PLASMON-LO-PHONON COUPLING EFFECTS ON THE DRAG RATE IN DOUBLE-QUANTUM-WELL SYSTEMS

We study the Coulomb drag rate for electrons in a double-quantum-well structure taking into account the electron-optical phonon interactions . The full wave vector and frequency dependent random-phase approximat ion (RPA) at finite temperature is employed to describe the effective interlayer Coulomb interaction. The electron-electron and electron-opt ical phonon couplings are treated on an equal footing. The electron-ph onon mediated interaction contribution is investigated for different l ayer separations and layer densities. We find that the drag rate at hi gh temperatures (i.e., T greater than or equal to 0.3 E-F) is dominate d by the coupled plasmon-phonon of the system. Including the local-fie ld effects in an approximate way we estimate the importance of intrala yer correlations to be significant. (C) 1997 Elsevier Science Ltd.