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

TL;DR

This paper investigates how non-Markovian interactions between emitters and dissipating matter, like plasmonic nanoparticles, lead to increased radiative decay and explain anomalous enhancements in surface-enhanced Raman spectroscopy and emission.

Contribution

It introduces a non-Markovian model for emitter-nanoparticle interactions, revealing significant effects on decay rates and spectral enhancements beyond traditional Markovian approaches.

Findings

Large increase in radiative decay observed

Diminished non-radiative loss explained

Enhanced emission due to small absorbing nanoparticles

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.