Effects of flavor-symmetry violation from staggered fermion lattice simulations of graphene

Abstract

We analyze the effects of flavor splitting from staggered fermion lattice simulations of graphene. Both the unimproved action, and the tadpole improved action with a Naik term show significant flavor symmetry breaking in the spectrum of the Dirac operator. We also measure the average plaquette term and describe how it calls for a reinterpretation of previous lattice Monte Carlo simulation results, due to tadpole improvement. From this we infer that the simulations are indicative of a semi-metal phase for suspended graphene.

Comments: 7 pages, 5 figures; v2. added results for noncompact gauge action; v3. added results for stout smearing, corrected rescaling of coupling, published version