Quantum Hall effect in epitaxial graphene with permanent magnets

TL;DR

This study demonstrates the observation of the quantum Hall effect in epitaxial graphene using only commercial permanent magnets, making the phenomenon more accessible and cost-effective for research and applications.

Contribution

First demonstration of quantum Hall effect in epitaxial graphene using only commercial permanent magnets at low temperature.

Findings

Quantum Hall states observed at Landau level filling factors ν=±2

Chirality of edge channels can be controlled by a top gate

Cost-effective method enables accessible quantum Hall physics experiments

Abstract

We have observed the well-kown quantum Hall effect (QHE) in epitaxial graphene grown on silicon carbide (SiC) by using, for the first time, only commercial NdFeB permanent magnets at low temperature. The relatively large and homogeneous magnetic field generated by the magnets, together with the high quality of the epitaxial graphene films, enables the formation of well-developed quantum Hall states at Landau level filling factors $\nu=\pm 2$, commonly observed with superconducting electro-magnets. Furthermore, the chirality of the QHE edge channels can be changed by a top gate. These results demonstrate that basic QHE physics are experimentally accessible in graphene for a fraction of the price of conventional setups using superconducting magnets, which greatly increases the potential of the QHE in graphene for research and applications.