Quasiparticle and Transport Properties of Disordered Bilayer Graphene

TL;DR

This paper investigates how disorder affects the electronic and transport properties of bilayer graphene, using advanced numerical methods to reveal the importance of multiple impurity scattering and its impact on quasiparticle behavior.

Contribution

It extends a nonperturbative recursive method to bilayer graphene, providing new insights into disorder effects and comparing results with traditional approximations.

Findings

Quasiparticle residue sharply decreases near charge neutrality.

Disorder induces non-Fermi liquid behavior in bilayer graphene.

Transport properties depend strongly on carrier density and temperature.

Abstract

In recent experimental and theoretical studies of graphene, disorder scattering processes have been suggested to play an important role in its electronic and transport properties. In the preceding paper, it has been shown that the nonperturbative momentum-space Lanczos method is able to accurately describe all the multiple impurity scattering events and account for the quasiparticle and transport properties of disordered monolayer graphene. In the present study, we expand the range of applicability of this recursive method by numerically investigating the quasiparticle and transport properties of Bernal-stacked bilayer graphene in the presence of scalar Anderson disorder. The results are further compared with the findings of the same system using a self-consistent Born approximation, as well as the central findings in the preceding paper for monolayer graphene. It is found that in both systems, proper inclusions of all the scattering events are needed in order to reliably capture the role of disorder via multiple impurity scattering. In particular, the quasiparticle residue is shown to decrease sharply near the charge neutrality point, suggesting that the system is either a marginal Fermi liquid or a non-Fermi liquid. Furthermore, we reveal the dependences of the transport properties of disordered bilayer graphene on the carrier density and temperature, and explore the role of interlayer scattering at varying strengths. Our findings help to provide some new angles into the quasiparticle and transport properties of disordered bilayer graphene.