Electron-electron drag between parallel two-dimensional gases

Abstract

Electron-electron (e-e) drag between parallel two-dimensional (2D) electron gases in a GaAs/${\mathrm{Al}}_{\mathit{x}}$${\mathrm{Ga}}_{1\mathrm{\ensuremath{-}}\mathit{x}}$As double quantum well (DQW) is investigated at 77 K by using two different ensemble Monte Carlo (EMC) methods. In the first one, the two-particle e-e collisions are modeled assuming a statically screened Coulomb interaction. In the second one, the many-particle e-e interaction is incorporated through classical 2D molecular dynamics. For properly chosen DQW parameters, both methods give a ratio of induced current to drive current of about 1/4 and an interwell momentum relaxation rate of about 4.4\ifmmode\times\else\texttimes\fi{}${10}^{10}$ ${\mathrm{s}}^{\mathrm{\ensuremath{-}}1}$. After appropriate changes of measurement parameters in the experiment of Gramila et al. [Phys. Rev. Lett. 66, 1216 (1991)], similar values would be measurable. The exchange effect and degeneracy, both included in the first EMC method, are also discussed.