Performance improvement of unidimensional continuous-variable quantum key distribution using heralded hybrid linear amplifier

Publication date: Available online 24 October 2019Source: Physics Letters AAuthor(s): Kunlin Zhou, Zhiya Chen, Ying Guo, Qin LiaoAbstractWe propose an improved scheme for unidimensional continuous-variable quantum key distribution (UCVQKD) using heralded hybrid linear amplifier, aiming to simplify the implementation and improve secret key rate. Different from the symmetrical continuous-variable quantum key distribution protocol (CVQKD), this scheme modulates one quadrature of the coherent state with security insurance. The heralded hybrid linear amplifier concatenates a deterministic linear amplifier (DLA) and a noiseless linear amplifier (NLA), which can tune between the high-gain or high noise-reduction for performance enhancement. Security analysis shows that the proposed scheme can be secured under the collective attacks. Compared with traditional UCVQKD involving noiseless amplifier, the security transmission distance of proposed protocol is increased by 24 kilometers. It not only simplifies the modulation process but also has approximate performance with symmetrical CVQKD in terms of maximal security transmission distance.Graphical abstract

Source: Physics Letters A - October 25, 2019 Category: Physics Source Type: research