THEORY OF THE ACOUSTOELECTRIC AND ACOUSTOMAGNETOELECTRIC EFFECTS IN UNIPOLAR SEMICONDUCTORS.

The acoustoelectric (AE) and acoustomagnetielectric (AME) effects in degenerate semiconductors are studied for arbitrary values of the parameter q**l (q is the acoustic wave number and l is the electron mean free path). In the geometric resonance region, both effects exhibit oscillations and the oscillations of the AME effect result in periodic changes of the sign of the effect. A general expression relating the acoustoelectric field to the absorption coefficient of sound is obtained. This expression, which is valid for arbitrary q**l reduces to the Weinreich result in the limit of strong magnetic fields.