The quantum acoustoelectric current in a doped superlattice GaAs:Si/GaAs:Be

The quantum acoustoelectric (QAE) current is studied theoretically in a doped superlattice (DSL). The physical problem is investigated in the region ql >> 1 (where q is the acoustic wave number and 1 is the electrons mean free path). We obtain analytical expression for the QAE current in the DSL by using the quantum kinetic equation for electron-external acoustic wave interaction and electron-acoustic phonon (internal acoustic wave) scattering. A nonlinear dependence of the QAE current on the frequency of external acoustic wave omega((q) over bar), the temperature T of the system and the characteristic parameters of DSL is achieved. The computational results for a specific GaAs:Si/GaAs:Be DSL indicates that the existent peaks in the DSL may be due to the transition between mini-bands n -> n'. All these results are compared with those for normal bulk semiconductors to show the differences. Finally, the quantum theory of the QAE current in the DSL is newly developed. (C) 2013 Elsevier Ltd. All rights reserved.