TRANSMITTED-ACOUSTIC-PHONON DRAG BETWEEN 2-DIMENSIONAL ELECTRON GASESIN GAAS ALXGA1-XAS SYSTEMS AT LOW-TEMPERATURES - MONTE-CARLO STUDY/

We present Monte Carlo simulation of the transmitted-acoustic-phonon ( TAP) drag between barrier-separated two-dimensional (2D) electron gase s in the AlxGa1-xAs/GaAs systems. Nonequilibrium acoustic phonons emit ted by hot 2D electron gas in the biased GaAs channel travel across th e sample. These phonons are partially absorbed in an unbiased 2D chann el where they induce a drag current. Simulation includes 2D electron-n onequilibrium acoustic-phonon interaction for both deformation-potenti al and piezoelectric coupling. Nonequilibrium phonon distribution is c alculated numerically. The TAP drag is simulated at 4.2 and 2.2 K in a multiple quantum well containing equivalent high-mobility 2D electron gases. Drift velocities around 1000 m/s are found in the drag channel (2D gas without outer field) when it is driven by the TAP drag from a large number (10-50) of 2D electron gases subjected to electric field of 1000 V/m. The TAP drag is mainly due to the deformation-potential coupling. The rate of momentum transfer between the drag channel and d rive channels is tau(d)(-1) approximate to 1.5 x 10(6) s(-1). We also demonstrate the enhancement of the TAP drag in thin samples due to mul tiple-phonon reflections from sample surfaces.