▎ 摘　　要

We investigate the direction-dependent Andreev reflection of normal state-superconductor junctions both in monolayer and bilayer graphene with a single magnetic barrier by means of the Green's function formalism. Such a barrier is capable of tuning the preferred angles of incidence for the Andreev retro-reflection. It enhances the specular reflection probability for certain angles of incidence in bilayer-based hybrid structures. We further study the impacts of magnetic barriers on the monolayer and bilayer hybrid structures by calculating the differential conductances within the Blonder-Tinkham-Klapwijk formula for experimental comparisons. (C) 2013 Elsevier B.V. All rights reserved.