AI 中文总结
本研究实验演示了基于零附加损耗复用（ZALM）的16个并行频率模式间纠缠交换，结合时频复用实现高贝尔对速率，为实用高速量子中继器和长距离量子网络奠定实验基础。
AI 中文摘要
提高量子网络的通信速率是量子信息科学的核心挑战。近期，一种基于时频复用的准确定性贝尔对源的高效纠缠分发方案被提出，称为零附加损耗复用（ZALM）。然而该方案的实施需要在密集复用的时频模式间实现高保真度的纠缠交换，这仍是一项实验挑战。本文演示了16个并行频率模式间的纠缠交换，平均保真度达93.9±1.4%。值得注意的是，每个频率模式中的偏振纠缠光子对仅使用现成的50 GHz密集波分复用（DWDM）滤波器即可实现光谱单模，无需额外的窄带滤波。此外，为充分利用时间自由度，泵浦脉冲以3.0 GHz的重复频率运行。通过结合频率和时间复用，总交换速率达到5.38±0.17 对/秒，对应ZALM贝尔对速率为8.2×10² 对/秒。我们的结果确立了ZALM所需的关键实验能力，展示了通向实用高速量子中继器和长距离量子网络的可扩展路径。
英文摘要
Boosting the communication rate of quantum networks is a central challenge in quantum information science. Recently, an efficient entanglement distribution scheme employing quasi-deterministic Bell-pair sources based on time-frequency multiplexing, referred to as zero-added-loss multiplexing~(ZALM), has been proposed. Its implementation, however, requires high-fidelity entanglement swapping across densely multiplexed time-frequency modes, which has remained an experimental challenge. Here we demonstrate entanglement swapping across 16 parallel frequency modes with a high average fidelity of 93.9$\pm$\SI{1.4}{\%}. Notably, polarization-entangled photon pairs in each frequency mode are spectrally single-mode using only off-the-shelf 50-GHz dense wavelength-division multiplexing~(DWDM) filters, eliminating the need for additional narrowband filtering. Furthermore, in order to fully exploit the temporal degree of freedom, the pump pulse is operated with a repetition frequency of \SI{3.0}{GHz}. By combining the frequency and time multiplexing, the total swapping rate reaches 5.38$\pm$0.17\,\si{pairs\,s^{-1}}, which corresponds to the ZALM Bell-pair rate of \SI{8.2e2}{pairs\,s^{-1}}. Our results establish the key experimental capabilities required for ZALM and demonstrate a scalable route toward practical high-rate quantum repeaters and long-haul quantum networks.
Comments13 pages, 5 figures
