Coulomb Drag and Magnetotransport in Graphene Double Layers

TL;DR

This paper reviews the fabrication, transport properties, and Coulomb drag phenomena in graphene double layers, highlighting experimental and theoretical insights into electron-electron interactions under various conditions.

Contribution

It provides a comprehensive analysis of Coulomb drag in graphene double layers, combining experimental results with theoretical models across different temperature regimes.

Findings

Excellent agreement between calculations and experiments at zero and high magnetic fields

Identification of diffusive and mesoscopic fluctuation regimes in Coulomb drag

Insights into electron-electron scattering mechanisms in graphene layers

Abstract

We review the fabrication and key transport properties of graphene double layers, consisting of two graphene monolayers placed in close proximity, independently contacted, and separated by an ultra-thin dielectric. We outline a simple band structure model relating the layer densities to the applied gate and inter-layer biases, and show that calculations and experimental results are in excellent agreement both at zero and in high magnetic fields. Coulomb drag measurements, which probe the electron-electron scattering between the two layers reveal two distinct regime: (i) diffusive drag at elevated temperatures, and (ii) mesoscopic fluctuation-dominated drag at low temperatures. We discuss the Coulomb drag results within the framework of existing theories.