  Gold intercalation between the buffer layer and a graphene monolayer of
epitaxial graphene on SiC(0001) leads to the formation of quasi free standing
small aggregates of clusters. Angle Resolved Photoemission Spectroscopy
measurements reveal that these clusters preserve the linear dispersion of the
graphene quasiparticles and surprisingly increase their Fermi velocity. They
also strongly modify the band structure of graphene around the Van Hove
singularities (VHs) by a strong extension without charge transfer. This result
gives a new insight on the role of the intercalant in the renormalization of
the bare electronic band structure of graphene usually observed in Graphite and
Graphene Intercalation Compounds.
