Surface modes of negative-parameter interfaces and the importance of rounding sharp corners

Surface (plasmon) resonances or electrostatic surface modes are possible on an interface between two materials with permittivity of opposite signs, and interfaces with permeability of opposite signs can support similar magnetostatic surface modes. This paper contains a review of the possible surface modes in several canonical geometries, and also numerical results demonstrating the importance of these surface modes for metamaterial modeling. Particular emphasis is placed on the unphysically singular surface modes that an ideal sharp wedge appears to support, and on how losses and rounded corners influence these modes.