The influence of external electric field on acoustoelectric effect in a superlattice

Abstract

The de acoustoelectric current jac induced by the interaction of acoustic phonons with the conducting electrons is calculated. The calculation is done in the hypersound regime where qℓ ≫ 1 (here q is the acoustic phonon number and t is the electron mean free path). The electric field consists of dc field E0 and a low frequency alternating field E1. A nonlinear dependence of jac on E0 and E1 is observed. Depending on the direction of the dc field E0 the acoustoelectric current can either be positive or negative. At ωq = 1011 s-1 and in the absence of E0, Jac is very small and tends to zero at E1 = 1.3 × 105 V m-1. Further increase of ωq from 1011 s-1 sees a dramatic shoot "up" of Jac. Lastly the acoustoelectric currrent in the presence of E0 is modulated by E1. © 2004 Elsevier Ltd. All rights reserved.