On-chip scalable highly pure and indistinguishable single-photon sources in ordered arrays: Path to quantum optical circuits

• Published in: Science advances Vol. 8; no. 35; p. eabn9252
• Main Authors: Zhang, Jiefei, Chattaraj, Swarnabha, Huang, Qi, Jordao, Lucas, Lu, Siyuan, Madhukar, Anupam
• Format: Journal Article
• Language: English
• Published: United States American Association for the Advancement of Science 02.09.2022
• Subjects: Applied Physics; Optics; Physical and Materials Sciences; SciAdv r-articles
• ISSN: 2375-2548; 2375-2548
• DOI: 10.1126/sciadv.abn9252

Realization of quantum optical circuits is at the heart of quantum photonic information processing. A long-standing obstacle, however, has been the absence of a suitable platform of single photon sources (SPSs). Such SPSs need to be in spatially ordered arrays and produce, on-demand, highly pure, and indistinguishable single photons with sufficiently uniform emission characteristics to enable controlled interference between photons from distinct sources underpinning functional quantum optical networks. We report on such a platform of SPSs based on a unique class of epitaxial quantum dots dubbed mesa-top single quantum dot. Under resonant excitation, the spatially ordered SPSs (without Purcell enhancement) show single photon purity of >99% [ (0) ~ 0.015], high two-photon Hong-Ou-Mandel interference visibilities of 0.82 ± 0.03 (at 11.5 kelvin, without cavity), and spectral nonuniformity of <3 nanometers, within established locally tunable technology. Our platform of SPSs paves the path to creating on-chip scalable quantum photonic networks for communication, computation, simulation, sensing and imaging.