Pseudospin-filter tunneling of massless Dirac fermions

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.