Giant oscillations of acoustoelectric current in a quantum channel

A theory of dc electric current induced in a quantum channel by a propagating surface acoustic wave (acoustoelectric current) is worked out. The first observation, to our knowledge, of the acoustoelectric current in such a situation was reported by J. M. Shilton et al., J. Phys. Condens. Matter 8, L337 (1996). The authors observed a very specific behavior of the acoustoelectric current in a quasi-one-dimensional channel defined in a GaAs-Alₓ{Ga}_{1{{-}}x}$As heterostructure by a split-gate depletion--giant oscillations as a function of the gate voltage. Such a behavior was qualitatively explained by an interplay between the energy-momentum conservation law for the electrons in the upper transverse mode with a finite temperature splitting of the Fermi level. In the present paper, a more detailed theory is developed, and important limiting cases are considered. {} 1996 The American Physical Society.