Pseudospin-filter tunneling of massless Dirac fermions

TL;DR

This paper theoretically investigates how massless Dirac fermions tunnel through vector potential barriers, revealing a pseudospin filtering effect that depends on the fermions' pseudospin, with potential implications for quantum transport control.

Contribution

It introduces the concept of pseudospin filtering via vector potential barriers, highlighting differences in tunneling behavior between pseudospin-1/2 and pseudospin-1 Dirac fermions.

Findings

Pseudospin-1/2 Dirac fermions are more transparent to vector potential barriers.

Pseudospin-1 Dirac fermions are obstructed by the same barriers.

Tuning the barrier height enables selective transmission based on pseudospin.

Abstract

The tunneling of the massless Dirac fermions through a vector potential barrier are theoretically investigated, where the vector potential can be introduced by the very high and very thin (delta-function) magnetic potential barriers. We show that, distinct from the previously studied electric barrier tunneling, the vector potential barriers are more transparent for pseudospin-1/2 Dirac fermions but more obstructive for pseudospin-1 Dirac fermions. By tuning the height of the vector potential barrier, the pseudospin-1/2 Dirac fermions remain transmitted, whereas the transmission of the pseudospin-1 Dirac fermions is forbidden, leading to a pseudospin filtering effect for massless Dirac fermions.