Quantum capacitance and compressibility of graphene: The role of Coulomb interactions

TL;DR

This paper theoretically investigates how Coulomb interactions influence the quantum capacitance, compressibility, and Fermi velocity in graphene, comparing results with recent experimental data to understand many-body effects.

Contribution

It provides a detailed theoretical analysis of Coulomb interaction effects on graphene's electronic properties using multiple approximation methods and compares with experimental findings.

Findings

Coulomb interactions significantly modify quantum capacitance and compressibility.

Theoretical results align with experimental measurements of Fermi velocity.

Disorder fluctuations combined with Coulomb effects are also considered.

Abstract

Many-body effects on quantum capacitance, compressibility, renormalized Fermi velocity, kinetic and interaction energies of massless Dirac electrons in graphene, induced by the Coulomb interactions, are analyzed theoretically in the first-order, Hartree-Fock and random phase approximations. Recent experimental data on quantum capacitance and renormalized Fermi velocity are analyzed and compared with the theory. The bare Fermi velocity and the effective dielectric constants are obtained from the experimental data. A combined effect of Coulomb interactions and Gaussian fluctuations of disorder potential is considered.