Conductivity and Fano factor in disordered graphene

TL;DR

This study investigates electron transport in disordered graphene, revealing how conductivity and shot noise Fano factor depend on disorder strength and sample size, aligning well with experimental observations.

Contribution

It provides a detailed analysis of conductivity and Fano factor behavior in disordered graphene using the recursive Green's function method, highlighting the influence of disorder parameters.

Findings

Conductivity is approximately e^2/h with a scaling form dependent on disorder.

Fano factor exhibits a dip near neutrality point at weak disorder.

At strong disorder, Fano factor becomes nearly doping independent.

Abstract

Using the recursive Green's function method, we study the problem of electron transport in a disordered single-layer graphene sheet. The conductivity is of order $e^2/h$ and its dependence on the carrier density has a scaling form that is controlled solely by the disorder strength and the ratio between the sample size and the correlation length of the disorder potential. The shot noise Fano factor is shown to have a narrow dip near the neutrality point for weak disorder and to develop a nearly doping independent behavior at strong disorder. Our results are in good qualitative and quantitative agreement with experiments and provide a way for extracting microscopic information about the magnitude of extrinsic disorder in graphene.