Plasmon hybridzation in coated metallic nanosphere

The plasmon frequencies of a general core/double-shell structure are studied by plasmon hybridization method, and three distinct plasmon modes (omega(0), omega(+), and omega(-)) are found, in which the value of omega(0) is always stable, and omega(+) as well as omega(-) is variable with the radius ratios. The influences of dielectric effect and permittivity difference between metallic core and outer-shell are also analyzed thoroughly. The origins of the stability and tunability of this core/double-shell structure are explored by comparing the charge densities and local field distributions at interfaces. Furthermore, our model can be simplified to different structures including metallic-core/dielectric-shell, dielectric-core/metallic-shell, metallic-core/metallic-shell and its complementary structures, of which the corresponding plasmon modes are also studied and compared with experimental results. VC 2011 American Institute of Physics. [doi:10.1063/1.3552939]