Quantum interference in bilayer graphene

TL;DR

This paper presents the first experimental investigation of quantum interference effects in bilayer graphene, revealing how weak localization is influenced by elastic scattering and carrier density variations.

Contribution

It provides new experimental insights into quantum interference corrections in bilayer graphene, highlighting the role of elastic scattering processes like intervalley scattering.

Findings

Weak localization causes positive magnetoconductivity at low fields.

Dephasing length agrees between magnetoconductivity and conductance fluctuation analyses.

Elastic scattering significantly affects quantum interference in bilayer graphene.

Abstract

We report the first experimental study of the quantum interference correction to the conductivity of bilayer graphene. Low-field, positive magnetoconductivity due to the weak localisation effect is investigated at different carrier densities, including those around the electroneutrality region. Unlike conventional 2D systems, weak localisation in bilayer graphene is affected by elastic scattering processes such as intervalley scattering. Analysis of the dephasing determined from the magnetoconductivity is complemented by a study of the field- and density-dependent fluctuations of the conductance. Good agreement in the value of the coherence length is found between these two studies.