The effect of electron dielectric response on the quantum capacitance of graphene in a strong magnetic field

Brian Skinner, G. L. Yu, A. V. Kretinin, A. K. Geim, K. S. Novoselov, B. I. Shklovskii

Published 2013-07-08Version 1

The quantum capacitance of graphene can be negative when the graphene is placed in a strong magnetic field, which is a clear experimental signature of positional correlations between electrons. Here we show that the quantum capacitance of graphene is also strongly affected by its dielectric polarizability, which in a magnetic field is wave vector-dependent. We study this effect both theoretically and experimentally. We develop a theory and numerical procedure for accounting for the graphene dielectric response, and we present measurements of the quantum capacitance of high-quality graphene capacitors on boron nitride. Theory and experiment are found to be in good agreement.