Reproducibility of high-performance quantum dot single-photon sources

TL;DR

This study benchmarks fifteen quantum dot single-photon sources, demonstrating high indistinguishability, purity, and brightness, and discusses challenges and solutions for scalable, identical quantum light sources.

Contribution

It provides a comprehensive performance benchmark of deterministically fabricated quantum dot single-photon sources and introduces techniques to identify their emitting states.

Findings

Average indistinguishability of 90.6%

Average single-photon purity of 95.4%

Average brightness of 13.6% with the first lens

Abstract

Single-photon sources based on semiconductor quantum dots have emerged as an excellent platform for high efficiency quantum light generation. However, scalability remains a challenge since quantum dots generally present inhomogeneous characteristics. Here we benchmark the performance of fifteen deterministically fabricated single-photon sources. They display an average indistinguishability of 90.6 +/- 2.8 % with a single-photon purity of 95.4 +/- 1.5 % and high homogeneity in operation wavelength and temporal profile. Each source also has state-of-the-art brightness with an average first lens brightness value of 13.6 +/- 4.4 %. Whilst the highest brightness is obtained with a charged quantum dot, the highest quantum purity is obtained with neutral ones. We also introduce various techniques to identify the nature of the emitting state. Our study sets the groundwork for large-scale fabrication of identical sources by identifying the remaining challenges and outlining solutions.