Nonlinear acoustoelectric interactions in GaAs/LiNbO3 structures

Surface acoustic waves accompanied by very large piezoelectric fields can b e created in a semiconductor/piezoelectric hybrid system. Such intense wave s interact with the mobile carries in semiconductor quantum well structures in a manner being strongly governed by nonlinear effects. At high sound in tensities, a formerly homogeneous two-dimensional electron system breaks up into well confined stripes surfing the wave. As a result, we observe a str ong reduction of electronic sound attenuation. On the other hand, large mom entum transfer between the electron system and the wave results in nonlinea r acoustoelectric effects and acoustoelectric amplification. We describe ou r experimental findings in terms of a generalized theory of the acoustoelec tric effect and discuss the importance for possible device applications. (C ) 1999 American Institute of Physics. [S0003-6951(99)02533-4].