Electrical conductivity in graphene with point defects

TL;DR

This paper investigates how point defects affect the electrical conductivity of graphene, revealing that the minimal conductivity depends on impurity resonance energy rather than the Dirac point, with notable asymmetry in gate voltage response.

Contribution

It demonstrates that the minimal conductivity in defective graphene is linked to impurity resonance energy, challenging the notion of universality at the Dirac point.

Findings

Minimal conductivity aligns with impurity resonance energy.

Conductivity dependence on gate voltage is asymmetric.

Shift of conductivity minimum is due to impurity states.

Abstract

The electrical conductivity of graphene containing point defects is studied within the binary alloy model in its dependence on the Fermi level position at the zero temperature. It is found that the minimal conductivity value does not have a universal character and corresponds to the impurity resonance energy rather than to the Dirac point position in the spectrum. The substantial asymmetry of the resulting dependence of the conductivity on the gate voltage magnitude is attributed as well to this same shift of the conductivity minimum to the resonance state energy.