Quantization of the acoustoelectric current in a two-dimensional electron system in a strong magnetic field

Abstract

An expression for the off-diagonal component of the acoustoelectric tensor is obtained from the momentum-conservation law. The acoustoelectric current along the direction of sound propagation exhibits plateaus as a function of gate voltage if the circuit in the perpendicular direction is open. The product jB has the same plateaus as a function of magnetic field. The values of jB at the plateaus are equidistant and are separated by deep minima. The ratio of the plateau values of the current to the open-circuit voltage is equal to ${\mathrm{\ensuremath{\sigma}}}_{\mathit{x}\mathit{y}}$. This effect can be used for measuring the intensity of a surface acoustic wave propagated through the heterojunction.