AI 中文总结
本研究利用铷原子偶极跃迁与腔辅助协议，产生保真度超91.4%的C波段自旋-光子纠缠，观测到贝尔不等式违反值2.455(77) > 2，验证贝尔非局域性，为大规模原子基量子网络提供关键构建模块。
AI 中文摘要
量子非局域性通常通过量子网络中的纠缠分布来揭示，是量子信息科学的基石。纠缠的长距离分布要求信息载体即飞行光子工作在光纤的最低损耗电信波段。尽管已为直接产生C波段电信光子与各类静止自旋之间的纠缠投入大量努力，但量子非局域性的验证仍是未解决的挑战。本研究利用铷原子中波长为1530 nm的偶极跃迁和腔辅助协议，实现了单原子的共振激发与C波段电信光子的直接发射，产生的自旋-光子纠缠经测量的贝尔态保真度超过91.4%。随后，利用该高质量纠缠对观测到贝尔不等式违反值为2.455(77) > 2，从而验证了贝尔非局域性。这些结果将单原子量子发射器的波长扩展至电信C波段，获得了足够高保真度的自旋-光子纠缠，最终实现了贝尔非局域性的验证。本研究为可实现分布式量子计量与长距离量子通信的大规模原子基量子网络提供了极具潜力的构建模块。
英文摘要
Quantum nonlocality, typically revealed through entanglement distribution across quantum networks, is a cornerstone of quantum information science. Long-distance distribution of entanglement requires the information carrier, i.e. flying photons, to operate in the minimum-loss telecom band of optical fiber. While extensive efforts have been devoted to the direct generation of entanglement between C-band telecom photons and various stationary spins, the verification of quantum nonlocality remains an outstanding challenge. Here, utilizing a dipole transition in rubidium atoms with a wavelength of 1530 nm and a cavity-assisted protocol, we achieve resonant excitation and direct emission of C-band telecom photons from a single atom, generating spin-photon entanglement with a measured Bell state fidelity exceeding 91.4%. We then verify Bell nonlocality by observing a Bell inequality violation of 2.455(77) > 2 using this high-quality entangled pair. These results extend the wavelength of a single-atom quantum emitter to the telecom C-band, achieving sufficiently high-fidelity spin-photon entanglement to finally verify Bell nonlocality. This work thereby provides a promising building block for a large-scale atom-based quantum network capable of distributed quantum metrology and long-distance quantum communication.
Comments13 pages, 4+5 figures, 1 table
