Quantum transport across van der Waals domain walls in bilayer graphene

TL;DR

This paper investigates how domain walls with different inter-layer couplings in bilayer graphene influence electronic transport, revealing valley-dependent effects and the potential to measure inter-layer coupling strength through conductance.

Contribution

It provides analytical expressions for transmission across domain walls and explores how multiple walls alter conductance, advancing understanding of transport in deformed bilayer graphene.

Findings

Transmission exhibits valley-dependent layer asymmetry.

Domain walls significantly affect chiral tunnelling.

Multiple domain walls modify conductance dependence on inter-layer potential.

Abstract

Bilayer graphene can exhibit deformations such that the two graphene sheets are locally detached from each other resulting in a structure consisting of domains with different inter-layer coupling. Here we investigate how the presence of these domains affect the transport properties of bilayer graphene. We derive analytical expressions for the transmission probability, and the corresponding conductance, across walls separating different inter-layer coupling domain. We find that the transmission can exhibit a valley-dependent layer asymmetry and that the domain walls have a considerable effect on the chiral tunnelling properties of the charge carriers. We show that transport measurements allow one to obtain the strength with which the two layers are coupled. We performed numerical calculations for systems with two domain walls and find that the availability of multiple transport channels in bilayer graphene modifies significantly the conductance dependence on inter-layer potential asymmetry.