We investigate the absorption properties of graphene-based anisotropic
metamaterial structures where the metamaterial layer possesses an
electromagnetic response corresponding to a near-zero permittivity. We find
that through analytical and numerical studies, near perfect absorption arises
over an unusually broad range of beam incidence angles. Due to the presence of
graphene, the absorption is tunable via a gate voltage, providing dynamic
control of the energy transmission. We show that this strongly enhanced
absorption arises due to a coupling between light and a fast wave-mode
propagating along the graphene/metamaterial hybrid.Comment: 9 pages, 6 figure