Transport in Bilayer Graphene: Calculations within a self-consistent Born approximation

TL;DR

This paper theoretically investigates the transport properties of bilayer graphene using a self-consistent Born approximation, revealing a crossover in conductivity behavior and a universal conductivity value in the strong-disorder limit.

Contribution

It provides a detailed theoretical analysis of bilayer graphene transport, highlighting the crossover from linear to quadratic dispersion and the universal conductivity in strong disorder.

Findings

Conductivity exhibits a crossover from linear to quadratic dispersion regimes.

In strong disorder, conductivity approaches a universal value of 2e^2/π^2ħ.

Transport properties are independent of disorder range at high disorder levels.

Abstract

The transport properties of a bilayer graphene are studied theoretically within a self-consistent Born approximation. The electronic spectrum is composed of $k$-linear dispersion in the low-energy region and $k$-square dispersion as in an ordinary two-dimensional metal at high energy, leading to a crossover between different behaviors in the conductivity on changing the Fermi energy or disorder strengths. We find that the conductivity approaches $2e^2/\pi^2\hbar$ per spin in the strong-disorder regime, independently of the short- or long-range disorder.