Through precise artificial manipulation of microscopic quantum particles such as single photons and atoms, quantum mechanics provides a radically new way to encode, store, transmit and process information, and thereby can break the bottlenecks in information security and computational power for classical information technology, which can have profound implications in the national security and the next generation of information technology industry. Quantum information science has become one of the most active frontier research fields since 1990s, and is under intense competition worldwide. For the realization of practical quantum technologies, a major challenge is the coherent control of multi-particle entanglement. The Chinese scientists in this program have been pioneering in the field of multiphoton entanglement and interferometry. They have performed systematic studies in large-scale quantum communication and optical quantum information processing, achieved a series of fundamental breakthroughs, and brought the quantum secure communication into real-life applications. The main achievement includes:

1. Multiphoton entanglement and interferometry. The first creation of verification of multiphoton states with genuine multipartite entanglement (2003); The first generation of five-photon entanglement (the maximal number of entangled particles in all physical systems, 2004); The first generation of six-photon graph state (2007), five-photon ten-qubit hyper-entanglement (2010), and eight-photon entanglement (2012) - the current record.

2. Physical realization of quantum algorithms. The first demonstrations of open-destination quantum teleportation, two-particle teleportation, and tele-cloning. Realizations of loss-tolerant quantum coding and topological quantum error correction. Demonstrations of two-photon logic gates, Shor’s factoring algorithm, Grover’s search algorithm, linear equations solving algorithm, and quantum simulation of anyons.

3. Practical and large-scale quantum communications. Used decoy state and measurement detector independent protocol to overcome the major security loopholes for practical quantum key distribution, extending the secure communication distance over 100 km, establishing all-pass quantum telephone, 46-nodes intracity quantum network, which made the practical intracity quantum communication possible. Theoretically proposed and experimentally demonstrate the basic quantum repeater node combining entanglement swapping and cold-atomic quantum memory, developed the best performance (storage time and retrieval efficiency) cold-atomic quantum memory, which laid the ground for intercity quantum communication. Free-space distribution of entangled photon pairs through the noisy ground atmosphere with a distance beyond the effective thickness of the aerosphere, quantum teleportation of independent qubits over a 100-kilometre free-space channel, which paved the way for future satellite-based ultra-long-distance quantum communication.