An Kui, Liu Zilei, Zhang Ting, Li Siqi, Zhou You, Yuan Xiao, Wang Leiran, Zhang Wenfu, Wang Guoxi, Lu He
School of Physics, State Key Laboratory of Crystal Materials, Shandong University, Jinan, 250100, China.
State Key Laboratory of Transient Optics and Photonics, Xi'an Institute of Optics and Precision Mechanics, Chinese Academy of Sciences, Xi'an, 710119, China.
Nat Commun. 2024 May 10;15(1):3944. doi: 10.1038/s41467-024-48213-4.
Metasurface enables the generation and manipulation of multiphoton entanglement with flat optics, providing a more efficient platform for large-scale photonic quantum information processing. Here, we show that a single metasurface optical device would allow more efficient characterizations of multiphoton entangled states, such as shadow tomography, which generally requires fast and complicated control of optical setups to perform information-complete measurements, a demanding task using conventional optics. The compact and stable device here allows implementations of general positive operator valued measures with a reduced sample complexity and significantly alleviates the experimental complexity to implement shadow tomography. Integrating self-learning and calibration algorithms, we observe notable advantages in the reconstruction of multiphoton entanglement, including using fewer measurements, having higher accuracy, and being robust against experimental imperfections. Our work unveils the feasibility of metasurface as a favorable integrated optical device for efficient characterization of multiphoton entanglement, and sheds light on scalable photonic quantum technologies with ultra-thin optical devices.
超表面能够利用平面光学技术产生和操纵多光子纠缠，为大规模光子量子信息处理提供了一个更高效的平台。在此，我们展示了单个超表面光学器件能够更高效地表征多光子纠缠态，例如阴影层析成像，这种方法通常需要对光学装置进行快速且复杂的控制才能执行信息完备测量，而使用传统光学技术这是一项艰巨的任务。这里紧凑且稳定的器件允许以降低的样本复杂度实现一般的正算子值测量，并显著减轻了实施阴影层析成像的实验复杂度。通过集成自学习和校准算法，我们在多光子纠缠的重构中观察到显著优势，包括使用更少的测量、具有更高的精度以及对实验缺陷具有鲁棒性。我们的工作揭示了超表面作为用于高效表征多光子纠缠的理想集成光学器件的可行性，并为利用超薄光学器件的可扩展光子量子技术提供了启示。
