Tuning localized surface resonances in graphene based Au nanosphere dimer antenna

Abstract

The tunable localized surface plasmons in novel antenna of Au nanosphere dimer coated by graphene is studied theoretically. We demonstrate the electronic tuning of graphene based Au nanosphere antenna via modifying the Femi level of graphene for realizing active tunable localized surface plasmons. It is found that localized electronic field shows an evident increasing, as the graphene layers increase. The resuts are explained as the more evidently enhanced resonance of localized surface plasmons for multilayer graphene than monolayer graphene nanoantenna when the incident light matches to the resonance wavelength of the Au-graphene hybrid system. In addition, it is revealed there is observable blue-shift for the resonance wavelength when the graphene layers get increased. The study provides basic understanding for tuning graphene based on Au nanosphere antenna for a wide range of applications such as single-molecule fluorescence, SERS and photothermal therapy.