Tunable Electron Interactions and Fractional Quantum Hall States in Graphene

TL;DR

This paper proposes a method to tune electron interactions in graphene via dielectric environment control, enabling enhanced or suppressed fractional quantum Hall states and facilitating the study of correlated phases and phase transitions.

Contribution

It introduces a novel approach to continuously tune electron interactions in graphene, advancing the exploration of strongly-correlated quantum Hall states.

Findings

Charge gaps of FQH states can be increased or reduced to zero.

Tunable interactions enable stabilization of various correlated phases.

Method allows exploration of phase transitions in FQH regime.

Abstract

The recent discovery of fractional quantum Hall states in graphene raises the question of whether the physics of graphene and its bilayer offers any advantages over GaAs-based materials in exploring strongly-correlated states of two-dimensional electrons. Here we propose a method to continuously tune the effective electron interactions in graphene and its bilayer by the dielectric environment of the sample. Using this method, the charge gaps of prominent FQH states, including \nu=1/3 or \nu=5/2 states, can be increased several times, or reduced all the way to zero. The tunability of the interactions can be used to realize and stabilize various strongly correlated phases in the FQH regime, and to explore the transitions between them.