2022/11/07 by Ozlem Erkilic, Özlem Erkılıç, Lorcán O. Conlon +17 · 2 citations
Computer Science · Physics and Astronomy · #Quantum Computing Algorithms and Architecture #Quantum Information and Cryptography #Quantum Mechanics and Applications #quant-ph
paper · pdf · doi:10.48550/arxiv.2211.03445
published as npj Quantum Information volume 9, 29 (2023)
arxiv created 2022/11/07 · openalex publication_date 2022/11/07 · openalex created_date 2022/11/13 · arxiv updated 2026/07/30 · openalex updated_date 2026/07/31
Decoherence is detrimental to quantum key distribution (QKD) over large distances. One of the proposed solutions is to use quantum repeaters, which divide the total distance between the users into smaller segments to minimise the effects of the losses in the channel. However, the secret key rates that repeater protocols can achieve are fundamentally bounded by the separation between each neighbouring node. Here we introduce a measurement-device-independent protocol which uses high-dimensional states prepared by two distant trusted parties and a coherent total photon number detection for the entanglement swapping measurement at the repeater station. We present an experimentally feasible protocol that can be implemented with current technology as the required states reduce down to the single-photon level over large distances. This protocol outperforms the existing measurement-device-independent and twin-field QKD protocols by surpassing the fundamental limit of the repeaterless bound for the pure-loss channel at a shorter distance and achieves a higher transmission distance in total when experimental imperfections are considered.