The resonance fluorescence spectra of N two-level quantum systems located around the spherical nanoantenna

Modification of the resonance fluorescence spec-trum of a two-level atom driving by a lasermonochromatic field in the close proximity of aplasmonic nanostructure (metal sphere) is studiedin detail. It is shown that one can control thisspectrum varying four key parameters: distancebetween the atom and the nanosphere, atom’s lo-cation around the nanosphere, the radius of thenanosphere, and polarization of the incident ra-diation. These parameters affect the local fieldenchancement, transition frequency shift and themodification of the radiative decay rate of the atominteracting with the nanosphere, which lead tomodification of the resonance fluorescence spec-trum of the atom (frequency shift of the satellitelines in the Mollow-type triplet, widths of the lines,the spectrum intensity) by contrast with that onein free space. The permittivity of the metal thenanosphere is made of is also an additional param-eter, which defines the nonradiative decay. The lat-ter in combination with other parameters allows tocontinuously control the transition from resonancefluorescence enhancement to its quenching. Thecalculation results are generalized to the case ofN two-level atoms, distributed around the nanopar-ticle in the close proximity of its surface. Thecalculations were performed for different positionsof the detector relative to the system nanoparticle-atom(s).