Topological Vortices in Chiral Gauge Theory of Graphene

TL;DR

This paper investigates novel vortex structures in a chiral gauge theory model of graphene, revealing that these vortices originate from Dirac fermion dynamics rather than background distortions, and broadening understanding of energy gap mechanisms.

Contribution

It introduces two new vortex types in graphene models by analyzing the inner structure of gauge potentials, expanding the theoretical framework beyond fixed background fields.

Findings

Discovered velocity field vortices on graphene surface.

Identified monopole-motion induced vortices.

Vortices arise from Dirac fermion motion, not background distortions.

Abstract

Generation mechanism of energy gaps between conductance and valence bands is at the centre of the study of graphene material. Recently Chamon, Jackiw, et al. proposed a mechanism of using a Kekul\'{e} distortion background field $% \varphi $ and its induced gauge potential $A_{i}$ to generate energy gaps. In this paper various vortex structures inhering in this model are studied. Regarding $\varphi $ as a generic background field rather than a fixed Nielson-Oleson type distribution, we have found two new types of vortices on the graphene surface --- the velocity field vortices and the monopole-motion induced vortices --- from the inner structure of the potential $A_{i}$. These vortex structures naturally arise from the motion of the Dirac fermions instead of from the background distortion field.