发表机构
TU Wien, Atominstitut & Vienna Center for Quantum Science and Technology; Institute for Quantum Optics and Quantum Information (IQOQI), Austrian Academy of Sciences（维也纳工业大学，原子研究所与维也纳量子科学与技术中心; 奥地利科学院量子光学与量子信息研究所）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
针对高维时间仓纠缠QKD协议，提出全面噪声模型，分析时间编码与时钟分辨率的权衡，证明在光子对到达率受限时高维编码优于量子比特方案。
AI 中文摘要
高维时间仓纠缠因其在量子密钥分发（QKD）应用中的巨大潜力而闻名，其易于实现、鲁棒性强，并且可能提供比简单量子比特协议更高的密钥率。然而，时间编码与有限的时钟分辨率相结合，意味着一种权衡：是发送更多低维编码的光子，还是发送少量高维光子？回答这个问题是一项艰巨的挑战，因为它取决于协议的整个上下文，包括产生率、损耗、暗计数、时间抖动等众多因素。我们针对基于单个Franson干涉仪的系统，以渐近密钥率和共享纠缠作为主要性能指标来回答这一问题。我们提出了一个灵活的噪声模型，纳入了所有相关参数，并发现当光子对到达率受限（例如由于损耗或有限的泵浦功率）时，确实存在高维编码仍优于任何基于量子比特的版本的区域。
英文摘要
High-dimensional time-bin entanglement is known for having high potential for quantum key distribution (QKD) applications, being easily implementable, robust and may offer better keyrates than simple qubit protocols. The temporal encoding, combined with limited clock resolution, however, implies a trade-off: Is it better to send more low-dimensionally encoded photons or few high-dimensional ones? Answering this question presents a hard challenge as it depends on the entire context of the protocol, including the production rates, losses, dark counts, timing jitters and many more. We answer this question for single Franson based interferometers and asymptotic key rate and shared entanglement as main figures of merit. We present a flexible noise model incorporating all relevant parameters and find that there are indeed regions where high-dimensional encoding still outperforms any qubit based version when the pair arrival rate is limited, for instance through loss or limited pump power.
Comments23 + 12 pages, 6 figures, 8 tables
