Measurement of Topological Berry Phase in Highly Disordered Graphene

TL;DR

This study demonstrates that the topological Berry phase in graphene remains robust despite high levels of disorder introduced through hydrogenation, as evidenced by quantum Hall and Shubnikov-de Haas measurements at high magnetic fields.

Contribution

It provides experimental evidence that the topological Berry phase in graphene is resilient to disorder caused by hydrogenation, expanding understanding of topological properties in disordered systems.

Findings

Quantum Hall effect observed in highly disordered graphene

Berry phase remains topologically robust despite hydrogenation-induced disorder

High magnetic field measurements confirm the stability of topological properties

Abstract

We have observed the quantum Hall effect (QHE) and Shubnikov-de Haas (SdH) oscillations in highly disordered graphene at magnetic fields up to 65 T. Disorder was introduced by hydrogenation of graphene up to a ratio H/C $\approx 0.1\%$. The analysis of SdH oscillations and QHE indicates that the topological part of the Berry phase, proportional to the pseudo-spin winding number, is robust against introduction of disorder by hydrogenation in large scale graphene.