Magnetized spiral chains of plasmonic ellipsoids for one-way optical waveguides

Abstract: When a linear chain of plasmonic nano-particles is subject to longitudinal magnetic field, it exhibits optical Faraday rotation. If the magnetized nano-particles are plasmonic ellipsoids arranged as a spiral chain, the interplay between the Faraday rotation and the geometrical spiral rotation (structural chirality) can strongly enhance non-reciprocity. This interplay forms a waveguide that permits one way propagation only, within four disjoint frequency bands; two bands for each direction.