虽然近年来对多体非定域性的兴趣有所增长，但它在大型量子系统中的存在很难通过实验证实。这主要是由于标准的多体贝尔不等式不适用于多体系统：这种不等式通常依赖于涉及多方的期望值，需要对每一方进行单独处理。在最近的工作[J.Tura et al.Science 344，6189（2014）]中，我们中的一些人提出了克服这些困难的更简单的贝尔不等式，为通过贝尔相关证人[R. Schmied et al. Science 352，441（2016）]，因此证明了Bell相关性与统计假设的存在。在这里，我们解决的问题，评估的粒子数量共享真正的非局部相关的多体系统。这种努力是先验的挑战，因为已知的真正非局域性的贝尔不等式具有上述缺点，加上许多测量设置随系统大小呈指数级缩放。我们首先表明，这些限制下降，一旦证人对应于这些不平等表示：在系统中，多方的期望值可以评估，这些证人可以揭示真正的非定域性的任意数量的粒子只有两个集体测量。然后，我们介绍了一个一般的框架，专注于两体钟状不等式。我们表明，他们也提供了信息的粒子的数量是真正的非本地。然后，我们描述了所有这样的不等式有限的系统大小。我们提供贝尔相关深度$k\leq6$的证人为任何数量的缔约方，在实验范围内。深度$6$的违规实现与现有的数据从480个原子的系综。
英文摘要：
While the interest in multipartite nonlocality has grown in recent years, its existence in large quantum systems is difficult to confirm experimentally. This is mostly due to the inadequacy of standard multipartite Bell inequalities to many-body systems: such inequalities usually rely on expectation values involving many parties and require an individual addressing of each party. In a recent work [J. Tura et al. Science 344, 6189 (2014)] some of us proposed simpler Bell inequalities overcoming such difficulties, opening the way for the detection of Bell correlations with trusted collective measurements through Bell correlation witnesses [R. Schmied et al. Science 352, 441 (2016)], hence demonstrating the presence of Bell correlations with assumptions on the statistics. Here, we address the question of assessing the number of particles sharing genuinely nonlocal correlations in a multipartite system. This endeavour is a priori challenging, as known Bell inequalities for genuine nonlocality suffer from the above shortcomings, plus a number of measurement settings scaling exponentially with the system size. We first show that most of these constraints drop once the witnesses corresponding to these inequalities are expressed: in systems where multipartite expectation values can be evaluated, these witnesses can reveal genuine nonlocality for an arbitrary number of particles with just two collective measurements. We then introduce a general framework focused on two-body Bell-like inequalities. We show that they also provide information about the number of particles that are genuinely nonlocal. Then, we characterize all such inequalities for a finite system size. We provide witnesses of Bell correlation depth $k\leq6$ for any number of parties, within experimental reach. A violation for depth $6$ is achieved with existing data from an ensemble of 480 atoms.
