相关论文: A new quantum hydrodynamic description of ferroele…
The phenomenological theory of ferroelectricity in spiral magnets presented in [M. Mostovoy, Phys. Rev. Lett. 96, 067601 (2006)] is generalized to describe consistently states with both uniform and modulated-in-space ferroelectric…
The spin current model of electric polarization of multiferroics is justified via the quantum hydrodynamic method and the mean-field part of the spin-orbit interaction. The spin current model is applied to derive the electric polarization…
It was recently observed that materials showing most striking multiferroic phenomena are frustrated spin-density-wave magnets. We present a simple phenomenological theory, which describes the orientation of the induced electric polarization…
The multiferroics are the materials, where single cell of a magnetically order crystal forms an electric dipole moment. We derive equation for the evolution of the macroscopic density of the electric dipole moment (polarization of the…
The compound Ba3HoRu2O9 magnetically orders at 50 K (TN1) followed by another complex magnetic ordering at 10.2 K (TN2). The 2nd magnetic phase transition was characterized by the co-existence of two competing magnetic ground states…
Ferroelectricity has been one major focus in modern fundamental research and technological application. We consider the physical origin of improper ferroelectricity in Mott insulating materials. Beyond the well-known…
The hydrodynamic model including the spin degree of freedom and the electromagnetic field was discussed. In this derivation, we applied electromagnetism for macroscopic medium proposed by Minkowski. For the equation of motion of spin, we…
We have investigated the variation of induced ferroelectric polarization under magnetic field with various directions and magnitudes in a staggered antiferromagnet Ba$_2$CoGe$_2$O$_7$. While the ferroelectric polarization cannot be…
The ferroelectricity of multiferroics induced by spin order is commonly explained by considering either purely electronic or ion-displacement contribution. However, there is no general model which includes both effects simultaneously. Here,…
In conventional ferroelectrics the electric dipoles are generated by off-center displacements of ions. In recent years, a new type of so-called electronic ferroelectrics has attracted great attention, where the polarization is driven by…
We uncover a new pathway towards multiferroicity, showing how magnetism can drive ferroelectricity without relying on inversion symmetry breaking of the magnetic ordering. Our free-energy analysis demonstrates that any commensurate…
We investigate in detail the initial susceptibility, magnetization curves, and microstructure of ferrofluids in various concentration and particle dipole moment ranges by means of molecular dynamics simulations. We use the Ewald summation…
A systematic microscopic theory of magnetically induced ferroelectricity and lattice modulation is presented for all electron configurations of Mott-insulating transition-metal oxides. Various mechanisms of polarization are identified in…
The spin-current model of electric polarization of spin origin is developed for a magnetic structure with anisotropic tensor gyromagnetic ratio (g-factor). Three mechanisms of the magnetoelectric effect are proposed, caused by the symmetric…
Multiferroics, showing simultaneous ordering of electrical and magnetic degrees of freedom, are remarkable materials as seen from both the academic and technological points of view. A prominent mechanism of multiferroicity is the…
We propose a microscopic theory for magnetic switching of electric polarization (P) in the spin-spiral multiferroics by taking TbMnO3 and DyMnO3 as examples. We reproduce their phase diagrams under a magnetic field H_ex by Monte-Carlo…
Recent progress in the field of multiferroics led to the discovery of many new materials in which ferroelectricity is induced by cycloidal spiral orders. The direction of the electric polarization is typically constrained by spin…
We present a phenomenological model for magnetoelectricity in multiferroic materials. The distinctive feature of the model is a two-component complex order parameter that encodes the electric polarization, along with a direct coupling…
The ferroelectric order and magnetic field induced effects observed in the spiral phase of MnWO4 are described theoretically. It is demonstrated explicitly that the Dzyaloshinskii-Moriya antisymmetric interactions contribute to the…
The field of spin hydrodynamics aims to describe magnetization dynamics from a fluid perspective. For ferromagnetic materials, there is an exact mapping between the Landau-Lifshitz equation and a set of dispersive hydrodynamic equations.…