Importance of on-site interaction in graphene

TL;DR

This paper investigates the impact of on-site Coulomb interactions on graphene's electronic properties using the Gutzwiller method, concluding that such interactions have minimal effect on kinetic energy and do not induce a metal-insulator transition.

Contribution

It applies the Gutzwiller method to the Hubbard model in graphene, revealing the weak influence of Coulomb interactions on its kinetic energy and metal-insulator transition.

Findings

On-site Coulomb interaction has minimal effect on graphene's kinetic energy.

Brinkmann-Rice transition is unlikely in graphene.

High kinetic energy explains the weak interaction effects.

Abstract

We use the Gutzwiller method to investigate the importance of the on-site Coulomb interaction in graphene. We apply it to Hubbard Hamiltonian to study the renormalization of the kinetic energy in graphene due to the on-site Coulomb interaction. We find that a reasonable strength of the interaction has a very weak effect in reducing the kinetic energy. Hence we predict that the Brinkmann-Rice metal-insulator transition in graphene is not possible. The effect is understood in terms of the high kinetic energy in graphene.