Compressibility of bilayer graphene

TL;DR

This paper provides a theoretical analysis of the electronic compressibility of bilayer graphene, highlighting the significant impact of electron-electron interactions at low carrier densities.

Contribution

It introduces a four-band continuum model combined with RPA to accurately quantify the compressibility of bilayer graphene considering correlations.

Findings

Compressibility is strongly suppressed by interactions at low densities.

Correlations are essential for quantitative accuracy but do not change qualitative behavior.

The study advances understanding of thermodynamic properties of graphene bilayers.

Abstract

Bilayer graphene is a recently isolated and intriguing class of many-body systems with massive chiral quasiparticles. We present theoretical results for the electronic compressibility of bilayer graphene that are based on a four-band continuum band structure model combined with a random phase approximation treatment of electronic correlations. We find that the compressibility is strongly suppressed by electron-electron interactions at low carrier densities. Correlations do not lead to any qualitative new features, but are crucially important for a quantitative understanding of this fundamental thermodynamic property of graphene bilayers.