Heterogeneous integration for on-chip quantum photonic circuits with single quantum dot devices

• Published in: Nature communications Vol. 8; no. 1; pp. 889 - 12
• Main Authors: Davanco, Marcelo, Liu, Jin, Sapienza, Luca, Zhang, Chen-Zhao, De Miranda Cardoso, José Vinícius, Verma, Varun, Mirin, Richard, Nam, Sae Woo, Liu, Liu, Srinivasan, Kartik
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 12.10.2017; Nature Publishing Group; Nature Portfolio
• Subjects: 639/624/399/1017; 639/624/399/1099; 639/624/400/482; 639/766/400/3925; Coupling; Devices; Emitters; Gallium arsenide; Humanities and Social Sciences; Indium arsenides; Integration; Microcavities; multidisciplinary; Photonics; Quantum dots; Qubits (quantum computing); Science; Science (multidisciplinary); Silicon nitride; Waveguides
• ISSN: 2041-1723; 2041-1723
• DOI: 10.1038/s41467-017-00987-6

Single-quantum emitters are an important resource for photonic quantum technologies, constituting building blocks for single-photon sources, stationary qubits, and deterministic quantum gates. Robust implementation of such functions is achieved through systems that provide both strong light–matter interactions and a low-loss interface between emitters and optical fields. Existing platforms providing such functionality at the single-node level present steep scalability challenges. Here, we develop a heterogeneous photonic integration platform that provides such capabilities in a scalable on-chip implementation, allowing direct integration of GaAs waveguides and cavities containing self-assembled InAs/GaAs quantum dots—a mature class of solid-state quantum emitter—with low-loss Si 3 N 4 waveguides. We demonstrate a highly efficient optical interface between Si 3 N 4 waveguides and single-quantum dots in GaAs geometries, with performance approaching that of devices optimized for each material individually. This includes quantum dot radiative rate enhancement in microcavities, and a path for reaching the non-perturbative strong-coupling regime. Effective use of single emitters in quantum photonics requires coherent emission, strong light-matter coupling, low losses and scalable fabrication. Here, Davanco et al. stride toward this goal by hybrid on-chip integration of Si3N4 waveguides and GaAs nanophotonic geometries with InAs quantum dots.