H. Rubel et al., STUDY OF THE CARRIER DENSITY-DEPENDENCE OF THE FRICTIONAL DRAG BETWEEN CLOSELY SPACED 2-DIMENSIONAL ELECTRON GASES, Semiconductor science and technology, 10(9), 1995, pp. 1229-1232
We have studied electron transport in two closely spaced, but electric
ally isolated, two-dimensional electron gases (2DEGs) formed in GaAs/A
lGaAs double quantum wells. A frictional drag voltage is found to be i
nduced in one layer when a current is passed through the other. This v
oltage represents a direct measure of the interlayer electron-electron
interactions, since it is determined by the momentum transfer due to
scattering events between electrons in the different layers. We presen
t new experimental data, based on a detailed carrier density dependenc
e of these electron-electron interactions. Our results strongly suppor
t a recent theory proposing an interaction via virtual acoustic phonon
s. We have shown, in particular, that the 'phonon part' of the interla
yer scattering rate is a function of the relative electron densities i
n the layers, with a maximum scattering rate when the densities are ma
tched.