Magnetoplasma Resonance in Germanium

Abstract

Microwave magnetoplasma resonances have been studied in small samples of $p$- and $n$-type germanium as a function of carrier concentration, sample shape, and field configuration. For sufficiently small samples in a uniform microwave field, a simple drift-velocity treatment appears to explain all of the observed phenomena, even when more than one type of carrier and tensor masses are involved. In the case of $p$-type germanium, it is demonstrated that a majority carrier can act to short out the plasma effects of a minority carrier and that one can observe a "cyclotron resonance" line even when the plasma frequency is high compared to the frequency of the applied field. In $n$-type germanium, the tensor mass results in a large longitudinal magnetoplasma effect, which is absent in indium antimonide where the mass is isotropic.