Metropolitan quantum key distribution with silicon photonics

TL;DR

This paper demonstrates high-speed polarization-based quantum key distribution using silicon photonics in field tests, achieving record secret key rates and showcasing PICs as scalable for metropolitan quantum-secure networks.

Contribution

It presents the first high-speed polarization QKD field tests with silicon photonics, achieving record secret key rates at telecom wavelengths.

Findings

950 kbps secret key rate in local test

106 kbps secret key rate in intercity test

Highest secret key rate for polarization-based QKD at telecom wavelength

Abstract

Photonic integrated circuits (PICs) provide a compact and stable platform for quantum photonics. Here we demonstrate a silicon photonics quantum key distribution (QKD) transmitter in the first high-speed polarization-based QKD field tests. The systems reach composable secret key rates of 950 kbps in a local test (on a 103.6-m fiber with a total emulated loss of 9.2 dB) and 106 kbps in an intercity metropolitan test (on a 43-km fiber with 16.4 dB loss). Our results represent the highest secret key generation rate for polarization-based QKD experiments at a standard telecom wavelength and demonstrate PICs as a promising, scalable resource for future formation of metropolitan quantum-secure communications networks.