  Exotic ordered ground states driven by electronic correlations are expected
to be induced in monolayer graphene when doped to the Van Hove singularity.
Such doping levels are reached by intercalating Gd in graphene on SiC(0001),
resulting in a strong homogeneity and stability. The electronic spectrum now
exhibits severe renormalizations. Flat bands develop which is driven by
electronic correlations according to our theoretical studies. Due to strong
electron-phonon coupling in this regime, polaron replica bands develop. Thus,
interesting ordered ground states should be made accessible.
