HEATING OF A 2-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 ele ctron temperature T-e, has been investigated. It is shown that the ene rgy balance of the electron gas is determined by electron scattering b y the piezoelectric potential of the acoustic phonons with T-e determi ned from measurements at frequencies f = 30 and 150 MHz. The experimen tal curves of the energy loss Q versus T-e at different SAW frequencie s 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 ener gy. Theoretical calculations of the heating of a two-dimensional elect ron gas by the electric field of the surface acoustic wave are present ed for the case of thermal electrons (Delta T much less than T). The c alculations show that for the same energy losses Q the degree of heati ng 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 b ar>(e) < 1 (f = 30 MHz). Experimental results confirming this calculat ion are presented. (C) 1997 American Institute of Physics. [S1063-7826 (97)02011-5].