Teleportation of an entangled state, known as entanglement swapping, plays an essential role in quantum communication and network.Here we report a field-test entanglement swapping experiment with two independent telecommunication band entangled photon-pair sources over the optical fibre network of Hefei city. The two sources are located at two nodes 12 km apart and the Bell-state measurement is performed in a third location which is connected to the two source nodes with 14.7 km and 10.6 km optical fibres. An average visibility of 79.9+/-4.8% is observed in our experiment, which is high enough to infer a violation of Bell inequality. With the entanglement swapping setup, we demonstrate a source independent quantum key distribution, which is also immune to any attack against detection in the measurement site.
@article{arxiv.1606.07503,
title = {Entanglement Swapping with Independent Sources over an Optical Fibre Network},
author = {Qi-Chao Sun and Ya-Li Mao and Yang-Fan Jiang and Qi Zhao and Sijing Chen and Wei Zhang and Weijun Zhang and Xiao Jiang and Teng-Yun Chen and Lixing You and Li Li and Yidong Huang and Xianfeng Chen and Zhen Wang and Xiongfeng Ma and Qiang Zhang and Jian-Wei Pan},
journal= {arXiv preprint arXiv:1606.07503},
year = {2017}
}