Chip-based quantum key distribution

TLDR

Secure transmission of information is urgently needed, and while quantum key distribution offers physics‑based security and has progressed from proof‑of‑concept to commercial deployment, its limited adoption suggests that large‑scale deployment will require chip‑based devices for improved performance, miniaturization, and functionality. The study reports low‑error, GHz‑clocked QKD operation using an indium phosphide transmitter chip and a silicon oxynitride receiver chip fabricated with telecom‑industry components and processes. The authors exploit the devices’ reconfigurability to demonstrate BB84, Coherent One Way, and Differential Phase Shift protocols with performance comparable to state‑of‑the‑art. When combined with integrated single‑photon detectors, these devices enable the integration of QKD into future telecommunications networks.

Abstract

Abstract Improvement in secure transmission of information is an urgent need for governments, corporations and individuals. Quantum key distribution (QKD) promises security based on the laws of physics and has rapidly grown from proof-of-concept to robust demonstrations and deployment of commercial systems. Despite these advances, QKD has not been widely adopted, and large-scale deployment will likely require chip-based devices for improved performance, miniaturization and enhanced functionality. Here we report low error rate, GHz clocked QKD operation of an indium phosphide transmitter chip and a silicon oxynitride receiver chip—monolithically integrated devices using components and manufacturing processes from the telecommunications industry. We use the reconfigurability of these devices to demonstrate three prominent QKD protocols—BB84, Coherent One Way and Differential Phase Shift—with performance comparable to state-of-the-art. These devices, when combined with integrated single photon detectors, pave the way for successfully integrating QKD into future telecommunications networks.