Continuous variable measurement-device-independent quantum key distribution based on photon subtraction and optical amplifiers

Abstract

Aiming at the problems of low secret key rate, short transmission distance and low detection efficiency of continuous-variable quantum key distribution protocol, we propose a measurement-device-independent continuous-variable quantum key distribution(MDI-CVQKD) protocol based on photon subtraction and noiseless linear amplifiers (NLA). The protocol uses non-Gaussian operation, in particular, photon subtraction to improve the entanglement between quantum states, and NLA is used to amplify quantum states to compensate for channel attenuation. In this paper, the principle of the protocol is analyzed theoretically, and the relationship between the secret key rate and the secure transmission distance is derived through the covariance matrix between quantum states. Simulation results show that the proposed protocol can not only improve the entanglement between quantum states, but also extend the transmission distance of key distribution and improve the performance of key distribution system.