Lattice gauge theory model for graphene
Abstract
The effects of the electromagnetic (e.m.) electron-electron interactions in half-filled graphene are investigated in terms of a lattice gauge theory model. By using exact Renormalization Group methods and lattice Ward Identities, we show that the e.m. interactions amplify the responses to the excitonic pairings associated to a Kekul\'e distortion and to a charge density wave. The effect of the electronic repulsion on the Peierls-Kekul\'e instability, usually neglected, is evaluated by deriving an exact non-BCS gap equation, from which we find evidence that strong e.m. interactions among electrons facilitate the spontaneous distortion of the lattice and the opening of a gap.
Keywords
Cite
@article{arxiv.1005.2528,
title = {Lattice gauge theory model for graphene},
author = {Alessandro Giuliani and Vieri Mastropietro and Marcello Porta},
journal= {arXiv preprint arXiv:1005.2528},
year = {2010}
}
Comments
5 pages, 2 figures; typos corrected. Final version published in Phys. Rev. B