Terahertz instability of field effect transistor in quantum regime

Abstract

The current-carrying state of a field effect transistor (FET) with asymmetric source and drain boundary conditions may become unstable and lead to generation of terahertz radiation. While previous studies of this instability are limited to the classical case, we extend this analysis to the nanometer FET with quantum effects. We find that quantum effects broaden the instability range of the drift velocity and enhance the radiation frequencies and the output power. These properties could make the nanometer FET advantageous for realization of practical terahertz oscillations.