Experimental 4-intensity decoy-state quantum key distribution with asymmetric basis-detector efficiency
Hui Liu, Zong‐Wen Yu, Mi Zou, Yan-Lin Tang, Yong Sheng Zhao, Jun Zhang, Xiang‐Bin Wang, Teng‐Yun Chen, Jian-Wei Pan · Physical Review A · 2019
The decoy-state method has been developed rapidly in quantum key distribution (QKD) since it is immune to photon-number splitting attacks. We examine two-basis-detector-efficiency asymmetry, which exists in realistic scenarios. By using the recent 4-intensity decoy-state optimization protocol, we report an implementation of high-rate QKD with asymmetric basis-detector efficiency, demonstrating a 1.9 to 33.2 times higher key rate than previous protocols in the situation of large basis-detector-efficiency asymmetry. The results ruled out an implicit assumption in QKD that the efficiency of $Z$ basis and $X$ basis are restricted to be the same. This work paves the way towards a morepractical QKD setting.