Continuous variable quantum key distribution**Project supported by the National Natural Science Foundation of China (Grant Nos. 61378010 and 11504219), the Key Project of the Ministry of Science and Technology of China (Grant No. 2016YFA0301403), the Natural Science Foundation of Shanxi Province, China (Grant No. 2014011007-1), and the Program for the Outstanding Innovative Teams of Higher Learning Institutions of Shanxi Province,

Abstract

Quantum key distribution enables unconditionally secure key distribution between two legitimate users. The information-theoretic security is guaranteed by the fundamental laws of quantum physics. Initially, the quantum key distribution protocol was proposed based on the qubits. Later on, it was found that quantum continuous variables can also be exploited for this target. The continuous variable quantum key distribution can build upon standard telecommunication technology and exhibits a higher secret key rate per pulse at a relatively short distance due to the possibility of encoding more than 1 bit per pulse. In this article, we review the current status of the continuous variable quantum key distribution research, including its basic principle, experimental implementations, security and future directions; the experimental progress in this field made by our group is also presented.