Plasmonic coupling between a metallic nanosphere and a thin metallic wire

Using the plasmon hybridization method the authors examine light-induced coupling between the localized plasmons of a metallic nanosphere and the propagating plasmons of an infinite metallic wire. The plasmon resonances of the coupled system are found to be shifted in frequency relative to the plasmonic structure of the isolated nanoparticles. The magnitude of the shifts depends on the polarization of the incident light and the system geometry. In the limit of a thin wire, it is shown that the nanosphere can serve as an efficient nanoantenna which can couple incident electromagnetic radiation into low-energy propagating wire plasmons.