基于磁敏感自旋波长寿命光与原子纠缠源产生的实验研究  

Experimental Study of a Long-lived Atom-photon Entanglement Source Based on Magnetically Sensitive Spin-waves

作　　者：高雁[1,2] 李雅 刘海龙 孙灿[1,2] 侯益博 樊永胜 李淑静 王海 GAO Yan;LI Ya;LIU Hai-long;SUN Can;HHOU Yi-bo;FAN Yong-sheng;LI Shu-jing;WANG Hai(State Key Laboratory of Quantum Optics and Quantum Optics Devices,Institute of Opto-Electronics,Shanxi University,Taiyuan 030006,China;Collaborative Innovation Center of Extreme Optics,Shanxi University,Taiyuan 030006,China)

机构地区：[1]量子光学与光量子器件国家重点实验室、山西大学光电研究所,山西太原030006 [2]山西大学极端光学协同创新中心,山西太原030006

出　　处：《量子光学学报》2023年第1期63-68,共6页Journal of Quantum Optics

基　　金：国家重点基础研究发展计划(2016YFA0301402);国家自然科学基金(11974228);山西省“1331工程”重点学科建设计划(133KSC)。

摘　　要：在87Rb冷原子系综中通过自发拉曼散射过程产生原子自旋波与光子的关联,利用偏振干涉仪将与磁敏感自旋波关联的Stokes光子的两个空间模式编码为一个偏振量子比特,产生磁敏感自旋波与光子的纠缠源。采用近共线装置和精确补偿地磁场,纠缠源的寿命达到900μs,Bell参量S=2.58±0.03。Quantum repeater is important for long-distance quantum communication and scalable quantum network.The basic idea of quantum repeater scheme is to divide the long-distance transmission channel into several shorter sub-channels and extend the entanglement to the whole transmission channel through the entanglement swap between two adjacent sub-channels.Duan-Lukin-Cirac-Zoller(DLCZ)protocol is a long-distance entanglement distribution scheme that has been widely studied in recent years.The core of DLCZ protocol is the spontaneous Raman scattering process,which produces a photon and an associated spinwave excitation with a certain probability.The entanglement lifetime is one of the key parameters of a quantum entanglement interface in the experiment of atom-photon entanglement.Although storage lifetime based on magnetic field insensitive spinwave atom-photon entanglement has reached the order of milliseconds,there is no report on long-lived atom-photon entanglement source based on magnetic field-sensitive spin-wave till now.Based on the above research background,we place the 87Rb cold atomic ensemble in a polarization interferometer formed by a pair of beam displacers,which encode two spatial modes of a photon associated with magnetic field sensitive spin waves generated by spontaneous Raman scattering process into a polarization qubit,realizing a long-lived atom-photon entanglement source based on magnetic field sensitive spin-wave.The storage lifetime of a magnetic field sensitive entanglement source is mainly affected by magnetic field noise and atomic motion.The effect of atomic motion is minimized by increasing the spin-wave wavelength through decreasing the angle between the write-read light and Stokes-anti-Stokes photon detection directions.The influence of magnetic field noise is minimized by accurately compensating for environmental magnetic field by utilizing retrieval efficiency as a reference.The entanglement source lifetime reaches 900μs,the Bell parameter S=2.58±0.03,which violates the Bell inequality

关 键 词：光与原子纠缠源 磁敏感自旋波 纠缠寿命 偏振干涉仪 

分 类 号：O431[机械工程—光学工程]