Shangduan Wu | Searcharxiv

arXiv2010

Criticality of Vacancy-Induced Metal-Insulator Transition in Graphene

The criticality of vacancy-induced metal-insulator transition (MIT) in graphene is investigated by Kubo-Greenwood formula with tight-binding recursion method. The critical vacancy concentration for the MIT is determined to be 0.053%. The scaling laws for transport properties near the critical point are examined showing several unconventional 2D localization behaviors. Our theoretical results have shed some new lights to the understanding of recent experiments in H-dosed graphene and of 2D disordered systems in general.

cond-mat.mtrl-sci↗

arXiv2007

Average Density of States in Disordered Graphene systems

In this paper, the average density of states (ADOS) with a binary alloy disorder in disordered graphene systems are calculated based on the recursion method. We observe an obvious resonant peak caused by interactions with surrounding impurities and an anti-resonance dip in ADOS curves near the Dirac point. We also find that the resonance energy (Er) and the dip position are sensitive to the concentration of disorders (x) and their on-site potentials (v). An linear relation, not only holds when the impurity concentration is low but this relation can be further extended to high impurity concentration regime with certain constraints. We also calculate the ADOS with a finite density of vacancies and compare our results with the previous theoretical results.

cond-mat.mes-hall↗