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

Theory of Coulomb drag for massless Dirac fermions

“…From now on, we will introduce the simplified notation J x k,λ ≡ vσ x kλ,kλ = vλcos(ϕ k ), where in the last equality we have used equation (15). The definition of J x k,λ should not be confused with the definition of the current-density operatorĴ i q, in second quantization given in equation (10).…”

“…Early on it was realized [1,2] that 'Coulomb mutual scattering' between spatially separated electronic systems provides a mechanism to relax momentum that tends to equalize drift velocities. This intrinsic friction due to electron-electron interactions is currently referred to as 'Coulomb drag' [3][4][5][6][7][8][9][10][11]. Early experimental work was carried out by Gramila et al [12] and Sivan et al [13] in semiconductor double quantum wells.…”

Experimental Progress towards Probing the Ground State of an Electron-Hole Bilayer by Low-Temperature Transport

“…This problem has been quite extensively analysed by several authors in the context of 2x2DEGs (or 2x2DHGs) [5,[37][38][39][40] and for EHBLs as well [16,41], using the linearized Boltzmann transport equation. Linearization is done in the way the Fermi distribution in the drive layer is assumed to change due to the current flow.…”

“…The intralayer correlations are dependent on r s which affects the screening at low densities. A comprehensive comparison of the predictions of various local-field theories, and the Fermi hypernetted chain approximation for Coulomb drag has been done by Asgari et al [39], more recently.…”