Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Log inSign up
Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Blog
Job Board
Q3AS

© 2026 Aqora Quantum S.A.S.

TermsPrivacyLegal Notice

Acta Physica Sinica

Analysis of entanglement source based on coherent feedback control

Yaoyao Zhou, Pengfei Li, Zhihui Yan, Xiaojun Jia

Published Jan 1, 2019• 1 citation
Publisher

Abstract

基于非测量的量子相干反馈控制系统不会引入额外的噪声, 可以用于稳定、操控和改善多种量子系统的性能. 利用相干反馈的方法可以操控非简并光学参量放大器, 在一定条件下能够增强其输出Einstein-Podolsky-Rosen (EPR)纠缠态光场的纠缠度. 相干反馈控制系统中的核心光学元件是控制耦合镜, 其透射率的选取直接影响反馈控制的效果. 本文针对控制耦合镜对偏振相互垂直的种子光场透射率不同的情况, 从理论上分析了该情况对相干反馈控制效果的影响, 得出相干反馈的正作用达到最佳时对控制镜透射率的要求, 理论分析与实验结果相吻合. 同时分析了相干反馈控制效果随其他物理参量的变化关系, 得出系统进一步优化的实验条件. 为今后相干反馈控制系统中物理参量的选择提供依据, 也为利用相干反馈操控更多的量子系统提供参考.

DOI
10.7498/aps.68.20191168

Related papers

Entangled Radiation through an Atomic Reservoir Controlled by Coherent Population Trapping

李茜, 钟文学, 胡响明

我们证明产生纠缠的 Einstein-Podolsky-Rosen (EPR ) 是可能的用一座原子水库的放射由协调人口套住控制了。三水平的原子的一根横梁开始在套住的在协调附近的人口(CPT ) 被准备状态和行为作为一座长寿控制连贯的水库。四波浪的混合导致与原子偶极子转变的 Rabi 边带反响的洞模式的扩大。洞模式演变为一个 EPR 状态，其纠纷的度被紧张和开车的频率控制，回答。这个计划使用长寿 CPT 连贯并且对原子横梁的自发的排放是柔韧的。同时，这个计划在一个一步舞过程，不是在在 Phys 被要求的一个二拍子的圆舞过程被实现。加快。Lett。98 (2007 ) 240401。[从作者抽象]

Chinese Physics Letters•Jan 1, 2008•0 citations

Einstein-Podolsky-Rosen steering based on coherent feedback control system in all-optical correlated noise channel

Zhou Jin-rui, Zhai Shu-Qin, Liu Kui

子导引是介于量子纠缠和贝尔非局域性之间的一种特殊的量子关联，具有天然的不对称性。这种不对称性使得量子导引作为量子信息科学的基础资源，成为实现量子安全通信网络的关键。在连续变量量子信息过程中，相干反馈控制系统可以用于增强压缩和控制量子关联，从而提升信息的安全性和操控性。在实际量子通讯过程中，量子系统不可避免地会与外界环境发生退相干现象，同时还会受到信道噪声的干扰，为使受损的量子信息实现恢复并增强，本文提出基于相干反馈控制的全光关联噪声方案，系统研究了反馈能力、噪声、损耗、产生关联噪声的四波混频增益对量子导引的影响。研究发现，在全光关联噪声信道中，引入相干反馈能够有效提升量子导引的恢复能力。全光技术规避了电光转换环节，大幅扩展了工作带宽，为抑制退相干效应、优化量子信息处理中的噪声抑制策略以及发展全光反馈架构下的量子通信技术提供了重要的理论依据。

Acta Physica Sinica•Sep 18, 2026•0 citations

Formulae for entanglement in a linear coherent feedback network of multiple nondegenerate optical parametric amplifiers: The infinite bandwidth case

Zhan Shi, Hendra I. Nurdin

This paper presents formulae for Einstein-Podolsky-Rosen (EPR) entanglement generated from N nondegenerate optical parametric amplifiers (NOPAs) interconnected in a linear coherent feedback (CFB) chain in the idealized lossless scenario and infinite bandwidth limit. The lossless scenario sets the ultimate EPR entanglement (two-mode squeezing) that can be achieved by this linear chain of NOPAs while the infinite bandwidth limit simplifies the analysis but gives an accurate approximation to the EPR entanglement at low frequencies of interest. Two adjustable phase shifts are placed at the outputs of the system to achieve the best EPR entanglement by selecting appropriate quadratures of the output fields.

arXiv:1603.03114•Proceedings of the ... American Control Conference/Proceedings of the American Control Conference•Jul 1, 2016•3 citations

Markovian-feedback-controlled entanglement and Einstein-Podolsky-Rosen steering in a nondegenerate optical parametric oscillator

