Fluctuations in solid state plasmas

Abstract

The dispersion relation for a solid plasma is derived from the generally anisotropic dielectric tensor in the presence of a magnetic field. The refractive indices for an arbitrary direction of propagation are derived and the special cases leading to helicon waves and magnetohydrodynamic waves are considered. The coupling of spin waves and electromagnetic waves in a ferromagnetic material leads to novel types of waves. The (itK, ω) spectrum of the fluctuations in an electron-hole plasma in an external magnetic field are derived from the particle distribution functions. The effective temperature for the collective fluctuations in a non-equilibrium plasma is introduced and shown to be useful for discussion of kinetic instability of the plasma-beam system. Scattering of electromagnetic waves by fluctuations and the mutual transformation of different types of wave arises from non-linearity of the kinetic equations. These effects are considered in the first order of perturbation with the initial wave amplitude as parameter. It is shown that instability of one type of wave can be provoked by the co-existence of another type of wave.