Fractional fermion charges induced by vector-axial and vector gauge potentials in planar graphene-like structures

TL;DR

This paper demonstrates that in a graphene-like model, fermion charge fractionalization can occur solely through gauge potentials, linking it to the parity anomaly in an extended QED framework.

Contribution

It introduces a model where fermion charge fractionalization occurs without lattice distortions, solely via gauge potentials, and relates this to the parity anomaly.

Findings

Fermion charge fractionalization occurs without Kekulé distortion.

External magnetic fields enable charge fractionalization through gauge potentials.

Fractional fermion charges are connected to the parity anomaly.

Abstract

We show that fermion charge fractionalization can take place in a recently proposed chiral gauge model for graphene even in the absence of Kekul\'e distortion of the graphene honeycomb lattice. We extend the model by adding the coupling of fermions to an external magnetic field and show that the fermion charge can be fractionalized by means of only gauge potentials. It is shown that the chiral fermion charge can also have fractional value. We also relate the fractionalization of the fermion charge to the parity anomaly in an extended Quantum Electrodynamics which involves vector and vector-axial gauge fields.