Group velocity and flow of electromagnetic energy in rhombic crystals

Abstract

At present, media with magnetoelectric, piezomagnetic and magnetostrictive effects are intensively studied. When studying the wave processes of such media, it is necessary to take into account the anisotropy of the magnetic permeability tensor. Wave processes in anisotropic media have qualitatively different regularities in comparison with
anisotropic ones. Along with the change in the value of the phase velocity from the direction of propagation, the directions of the phase and group velocities do not coincide. In this regard, this article considers the propagation of electromagnetic waves ET and ET polarization in an anisotropic medium of rhombic symmetry in the xoz coordinate plane. Defined by
equations of the distribution of phase and group speed and velocity Vθ .The formula for the angle between the vectors of phase and group velocities γ is obtained . The direction of the group velocity in the xoz plane is determined. Received vector of electromagnetic energy flow S~ . The coincidence of the direction of the energy flow and the group velocity is shown. The refraction of ET and ET
waves at the boundary of isotropic half-space and anisotropic half-space of rhombic anisotropy is considered. The angle of refraction and the angle of total internal reflection are determined.