Metal-to-insulator transition and electron-hole puddle formation in disordered graphene nanoribbons

TL;DR

This paper numerically confirms the metal-insulator transition in disordered graphene, showing how electron-hole puddles form and influence localization, with implications for understanding charge inhomogeneities in graphene nanoribbons.

Contribution

It provides a detailed numerical analysis of the metal-insulator transition and puddle formation in realistic graphene samples with disorder, including effects of short- and long-range correlations.

Findings

Confirmation of metal-insulator transition in hydrogenated graphene.

Observation of electron-hole puddles with experimental length scales.

Evidence of localized states despite charge inhomogeneities.

Abstract

The experimentally observed metal-to-insulator transition in hydrogenated graphene is numerically confirmed for actual sized graphene samples and realistic impurity concentrations. The eigenstates of our tight-binding model with substitutional disorder corroborate the formation of electron-hole-puddles with characteristic length scales comparable to the ones found in experiments. The puddles cause charge inhomogeneities and tend to suppress Anderson localization. Even though, monitoring the charge carrier quantum dynamics and performing a finite-size scaling of the local density of states distribution, we find strong evidence for the existence of localized states in graphene nanoribbons with short-range but also correlated long-range disorder.