Enhanced Andreev reflection in Kekulé-Y patterned graphene

We theoretically investigate the electron-hole conversions in normal metal-superconductor junctions based on the Kekul\'e-Y (Kek-Y) patterned graphene. It is shown that, in contrast to the Klein tunneling in the pristine graphene, the perfect Andreev reflection with almost unit efficiency can be extended to a large range of incident angles in the Kek-Y patterned graphene in single-Dirac cone phase with the bias voltage in the gap. The normalized zero-bias conductance is also obtained.