dmu/dn In suspended bilayer graphene: the interplay of disorder and band gap

TL;DR

This paper interprets experimental data of dmu/dn in suspended bilayer graphene, attributing it to spatially varying band gaps caused by local electric fields, and predicts optical and transport properties based on these findings.

Contribution

It introduces a model linking charge density fluctuations to band gap variations in suspended bilayer graphene, highlighting the role of extrinsic effects.

Findings

Band gap fluctuations vary among samples

Gap fluctuations correlate with charge density fluctuations

Predictions for optical conductivity and mobility are provided

Abstract

We present an interpretation of recent experimental measurements of dmu/dn in suspended bilayer graphene samples. We demonstrate that the data may be quantitatively described by assuming a spatially varying band gap induced by local electric fields. We demonstrate that the gap fluctuations vary amongst different samples and that the gap fluctuations are correlated with the associated charge density fluctuations, indicating that the mechanism causing this effect is likely to be an extrinsic effect. We also provide predictions for the optical conductivity and mobility of suspended bilayer graphene samples with small band gaps.