# Microcavity-engineered plasmonic resonances for radiation enhancement and strong coupling of a quantum emitter

## TL;DR

This paper proposes microcavity engineering of metallic nanoparticles to significantly enhance plasmonic radiation and enable strong coupling with quantum emitters, advancing quantum optics and sensing applications.

## Contribution

It introduces an analytical quantum model for MNP-microcavity interaction, demonstrating enhanced quantum yield, reduced dissipation, and strong coupling regimes in plasmonic systems.

## Key findings

- Quantum yield increased over 40 times
- Radiative power enhanced by over an order of magnitude
- System can achieve strong coupling in cavity QED

## Abstract

Localized-surface plasmon resonance is of importance in both fundamental and applied physics for the subwavelength confinement of optical field, but realization of quantum coherent processes is confronted with challenges due to strong dissipation. Here we propose to engineer the electromagnetic environment of metallic nanoparticles (MNPs) using optical microcavities. An analytical quantum model is built to describe the MNP-microcavity interaction, revealing the significantly enhanced dipolar radiation and consequentially reduced Ohmic dissipation of the plasmonic modes. As a result, when interacting with a quantum emitter, the microcavity-engineered MNP enhances the quantum yield over 40 folds and the radiative power over one order of magnitude. Moreover, the system can enter the strong coupling regime of cavity quantum electrodynamics, providing a promising platform for the study of plasmonic quantum electrodynamics, quantum information processing, precise sensing and spectroscopy.