  Intercalation of different species under graphene on metals is an effective
way to tailor electronic properties of these systems. Here we present the
successful intercalation of metallic (Cu) and gaseous (oxygen) specimens
underneath graphene on Ir(111) and Ru(0001), respectively, that allows to
change the charge state of graphene as well as to modify drastically its
electronic structure in the vicinity of the Fermi level. We employ ARPES and
STS spectroscopic methods in combination with state-of-the-art DFT calculations
in order to illustrate how the energy dispersion of graphene-derived states can
be studied in the macro- and nm-scale experiments.
