Graphene Plasmons in Triangular Wedges and Grooves
  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. 
P. A. D. Gon\c{c}alves, E. J. C. Dias, Sanshui Xiao, M. I.   Vasilevskiy, N. Asger Mortensen, N. M. R. Peres
cond-mat.mes-hall physics.optics