Subwavelength electromagnetic energy transport by stack of metallic nanorings

In this paper, we consider linear ordered stack of metallic nanorings in the presence of Aharonov- Bohm magnetic flux for externally tunable electromagnetic energy transport below the diffraction limit. Using random phase approximation, we demonstrate that such structure supports propagating surface plasmon modes with negative group velocities and with magnetic flux dependent frequencies. Our results for dispersion relations, bandwidths, and tunabilities of surface plasmon modes give an explicit demonstration that nanoring based subwavelength waveguides are potential candidate for electromagnetic energy transport below the diffraction limit in the terahertz part of spectrum. (C) 2010 American Institute of Physics. [doi:10.1063/1.3480990]