Observation of Ten-photon Entanglement Using Thin BiB$_{3}$O$_{6}$   Crystals
  We report on the experimental realization of a ten-photon Greenberger-Horne-Zeilinger state using thin BiB$_{3}$O$_{6}$ crystals. The observed fidelity is $0.606\pm0.029$, demonstrating a genuine entanglement with a standard deviation of 3.6 $\sigma$. This result is further verified using $p$-value calculation, obtaining an upper bound of $3.7\times10^{-3}$ under an assumed hypothesis test. Our experiment paves a new way to efficiently engineer BiB$_{3}$O$_{6}$ crystal-based multi-photon entanglement systems, which provides a promising platform for investigating advanced optical quantum information processing tasks such as boson sampling, quantum error correction and quantum-enhanced measurement. 
Luo-Kan Chen, Zheng-Da Li, Xing-Can Yao, Miao Huang, Wei Li, He Lu,   Xiao Yuan, Yan-Bao Zhang, Xiao Jiang, Cheng-Zhi Peng, ...
quant-ph