Comparative study of screened interlayer interactions in the Coulomb drag effect in bilayer electron systems

Abstract

Coulomb drag experiments in which the interlayer resistivity is measured are important as they provide information on the Coulomb interactions in bilayer systems. When the layer densities are low correlation effects become significant to account for the quantitative description of experimental results. We investigate systematically various models of effective interlayer interactions in a bilayer system and compare our results with recent experiments. In the low density regime, the correlation effects are included via the intra- and interlayer local-field corrections. We employ several theoretical approaches to construct static local-field corrections. Our comparative study demonstrates the importance of including the correlation effects accurately in the calculation of drag resistivity. Recent experiments performed at low layer densities are adequately described by effective interlayer interactions incorporating static correlations. © 2008 The American Physical Society.