Dephasing of Bloch oscillations in epitaxial superlattices

Abstract

We show that the essential features of the decay of Bloch oscillations observed in epitaxially grown semiconductor superlattices subject to a dc electric field can be reproduced using a one-dimensional model of interface roughness (IR). As a result of IR, the electron dynamics can be characterized in terms of many discrete, incommensurate frequencies near the Bloch frequency. The interference effects associated with these frequencies cause a substantial decrease in amplitude of the signal after several Bloch periods. \textcopyright{} 1996 The American Physical Society.