A Theory for Microwave Instabilities in InSb

摘要

This paper derives and analyzes the dispersion relation for wave propagation along a drifted electron‐hole plasma in a semiconductor in the presence of a transverse magnetic field. In short samples of high‐mobility semiconductors (InSb, in particular), this transverse magnetic field and the boundary condition at the sample contacts (vanishing of the tangential electric field) introduce a strong magnetoresistive effect. This effect is shown to result in a plasma instability when the applied fields exceed certain threshold values. The instability is found to have many features in common with the experimental results on microwave emission from InSb and it is proposed here as a possible explanation of this phenomenon.