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.
@article{arxiv.1204.4177,
title = {Transconductance fluctuations as a probe for interaction induced quantum Hall states in graphene},
author = {Dong Su Lee and Viera Skakalova and R. Thomas Weitz and Klaus von Klitzing and Jurgen H. Smet},
journal= {arXiv preprint arXiv:1204.4177},
year = {2012}
}