Magnetic Field Effect on the Localized Plasmon Resonance in Patterned Noble Metal Nanostructures

Sizable rotation of light polarization plane induced by magnetic field when transmitting through gold nanostructures was observed which was characterized by Faraday rotation and ellipticity. The dependence of disk diameter and disk to disk distance were investigated. The plot of Faraday effect versus disk diameter showed resonant features which were associated with the excitation of localized surface plasmon (LSPR). The magnitude of Faraday rotation or ellipticity from gold nanodisks was found to be at the order of 0.01 degree at magnetic field of 1 Tesla. The MO activity was modeled by the effective medium model, resonant behavior was observed around LSPR resonance and the magnitude of experimental MO activities show good correspondence with the calculation. The results suggest active control on the plasmonic modes by external magnetic field.