Quenching of the quantum Hall effect in graphene with scrolled edges

TL;DR

This paper demonstrates that edge nanoscrolls in suspended graphene significantly disrupt quantum Hall effect measurements by creating nonchiral channels that short-circuit current paths, independent of contact placement or sample size.

Contribution

It introduces a novel mechanism where edge nanoscrolls cause the quenching of the quantum Hall effect in graphene, contrasting previous theories based on contact placement or strain.

Findings

Edge nanoscrolls form many nonchiral transport channels.

These channels short-circuit bulk current paths.

The effect inhibits quantized resistance measurements.

Abstract

Edge nanoscrolls are shown to strongly influence transport properties of suspended graphene in the quantum Hall regime. The relatively long arc length of the scrolls in combination with their compact transverse size results in formation of many nonchiral transport channels in the scrolls. They short-circuit the bulk current paths and inhibit the observation of the quantized two-terminal resistance. Unlike competing theoretical proposals, this mechanism of disrupting the Hall quantization in suspended graphene is not caused by ill-chosen placement of the contacts, singular elastic strains, or a small sample size.