Electron transport in disordered graphene

TL;DR

This paper investigates how different types of disorder affect electron transport in graphene, revealing that conductivity behavior varies with disorder strength and symmetry, aligning with experimental findings.

Contribution

It provides a detailed analysis of how disorder type influences graphene's transport properties, highlighting the role of chiral symmetry in conductivity at half filling.

Findings

Conductivity is linear with concentration for strong scatterers away from half filling.

Conductivity is logarithmic with concentration for weak scatterers away from half filling.

At half filling, conductivity depends on chiral symmetry preservation, affecting localization.

Abstract

We study electron transport properties of a monoatomic graphite layer (graphene) with different types of disorder. We show that the transport properties of the system depend strongly on the character of disorder. Away from half filling, the concentration dependence of conductivity is linear in the case of strong scatterers, in line with recent experimental observations, and logarithmic for weak scatterers. At half filling the conductivity is of the order of e^2/h if the randomness preserves one of the chiral symmetries of the clean Hamiltonian; otherwise, the conductivity is strongly affected by localization effects.