  The ability to effectively guide electromagnetic radiation below the
diffraction limit is of the utmost importance in the prospect of all-optical
plasmonic circuitry. Here, we propose an alternative solution to conventional
metal-based plasmonics by exploiting the deep subwavelength confinement and
tunability of graphene plasmons guided along the apex of a graphene-covered
dielectric wedge or groove. In particular, we present a quasi-analytic model to
describe the plasmonic eigenmodes in such a system, including the complete
determination of their spectrum and corresponding induced potential and
electric field distributions. We have found that the dispersion of wedge/groove
graphene plasmons follows the same functional dependence as their flat-graphene
plasmons counterparts, but now scaled by a (purely) geometric factor in which
all the information about the system's geometry is contained. We believe our
results pave the way for the development of novel custom-tailored photonic
devices for subwavelength waveguiding and localization of light based on
recently discovered 2D materials.
