Fingerprints of disorder in graphene

TL;DR

This paper systematically investigates how various types of disorder affect the electronic, transport, and optical properties of graphene, highlighting the roles of different scattering mechanisms and their experimental signatures.

Contribution

It provides a comprehensive analysis of disorder effects in graphene, emphasizing the impact of next-nearest-neighbor hopping and distinguishing disorder types through their spectral fingerprints.

Findings

Long-range disorder dominates the minimum conductivity in graphene.

Resonant scatterers influence the conductivity value of 4e^2/πh.

Next-nearest-neighbor hopping affects resonant scattering but not long-range disorder.

Abstract

We present a systematic study of the electronic, transport and optical properties of disordered graphene including the next-nearest-neighbor hopping. We show that this hopping has a non-negligible effect on resonant scattering but is of minor importance for long-range disorder such as charged impurities, random potentials or hoppings induced by strain fluctuations. Different types of disorders can be recognized by their fingerprints appearing in the profiles of dc conductivity, carrier mobility, optical spectroscopy and Landau level spectrum. The minimum conductivity $4e^{2}/h$ found in the experiments is dominated by long-range disorder and the value of $4e^{2}/\pi h$ is due to resonant scatterers only.