Bilayer-induced asymmetric quantum Hall effect in epitaxial graphene

TL;DR

This paper investigates how bilayer inclusions in epitaxial graphene on SiC influence its quantum Hall effect, revealing asymmetric transport properties and proposing a model to explain these phenomena.

Contribution

It demonstrates the impact of bilayer inclusions on quantum Hall transport in epitaxial graphene and introduces a quantitative scattering model.

Findings

Bilayer inclusions cause asymmetry in quantum Hall transport.

Transport properties deviate from conventional quantum Hall behavior.

A scattering model explains the influence of bilayer regions.

Abstract

The transport properties of epitaxial graphene on SiC(0001) at quantizing magnetic fields are investigated. Devices patterned perpendicularly to SiC terraces clearly exhibit bilayer inclusions distributed along the substrate step edges. We show that the transport properties in the quantum Hall regime are heavily affected by the presence of bilayer inclusions, and observe a significant departure from the conventional quantum Hall characteristics. A quantitative model involving enhanced inter-channel scattering mediated by the presence of bilayer inclusions is presented that successfully explains the observed symmetry properties.