Control of polariton spectrum in bigyrotropic medium

Abstract

The ion and electron polarizations under the influence of high-frequency electromagnetic field and external magnetostatic field in a bigyrotropic medium (dielectric with magnetic subsystem) are considered. The polariton spectra in the bigyrotropic medium are received. It is shown that the polariton spectrum and the velocity of polariton wave can be controlled by the variation of the intensity and direction of external magnetostatic field. It becomes possible because the ion and electron Larmor's frequencies depend on the external magnetostatic field that leads to the appearance of several additional resonances of the permittivity and permeability of the medium. The wave vector and velocity of polariton wave that are close to the resonance frequencies vary depending on the wave frequency: the polariton wave velocity drops to zero before the resonance and increases after it. The wave velocity control may be used for designing controllable devices for a data-transmitting line.