Epitaxial lift-off for solid-state cavity quantum electrodynamics

TL;DR

This paper introduces an epitaxial lift-off technique to integrate quantum dots into microcavities, achieving high finesse and demonstrating cavity-QED effects, paving the way for solid-state quantum information applications.

Contribution

The study presents a novel epitaxial lift-off method for embedding quantum dots into microcavities with high finesse, enabling strong light-matter interactions in solid-state systems.

Findings

Achieved a finesse of 4,100 limited by mirror reflectivity

Demonstrated cavity-quantum dot interaction in the weak coupling regime

Estimated coupling strength close to the strong coupling regime

Abstract

We present a new approach to incorporate self-assembled quantum dots into a Fabry-P\'{e}rot-like microcavity. Thereby a 3$\lambda$/4 GaAs layer containing quantum dots is epitaxially removed and attached by van der Waals bonding to one of the microcavity mirrors. We reach a finesse as high as 4,100 with this configuration limited by the reflectivity of the dielectric mirrors and not by scattering at the semiconductor - mirror interface, demonstrating that the epitaxial lift-off procedure is a promising procedure for cavity quantum electrodynamics in the solid state. As a first step in this direction, we demonstrate a clear cavity-quantum dot interaction in the weak coupling regime with a Purcell factor in the order of 3. Estimations of the coupling strength via the Purcell factor suggests that we are close to the strong coupling regime.