PAN Jianwei-Global Quantum Communication Network and Future Prospects

Speaker: PAN Jianwei

Title: Global Quantum Communication Network and Future Prospects

Abstract:

Driven by the initial curiosity in Bell’s inequality, the last few decades have witnessed tremendous progress in the coherent control of individual quantum systems, which has subsequently lead to a gradual transition from the fundamental physics to potential practical technologies. Today, there have been already some quantum communication networks constructed that allow real-world applications in the metropolitan area. In addition, based on photonic qubits and linear optics, a number of experiments have demonstrated fundamental elements in quantum computing, quantum simulation and quantum metrology.

However, there are still significant obstacle before quantum information science can become a useful technology. In this talk, I will describe our recent experiments toward scalable quantum information processing aiming for practical technologies. In the field of quantum cryptography, we have experimentally realized measurement device independent quantum key distribution, whose security can be ensured even under photon detector attack. In the field of quantum teleportation, we have realized quantum teleportation of multiple degrees of freedom in a single photon.

To extend the secure distance of quantum cryptography, two approaches are undertaken in my group. One is to use cold atom quantum repeaters. To this end, we have developed high-performance quantum memories for single photons, with a storage time of ~0.3s and high readout efficiency. Another route is through the low-loss atmospheric free-space channel. We have established a 100-km free-space link for quantum communication. Moreover, direct and full-scale experimental verifications have been performed for ground-satellite quantum key distribution. Recently, we have demonstrated free-space quantum communication under sunlight, towards a satellite constellation based global quantum network. We have launched a satellite for quantum science, which will offer a unique opportunity to test Bell’s inequality in large scale. The technological advance will, in return, push the fundamental physics forward.