利用自发拉曼散射建立三个原子节点的纠缠  

Establishing of quantum entanglement among three atomic nodes via spontanenous Raman scattering

作　　者：刘艳红 周瑶瑶 闫智辉[3,4] 贾晓军 Liu Yan-Hong;Zhou Yao-Yao;Yan Zhi-Hui;Jia Xiao-Jun(Department of Physics,Taiyuan Normal University,Jinzhong 030619,China;Institute of Computational and Applied Physics,Taiyuan Normal University,Jinzhong 030619,China;Institute of Opto-Electronics,State Key Laboratory of Quantum Optics and Quantum Optics Devices,Shanxi University,Taiyuan 030006,China;Collaborative Innovation Center of Extreme Optics,Shanxi University,Taiyuan 030006,China)

机构地区：[1]太原师范学院物理系,晋中030619 [2]太原师范学院,计算物理与应用物理研究所,晋中030619 [3]山西大学光电研究所,量子光学与光量子器件国家重点实验室,太原030006 [4]山西大学,极端光学协同创新中心,太原030006

出　　处：《物理学报》2021年第9期264-271,共8页Acta Physica Sinica

基　　金：国家重点研发计划(批准号:2016YFA0301402);国家自然科学基金(批准号:61775127,61925503,11904218,11804246,12004276);山西省高等学校科技创新项目(批准号:2020L0516);山西青年三晋学者项目;山西省高等学校创新人才支持计划;山西省“1331工程”重点学科建设计划;山西省自然科学基金(批准号:201901D111293)资助的课题。

摘　　要：量子纠缠是一种关键的量子资源.随着量子信息技术的发展,由量子通道和量子节点组成的量子网络成为研究的热点.量子信息网络的建立需要在多个远距离的量子节点间建立纠缠,它在分步式量子计算及量子因特网等方面有很重要的应用价值.本文在光和原子混合纠缠的基础上,提出了结合前馈网络建立三个独立的远程原子系综之间的连续变量确定性纠缠.三个原子系综分别放置在三个远程的节点中,每个节点首先通过自发拉曼散射过程制备光和原子的混合纠缠;然后,利用平衡零拍探测器测量三束Stokes光场干涉后的量子噪声,并将测量的结果前馈到原子系综,在三个独立的远距离的原子系综间建立纠缠;最后,利用来自三个原子系综的三束反斯托克斯光束的关联方差通过三组份不可分判据验证三个原子系综的纠缠.该方案简单可行,可以拓展到基于不同物理系统的量子节点,甚至实现更多原子节点的纠缠,从而实现大规模量子信息网络.Quantum entanglement is an essential quantum resource.With the development of quantum information science,quantum network consisting of quantum nodes and quantum channels has attracted extensive attention.The development of quantum information network requires the capability of generating,storing and distributing quantum entanglement among multiple quantum nodes.It is significant to construct the quantum information,and it has very important applications in the distributed quantum computation and quantum internet.Here we propose a simple and feasible scheme to deterministically entangle three distant atomic ensembles via the interference and feedforward network of the light-atom mixed entanglement.Firstly,three atomic ensembles placed at three remote nodes in a quantum network are prepared into the mixed entangled state of light and atomic ensembles via the spontaneous Raman scattering(SRS)process.Then,the first and second Stokes optical field are interfered on an R1∶T1 optical beam splitter(BS1),and one of the output optical fields from the first optical beam splitter is interfered with the third Stokes field on the second R2∶T2 optical beam splitter(BS2).The quantum fluctuations of the amplitude and phase quadratures of these three output optical fields from BS1 and BS2 are detected by three sets of balanced homodyne detectors,respectively.Finally,the detected signals of the amplitude and phase quadratures are fed to the three atomic ensembles via the radio frequency coils to establish the entanglement among three remote atomic ensembles.At the usercontrolled time,three read optical pulses can be applied to these three atomic ensembles to convert the stored entangled state from the atomic spin waves into the anti-Stokes optical fields via the SRS process.According to the tripartite inseparability criterion,the correlation variance combinations of these three anti-Stokes optical fields can be used to verify the performance of entanglement of three atomic ensembles.This scheme can be extended to larger-scale

关 键 词：自发拉曼散射 前馈网络 三组份不可分判据 

分 类 号：O431.2[机械工程—光学工程]