Average Density of States in Disordered Graphene systems

TL;DR

This paper investigates how disorder, including impurities and vacancies, affects the average density of states in graphene, revealing resonant features and their dependence on disorder parameters using the recursion method.

Contribution

It introduces a detailed analysis of the average density of states in disordered graphene, highlighting the effects of impurity concentration and potential, and extends the linear relation of resonance energy to high impurity regimes.

Findings

Resonant peaks and anti-resonance dips are observed near the Dirac point.

Resonance energy and dip position depend on impurity concentration and potential.

A linear relation for resonance energy holds across different impurity concentrations.

Abstract

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.