相关论文: Zone-Center Dynamical Matrix in Magnetoelectrics
We report the observation of multiple magnetic transitions in single crystals of EuPtAs using magnetization, transport, and thermodynamic measurements. EuPtAs crystallizes in the noncentrosymmetric tetragonal LaPtSi-type structure (space…
We simulate QED in a strong constant homogeneous external magnetic field on a euclidean space-time lattice using the Rational Hybrid Monte Carlo method, developed for simulating lattice QCD. Our primary goal is to measure the chiral…
Statistical theory of the dielectric susceptibility of polar liquid crystals is proposed. The molecules are not uniaxial but similar to cones. It is assumed that the permanent dipole moment of a molecule is parallel to the axis of the…
Magneto-dielectric spectra of La0.95Ca0.05CoO3 covering the crossover of spin states reveals strong coupling of its spin and dipolar degrees of freedom. Signature of spin-state transition at 30K clearly manifests in magnetization, supported…
Since the late 1950's, the dynamics of a charged particle's ``guiding center" in a strong, inhomogeneous magnetic field have been understood in terms of near-identity coordinate transformations. The basic idea has been to approximately…
The physics of interacting nuclear spins arranged in a crystalline lattice is typically described using a thermodynamic framework: a variety of experimental studies in bulk solid-state systems have proven the concept of a spin temperature…
The elements of the magneto-dipole (MD) interaction matrix are calculated for a pair of oriented spheroidal magnetic nanoparticles with a semiaxes ratio a/b = 1.25, 1.5, 2.0 and 3.0 as a function of the distance between the particle…
The technique of density matrix equation (DME) for a small system interacting with a bath is explained in detail. Special attention is given to the nonsecular DME that is needed in the vicinity of overdamped tunnelling resonances in…
I define the fields that describe electrical macrostructure, and their rates of change, in terms of the microscopic charge density, electric field, electric potential, and their rates of change. To deduce these definitions, I lay some new…
Dielectric study on Ca3Mn2O7 features relaxor-like segmented dynamics below the antiferromagnetic ordering. Dipolar relaxations of different origin are spectrally resolved exhibiting distinct H-field alterations. This identifies their…
We have investigated magnetoelectric coupling in the single-molecule magnet $\mathrm{Mn}_{4}\mathrm{Te}_{4}(\mathrm{P}\mathrm{Et}_{3})_{4}$ with tetrahedral spin frustration. Our density functional studies found that an electric dipole…
We study the decay of the interatomic force constants (equivalently, the smoothness properties of the dynamical matrix) in perfect crystals both at finite electronic temperature, and for insulators at zero temperature, within the reduced…
We extend a microscopic theory of polarization and magnetization to include the spin degree of freedom of the electrons, introducing a general spin orbit coupling and Zeeman interaction term in the Hamiltonian. At finite frequencies and…
We investigate in this paper the ground state and the nature of the transition from an orientational ordered phase at low temperature to the disordered state at high temperature in a molecular crystal. Our model is a Potts model which takes…
We formulate a new scheme to study the combined magnetization and lattice dynamics in magnets, so-called magnetoelastics. The coupling between magnetization and lattice are considered through an expansion of electron-phonon coupling, while…
An expression for the electrical conductivity at the core of a magnetar is derived using Boltzmann kinetic equation with the relaxation time approximation. The rates for the relevant scattering processes, e.g., electron-electron and…
The magnetic field dependence of the low frequency dielectric constant $e_r$(H) of a structural glass a - SiO2 + xCyHz was studied from 400 mK to 50 mK and for H up to 3T. Measurement of both the real and the imaginary parts of $e_r$ is…
Using the previously developed model we revisit the problem of the electric field induced polarization rotation in antiferroelectric crystals of squaric acid. We test an alternative set of the model parameters, according to which the dipole…
Magnetoelectric multiferroics promise direct cross-control between coexisting ferroelectric and ferromagnetic orders, which is of interest for applications in magnetism and spintronics. A particularly interesting type of cross-control is…
Inhomogeneous magnetoelectric effect in magnetization distribution heterogeneities (0-degree domain walls) appeared on crystal lattice defect of the multiferroic material has been investigated. Magnetic symmetry based predictions of kind of…