  The electromagnetic response of a two-dimensional metal embedded in a
periodic array of a dielectric host can give rise to a plasmonic Dirac point
that emulates Epsilon-Near-Zero (ENZ) behavior. This theoretical result is
extremely sensitive to tructural features like periodicity of the dielectric
medium and thickness imperfections. We propose that such a device can actually
be realized by using graphene as the 2D metal and materials like the layered
semiconducting transition-metal dichalcogenides or hexagonal boron nitride as
the dielectric host. We propose a systematic approach, in terms of design
characteristics, for constructing metamaterials with linear, elliptical and
hyperbolic dispersion relations which produce ENZ behavior, normal or negative
diffraction.
