Ultraslow surface plasmons in metamaterial waveguides

A modified planar waveguide made of a metamaterial with negative permittivity and permeability has been considered. The modification of the waveguide by the introduction of an air channel qualitatively changes its dispersion characteristics due to the appearance of an ultraslow mode. The fields and properties of this mode have been investigated. The mode has been shown to be similar to a surface plasmon. In addition, it has been shown that the plasmons can propagate in subwavelength waveguides. Such ultraslow plasmons can be used in plasmonics and microwave and accelerator techniques.