Analytical model of plasmonic resonance from multiple core-shell nanoparticles

We present the analytical solution of multiple core-shell nanoparticles using the multiple scattering theory. Plasmonic resonance from two and three core-shell nanoparticles is investigated to understand the optical properties of multiple core-shell nanoparticles. It is shown that the optical properties can be tuned either by changing the distance between core-shell nanoparticle or by changing their core-to-shell ratio. If the distance of two core-shell nanoparticle increases, the particles respond like two isolated core-shell nanoparticle, and if the distance decreases they show stronger resonance. We also demonstrate that the relative position of multiple core-shell nanoparticles plays a vital role for the enhancement of field intensity. The results provide a fast approach to analytically probe the tunable optical properties that solid single or multiple metal nanoparticles can demonstrate. We have validated our results using finite element method.