CIRCUIT‐CONTROLLED CURRENT INSTABILITIES IN n‐GaAs

A theoretical analysis of an inhomogeneous n‐GaAs element with low cathode boundary fields in a series L‐parallel C circuit shows that, for this circuit, the dominant mode of circuit‐controlled oscillation is the quenched multiple dipole relaxation mode. LSA relaxation oscillations occur only for a narrow range of circuit parameters and LSA sinusoidal voltage oscillations are excluded, even for elements with small doping fluctuations. This produces an upper frequency limit for circuit control which must be considered in addition to that imposed by finite intervalley relaxation times. We report experimental results that are in qualitative agreement with theory.