光子纠缠态在海洋湍流中纠缠退化的研究  

Entanglement Degradation of Photons Entangled States in Oceanic Turbulence

作　　者：张钦伟 刘霞[1] 曹连振[1] 杨阳[1] 李英德[1] 赵加强[1] ZHANG Qinwei;LIU Xia;CAO Lianzhen;YANG Yang;LI Yingde;ZHAO Jiaqiang(Shandong Provincial Key Laboratory of Multi-photon Entanglement and Manipulation,Department of Physics and Optoelectronic Engineering,Weifang University,Weifang,Shandong 261061,China)

机构地区：[1]潍坊学院物理与光电工程学院山东省高校多光子纠缠与操纵重点实验室,山东潍坊261061

出　　处：《光子学报》2021年第12期70-78,共9页Acta Photonica Sinica

基　　金：National Natural Science Foundation of China(Nos.62005199,11404246);Natural Science Foundation of Shandong Province(Nos.ZR2020LLZ001,ZR2020KF017,ZR2019LLZ006,2019GGX101073,ZR2018LA014)。

摘　　要：基于量子光学和Kolmogorov海洋湍流谱理论,建立了双量子比特路径纠缠态在海洋湍流中传输的数学模型,得到了其纠缠退化的解析表达式。利用共生纠缠度度量方法,进一步数值分析了双量子比特路径纠缠态在海洋湍流中的纠缠退化问题。结果表明:双量子比特路径纠缠态在海洋湍流中传输时,其纠缠退化程度与制备该纠缠态的实验装置密切相关。空间距离分布较小的双量子比特路径纠缠态在海洋湍流中传输时纠缠保真度较高。通过数值计算进一步定量分析了多种海洋湍流因素及传输距离对纠缠态退相干问题,得出了双量子比特路径纠缠态在均方温度耗散率较低且动能耗散率较大的海洋湍流中传输时纠缠保真度较高。研究结果对基于光子纠缠态的远距离水下量子通信具有参考意义。Based on the theory of Kolmogorov oceanic turbulence spectrum and quantum optics,the theoretical model that the spatial two-qubit photons entangled states prepared by parametric down-converted propagate through the Kolmogorov oceanic turbulence is constructed.The theoretical expressions for entanglement degradation of the spatial two-qubit photons entangled states in oceanic turbulence are obtained.Then,using the Wootters's concurrence,the influence of Kolmogorov oceanic turbulence on the spatial two-qubit photons entangled states with numerical simulation is analyzed.The results show that the parameters of the laboratory device which are prepared the spatial two-qubit entangled states will make a great impact on the entanglement.And the smaller separation of two signal(idler)apertures or the separation between the two signal and the idler apertures is,the higher fidelity of the spatial two-qubit photon entangled states is.The entanglement of spatial two-qubit states can well maintain in the salinity-induced oceanic turbulence when the rate of dissipation of mean-square temperature is small and the rate of dissipation of turbulent kinetic energy per unit mass of fluid is big with numerical calculation.These results have important significance for long distance underwater quantum communication via quantum entangled channel.

关 键 词：量子光学 海洋光学 Kolmogorov海洋湍流 双量子比特路径纠缠态 共生纠缠度 

分 类 号：O431.2[机械工程—光学工程] O436.2[理学—光学]