Modal Approach to the Theory of Energy Transfer Mediated by a Metallic Nanosphere

Theoretically, the presence of a metallic nanoparticle enhances the intermolecular energy transfer. We calculate this enhancement factor with a modal approach pertaining analytical results in the case of a nanosphere. We calculate the Green's function of the system relaying on the spectral properties of the electrostatic operator, fully known for spherical geometry. In contrast to other treatments, the present calculations are straightforward for any molecular orientation giving modal information about the response of the system. Numerical calculations and further discussions are also provided.