标题： 所有纠缠态都可以通过非定域性不等式的违背来证实 显示英文标题

标题： All entangled states can be certified by a violation of noncontextuality inequalities

摘要： 通过将贝尔局域性假设与广义非定域性假设相结合，我们定义了在双部分贝尔情景中相关性的不同非定域性不等式类别。 这些类别是根据所强制执行的操作身份来区分的，其中某些自然子集形成一个层次结构，并提供了一种新的方式来理解和分类不同的量子相关形式。 具体而言，我们表明该层次结构中不同层次的不等式违反可以作为检测双部分量子态是否表现出纠缠、引导或非定域性的见证者，从而为认证这些不同的双部分量子资源提供了一种系统且统一的方法。 为了展示这种方法的力量，我们在偏振纠缠光子的实验中演示了其中一个不等式的违反。 这种实验实现使我们能够认证某些二维各向同性态的纠缠，而这些态通过贝尔或引导不等式进行认证是已知不可能的。 我们的纠缠认证方案是第一个结合以下所有理想特性的方案：它不需要对测量进行事先表征，它基于与层析成像规范自由度无关的量得出结论，并且能够在不使用任何辅助纠缠源的情况下认证{\em 任何}纠缠态。 显示英文摘要

摘要： By combining the assumption of Bell locality with that of generalized noncontextuality, we define different classes of noncontextuality inequalities for correlations in a bipartite Bell scenario. These classes are distinguished by which operational identities are enforced, where certain natural subsets form a hierarchy and provide a new way to understand and classify different forms of quantum correlations. Specifically, we show that violations of inequalities at different levels of this hierarchy can serve as witnesses to determine whether a bipartite quantum state exhibits entanglement, steering, or nonlocality, thereby giving a systematic and unified method for certifying these distinct bipartite quantum resources. To illustrate the power of this approach, we demonstrate the violation of one such inequality in an experiment with polarization-entangled photons. This experimental implementation enables us to certify entanglement in certain two-qubit isotropic states for which certification by Bell or steering inequalities is known to be impossible. Our entanglement certification scheme is the first to combine all of the following desirable features: it requires no prior characterization of the measurements, it delivers a verdict based on quantities that are independent of the tomographic gauge freedom, and it is able to certify {\em any} entangled state without requiring any auxiliary entangled sources.