  We report first principles investigations of the nonequilibrium transport
properties of a Cu(111)|graphene interface. The Cu(111) electrode is found to
induce a transmission minimum (TM) located -0.68eV below the Fermi level, a
feature originating from the Cu-induced charge transfer resulting in n-type
doped graphene with the Dirac point coinciding with the TM. An applied bias
voltage shifts the n-graphene TM relative to the pure graphene TM and leads to
a distinctive peak in the differential conductance indicating the doping level,
a characteristic not observed in pure graphene.
