Nonlocality captures one of the counterintuitive features of nature that defies classical intuition. Recent investigations reveal that our physical world’s nonlocality is at least tripartite; i.e., genuinely tripartite nonlocal correlations in nature cannot be reproduced by any causal theory involving bipartite nonclassical resources and unlimited shared randomness. Here, by allowing the fair sampling assumption and postselection, we experimentally demonstrate such genuine tripartite nonlocality in a network under strict locality constraints that are ensured by spacelike separating all relevant events and employing fast quantum random number generators and high-speed polarization measurements. In particular, for a photonic quantum triangular network we observe a locality-loophole-free violation of the Bell-type inequality by 7.57 standard deviations for a postselected tripartite Greenberger-Horne-Zeilinger state of fidelity $(93.13\pm 0.24)\%$, which convincingly disproves the possibility of simulating genuine tripartite nonlocality by bipartite nonlocal resources with globally shared randomness.

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严格局域性条件下真正三方非局域性的实验论证

非定域性捕捉到了违背经典直觉的自然反直觉特征之一。最近的调查表明，我们物理世界的非局域性至少是三方的；即，任何涉及二分非经典资源和无限共享随机性的因果理论都无法再现自然界中真正的三方非局部相关性。在这里，通过允许公平采样假设和后选择，我们在严格的局部性约束下通过实验证明了网络中这种真正的三方非局部性，这些约束是通过空间分离所有相关事件并采用快速量子随机数发生器和高速极化测量来确保的。特别是，对于光子量子三角网络，我们观察到贝尔型不等式的局部性无漏洞违反 7。$(93.13\pm 0.24)\%$，这令人信服地反驳了通过具有全球共享随机性的二分非本地资源来模拟真正三方非本地性的可能性。