  We consider the relaxation of an excited two-level system (TLS) positioned
near a spherical plasmonic nanoparticle (NP). The transition frequency of the
TLS is assumed to coincide with the frequency of the condensation point of NP
plasmonic resonances. We show that the relaxation of the TLS excitation is a
two-step process. Following an initial exponential decay, the TLS breaks in to
Rabi oscillations. Depending upon the distance between the TLS and NP, the
probability of the TLS being in the excited state exhibits either chaotic or
nearly regular oscillations. In the latter case, the eigenfrequency of the
TLS-NP system coincides with one of NP multipole modes.
