Charge conveyance and nonlinear acoustoelectric phenomena for intense surface acoustic waves on a semiconductor quantum well

The combination of semiconductor quantum well structures and strongly piezo electric crystals leads to a system in which surface acoustic waves with ve ry large amplitudes can interact with charge carriers in the well. The surf ace acoustic wave induces a dynamic lateral superlattice potential in the p lane of the quantum well which is strong enough to spatially break up a two -dimensional electron system into moving wires of trapped charge. This tran sition is manifested in an increase of the electron transport velocity with sound amplitude, eventually reaching the sound velocity. The sound absorpt ion by the electron system then becomes governed by nonlinearities and is s trongly reduced. We study the transition from the linear towards the strong ly nonlinear regime of interaction and present a theoretical description of such phenomena in a 2D system.