Entanglement without hidden nonlocality
Entanglement without hidden nonlocality
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DOI：
10.1088/1367-2630/18/11/113019
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发表时间：
2016-06
影响因子：
3.3
通讯作者：
Flavien Hirsch;Marco T'ulio Quintino;Joseph Bowles;T. V'ertesi;N. Brunner
中科院分区：
文献类型：
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作者：
Flavien Hirsch;Marco T'ulio Quintino;Joseph Bowles;T. V'ertesi;N. Brunner
我们考虑贝尔检验，其中在检验贝尔不等式之前，远程观察者可以执行局部滤波。值得注意的是，在这种设置中，某些纠缠态在标准贝尔场景中承认局部隐藏变量模型，但在过滤后仍然违反贝尔不等式，显示所谓的隐藏非局部性。在这里，我们问是否所有的纠缠态在经过精心选择的局部滤波后都能违反贝尔不等式。我们以否定的方式回答了这个问题，证明存在没有隐藏非定域性的纠缠态。具体来说，我们证明了一些双量子位Werner状态在对状态的单个副本进行任何可能的局部滤波后仍然承认一个局部隐变量模型。
We consider Bell tests in which the distant observers can perform local filtering before testing a Bell inequality. Notably, in this setup, certain entangled states admitting a local hidden variable model in the standard Bell scenario can nevertheless violate a Bell inequality after filtering, displaying so-called hidden nonlocality. Here we ask whether all entangled states can violate a Bell inequality after well-chosen local filtering. We answer this question in the negative by showing that there exist entangled states without hidden nonlocality. Specifically, we prove that some two-qubit Werner states still admit a local hidden variable model after any possible local filtering on a single copy of the state.