Exchange and correlation effects on drag in low density electron bilayers: Coulomb and virtual-optical-phonon-mediated electron-electron interaction

摘要

We investigate the effect of exchange and correlation (xc) in low-densityelectron bilayers. Along with the direct Coulomb interaction, the effectiveelectron-electron interaction mediated by the exchange of virtual polar optical(PO) phonons is considered. We find that the introduction of xc correctionsresults in a significant enhancement of the transresistivity and qualitativechanges in its temperature dependence. The virtual PO-phonon contributionbehaves similarly to the Coulomb drag and reduces noticeably the total dragthereby resulting in a better agreement with the recent experimental findings.