  We present an ab-initio density function theory to investigate the electronic
and magnetic structures of the bilayer graphene with intercalated atoms C, N,
and O. The intercalated atom although initially positioned at the middle site
of the bilayer interval will finally be adsorbed to one graphene layer. Both N
and O atoms favor the bridge site (i.e. above the carbon-carbon bonding of the
lower graphene layer), while the C atom prefers the hollow site (i.e. just
above a carbon atom of the lower graphene layer and simultaneously below the
center of a carbon hexagon of the upper layer). Concerning the magnetic
property, both C and N adatoms can induce itinerant Stoner magnetism by
introducing extended or quasilocalized states around the Fermi level. Full spin
polarization can be obtained in N-intercalated system and the magnetic moment
mainly focuses on the N atom. In C-intercalated system, both the foreign C atom
and some carbon atoms of the bilayer graphene are induced to be spin-polarized.
N and O atoms can easily get electrons from carbon atoms of bilayer graphene,
which leads to Fermi level shifting downward to valence band and thus producing
the metallic behavior in bilayer graphene.
