Current-induced cleaning of graphene

TL;DR

The paper presents a simple, reproducible method to clean graphene by applying high current densities, effectively removing surface contamination and enabling high-quality quantum transport measurements.

Contribution

It introduces a novel current-induced cleaning technique for graphene that improves surface purity without complex procedures.

Findings

Effective removal of surface contamination from graphene

Successful observation of the anomalous quantum Hall effect after cleaning

Method is suitable for low-temperature quantum transport studies

Abstract

A simple yet highly reproducible method to suppress contamination of graphene at low temperature inside the cryostat is presented. The method consists of applying a current of several mA through the graphene device, which is here typically a few $\mu$m wide. This ultra-high current density is shown to remove contamination adsorbed on the surface. This method is well suited for quantum electron transport studies of undoped graphene devices, and its utility is demonstrated here by measuring the anomalous quantum Hall effect.