Self-Aligned Heterogeneous Quantum Photonic Integration

TL;DR

This paper introduces a self-aligned heterogeneous quantum photonic integration method that achieves near-perfect interface coupling efficiency, enabling scalable quantum photonic circuits with diverse solid-state emitters and mature photonic platforms.

Contribution

The authors present a novel self-aligned integration approach that deterministically achieves high coupling efficiency, demonstrated with SiV centers and TiO2 photonic structures, applicable broadly to solid-state quantum emitters.

Findings

Achieved near-unity coupling efficiency at material interfaces.

Demonstrated Purcell enhancement of SiV centers in a TiO2 photonic crystal cavity.

Enabled broadband collection of single photons into heterogeneous waveguides.

Abstract

Integrated quantum photonics holds significant promise for scalable photonic quantum information processing, quantum repeaters, and quantum networks, but its development is hindered by the mismatch between materials hosting high-quality quantum emitters and those compatible with mature photonic technologies. Heterogeneous integration offers a potential solution to this challenge, yet practical implementations have been limited by inevitable insertion losses at material interfaces. Here, we present a self-aligned heterogeneous quantum photonic integration approach that can deterministically achieve near-unity coupling efficiency at the interface. To showcase our approach, we demonstrate Purcell enhancement of a silicon vacancy (SiV) center in diamond induced by a heterogeneous photonic crystal cavity defined by titanium dioxide (TiO2), as well as optical spin control and readout via a TiO2 photonic circuit. We further show that, when combined with inverse photonic design, our approach enables efficient and broadband collection of single photons from a color center into a heterogeneous waveguide. Our approach is not restricted to SiV centers or TiO2; it can be broadly applied to integrate diverse solid-state quantum emitters with thin-film photonic devices where conformal deposition is possible. Together, these results establish a practical route to scalable quantum photonic integrated circuits that combine high-quality quantum emitters with technologically mature photonic platforms.