Transconductance fluctuations as a probe for interaction induced quantum Hall states in graphene

TL;DR

This paper shows that transconductance fluctuations in graphene can reveal fragile quantum Hall states, including fractional and broken-symmetry states, which are hidden in traditional transport measurements due to disorder.

Contribution

It introduces a novel method using transconductance fluctuations to detect fragile quantum Hall states in graphene, overcoming limitations of conventional transport measurements.

Findings

Transconductance fluctuations reflect charge localization on nanometer scale.

Fragile quantum Hall states are observable via this method.

The approach reveals states hidden in standard measurements.

Abstract

Transport measurements normally provide a macroscopic, averaged view of the sample, so that disorder prevents the observation of fragile interaction induced states. Here, we demonstrate that transconductance fluctuations in a graphene field effect transistor reflect charge localization phenomena on the nanometer scale due to the formation of a dot network which forms near incompressible quantum states. These fluctuations give access to fragile broken-symmetry and fractional quantum Hall states even though these states remain hidden in conventional magnetotransport quantities.