Generation and read-out of many-body Bell correlations with a probe qubit
Qilimanjaro Quantum Tech（奇力马扎罗量子技术）；ICFO-Institut de Ciencies Fotoniques, The Barcelona Institute of Science and Technology（ICFO-光子科学研究所，巴塞罗那科学技术研究院）；Faculty of Physics, University of Warsaw（华沙大学物理学院）
Experimental certification of multipartite Bell correlations using only few-body symmetric correlations
East China Normal University（华东师范大学）；National University of Singapore（新加坡国立大学）；Universiteit Leiden（莱顿大学）；Sun Yat-sen University（中山大学）；Quantum Science Center of Guangdong–Hong Kong–Macao Greater Bay Area (Guangdong)（粤港澳大湾区量子科学中心（广东））
Observing Bell Inequality Violation Beyond the Qubit Bound in a Spinor Bose--Einstein Condensate
Tsinghua University（清华大学）；Jagiellonian University（雅盖隆大学）；Beijing Academy of Quantum Information Sciences（北京量子信息科学研究院）；Nanjing University（南京大学）；ETH Zürich（苏黎世联邦理工学院）；Frontier Science Center for Quantum Information（量子信息前沿科学中心）；Hefei National Laboratory（合肥国家实验室）
Probing many-body Bell correlation depth with superconducting qubits
School of Physics, Zhejiang University（浙江大学物理学院）；Center for Quantum Information, IIIS, Tsinghua University（清华大学信息科学技术研究院量子信息中心）；Instituut-Lorentz, Universiteit Leiden（莱顿大学洛伦兹研究所）；ZJU-Hangzhou Global Scientific and Technological Innovation Center（浙江大学杭州国际科技创新中心）；Hefei National Laboratory（合肥国家实验室）；Shanghai Qi Zhi Institute（上海量子科学研究中心）
QPU-scale randomized benchmarking via Bell-pair injection
Moth, Switzerland（Moth）；Center for Quantum Computing and Quantum Coherence (QC2), University of Basel, Switzerland（巴塞尔大学量子计算与量子相干中心（QC2））；Moth, United Kingdom（Moth）；ICCMR, University of Plymouth, United Kingdom（普利茅斯大学ICCMR）
Three-outcome multipartite Bell inequalities: applications to dimension witnessing and spin-nematic squeezing in many-body systems
ICFO-Institut de Ciencies Fotoniques, The Barcelona Institute of Science and Technology（ICFO-光子科学研究所，巴塞罗那科学技术研究所）；Institute for Quantum Optics and Quantum Information, Austrian Academy of Sciences（奥地利科学院量子光学与量子信息研究所）；Vienna Center for Quantum Science and Technology (VCQ), Faculty of Physics, University of Vienna（维也纳大学物理学院量子科学与技术维也纳中心）；ICREA（加泰罗尼亚高级研究局）；Department of Physics, ETH Zürich（苏黎世联邦理工学院物理系）；Instituut-Lorentz, Universiteit Leiden（莱顿大学洛伦兹研究所）
Generalized Mermin Inequalities for Benchmarking Large-Scale GHZ States
Hefei National Research Center for Physical Sciences at the Microscale and School of Physical Sciences, University of Science and Technology of China（中国科学技术大学物理科学学院和微观尺度物理国家研究中心）；Shanghai Research Center for Quantum Science and CAS Center for Excellence in Quantum Information and Quantum Physics, University of Science and Technology of China（中国科学技术大学上海量子科学研究中心和中科院量子信息与量子物理学前沿卓越中心）；Hefei National Laboratory, University of Science and Technology of China（中国科学技术大学合肥国家实验室）；Center on Frontiers of Computing Studies, Peking University（北京大学前沿计算研究中心）；School of Computer Science, Peking University（北京大学计算机学院）；Naturwissenschaftlich-Technische Fakultät, Universität Siegen（锡根大学自然科学技术学院）
Optical depth dictates universal bounds on many-body decay in atomic ensembles
Instituto de Física Fundamental - Consejo Superior de Investigaciones Científica (CSIC)（基础物理研究所 - 西班牙国家研究委员会）；Department of Physics, Columbia University（哥伦比亚大学物理系）；Institute for Quantum Information and Matter, California Institute of Technology（加州理工学院量子信息与物质研究所）；Department of Physics, Harvard University（哈佛大学物理系）；Physikalisches Institut, University of Bonn（波恩大学物理研究所）
Bell's theorem: A bridge between the measurement and the mind/body problems
本文进一步发展了量子力学的量子二元论、透视和共时性解释，其中被感知的经典的来自退相干的世界（退相干）和被感知的经典的意识中的世界（坍缩）不一定是同一的。因此，量子实在或“{ \it unus mundus}”被视为i）一个物理的非透视因果实在，其中量子到经典的转变是由退相干操作的，以及ii）所有经典的心理物理透视实在的量子线性叠加，由同步性以及因果关系（对应于实际填充世界的经典第一人称观察者）支配。这种解释被称为尼采-荣格-泡利解释，是对维格纳-冯·诺依曼解释的重新想象，这也与玻尔的量子哲学的一些解读相一致。
