The triggering role of carrier mobility in the fractional quantum Hall effect-evidence in graphene

TL;DR

This paper explores how carrier mobility influences the emergence of the fractional quantum Hall effect in graphene, challenging traditional views on the role of interactions and providing topological explanations for observed phenomena.

Contribution

It introduces topological arguments to explain the role of carrier mobility in triggering FQHE in graphene, highlighting a departure from standard interaction-based models.

Findings

Carrier mobility is crucial for FQHE in graphene.

FQHE observed at low densities where interactions are weaker.

Topological explanations account for FQHE features in graphene.

Abstract

Recent experiments on suspended graphene layers have indicated the crucial role of carrier mobility in the competition between Laughlin collective state and insulating state, probably of Wigner-crystal-type. Moreover, the fractional quantum Hall effect (FQHE) in graphene has been observed at a low carrier density where the interaction is reduced as a result of particles dilution. This suggests that the interaction may not be as important in the triggering of FQHE as expected based on the standard formulation of the composite fermions model. Here, the topological arguments are presented to explain these novel features of the FQHE in graphene and, the triggering role of carriers mobility in particular.