论文标题
时间步长之间的信号传导不允许超出隐藏非局部性的非局部性
Signaling between time steps does not allow for nonlocality beyond hidden nonlocality
论文作者
论文摘要
隐藏的非局部性是纠缠状态可以在标准钟场景中局部的现象，但在局部过滤后显示非局部性。但是，存在纠缠状态，即使在局部过滤后，也可以通过局部隐藏变量模型来描述所有测量统计信息。在这项工作中，我们考虑了这样一种情况：爱丽丝的测量结果和设置可以影响随后的时间步骤（反之亦然），但是，它们之间没有信号在同一时间步骤中进行测量。我们表明，在这种情况下，即使在考虑任意序列的完整统计数据时，仅在局部过滤后显示本地统计信息，因此在这种情况下执行更长的序列可以获得任何优势。我们首先确定在同一时间步骤和箭头限制内的无信号条件定义的多层频率的极端点。基于这些结果，我们介绍了局部性的概念，并根据最简单的情况在不平等方面提供了相应的局部多层人士的完整表示。这些结果表明，在这里考虑的情况下，除了隐藏的非销售之外，没有非局部性。我们进一步提出了一个依赖设备的Schmidt数字见证，并将我们的发现与顺序场景中的已知本地模型进行了比较。
Hidden nonlocality is the phenomenon that entangled states can be local in the standard Bell scenario but display nonlocality after local filtering. However, there exist entangled states for which all measurement statistics can be described via a local hidden variable model even after local filtering. In this work we consider the scenario that measurement outcomes and settings of Alice can influence measurements of Bob in subsequent time steps (and vice versa), however, there is no signaling among them for measurements at the same time step. We show that in this scenario states that only display local statistics after local filtering remain local even when considering the complete statistics of arbitrary sequences and therefore no advantage can be gained by performing longer sequences in this scenario. We first determine the extreme points of the polytope defined by the no-signaling conditions within the same time step and the arrow-of-time constraints. Based on these results we introduce a notion of locality and provide a complete representation of the corresponding local polytope in terms of inequalities in the simplest scenario. These results imply that in the scenario considered here there is no nonlocality beyond hidden nonlocality. We further propose a device-dependent Schmidt number witness and we compare our finding to known local models in the sequential scenario.
