Silica-on-Silicon Waveguide Quantum Circuits

TL;DR

This paper demonstrates high-fidelity integrated silica-on-silicon quantum photonic circuits, including two-photon interference, a CNOT gate, and entangled photon states, advancing scalable quantum photonic technology.

Contribution

It presents the first high-fidelity silica-on-silicon quantum photonic circuits for key quantum information processing tasks.

Findings

Two-photon interference visibility of 94.8%

CNOT gate fidelity of 94.3%

Path entangled state fidelity over 92%

Abstract

Quantum technologies based on photons are anticipated in the areas of information processing, communication, metrology, and lithography. While there have been impressive proof-of-principle demonstrations in all of these areas, future technologies will likely require an integrated optics architecture for improved performance, miniaturization and scalability. We demonstrated high- fidelity silica-on-silicon integrated optical realizations of key quantum photonic circuits, including two-photon quantum interference with a visibility of 94.8(5)%; a controlled-NOT gate with logical basis fidelity of 94.3(2)%; and a path entangled state of two photons with fidelity >92%.