Balancing four-state continuous-variable quantum key distribution with linear optics cloning machine*Project supported by the National Natural Science Foundation of China (Grant Nos. 61379153 and 61572529).

Abstract

We show that the secret key generation rate can be balanced with the maximum secure distance of four-state continuous-variable quantum key distribution (CV-QKD) by using the linear optics cloning machine (LOCM). Benefiting from the LOCM operation, the LOCM-tuned noise can be employed by the reference partner of reconciliation to achieve higher secret key generation rates over a long distance. Simulation results show that the LOCM operation can flexibly regulate the secret key generation rate and the maximum secure distance and improve the performance of four-state CV-QKD protocol by dynamically tuning parameters in an appropriate range.