光子纠缠态在non-Kolmogorov大气湍流中纠缠退化的研究  

Entanglement degradation of photon entangled states in non-Kolmogorov atmospheric turbulence

作　　者：张钦伟 曹连振[1] 刘霞[1] 杨阳[1] 赵加强[1] 李英德[1] ZHANG Qinwei;CAO Lianzhen;LIU Xia;YANG Yang;ZHAO Jiaqiang;LI Yingde(Shandong Provincial Key Laboratory of Multi-Photon Entanglement and Manipulation,Department of Physics and Optoelectronic Engineering,Weifang University,Weifang 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：《量子电子学报》2021年第4期496-503,共8页Chinese Journal of Quantum Electronics

基　　金：国家自然科学基金青年基金,62005199,11404246;山东省自然科学基金,ZR2020LLZ001,ZR2020KF017,ZR2019LLZ006,2019GGX101073,ZR2018LA014。

摘　　要：基于non-Kolmogorov大气湍流谱理论,建立了双量子比特路径纠缠态在大气湍流中传输的数学模型,获得其纠缠退化的解析表达式,并进行了数值仿真。研究结果表明:当空间距离分布较小的双量子比特路径纠缠态在大气湍流中传输时,其纠缠度的保真度较高;同时,较长波长的纠缠光在折射率功率谱指数α较大、广义湍流折射率结构起伏结构函数C_(n)^(2)较大的non-Kolmogorov大气湍流中传输保真度较高。所建立的远距离纠缠态传输模型可定量分析纠缠退化问题,为自适应低误码率的远距离大气量子通信提供了可靠的理论参考。Based on the theory of non-Kolmogorov atmospheric turbulence spectrum,a mathematical model of spatial two-qubit entangled states propagation in non-Kolmogorov atmospheric turbulence is established,the corresponding mathematical expression of entanglement degradation is obtained,and the influence of non-Kolmogorov turbulence on the entanglement of spatial two-qubit states is analyzed by numerical simulation.The results show that high entanglement of the spatial two-qubit entangled states can be maintained when the physical size and separation between each signal and the corresponding idler apertures is small.Moreover,it is found that when the long wavelength entangled photons propagate through non-Kolmogorov atmospheric turbulence with larger generalized refractive-index exponent parameterαand generalized refractive-index structure parameter C_(n)^(2),the entanglement degradation is relatively weak.The proposed model can be used to quantitatively analyze the entanglement degradation,which is helpful for long distance self-adaption quantum communication with low bit error rate.

关 键 词：量子光学 大气光学 湍流效应 non-Kolmogorov大气湍流 路径纠缠 共生纠缠度 

分 类 号：O431.2[机械工程—光学工程] O439[理学—光学]