COUPLING OF THE SURFACE AND INTERFACE EXCITATIONS IN SMALL COATED PARTICLES

In small coated particles, the internal and external surface excitations of the shell material and the surface excitation of the core material interact with one another. We examine how the inner and outer surface excitations of the shell are coupled with each other in the presence of the dielectric core, and how this coupling varies its characteristics with change of the shell thickness, the multipole order and the core dielectric constant. In addition, we make a similar analysis of the effect of the dielectric coating on the surface excitation of the core. Although we employ a simple approach of the local response theory, our results do not depend upon the explicit frequency dependence of the local dielectric function characterising the shell or core material.