Andreev reflection of massive pseudospin-1 fermions

TL;DR

This paper theoretically studies Andreev reflection in massive pseudospin-1 Dirac fermions, revealing enhanced and super reflection phenomena depending on doping type, mass term, and incident angle, with potential implications for quantum transport.

Contribution

It introduces a theoretical framework for Andreev reflection in massive pseudospin-1 fermions, highlighting novel angle-dependent enhancement and super reflection effects.

Findings

Oblique incidence can enhance Andreev reflection probability.

Super Andreev reflection with unit efficiency predicted at specific conditions.

Distinct behaviors for $ ext{U}$-type and $S_z$-type massive 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.