Non-Local Coulomb Drag in Weyl Semimetals

TL;DR

This paper proposes a novel way to detect the topological non-locality of Weyl semimetals through a magnetic field dependent Coulomb drag measurement between graphene sheets separated by the semimetal.

Contribution

It introduces a new Coulomb drag mechanism based on split cyclotron orbits that remains robust with increasing material thickness, highlighting non-local topological effects.

Findings

Predicts a magnetic field dependent Coulomb drag signal

Demonstrates non-decaying drag with increasing Weyl semimetal thickness

Identifies a new topological transport mechanism

Abstract

Non-locality is one of the most striking signatures of the topological nature of Weyl semimetals. We propose to probe the non-locality in these materials via a measurement of a magnetic field dependent Coulomb drag between two sheets of graphene which are separated by a three-dimensional slab of Weyl semimetal. We predict a new mechanism of Coulomb drag, based on cyclotron orbits that are split between opposite surfaces of the semi-metal. In the absence of impurity scattering between different Weyl nodes, this mechanism does not decay with the thickness of the semi-metal.