TY - JOUR

T1 - Plasmon enhancement of Coulomb drag in double-quantum-well systems

AU - Flensberg, Karsten

AU - Hu, Ben Yu-Kuang

PY - 1995/11/15

Y1 - 1995/11/15

N2 - We derive an expression for the drag rate (i.e., interlayer momentum transfer rate) for carriers in two coupled two-dimensional gases to lowest nonvanishing order in the screened interlayer electron-electron interaction, valid for arbitrary intralayer scattering mechanisms, using the Boltzmann transport equation. We calculate the drag rate for experimentally relevant parameters, and show that for moderately high temperatures (T≳0.2TF, where TF is the Fermi temperature) the dynamical screening of the interlayer results in a large enhancement of the drag rate due to the presence of coupled plasmon modes. This plasmon enhancement causes the scaled drag rate to have a peak (i) as a function of temperature at T≊0.5TF, and (ii) as a function of the ratio of densities of the carriers in the two layers when their Fermi velocities are equal. We also show that the drag rate can be significantly affected by the intralayer scattering mechanisms; in particular, the drag rate changes approximately by a factor of 2 when the dopant-layer modulation-doped structures are moved in from 400 to 100 Å.

AB - We derive an expression for the drag rate (i.e., interlayer momentum transfer rate) for carriers in two coupled two-dimensional gases to lowest nonvanishing order in the screened interlayer electron-electron interaction, valid for arbitrary intralayer scattering mechanisms, using the Boltzmann transport equation. We calculate the drag rate for experimentally relevant parameters, and show that for moderately high temperatures (T≳0.2TF, where TF is the Fermi temperature) the dynamical screening of the interlayer results in a large enhancement of the drag rate due to the presence of coupled plasmon modes. This plasmon enhancement causes the scaled drag rate to have a peak (i) as a function of temperature at T≊0.5TF, and (ii) as a function of the ratio of densities of the carriers in the two layers when their Fermi velocities are equal. We also show that the drag rate can be significantly affected by the intralayer scattering mechanisms; in particular, the drag rate changes approximately by a factor of 2 when the dopant-layer modulation-doped structures are moved in from 400 to 100 Å.

U2 - 10.1103/PhysRevB.52.14796

DO - 10.1103/PhysRevB.52.14796

M3 - Journal article

C2 - 9980818

VL - 52

SP - 14796

EP - 14808

JO - Physical Review B

JF - Physical Review B

SN - 2469-9950

IS - 20

ER -