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

TL;DR

This paper investigates how flavor symmetry breaking in lattice simulations affects the electronic properties of graphene, revealing that certain lattice actions induce significant symmetry violations and suggesting a semi-metal phase in suspended graphene.

Contribution

It provides a detailed analysis of flavor symmetry violation effects in staggered fermion lattice simulations of graphene, including the impact of tadpole improvement and Naik terms.

Findings

Significant flavor symmetry breaking observed in the spectrum

Tadpole improvement influences interpretation of previous results

Simulations suggest a semi-metal phase for suspended 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.