2016/10/06 by Yunhong Ding, Davide Bacco, Kjeld Dalgaard +4 · 1 voice · 2 citations
Computer Science · Engineering · Physics and Astronomy · #Advanced Photonic Communication Systems #Computer science #Electronic engineering #Engineering #Key (lock) #Materials science #Multi-core processor #Optoelectronics #Parallel computing #Photonic and Optical Devices #Photonic integrated circuit #Photonics #Physics #Quantum #Quantum Information and Cryptography #Quantum computer #Quantum key distribution #Quantum mechanics #quant-ph
paper · pdf · doi:10.1038/s41534-017-0026-2
published as npj Quantum Information 3, 25 (2017) · Please see the complementary work arXiv:1610.01682 (2016)
arxiv published 2016/10/06 · arxiv created 2016/10/07 · openalex publication_date 2017/06/12 · arxiv updated 2017/06/27 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
Quantum Key Distribution (QKD) provides an efficient means to exchange information in an unconditionally secure way. Historically, QKD protocols have been based on binary signal formats, such as two polarisation states, and the transmitted information efficiency of the quantum key is intrinsically limited to 1 bit/photon. Here we propose and experimentally demonstrate, for the first time, a high-dimensional QKD protocol based on space division multiplexing in multicore fiber using silicon photonic integrated lightwave circuits. We successfully realized three mutually unbiased bases in a four-dimensional Hilbert space, and achieved low and stable quantum bit error rate well below both coherent attack and individual attack limits. Compared to previous demonstrations, the use of a multicore fiber in our protocol provides a much more efficient way to create high-dimensional quantum states, and enables breaking the information efficiency limit of traditional QKD protocols. In addition, the silicon photonic circuits used in our work integrate variable optical attenuators, highly efficient multicore fiber couplers, and Mach-Zehnder interferometers, enabling manipulating high-dimensional quantum states in a compact and stable means. Our demonstration pave the way to utilize state-of-the-art multicore fibers for long distance high-dimensional QKD, and boost silicon photonics for high information efficiency quantum communications.