Linear optical realizations of Bell state measurement (BSM) on two single-photon qubits succeed with probability $p_s$ no higher than $0.5$. However pre-detection quadrature squeezing, i.e., quantum noise limited phase sensitive amplification, in the usual linear-optical BSM circuit, can yield ${p_s \approx 0.643}$. The ability to achieve $p_s > 0.5$ has been found to be critical in resource-efficient realizations of linear optical quantum computing and all-photonic quantum repeaters. Yet, the aforesaid value of $p_s > 0.5$ is not known to be the maximum achievable using squeezing, thereby leaving it open whether close-to-$100\%$ efficient BSM might be achievable using squeezing as a resource. In this paper, we report new insights on why squeezing-enhanced BSM achieves $p_s > 0.5$. Using this, we show that the previously-reported ${p_s \approx 0.643}$ at single-mode squeezing strength $r=0.6585$---for unambiguous state discrimination (USD) of all four Bell states---is an experimentally unachievable point result, which drops to $p_s \approx 0.59$ with the slightest change in $r$. We however show that squeezing-induced boosting of $p_s$ with USD operation is still possible over a continuous range of $r$, with an experimentally achievable maximum occurring at $r=0.5774$, achieving ${p_s \approx 0.596}$. Finally, deviating from USD operation, we explore a trade-space between $p_s$, the probability with which the BSM circuit declares a "success", versus the probability of error $p_e$, the probability of an input Bell state being erroneously identified given the circuit declares a success. Since quantum error correction could correct for some $p_e > 0$, this tradeoff may enable better quantum repeater designs by potentially increasing the entanglement generation rates with $p_s$ exceeding what is possible with traditionally-studied USD operation of BSMs.
Enhancing distributed sensing with imperfect error correction
通过分布式量子传感协议，纠缠在增强传感器网络中的信息处理任务方面显示出了希望。由于噪声在传感器网络中无处不在，需要基于Gottesman，Kitaev和Preskill（GKP）状态的纠错方案来提高性能，如[New J. Phys. 22，022001（2020）]所示，假设传感器之间的均匀噪声和完美的GKP状态。在这里，我们扩展的性能增强的分析有限压缩GKP态在非均匀噪声模型。首先，我们研究了GKP双模压缩码的不同级联方案。虽然传统的顺序级联方案在以前的作品中提高了噪声的抑制，我们提出了一个平衡的级联方案，优于顺序方案存在有限的GKP压缩。然后，我们将这些结果应用于分布式量子传感中的两个特定任务-参数估计和假设检验-以了解不完美压缩和性能之间的权衡。对于前一个任务，我们考虑了一个能量受限的情况下，并提供了一个最佳的方式来分配有限压缩GKP态的能量之间的传感器。对于后者的任务，我们表明，错误概率仍然可以大大降低，通过级联现实有限压缩GKP码。
Boosting State Discrimination in Quantum Brownian Motion Channel via Memory-Induced Coherence Preservation
Federal University of Piauí（皮奥伊联邦大学）；Federal University of Paraná（巴拉那联邦大学）；Universidade Federal do ABC（ABC联邦大学）；Southern University of Science and Technology（南方科技大学）；University of Coimbra（科英布拉大学）
Residual-Squeezing Mechanism of Mismatch in Inverse-Squeezing Kennedy Receivers
Information Support Force Engineering University（信息支援部队工程大学）；Guangxi Key Laboratory of Multimedia Communications and Network Technology, Guangxi University（广西大学）；Wuhan Maritime Communication Research Institute（武汉航海通信研究所）
Near-optimal discrimination of displaced squeezed binary signals using displacement, inverse-squeezing, and photon-number-resolving detection
Information Support Force Engineering University（信息支援部队工程大学）；Guangxi Key Laboratory of Multimedia Communications and Network Technology, Guangxi University（广西大学）；Henan Key Laboratory of Quantum Information and Cryptography, SSF IEU（河南量子信息与密码学重点实验室）；Wuhan Maritime Communication Research Institute（武汉海事通信研究所）
Dicke materials as a resource for quantum squeezing
Rice University（莱斯大学）；Smalley-Curl Institute, Rice University（斯莫利-柯尔研究所，莱斯大学）；Department of Physics and Astronomy, Rice University（莱斯大学物理与天文学系）；Department of Materials Science and NanoEngineering, Rice University（莱斯大学材料科学与纳米工程系）；Max Planck Institute for the Structure and Dynamics of Matter（马克斯·普朗克物质结构动力学研究所）；Yokohama National University（横滨国立大学）；Interfaculty Graduate School of Innovative and Practical Studies, Yokohama National University（横滨国立大学跨学科创新与实践研究生院）；Department of Physics, College of Engineering Science, Yokohama National University（横滨国立大学工程科学部物理系）；Department of Physics, Graduate School of Engineering Science, Yokohama National University（横滨国立大学工学研究科物理系）；Institute for Multidisciplinary Sciences, Yokohama National University（横滨国立大学多学科科学研究院）
Dual Role of Squeezed-Reservoir in Quantum Phase Synchronization: Boosting and Blockade
School of Physics and Electronic Information, Gannan Normal University（赣南师范大学物理与电子信息学院）；School of Information Engineering, Jiangxi University of Science and Technology（江西理工大学信息工程学院）；Jiangxi Provincial Key Laboratory of Multidimensional Intelligent Perception and Control, Jiangxi University of Science and Technology（江西理工大学多维智能感知与控制江西省重点实验室）
Generation of Motional Squeezed States for Neutral Atoms in Optical Tweezers
Institute for Molecular Science, National Institutes of Natural Sciences（国立自然科学研究所分子科学研究所）；Nanomaterials and Nanotechnology Research Center (CINN-CSIC), Universidad de Oviedo (UO)（阿斯图里亚斯自治区乌维多大学纳米材料与纳米技术研究中心）；Université Paris-Saclay, Institut d’Optique Graduate School, CNRS, Laboratoire Charles Fabry（巴黎萨克雷大学）；SOKENDAI (The Graduate University for Advanced Studies)（综合研究大学院大学）；RIKEN Center for Quantum Computing (RQC), RIKEN（理化学研究所）
