Towards high cooperativity strong coupling of a quantum dot in a tunable microcavity

TL;DR

This paper explores achieving high cooperativity in strong coupling between a quantum dot and a tunable microcavity, emphasizing the importance of emitter linewidths and cavity quality for quantum information applications.

Contribution

It demonstrates the necessity of lifetime-limited emitter linewidths alongside high-Q, low mode-volume cavities to attain high cooperativity in quantum dot-microcavity systems.

Findings

Agreement with a model including exciton dephasing reduces cooperativity from 9.0 to 5.5.

High-quality spectra reveal quantum interferences affecting lineshapes.

Equal emphasis on emitter linewidths and cavity quality is crucial for high cooperativity.

Abstract

We investigate the strong coupling regime of a self-assembled quantum dot in a tunable microcavity with dark-field laser spectroscopy. The high quality of the spectra allows the lineshapes to be analyzed revealing subtle quantum interferences. Agreement with a model calculation is achieved only by including exciton dephasing which reduces the cooperativity from a bare value of 9.0 to the time-averaged value 5.5. In the pursuit of high cooperativity, besides a high-Q and low mode-volume cavity, we demonstrate that equal efforts need to be taken towards lifetime-limited emitter linewidths.