Abstract: Quantum key distribution can establish information-theoretically secure keys based on quantum physics. There are two main issues in practice — implementation security and system performance. The proposal of the measurement-device-independent scheme primarily enhances the former. The latter is characterized by the dependence of the key rate on the channel transmittance, R(η). In this tutorial, I shall review the security proofs of various measurement-device-independent schemes. I shall emphasize the recent developments, such as twin-field and mode-pairing schemes, that achieve the quadratic key-rate improvement.
Bio: Xiongfeng Ma obtained his B.Sc. degree at Peking University in 2003 and his Ph.D. degree at the University of Toronto in 2008. In 2012, he joined Tsinghua University. Xiongfeng is currently an associate professor and holds a Changjiang Scholarship. Xiongfeng’s main research interest lies in quantum information science, particularly in quantum cryptography, quantum computing, and quantum foundation. According to the Scientometric Assessment of Global Publications from 1992 to 2019, Xiongfeng was one of the most productive researchers worldwide in quantum cryptography by ResearchGate.