# Ensemble-induced strong light-matter coupling of a single quantum emitter

## TL;DR

This paper introduces a novel method to achieve strong light-matter coupling of a single quantum emitter by leveraging virtual excitations of a nearby ensemble, enabling enhanced non-linearities and potential quantum applications.

## Contribution

The authors propose a new technique using ensemble-induced virtual excitations to strongly couple a single emitter to a cavity, surpassing traditional ensemble coupling schemes.

## Key findings

- Strong coupling of a single emitter achieved via ensemble interactions.
- Realistic parameters provided for SiV− defects in diamond.
- Potential applications in quantum information and cavity-assisted chemistry.

## Abstract

We discuss a technique to strongly couple a single target quantum emitter to a cavity mode, which is enabled by virtual excitations of a nearby mesoscopic ensemble of emitters. A collective coupling of the latter to both the cavity and the target emitter induces strong photon non-linearities in addition to polariton formation, in contrast to common schemes for ensemble strong coupling. We demonstrate that strong coupling at the level of a single emitter can be engineered via coherent and dissipative dipolar interactions with the ensemble, and provide realistic parameters for a possible implementation with SiV$^{-}$ defects in diamond. Our scheme can find applications, amongst others, in quantum information processing or in the field of cavity-assisted quantum chemistry.