Screening and gap generation in bilayer graphene

TL;DR

This paper presents a selfconsistent theoretical approach to study gap generation and Coulomb screening in bilayer graphene, predicting an excitonic ground state with a significant energy gap.

Contribution

It introduces a novel selfconsistent method combining equations of motion and variational techniques for excitonic insulators.

Findings

Predicted an excitonic ground state in bilayer graphene with a gap over 10 meV.

Demonstrated the importance of Coulomb screening in gap formation.

Provided a new theoretical framework for excitonic insulators.

Abstract

A fully selfconsistent treatment for gap generation and Coulomb screening in excitonic insulators is presented. The method is based on the equations of motion for the relevant dynamical variables combined with a variational approach. Applying the theory for a model system of bilayer graphene, an excitonic groundstate with a gap exceeding 10 meV is predicted.