Pan Jianwei, Bao Xiaohui and Zhang Qiang et al. at the University of Science and Technology of China, in cooperation with Jinan Institute of Quantum Technology and Shanghai Institute of Microsystem and Information Technology of the Chinese Academy of Sciences, have made a significant breakthrough in quantum repeater and quantum network. By developing the bright source of the atom-photon entanglement, low-noise and efficient single-photon frequency conversion technology and long-distance single-photon precision interference technology, they successfully entangled two quantum memories over 50 km fibres, which laid the foundation for the construction of quantum network based on quantum repeater. This achievement was recently published in the internationally renowned academic journal Nature.