On Coulomb drag in double layer systems

TL;DR

This paper analyzes Coulomb drag in double layer systems like graphene, showing that under certain conditions the drag resistivity scales as d^{-4} and emphasizing the importance of proper electron-electron interaction modeling for experimental agreement.

Contribution

It demonstrates the d^{-4} dependence of drag resistivity in a broad class of systems and highlights the impact of dielectric environment modeling on theoretical predictions.

Findings

Drag resistivity scales as d^{-4} in specified limits

Dependence on energy dispersion and wave function structure factors is negligible

Proper treatment of dielectric background is crucial for matching experimental data

Abstract

We argue, for a wide class of systems including graphene, that in the low temperature, high density, large separation and strong screening limits the drag resistivity behaves as d^{-4}, where d is the separation between the two layers. The results are independent of the energy dispersion relation, the dependence on momentum of the transport time, and the wave function structure factors. We discuss how a correct treatment of the electron-electron interactions in an inhomogeneous dielectric background changes the theoretical analysis of the experimental drag results of Ref. [1]. We find that a quantitative understanding of the available experimental data [1] for drag in graphene is lacking.