Electronic Properties of Graphene Quantum Ring with Wedge Disclination

TL;DR

This paper investigates how wedge disclinations affect the electronic energy spectrum and persistent currents in graphene quantum rings, revealing the impact of topological defects on quantum transport properties.

Contribution

It introduces a model incorporating boundary conditions for various disclination types and derives quantized energy levels and persistent currents in defective graphene rings.

Findings

Wedge disclinations modify the energy spectrum of graphene quantum rings.

Persistent currents are influenced by the presence of topological defects.

The model provides insights into defect-induced changes in quantum transport.

Abstract

We study the energy spectrum and persistent current of charge carriers confined in a graphene quantum ring geometry of radius $R$ and width $w$ subjected to a magnetic flux. We consider the case where the crystal symmetry is locally modified by replacing a hexagon by a pentagon, square, heptagon or octagon. To model this type of defect we include appropriate boundary conditions for the angular coordinate. The electrons are confined to a finite width strip in radial direction by setting infinite mass boundary conditions at the edges of the strip. The solutions are expressed in terms of Hankel functions and their asymptotic behavior allows to derive quantized energy levels in the presence of an energy gap. We also investigate the persistent currents that appear in the quantum ring and how wedge disclination influences different quantum transport quantities.