Photonic integrated circuits (PICs) are key in advancing quantum technologies for secure communications. They offer inherent stability, low losses and compactness compared to standard fiber-based and free-space systems. Our reasearch demonstrates PIC's effectivness in enhancing quantum communications, implementing a three-state BB84 protocol with decoy-state method. We employ an integrated receiver and superconducting nanowire single photon detectors (SNSPDs) to achieve technological advancements. One of the most notable results is the extraction of a secret key over a record-breaking 45 dB channel attenuation. Our results demonstrate a remarkable 220% boost in key rate compared to our prototype fiber-based receiver over a 10 dB channel attenuation. This improvement in the secret key rate (SKR) signifies the potential of integrated photonics to advance the field of quantum communication.
@article{arxiv.2310.16702,
title = {Quantum Key Distribution With an Integrated Photonic Receiver},
author = {Giulia Guarda and Domenico Ribezzo and Tommaso Occhipinti and Alessandro Zavatta and Davide Bacco},
journal= {arXiv preprint arXiv:2310.16702},
year = {2023}
}