Li Yan-Ling, Wei Dong-Mei, Zu Chuan-Jin, Xiao Xing
School of Information Engineering, Jiangxi University of Science and Technology, Ganzhou 341000, China.
College of Physics and Electronic Information, Gannan Normal University, Ganzhou 341000, China.
Entropy (Basel). 2019 Jun 16;21(6):598. doi: 10.3390/e21060598.
Quantum channels with correlated effects are realistic scenarios for the study of noisy quantum communication when the channels are consecutively used. In this paper, superdense coding is reexamined under a correlated amplitude damping (CAD) channel. Two techniques named as weak measurement and environment-assisted measurement are utilized to enhance the capacity of superdense coding. The results show that both of them enable us to battle against the CAD decoherence and improve the capacity with a certain probability. Remarkably, the scheme of environment-assisted measurement always outperforms the scheme of weak measurement in both improving the capacity and successful probability. These notable superiorities could be attributed to the fact that environment-assisted measurement can extract additional information from the environment and thus it performs much better.
当连续使用量子信道时，具有关联效应的量子信道是研究有噪声量子通信的现实场景。本文在关联振幅阻尼（CAD）信道下重新审视了超密集编码。利用弱测量和环境辅助测量这两种技术来提高超密集编码的容量。结果表明，这两种技术都能使我们对抗CAD退相干，并以一定概率提高容量。值得注意的是，在提高容量和成功概率方面，环境辅助测量方案总是优于弱测量方案。这些显著的优势可归因于环境辅助测量可以从环境中提取额外信息，因此表现得更好。
