Nonlinear conformal-degree-preserving Dirac equations in 2+1 space-time

TL;DR

This paper introduces nonlinear Dirac equations in 2+1 dimensions that preserve conformal degree and invariance, potentially applicable to 2D materials like graphene.

Contribution

It proposes new conformal degree-preserving nonlinear Dirac models with dimensionless couplings for 2+1 space-time.

Findings

Massless equation is conformally invariant.

Models applicable to 2D systems such as graphene.

Three- and four-parameter nonlinear Dirac equations.

Abstract

We propose nonlinear Dirac equations where the conformal degree of the self-interaction terms are equal to that of the Dirac operator and the coupling parameters are dimensionless. As such, the massless equation is conformally invariant and preserves the conformal degree for both the linear and nonlinear components. In 2+1 space-time, we use these features to propose three- and four-parameter nonlinear Dirac equation models that might be useful for applications in 2D systems such as graphene sheets, ribbons and nanotubes.