THE NONLINEAR EFFECTS IN 2DEG CONDUCTIVITY INVESTIGATION BY AN ACOUSTIC METHOD

The parameters of a two-dimensional electron gas (2DEG) in a GaAs/AlGa As heterostructure ware determined by an acoustic (contactless) method in the delocalized electron region (B less than or equal to 2.5 T). N onlinear effects in Surface Acoustic Wave (SAW) absorption by 2DEG are determined by electron heating in the electric field of SAW. which ma y be described in terms of the electron temperature T-e. The energy re laxation time tau(epsilon) is determined by tile scattering at piezoel ectric potential of acoustic phonons with strong screening. At differe nt SAW frequencies the heating depends on the relationship between ome ga tau(epsilon) and 1 and is determined either by the instantaneously changing wave field (omega tau(epsilon) < 1), or by the average wave p ower (omega tau(epsilon) > 1).