Radiative decay of an emitter due to non-Markovian interactions with dissipating matter

Abstract

It is known that the more tractable Markovian models of coupling suited for weak interactions may overestimate the Rabi frequency notably when applied to the strong-coupling regime. Here, a more significant consequence of the non-Markovian interaction between a photon emitter and dissipating matter such as resonant plasmonic nanoparticles is described. A large increase of radiative decay and a diminished non-radiative loss is shown, which unravels the origin of unexpected large enhancements of surface-enhanced-Raman-spectroscopy (SERS), as well as the anomalous enhancements of emission due to extremely small fully absorbing metal nanoparticles less than 10 nm in dimensions. We construct the mixture of pure states of the coupled emitter-nanoparticle system, unlike conventional methods that rely on the orthogonal modes of the nanoparticle alone.

Role of Rabi oscillations in radiative states due to the fully absorbing smaller plasmonic nanoparticles

“…It should be noted that when the coupling of the emitter becomes stronger at small relative separations with the metal particle, this one-loop perturbation diverges and a full non-Markovian model of interaction becomes indispensable. 39 Considering the lower dissipative loss of these very small metal particles, they are expected to be much more effective in enhancement of spontaneous emission, compared to the highly scattering larger metal particles required in the weak-coupling regime. Further, the dynamics in spontaneous emission from such materials can be exploited for applications other than light generation.…”

“…A recent work on the effect of non-Markovian interaction between an emitter and a metal nanoparticle, on the radiative and non-radiative parts of the decay, validates this one-loop correction. 39 The effects of non-Markovian interactions on the total decay, and its dynamics, have been studied before for both cavities and a metal surface. [36][37][38] The one-loop correction for the efficiency of emission is especially useful for studying bulk materials with many emitters and the smaller metal nanostructures interacting with each other, and is the main goal of this work.…”