Quantum Key Distribution (QKD) is considered the most immediate application to be widely implemented amongst a variety of potential quantum technologies. QKD enables sharing secret keys between distant users, using photons as information carriers. An ongoing endeavour is to implement these protocols in practice in a robust, and compact manner so as to be efficiently deployable in a range of real-world scenarios. Single Photon Sources (SPS) in solid-state materials are prime candidates in this respect. Here, we demonstrate a room temperature, discrete-variable quantum key distribution system using a bright single photon source in hexagonal-boron nitride, operating in free-space. Employing an easily interchangeable photon source system, we have generated keys with one million bits length, and demonstrated a secret key of approximately 70,000 bits, at a quantum bit error rate of 6%, with ε-security of 10−10. Our work demonstrates the first proof of concept finite-key BB84 QKD system realised with hBN defects.
@article{arxiv.2302.06212,
title = {Quantum Key Distribution Using a Quantum Emitter in Hexagonal Boron Nitride},
author = {Ali Al-Juboori and Helen Zhi Jie Zeng and Minh Anh Phan Nguyen and Xiaoyu Ai and Arne Laucht and Alexander Solntsev and Milos Toth and Robert Malaney and Igor Aharonovich},
journal= {arXiv preprint arXiv:2302.06212},
year = {2023}
}