▎ 摘　　要

Based on first-principles total-energy calculations, we investigate the electronic structure of bilayer graphene under a vertical electric field for various stacking arrangements. We find that the electronic structure of bilayer graphene near the Dirac point is robust against an external electric field and, with the exception of the bilayer graphene in a Bernal stacking arrangement, maintains its original electronic structure under zero electric field. We also find that the nearly free electron state crosses the Fermi level under an electric field of about 0.7V/angstrom for all considered stacking arrangements of bilayer graphene.