Photon loss is the biggest enemy for scalable photonic quantum information processing. This problem can be tackled by using quantum error correction, provided that the overall photon loss is below a threshold of 1/3. However, all reported on-demand and indistinguishable single-photon sources still fall short of this threshold. Here, by using tailor shaped laser pulse excitation on a high-quantum efficiency single quantum dot deterministically coupled to a tunable open microcavity, we demonstrate a high-performance source with a single-photon purity of 0.9795(6), photon indistinguishability of 0.9856(13), and an overall system efficiency of 0.712(18), simultaneously. This source for the first time reaches the efficiency threshold for scalable photonic quantum computing. With this source, we further demonstrate 1.89(14) dB intensity squeezing, and consecutive 40-photon events with 1.67 mHz count rate.
@article{arxiv.2311.08347,
title = {High-efficiency single-photon source above the loss-tolerant threshold for efficient linear optical quantum computing},
author = {Xing Ding and Yong-Peng Guo and Mo-Chi Xu and Run-Ze Liu and Geng-Yan Zou and Jun-Yi Zhao and Zhen-Xuan Ge and Qi-Hang Zhang and Hua-Liang Liu and Lin-Jun Wang and Ming-Cheng Chen and Hui Wang and Yu-Ming He and Yong-Heng Huo and Chao-Yang Lu and Jian-Wei Pan},
journal= {arXiv preprint arXiv:2311.08347},
year = {2023}
}