Benyuan Zhou, Ni Pan, Li Yu +1 more

We propose a scheme to manipulate entanglement and the direction of asymmetric Einstein-Podolsky-Rosen (EPR) steering between two interacting bosonic modes in a nonlinear optical apparatus, in which a pumped Fabry-P\'erot cavity system containing two nonlinear waveguides is coupled to two feedback loops. It is found that Markovian feedback plays a key role in controlling both entanglement and EPR steering, the maximal entanglement can only be achieved through two symmetric feedback loops, while one-way EPR steering can only occur when both asymmetric feedback loops and an unbalanced beam-splitter are satisfied simultaneously. Furthermore, in terms of an unequal beam-splitter and two different feedback loops, it is demonstrated that the directionality and extent of the asymmetric EPR steering can be readily controlled under certain conditions. A simple and sufficient condition is also revealed for generating two-way EPR steering. Moreover, the entanglement and EPR steering can be effectively enhanced by performing Markovian feedback. In addition, By choosing appropriate feedback strengths, two cavity modes can be driven into a pure two-mode squeezed vacuum state rather than a mixed two-mode Gaussian entangled state or a pure entangled dark state. We hope the proposed scheme will enhance our understanding of the fundamental asymmetry of EPR steering, and it may have potential applications in quantum computation and quantum communication.

Physical Review A•Sep 4, 2024•7 citations

Effect of phase shifts on EPR entanglement generated on two propagating Gaussian fields via coherent feedback

Zhan Shi, Hendra I. Nurdin

Recent work has shown that deploying two non-degenerate optical parametric amplifiers (NOPAs) separately at two distant parties in a coherent feedback loop generates stronger Einstein-Podolski-Rosen (EPR) entanglement between two propagating continuous-mode output fields than a single NOPA under same pump power, decay rate and transmission losses. This paper aims to investigate the stability and EPR entanglement of a dual-NOPA coherent feedback system under the effect of phase shifts in the transmission channel between two distant parties. It is shown that, in the presence of phase shifts, EPR entanglement worsens or can vanish, but can be improved to some extent in certain scenarios by adding a phase shifter at each output with a certain value of phase shift.

arXiv:1410.3068•IEEE Conference on Decision and Control (CDC)•Dec 1, 2014•3 citations

全光三光纠缠交换（特邀）

朱琦琦 Zhu Qiqi, 刘胜帅 Liu Shengshuai, 荆杰泰 Jing Jietai

量子纠缠交换能够使两个从未发生直接相互作用的粒子产生纠缠，是实现量子中继的核心技术以及构建量子网络的关键环节。在连续变量量子体系中，传统三光纠缠交换中的Bell态测量过程涉及光电和电光转换，这限制了量子纠缠交换的带宽。因此，提出一种无需测量的全光三光纠缠交换方案。通过一个低噪声光学参量放大器来实现Bell态测量的功能，能够避免光电和电光转换过程中的带宽限制。分析结果表明，三光纠缠交换可以通过两种方案实现：其一是使用一对EPR（Einstein-Podolsky-Rosen）纠缠态作为量子通道；其二是使用两对EPR纠缠态作为量子通道。该研究提出了一种无需测量的全光宽带量子网络方案，为发展全光量子网络以及多节点间的全光量子通信提供了理论支撑。

