Multilayered L-shaped nanoantenna arrays with an increased electric field enhancement

The performance of the composite metal/dielectric multilayered L-shaped nanoantennas for strong electric field enhancement has been investigated. The bonding and antibonding modes arising from the plasmon hybridization modes of the multilayered nanoantennas are presented. It is observed that the plasmon coupling of the proposed composite nanostructures can form three states of in-phase bonding, out-of-phase bonding and out-of-phase antibonding. The out-of-phase charge distribution indicates that dark plasmon modes can be revealed on the bonding modes of the proposed multilayered structures. The response of the proposed L-shaped nanoantennas to the attachment of a dielectric spherical nanoparticle and their molecular sensitivity are investigated. According to this study, the proposed multilayered nanostructures are good candidates for strong electric field localization in sensing and detection applications.