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

TLDR

Photonic integration enables scalable, stable, and functional quantum photonics, and InAs/GaAs quantum dots provide bright, pure, indistinguishable single‑photon emission, while Si₃N₄ waveguides offer low‑loss propagation, tunable dispersion, and strong Kerr nonlinearities. The authors aim to develop a scalable heterogeneous III‑V/silicon platform that integrates Si₃N₄ photonic circuits with GaAs nanophotonic devices containing self‑assembled InAs/GaAs quantum dots, enabling efficient, versatile quantum photonic devices. They fabricate a heterogeneous III‑V/silicon platform that couples GaAs waveguides and cavities containing InAs/GaAs quantum dots to Si₃N₄ waveguides via evanescent coupling, achieving >90 % coupling efficiency. They demonstrate pure single‑photon emission from individual quantum dots in GaAs waveguides and cavities, with strong control of.

Abstract

Photonic integration is an enabling technology for photonic quantum science, offering greater scalability, stability, and functionality than traditional bulk optics. Here, we describe a scalable, heterogeneous III-V/silicon integration platform to produce Si$_3$N$_4$ photonic circuits incorporating GaAs-based nanophotonic devices containing self-assembled InAs/GaAs quantum dots. We demonstrate pure singlephoton emission from individual quantum dots in GaAs waveguides and cavities - where strong control of spontaneous emission rate is observed - directly launched into Si$_3$N$_4$ waveguides with > 90 % efficiency through evanescent coupling. To date, InAs/GaAs quantum dots constitute the most promising solidstate triggered single-photon sources, offering bright, pure and indistinguishable emission that can be electrically and optically controlled. Si$_3$N$_4$ waveguides offer low-loss propagation, tailorable dispersion and high Kerr nonlinearities, desirable for linear and nonlinear optical signal processing down to the quantum level. We combine these two in an integration platform that will enable a new class of scalable, efficient and versatile integrated quantum photonic devices