Acta Optica Sinica•Jan 1, 2025•0 citations
基于非测量的量子相干反馈控制系统不会引入额外的噪声, 可以用于稳定、操控和改善多种量子系统的性能. 利用相干反馈的方法可以操控非简并光学参量放大器, 在一定条件下能够增强其输出Einstein-Podolsky-Rosen (EPR)纠缠态光场的纠缠度. 相干反馈控制系统中的核心光学元件是控制耦合镜, 其透射率的选取直接影响反馈控制的效果. 本文针对控制耦合镜对偏振相互垂直的种子光场透射率不同的情况, 从理论上分析了该情况对相干反馈控制效果的影响, 得出相干反馈的正作用达到最佳时对控制镜透射率的要求, 理论分析与实验结果相吻合. 同时分析了相干反馈控制效果随其他物理参量的变化关系, 得出系统进一步优化的实验条件. 为今后相干反馈控制系统中物理参量的选择提供依据, 也为利用相干反馈操控更多的量子系统提供参考.
我们证明产生纠缠的 Einstein-Podolsky-Rosen (EPR ) 是可能的用一座原子水库的放射由协调人口套住控制了。三水平的原子的一根横梁开始在套住的在协调附近的人口(CPT ) 被准备状态和行为作为一座长寿控制连贯的水库。四波浪的混合导致与原子偶极子转变的 Rabi 边带反响的洞模式的扩大。洞模式演变为一个 EPR 状态，其纠纷的度被紧张和开车的频率控制，回答。这个计划使用长寿 CPT 连贯并且对原子横梁的自发的排放是柔韧的。同时，这个计划在一个一步舞过程，不是在在 Phys 被要求的一个二拍子的圆舞过程被实现。加快。Lett。98 (2007 ) 240401。[从作者抽象]
子导引是介于量子纠缠和贝尔非局域性之间的一种特殊的量子关联，具有天然的不对称性。这种不对称性使得量子导引作为量子信息科学的基础资源，成为实现量子安全通信网络的关键。在连续变量量子信息过程中，相干反馈控制系统可以用于增强压缩和控制量子关联，从而提升信息的安全性和操控性。在实际量子通讯过程中，量子系统不可避免地会与外界环境发生退相干现象，同时还会受到信道噪声的干扰，为使受损的量子信息实现恢复并增强，本文提出基于相干反馈控制的全光关联噪声方案，系统研究了反馈能力、噪声、损耗、产生关联噪声的四波混频增益对量子导引的影响。研究发现，在全光关联噪声信道中，引入相干反馈能够有效提升量子导引的恢复能力。全光技术规避了电光转换环节，大幅扩展了工作带宽，为抑制退相干效应、优化量子信息处理中的噪声抑制策略以及发展全光反馈架构下的量子通信技术提供了重要的理论依据。
This paper presents formulae for Einstein-Podolsky-Rosen (EPR) entanglement generated from N nondegenerate optical parametric amplifiers (NOPAs) interconnected in a linear coherent feedback (CFB) chain in the idealized lossless scenario and infinite bandwidth limit. The lossless scenario sets the ultimate EPR entanglement (two-mode squeezing) that can be achieved by this linear chain of NOPAs while the infinite bandwidth limit simplifies the analysis but gives an accurate approximation to the EPR entanglement at low frequencies of interest. Two adjustable phase shifts are placed at the outputs of the system to achieve the best EPR entanglement by selecting appropriate quadratures of the output fields.
We propose a scheme to manipulate entanglement and the direction of asymmetric Einstein-Podolsky-Rosen (EPR) steering between two interacting bosonic modes in a nonlinear optical apparatus, in which a pumped Fabry-P\'erot cavity system containing two nonlinear waveguides is coupled to two feedback loops. It is found that Markovian feedback plays a key role in controlling both entanglement and EPR steering, the maximal entanglement can only be achieved through two symmetric feedback loops, while one-way EPR steering can only occur when both asymmetric feedback loops and an unbalanced beam-splitter are satisfied simultaneously. Furthermore, in terms of an unequal beam-splitter and two different feedback loops, it is demonstrated that the directionality and extent of the asymmetric EPR steering can be readily controlled under certain conditions. A simple and sufficient condition is also revealed for generating two-way EPR steering. Moreover, the entanglement and EPR steering can be effectively enhanced by performing Markovian feedback. In addition, By choosing appropriate feedback strengths, two cavity modes can be driven into a pure two-mode squeezed vacuum state rather than a mixed two-mode Gaussian entangled state or a pure entangled dark state. We hope the proposed scheme will enhance our understanding of the fundamental asymmetry of EPR steering, and it may have potential applications in quantum computation and quantum communication.
Recent work has shown that deploying two non-degenerate optical parametric amplifiers (NOPAs) separately at two distant parties in a coherent feedback loop generates stronger Einstein-Podolski-Rosen (EPR) entanglement between two propagating continuous-mode output fields than a single NOPA under same pump power, decay rate and transmission losses. This paper aims to investigate the stability and EPR entanglement of a dual-NOPA coherent feedback system under the effect of phase shifts in the transmission channel between two distant parties. It is shown that, in the presence of phase shifts, EPR entanglement worsens or can vanish, but can be improved to some extent in certain scenarios by adding a phase shifter at each output with a certain value of phase shift.
量子纠缠交换能够使两个从未发生直接相互作用的粒子产生纠缠，是实现量子中继的核心技术以及构建量子网络的关键环节。在连续变量量子体系中，传统三光纠缠交换中的Bell态测量过程涉及光电和电光转换，这限制了量子纠缠交换的带宽。因此，提出一种无需测量的全光三光纠缠交换方案。通过一个低噪声光学参量放大器来实现Bell态测量的功能，能够避免光电和电光转换过程中的带宽限制。分析结果表明，三光纠缠交换可以通过两种方案实现：其一是使用一对EPR（Einstein-Podolsky-Rosen）纠缠态作为量子通道；其二是使用两对EPR纠缠态作为量子通道。该研究提出了一种无需测量的全光宽带量子网络方案，为发展全光量子网络以及多节点间的全光量子通信提供了理论支撑。