Coulomb drag in graphene single layers separated by a thin spacer

TL;DR

This paper develops a theoretical model for Coulomb drag in graphene layers separated by a thin spacer, analyzing how the drag resistivity depends on electron concentration and spacer thickness across different regimes.

Contribution

It introduces a comprehensive theory for Coulomb drag in graphene with arbitrary spacer thickness, extending previous models to cover the thin spacer limit.

Findings

Drag resistivity varies from $n^{-3}d^{-4}$ to $n^{-1}| abla{(nd^2)}|$ depending on spacer thickness.

The theory captures the transition between different regimes of Coulomb drag behavior.

Provides insights into how electron concentration and spacer thickness influence Coulomb drag in graphene.

Abstract

Motivated by very recent studies of Coulomb drag in grahene-BN-graphene system we develop a theory of Coulomb drag for the Fermi liquid regime, for the case when the ratio of spacer thickness $d$ to the Fermi wavelength of electrons is arbitrary. The concentration ($n$) and thickness dependence of the drag resistivity is changed from $n^{-3}d^{-4}$ for the thick spacer to $n^{-1}|\ln{(nd^2)}|$ for the thin one.