Heating of a two-dimensional electron gas by the electric field of a surface acoustic wave

The heating of a two-dimensional electron gas by an rf electric field generated by a surface acoustic wave, which can be described by an electron temperature T-e, has been investigated. It is shown that the energy balance of the electron gas is determined by electron scattering by the piezoelectric potential of the acoustic phonons with T-e determined from measurements at frequencies f = 30 and 150 MHz. The experimental curves of the energy loss Q versus T-e at different SAW frequencies depend on the value of omega<(tau)over bar>(e) compared to 1, where <(tau)over bar>(e) is the relaxation time of the average electron energy. Theoretical calculations of the heating of a two-dimensional electron gas by the electric field of the surface acoustic wave are presented for the case of thermal electrons (Delta T much less than T). The calculations show that for the same energy losses Q the degree of heating of the two-dimensional electrons (i.e., the ratio T-e/T) for omega<(tau)over bar>(e) > 1 (f = 150 MHz) is less than for omega<(tau)over bar>(e) < 1 (f = 30 MHz). Experimental results confirming this calculation are presented. (C) 1997 American Institute of Physics. [S1063-7826(97)02011-5].