On semi-classical optical reponse of metallic silver and silver coated silica nanoparticles

Like a pair of metallic nanostructures the two core-shells nanoparticles with dielectric core in close proximity, also exhibit multiple resonances at higher energy end of their spectrum. In this paper we have deeply investigated the disparity in electric filed when the gap between two core-shells become equal to a few Å. We used simple Planewave as an excitation source. To simulate the problem we used frequency domain with Finite Element Method (FEM) using CST Microwave studio. The gap g between surfaces of nanoparticle was varied in the range from 0.1–352nm. Both Local Response Approximations (LRA) and Generalized Non-local Optical Resonance (GNOR) theory was considered to explain the gap induced local and non-local resonances of the two particle system.