TRANSIENT RESPONSE THEORY OF SEMICONDUCTOR SUPERLATTICES: CONNECTION WITH BLOCH OSCILLATIONS

Abstract

Results of an analytical calculation of the drift velocity transient response of semiconductor superlattices (SL) based on the moment balance equations method are presented. It is shown that under definite conditions the transient response can exhibit oscillation behaviour at the characteristic "effective Bloch frequency" depending on the momentum and energy relaxation times. The criterion that determines when the negative differential velocity (NDV) effect in superlattices is accompanied by Bloch oscillations (BO) is formulated. The method used permits one to estimate the time of NDV formation in SL solely on the basis of the measured (or simulated) static V – E characteristic.