A new type of vacancy-induced localized states in multilayer graphene

TL;DR

This paper discovers a new vacancy-induced zero energy state in multilayer graphene that can be tuned from localized to delocalized by an external electric field, with potential implications for electronic properties.

Contribution

It introduces a novel type of vacancy-related state in multilayer graphene and shows how external gating can control its localization properties.

Findings

Existence of a new zero energy vacancy state in multilayer graphene.

State localization can be tuned by an external electric field.

Transition from localized to extended states is experimentally accessible.

Abstract

We demonstrate the existence of a new type of zero energy state associated to vacancies in multilayer graphene that has a finite amplitude over the layer with a vacancy and adjacent layers, and the peculiarity of being quasi-localized in the former and totally delocalized in the adjacent ones. In a bilayer, when a gap is induced in the system by applying a perpendicular electric field, these states become truly localized with a normalizable wavefunction. A transition from a localized to an extended state can be tuned by the external gate for experimentally accessible values of parameters.