Supporting quantum technologies with an ultra-low loss silicon photonics platform

TL;DR

This paper reviews advancements in an ultra-low loss silicon photonics platform designed to support quantum technologies, focusing on reducing losses, integrating quantum-compatible components, and enabling scalable quantum communication and computing.

Contribution

The paper presents recent progress in upgrading silicon photonics for quantum applications, including ultra-low losses and integration of quantum-compatible elements.

Findings

Achieved ultra-low propagation and fibre coupling losses.

Integrated superconducting elements and quantum-compatible modulators.

Enhanced quantum key distribution and cryogenic quantum computing capabilities.

Abstract

Photonic integrated circuits (PICs) are expected to play a significant role in the ongoing second quantum revolution, thanks to their stability and scalability. Still, major upgrades are needed for available PIC platforms to meet the demanding requirements of quantum devices. In this paper, we present a review of our recent progress in upgrading an unconventional silicon photonics platform towards such goal, including ultra-low propagation losses, low fibre coupling losses, integration of superconducting elements, Faraday rotators, fast and efficient detectors, as well as phase modulators with low loss and/or low energy consumption. We show the relevance of our developments and of our vision in two main applications: quantum key distribution - to achieve significantly higher key rates and large-scale deployment - and cryogenic quantum computers - to replace electrical connections to the cryostat with optical fibres.