resonant scatterings, the spectra showed asymmetric absorption and scattering profiles depending on beam incidence angles. The spectra were reproduced via

Magnetic skyrmions, which are topologically protected particle-like spin textures, exhibit Brownian motion at ambient temperatures in a ferromagnetic thin film. The potential applications of a skyrmions’ diffusive motion to the ultra-low energy stochastic and Brownian computation make research on its thermal dynamics necessary. Herein we experimentally demonstrate the mobility anomaly of the diffusion

This review discusses the ultrafast magnetization dynamics within the gigahertz to terahertz frequency range in ferrimagnetic rare-earth iron garnets with different substitutions. In these garnets, the roles of spin–orbit and exchange interactions have been detected using femtosecond laser pulses via the inverse Faraday effect. The all-optical control of spin-wave and Kaplan–Kittel exchange resonance

In this article, we discuss the random graph, Barabási–Albert (BA) model, and lattice networks from a unified view point, with the parameter ω with values \(1,0, - 1\) characterizing these networks, respectively. The parameter is related to the preferential attachment of nodes in the networks and has different weights for the incoming and outgoing links. In addition, we discuss the correspondence between

We report some spintronic properties including Gilbert damping, spin Seebeck effect, and magnon–photon coupling for a spinel ferrite Mg0.5−δMn0.5Fe2O4 (MMFO). Bulk single crystals of MMFO (δ ≈ 0.12) grown by a floating zone method are well insulating and soft ferrimagnetic with saturation magnetization of 0.3 T at room temperature. The measurement of ferromagnetic resonance yields the Gilbert damping

The electronic structure of MoTe2 undergoing a monoclinic–orthorhombic transition around 250 K has been investigated by means of scanning photoemission spectromicroscopy (SPEM), angle-resolved photoemission spectroscopy (ARPES), and band structure calculation. The ARPES results show that the electron and hole pockets are modified due to electronic correlation similar to WTe2. In the SPEM results, MoTe2

We report the topochemical protonation of rutile oxides Rh0.5V0.5O2 and Cr0.5V0.5O2 by low-temperature hydrogen gas treatment. After the treatment, nonmagnetic V5+ (d0) ions were selectively reduced to +3.5 (d1.5) for HxRh0.5V0.5O2 (x ∼ 0.75) and +4 (d1) for HxCr0.5V0.5O2 (x ∼ 0.5). HxRh0.5V0.5O2 with nonmagnetic Rh3+ ions has weak magnetic interactions with a spin glass transition at Tf = 6 K. In

We theoretically study current- and charge-induced spin torques in magnetic Weyl semimetals (WSMs). In magnetic WSMs, a topologically nontrivial band structure mediates the anomalous coupling between magnetization and transport, making WSMs preferable for spintronics systems. In this study, we determine all current-induced spin torques including spin–orbit torque and spin-transfer torque, up to the

A powerful propulsion device that enables ultimate simplification is one of the core technologies of microswimmers and microrobots. Here, we report a high-speed swimmer that is self-propelled by the spontaneous asymmetrical heat transfer from a novel hot wire microengine. In particular, we demonstrate that the swimmer, consisting of a U-shaped wire, reciprocated while rotating on the rail in water

We have clarified that the internal magnetic field in α-Mn is suppressed by pressure and that a first-order phase transition occurs at around 1.4–1.5 GPa by zero-field nuclear magnetic resonance. In the pressure-induced ordered state above about 1.4 GPa, the scenario of the canted-antiferromagnetic order or the ferrimagnetic order seems to be preferable to account for the weak ferromagnetism.

We investigated the effects of Fe substitution on ferromagnetic fluctuations in the superconducting overdoped and non-superconducting heavily overdoped regimes of Bi-2201 cuprates by magnetization and electrical resistivity measurements. It was found that the spin-glass state was induced at low temperatures by the Fe substitution. The Curie constant and the effective Bohr magneton, estimated from magnetic

Plasma current behavior is affected by interactions between a cold plasma and a metal object. The plasma charge depends on the surface area of the metal object, which does not provide information regarding the shape of the object. A metal disk has a side edge and a square metal plate has corners. The edge effects associated with the metal disk and plate reflect the relationship between the plasma current

Synchrotron-radiation-based (SR-based) Mössbauer spectroscopy for the 73 keV transition in 193Ir nuclei was successful. 193Ir SR-based Mössbauer spectra of Ca5Ir3O12, as well as those of Ir metal and IrO2 were measured. The results for Ir metal and IrO2 agree with those reported previously. On the other hand, the spectra of Ca5Ir3O12 exhibit temperature dependence. Differences in the observed spectra

Ultrafast control of thin film nanomagnets using femtosecond laser pulses has attracted considerable attention for future ultrafast and energy-efficient photo-spintronics storage/memory devices. Single femtosecond laser pulse magnetization switching without an applied external magnetic field has been recently observed on various metallic thin films. Herein, a recent understanding of the physical mechanism

Spin current — a flow of the spin degree of freedom in matter — has vital importance in spintronics. Propagation of the spin current ranges over a whole momentum space; however, generated spin currents are mainly detected in the long-wavelength limit. To facilitate practical uses of spintronics and magnonics, microscopic understanding of the spin current is necessary. We here address yttrium iron garnet

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