Impurity and vacancy effects in graphene

Abstract

A Green function analysis has been developed for quasiparticle spectrum of a 2D graphene sheet in presence of different types of substitutional disorder, including vacancies. The anomalous character of impurity effects in this system is demonstrated, compared to those in well known doped semiconductors, and explained in terms of conical singularities in the band spectrum of pure graphene. The criteria for appearance of localized states on clusters of impurity scatterers and for qualitative restructuring of band spectrum are established and a possibility for a specific metal/insulator transition at presence of vacancies is indicated.

Electron states in the field of charged impurities in two-dimensional Dirac systems (Review Article)

“…Thus, the potential of charged impurities should be necessarily regularized at small distances in order that the continuum problem be well posed physically. For instance, the charged impurities displaced from the graphene plane provide such a natural regularization and help to avoid the reconstruction of the band spectrum which takes place if they are placed directly into the graphene plane or a disorder is present [17][18][19][20].…”