Enhanced Absorption Induced by a Metallic Nanoshell

Nanoshells have been previously shown to have tunable absorption frequencies that are dependent on the ratio of their inner and outer radii. Inspired by this, we ask: can a nanoshell increase the absorption of a small core system embedded within it? A theoretical model is constructed to answer this question. A core, composed of a "jellium" ball of the density of gold is embedded within a jellium nanoshell of nanometric diameter. The shell plasmon frequency is tuned to the core absorption line. A calculation based the time-dependent density functional theory was performed showing a 10 fold increase in core excitation yield.