Reversal of Klein reflection in bilayer graphene

TL;DR

This paper demonstrates that magnetic barriers can enable normally incident massive Dirac fermions in bilayer graphene to transmit through potential barriers, reversing the usual reflection seen in such systems.

Contribution

It introduces the concept that magnetic barriers can reverse Klein reflection in bilayer graphene, a novel control mechanism for Dirac fermion transport.

Findings

Magnetic barriers enable transmission of massive Dirac fermions at normal incidence.

Magnetotransport properties are affected by bias voltage.

Implications for multilayer graphene transport are discussed.

Abstract

Whereas massless Dirac fermions in monolayer graphene exhibit Klein tunneling when passing through a potential barrier upon normal incidence, such a barrier totally reflects massive Dirac fermions in bilayer graphene due to difference in chirality. We show that, in the presence of magnetic barriers, such massive Dirac fermions can have transmission through even at normal incidence. The general consequence of this behaviour for multilayer graphene consisting of massless and massive modes are mentioned. We also briefly discuss the effect of a bias voltage on such magnetotransport.