Andreev reflection of massive pseudospin-1 fermions

Abstract

We theoretically investigate the Andreev reflection of the pseudospin-1 Dirac fermions with either the $\pm U$-type or the $S_z$-type mass term. For the $\pm U$-type fermions, it is found that the Andreev reflection probability at the oblique incidence can be even larger than that at the normal incidence. For the retro-reflection, such an oblique enhancement occurs in the $n$-doped $+U$-type ($p$-doped $-U$-type) massive fermion systems. While for the specular reflection, the enhancement occurs in the $n$-doped $-U$-type ($p$-doped $+U$-type) systems. For the $S_z$-type massive fermions, a super Andreev reflection with all-angle unit efficiency is predicted in an undoped junction with the incident energy equal to the superconducting gap.