Liang Yeong-Cherng, Zhang Yanbao
Department of Physics and Center for Quantum Frontiers of Research & Technology (QFort), National Cheng Kung University, Tainan 701, Taiwan.
NTT Basic Research Laboratories and NTT Research Center for Theoretical Quantum Physics, NTT Corporation, 3-1 Morinosato-Wakamiya, Atsugi, Kanagawa 243-0198, Japan.
Entropy (Basel). 2019 Feb 15;21(2):185. doi: 10.3390/e21020185.
The device-independent approach to physics is one where conclusions about physical systems (and hence of Nature) are drawn directly and solely from the observed correlations between measurement outcomes. This operational approach to physics arose as a byproduct of Bell's seminal work to distinguish, via a Bell test, quantum correlations from the set of correlations allowed by local-hidden-variable theories. In practice, since one can only perform a finite number of experimental trials, deciding whether an empirical observation is compatible with some class of physical theories will have to be carried out via the task of hypothesis testing. In this paper, we show that the prediction-based-ratio method-initially developed for performing a hypothesis test of local-hidden-variable theories-can equally well be applied to test many other classes of physical theories, such as those constrained only by the nonsignaling principle, and those that are constrained to produce any of the outer approximation to the quantum set of correlations due to Navascués-Pironio-Acín. We numerically simulate Bell tests using hypothetical nonlocal sources of correlations to illustrate the applicability of the method in both the independent and identically distributed (i.i.d.) scenario and the non-i.i.d. scenario. As a further application, we demonstrate how this method allows us to unveil an apparent violation of the nonsignaling conditions in certain experimental data collected in a Bell test. This, in turn, highlights the importance of the randomization of measurement settings, as well as a consistency check of the nonsignaling conditions in a Bell test.
物理学的与设备无关的方法是一种直接且仅从测量结果之间观察到的相关性得出关于物理系统(进而关于自然)结论的方法。这种物理学的操作方法是作为贝尔开创性工作的副产品出现的,该工作通过贝尔测试将量子相关性与局部隐变量理论所允许的相关性集合区分开来。在实践中,由于只能进行有限次数的实验试验,因此必须通过假设检验任务来确定经验观察是否与某类物理理论兼容。在本文中,我们表明最初为执行局部隐变量理论的假设检验而开发的基于预测比率的方法同样可以很好地应用于检验许多其他类别的物理理论,例如那些仅受无信号原理约束的理论,以及那些由于纳瓦斯克斯 - 皮罗尼奥 - 阿辛而被约束产生量子相关性集合的任何外部近似的理论。我们使用假设的非局部相关性源对贝尔测试进行数值模拟,以说明该方法在独立同分布(i.i.d.)场景和非 i.i.d. 场景中的适用性。作为进一步的应用,我们展示了这种方法如何使我们揭示在贝尔测试中收集的某些实验数据中明显违反无信号条件的情况。这反过来又突出了测量设置随机化的重要性,以及贝尔测试中无信号条件的一致性检查的重要性。