Spontaneous emission of an atom placed near a prolate nanospheroid

Abstract:

The frequency shift and linewidth variation of an atomic oscillator placed next to a prolate dielectric or metal spheroid are found within the framework of the classical approach. Both the frequency shift and linewidth are shown to be substantially dependent on the location of the atom and the form of the nanospheroid and capable of reaching very high values near the surface of the nanospheroid under plasmon (polariton) resonance conditions. The predictions are compared with those found for spherical and cylindrical geometries. The prolate spheroid is treated as a model of a needle tip in apertureless optical scanning microscopy. Effects of sharpness of interaction between the nanospheroid tip and atoms are considered.