Interaction between two hybrid modes in n-GaAs

Abstract

Small-signal temporal instability has been studied in n-GaAs in the range of the electric field for which the electron concentration in the central and the satellite valleys are comparable to each other. The samplo is subjected to a crossed d.e. electric field E 0 and magetic field B 0 and the wave is assumed to be propagating perpendicular to the plane of E 0 and B 0. The light electron hybrid mode (E 1x, E 1z) interacts with the heavy electron hybrid mode and thus produces hybrid-hybrid interaction. The diffusion-incorporated dispersion relation has been derived, taking into account the appropriate scattering mechanisms at 300°K. It is analysed to look for instability for real k and complex ω (= ωr + iωt). One of the modes becomes unstable and propagates with a phase velocity equal to the transverse drift velocity of the light electrons. Instability is possible in the range of the magnetic field 2.5  B 0  6.0 Tesla. The instability is observed only for small values of k. At large k the modes are dampe...