Pseudo standard entanglement structure cannot be distinguished from standard entanglement structure
Pseudo standard entanglement structure cannot be distinguished from standard entanglement structure
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DOI：
10.1088/1367-2630/acb565
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发表时间：
2022-03
影响因子：
3.3
通讯作者：
Hayato Arai;Masahito Hayashi
中科院分区：
文献类型：
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作者：
Hayato Arai;Masahito Hayashi
对最大纠缠态的实验验证保证了所构造的态与最大纠缠态接近，但并不保证所构造的态与最大纠缠态完全相同。此外，纠缠结构不是唯一确定的一般概率理论，即使我们强加的本地子系统是完全等同于量子系统。因此，最大纠缠态的存在依赖于标准纠缠结构（SES）是否成立。为了研究这个问题，我们引入伪SES作为量子复合系统的结构，在自然的假设下，基于投影测量的存在性和所有最大纠缠标准态的近似的存在性。令人惊讶的是，存在无限多的伪SES不同于SES。在我们的设定中，任何最大纠缠态都可以任意地近似为属于我们得到的伪标准纠缠结构的纠缠态。也就是说，实验验证并不排除我们获得的伪标准纠缠结构不同于标准纠缠结构的可能性。另一方面，这种伪结构不具有整体么正对称性，即整体么正对称性是SES的必要条件。
An experimental verification of the maximally entangled state ensures that the constructed state is close to the maximally entangled state, but it does not guarantee that the state is exactly the same as the maximally entangled state. Further, the entanglement structure is not uniquely determined in general probabilistic theories even if we impose that the local subsystems are fully equal to quantum systems. Therefore, the existence of the maximally entangled state depends on whether the standard entanglement structure (SES) is valid. To examine this issue, we introduce pseudo SES as a structure of quantum composite system under natural assumptions based on the existence of projective measurements and the existence of approximations of all maximally entangled standard states. Surprisingly, there exist infinitely many pseudo SESs different from the SES. In our setting, any maximally entangled state can be arbitrarily approximated by an entangled state that belongs to our obtained pseudo standard entanglement structure. That is, experimental verification does not exclude the possibility of our obtained pseudo standard entanglement structure that is different from the standard entanglement structure. On the other hand, such pseudo structures never possess global unitary symmetry, i.e. global unitary symmetry is essential condition for the SES.