Andreev Reflection in Pseudospin-1 System*

An incoming electron can be reflected as a hole at a normal-metal (N)/superconductor (S) interface, known as Andreev reflection. And a perfect Andreev reflection is predicted at two-dimensional metal/s-wave superconductor interface. Compared with previous models in which the N sides are of two-dimensional electron gas and graphene, we find a perfect Andreev reflect with a larger incident angle allowed at pseudospin-1 metal/s-wave superconductor interface. Additionally, an all-angle perfect Andreev reflection occurs in the limits. To support our discoveries, we study the differential conductance which can be observed directly in experiments.