Edge State Magnetism of Single Layer Graphene Nanostructures

TL;DR

This study demonstrates that zigzag edge magnetism in graphene nanostructures is robust and persists despite edge irregularities and defects, with longer edges consistently exhibiting magnetic properties.

Contribution

It provides a detailed analysis showing that edge irregularities do not eliminate magnetism in zigzag edges of graphene nanostructures.

Findings

Magnetism in zigzag edges is very robust.

Edges longer than three to four units are always magnetic.

Edge irregularities and defects do not destroy edge state magnetism.

Abstract

We study edge state magnetism in graphene nanostructures using a mean field theory of the Hubbard model. We investigate how the magnetism of the zigzag edges of graphene is affected by the presence of other types of terminating edges and defects. By a detailed study of both regular shapes, such as polygonal nanodots and nanoribbons, and irregular shapes, we conclude that the magnetism in zigzag edges is very robust. Our calculations show that the zigzag edges that are longer than three to four repeat units are always magnetic, irrespective of other edges, regular or irregular. We, therefore, clearly demonstrate that the edge irregularities and defects of the bounding edges of graphene nanostructures does not destroy the edge state magnetism.