Effect of spatial dispersion on acoustoelectric current in a high-mobility two-dimensional electron gas

Abstract

We report the observation of geometric resonances of electron-cyclotron orbits with the wavelength of a surface acoustic wave (SAW) in a high-mobility two-dimensional electron gas (2DEG). The resonances were observed by measuring the acoustoelectric current induced in the 2DEG by the SAW. The experimental data are compared with calculations based on the theoretical expression for the wave-vector-dependent 2DEG conductivity. The acoustoelectric effects are shown to be a sensitive probe of 2DEG transport properties in the low-magnetic-field regime where the conductivity is high and other SAW methods become insensitive.