FRICTIONAL DRAG BETWEEN CLOSELY SPACED 2-DIMENSIONAL ELECTRON GASES

We have studied electron transport in two closely spaced, electrically isolated, two-dimensional electron gases (2DEGs) using GaAs/AlGaAs do uble quantum wells. A frictional drag voltage due to interlayer electr on-electron (e-e) scattering is induced in one layer when a current is passed through the other. We present new experimental data based on a detailed carrier-density dependence of these e-e interactions. We hav e shown, in particular, that the interlayer scattering rate is a funct ion of the relative electron densities in thr layers, with a maximum s cattering rats when the two carrier densities are matched.