  We discuss theoretically the local density of states (LDOS) of a graphene
sheet hosting two distant adatoms located at the center of the hexagonal cells.
By putting laterally a Scanning Tunneling Microscope (STM) tip over a carbon
atom, two remarkable novel effects can be detected: i) a multilevel structure
in the LDOS and ii) beating patterns in the induced LDOS. We show that both
phenomena occur nearby the Dirac points and are highly anisotropic.
Furthermore, we propose conductance experiments employing STM as a probe for
the observation of such exotic manifestations in the LDOS of graphene induced
by inter-adatoms correlations.
