Magneto-Coulomb Drag and Hall Drag in Double-Layer Dirac Systems

TL;DR

This paper develops a theoretical framework for Coulomb and Hall drag in double-layer graphene under strong magnetic fields, revealing finite longitudinal drag and significant Hall drag resistivity, especially near charge neutrality.

Contribution

It introduces a new theory for magneto-Coulomb and Hall drag in double-layer Dirac systems, accounting for disorder and magnetic field effects, not previously addressed in detail.

Findings

Longitudinal magneto-Coulomb drag is finite and peaks at charge neutrality.

Hall drag resistivity is sizable away from charge neutrality.

The theory applies to weak Landau level mixing and disorder regimes.

Abstract

We develop a theory of Coulomb drag due to momentum transfer between graphene layers in a strong magnetic field. The theory is intended to apply in systems with disorder that is weak compared to Landau level separation, so that Landau level mixing is weak, but strong compared to correlation energies within a single Landau level, so that fractional quantum Hall physics is not relevant. We find that in contrast to the zero-field limit, the longitudinal magneto-Coulomb drag is finite, and in fact attains a maximum at the simultaneous charge neutrality point (CNP) of both layers. Our theory also predicts a sizable Hall drag resistivity at densities away from the CNP.