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 Te determined from measurements at frequencies f=30 and 150 MHz. The experimental curves of the energy loss Q versus Te at different SAW frequencies depend on the value of ωτ»̄_e compared to 1, where τ̄_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 (ΔT≪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 ωτ̄_e>1 (f=150 MHz) is less than for ωτ̄_e<1 (f=30 MHz). Experimental results confirming this calculation are presented.