Absence of a supercritical regime induced by short-range impurity scattering in gapped graphene

TL;DR

This paper demonstrates that short-range impurity scattering in gapped graphene does not induce a supercritical regime, contrasting with long-range Coulomb interactions, and reveals distinct impurity state properties.

Contribution

It provides a detailed comparison showing that short-range impurities in gapped graphene do not lead to supercritical behavior, unlike long-range Coulomb impurities.

Findings

Short-range impurities do not cause supercritical regimes in gapped graphene.

Impurity-induced states differ significantly from those caused by long-range Coulomb potentials.

Properties of impurity states resemble those in other bipartite lattices with short-range impurities.

Abstract

We show that the changes in the electronic density of states (DOS) in graphene induced by impurity scattering with short-range potentials are completely different from those caused by the long-range Coulomb potential. The spectral weight of the state that eventually disappears into the valence band (as the strength of scattering increases) does not transform into a resonance state. Therefore no unusual screening effects related to a redistribution of the density of states in the valence band are observed. The states induced by the short-range impurities in graphene, therefore, have distinctively different properties compared with the long-range potential case. These properties, in fact, closely resemble the case of a short-range single impurity in other bipartite lattices, such as the square, body centered cubic, and simple cubic lattices.