Scaling approach to tight-binding transport in realistic graphene devices: the case of transverse magnetic focusing

TL;DR

This paper introduces a new scaling method for microscopic tight-binding calculations of non-local ballistic transport in high-quality graphene devices, validated through comparison with experimental transverse magnetic focusing data.

Contribution

A novel scaling approach for tight-binding non-local transport calculations in realistic graphene devices, enabling better interpretation of experimental TMF signals.

Findings

Successful numerical method validation against experimental data

Physical interpretation of TMF oscillations and sign changes

Enhanced understanding of ballistic transport in graphene devices

Abstract

Ultra-clean graphene sheets encapsulated between hexagonal boron nitride crystals host two-dimensional electron systems in which low-temperature transport is solely limited by the sample size. We revisit the theoretical problem of carrying out microscopic calculations of non-local ballistic transport in such micron-scale devices. By employing the Landauer-Buttiker scattering theory, we propose a novel scaling approach to tight-binding non-local transport in realistic graphene devices. We test our numerical method against experimental data on transverse magnetic focusing (TMF), a textbook example of non-local ballistic transport in the presence of a transverse magnetic field. This comparison enables a clear physical interpretation of all the observed features of the TMF signal, including its oscillating sign.