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 l 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 ωq→, 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.