▎ 摘　　要

We consider the differential conductance of a normal-superconductor junction in clean bilayer graphene in the framework of the Dirac-Bogoliubov-de Gennes equation. A remarkable suppression of the differential conductance at voltages just below the superconducting gap is found. This can be understood in terms of the spinor structures of the electron and hole excitations, in particular, the reflected valence-band hole being orthogonal to the incoming electron at normal incidence.