Signature of chirality in scanning-probe imaging of charge flow in graphene

TL;DR

This paper proposes a theoretical method to observe the chiral nature of charge carriers in graphene using a scanning probe microscope, revealing unique features in ballistic transport due to chirality.

Contribution

It introduces a novel scattering formalism within the first-order Born approximation to model charge flow in graphene with a controllable SPM tip.

Findings

Unambiguous signatures of chirality in charge transport.

Development of a theoretical framework for SPM-based charge flow imaging.

Prediction of characteristic current variations with tip position.

Abstract

We theoretically propose to directly observe the chiral nature of charge carriers in graphene mono- and bilayers within a controlled scattering experiment. The charge located on a capacitively coupled scanning probe microscope (SPM) tip acts as a scattering center with controllable position on the graphene sheet. Unambiguous features from the chirality of the particles in single and bilayer graphene arise in the ballistic transport in the presence of such a scattering center. To theoretically model the scattering from the smooth potential created by the SPM tip, we develop the scattering formalism within first-order Born approximation. We calculate the current through a device with an SPM tip between two constrictions (quantum point contacts) as a function of the tip position.