Defect induced Anderson localization and magnetization in graphene quantum dots

TL;DR

This paper models how atomic defects and electron interactions induce localization and magnetization in graphene quantum dots, revealing defect distribution effects on localization length and magnetic structures.

Contribution

It introduces a theoretical framework combining defect disorder and electron interactions to study localization and magnetization in graphene quantum dots.

Findings

Random defects cause localization and magnetic puddles.

Even defect distribution does not affect localization length.

Uneven defect distribution enhances localization.

Abstract

We theoretically investigate the effects of atomic defect related short-range disorders and electron-electron interactions on Anderson type localization and the magnetic properties of hexagonal armchair graphene quantum dots using an extended mean-field Hubbard model. We observe that randomly distributed defects with concentrations between 1-5\% of the total number of atoms leads to localization alongside magnetic puddle-like structures. We show that localization lenght is not affected by magnetization if there is an even distribution of defects between the two sublattices of the honeycomb lattice. However, for an uneven distributions, localization is found to be significantly enhanced.