Modeling of resonance fluorescence excitation spectra of two different two-level interacting nanoparticles

Abstract

Numerical simulations of the excitation spectra of resonant fluorescence bound by the dynamic interaction of two different two-level nanoparticles have been performed. We considered the excitation of one of the particles by monochromatic light with a frequency close to the transition frequency of this particle, at an irradiation intensity leading to a small population of its excited state. The formalism for the description of resonance fluorescence by the Heitler--Ma method was applied to a complete compound system of the marked particle pair and quantized emission field. The resulting expressions for the excitation spectrum reflect consideration of the absorption of the fluorescence photon without attributing it to the emission of any one particle. Expressions for the excitation spectra when taking into account such absorption of the fluorescence photon that allows us to attribute it to the radiation of one or another of the particles were obtained by solving a modified system of equations of the Heitler--Ma method, which reflects the addition of non-interfering amplitudes of the emission field states of each particle. It was found that the shape of the excitation spectra of the stationary resonance fluorescence of the particles in question is determined by the shape of the corresponding intensity spectra of the spontaneous fluorescence of these particles. Keywords: mathematical modeling, interacting two-level nanoparticles, resonant fluorescence, excitation spectrum.