Chirality-Assisted Electronic Cloaking in Bilayer Graphene Nanostructures

TL;DR

This paper reveals that in bilayer graphene, pseudospin-dependent effects can cause certain electronic states to be cloaked from detection, significantly affecting transport properties and conductance resonances.

Contribution

It introduces the concept of electronic cloaking in bilayer graphene due to pseudospin coupling, a novel phenomenon affecting electron transport in nanostructures.

Findings

Confined states are cloaked from electrons in outer regions.

Transmission resonances exhibit non-Lorentzian, singular peak shapes.

Magnetic field or electric gap can serve as experimental signatures.

Abstract

We show that the strong coupling of pseudospin orientation and charge carrier motion in bilayer graphene has a drastic effect on transport properties of ballistic p-n-p junctions. Electronic states with zero momentum parallel to the barrier are confined under it for one pseudospin orientation, whereas states with the opposite pseudospin tunnel through the junction totally uninfluenced by the presence of confined states. We demonstrate that the junction acts as a cloak for confined states, making them nearly invisible to electrons in the outer regions over a range of incidence angles. This behavior is manifested in the two-terminal conductance as transmission resonances with non-Lorentzian, singular peak shapes. The response of these phenomena to a weak magnetic field or electric-field-induced interlayer gap can serve as an experimental fingerprint of electronic cloaking.