Resonant transmission of electromagnetic fields through subwavelength zero-ε slits

We theoretically investigate the transmission of electromagnetic radiation through a metal plate with a zero-e metamaterial slit, where the permittivity tends towards zero over a given bandwidth. Our analytic results demonstrate that the transmission coefficient can be substantial for a broad range of slit geometries, including subwavelength widths that are many wavelengths long. This resonant effect has features quite unlike the Fabry-Perot-like resonances that have been observed in conductors with deep channels. We further reveal that ultranarrow zero-c channels can have significantly greater transmission compared to slits with no wave impedance difference across them.