Effects of electron-electron interactions in suspended graphene

Abstract

We investigate the problem of dynamical gap generation in suspended graphene by long-range Coulomb interactions at strong coupling with Dyson-Schwinger equations. Including renormalization effects on the Fermi velocity we obtain a critical coupling constant $α_c=2.85$ which is larger than the bare coupling $α_0=2.19$ of suspended graphene. This suggests that at low energies the running of the Fermi velocity prevents the emergence of a gapped phase. Our calculation is thus in agreement with the experimental observation that suspended graphene remains in the semimetal phase.

8 pages, 2 figures. Talk given at Xth Quark Confinement and the Hadron Spectrum, October 8--12, 2012 TUM Campus Garching, Munich, Germany