ABSTRACT
This chapter refers to systems of more than one nanoparticle. It begins by discussing the inter-particle hybridization of localized polaritons for the case of a laterally coupled dimer. The chapter then analyzes various hybridization effects with focus on the commonly studied multi-particle systems such as trimers, hexamers, asymmetric dimers, stereo-metamaterials, and nanospheres-innanoshells and examines the more complex multi-particle systems. The hybridization method was then employed to understand nanoparticle dimers. The dimer polaritons can be understood as the bonding and anti-bonding couplings of the individual nanoparticle eigenmodes. Here, bonding corresponds to the two dipole moments moving in phase (symmetric fields), and the anti-bonding corresponds to anti-phase (anti-symmetric fields). The coexistence of electric and magnetic resonances in a dielectric dimer enables the directional control of scattered light. The directional radiation can be further tuned with one-dimensional (1D) dielectric nanoparticle chains.
