K. Flensberg et Byk. Hu, PLASMON ENHANCEMENT OF COULOMB DRAG IN DOUBLE-QUANTUM-WELL SYSTEMS, Physical review. B, Condensed matter, 52(20), 1995, pp. 14796-14808
We derive an expression for the drag rate (i.e., interlayer momentum t
ransfer rate) for carriers in two coupled two-dimensional gases to low
est nonvanishing order in the screened interlayer electron-electron in
teraction, valid for arbitrary intralayer scattering mechanisms, using
the Boltzmann transport equation. We calculate the drag rate for expe
rimentally relevant parameters, and show that for moderately high temp
eratures (T greater than or similar to 0.2T(F), where T-F is the Fermi
temperature) the dynamical screening of the interlayer results in a l
arge enhancement of the drag rate due to the presence of coupled plasm
on modes. This plasmon enhancement causes the scaled drag rate to have
a peak (i) as a function of temperature at T approximate to 0.5T(F),
and (ii) as a function of the ratio of densities of the carriers in th
e two layers when their Fermi velocities are equal. We also show that
the drag rate can be significantly affected by the intralayer scatteri
ng mechanisms; in particular, the drag rate changes approximately by a
factor of 2 when the dopant-layer modulation doped structures are mov
ed in from 400 to 100 Angstrom.