Impurity effects on Dirac modes in graphene armchair nanoribbons

TL;DR

This paper investigates how impurities affect Dirac modes in graphene armchair nanoribbons, revealing potential for localization and mobility gap formation, and discusses phase transitions in disordered electronic systems.

Contribution

It introduces a detailed analysis of impurity effects on Dirac modes in graphene nanoribbons using the Anderson hybrid model, highlighting localization and phase transition phenomena.

Findings

Impurities can induce Mott localization in graphene nanoribbons.

Impurity parameters influence the opening of a mobility gap.

Disorder can lead to electronic phase transitions.

Abstract

We consider finite ribbons of graphene with armchair orientation of their edges to study in detail impurity effects on specific Dirac-like modes. In the framework of Anderson hybrid model of impurity perturbation, a possibility for Mott localization and for opening of a mobility gap under local impurity perturbations is found and analyzed in function of this model parameters: the impurity energy level, its hybridization with the host Dirac modes, and the impurity concentration. Possible electronic phase states in such disordered system and subsequent phase transitions between them are discussed.