Plávala Martin, Gühne Otfried
Naturwissenschaftlich-Technische Fakultät, Universität Siegen, 57068 Siegen, Germany.
Phys Rev Lett. 2024 Mar 8;132(10):100201. doi: 10.1103/PhysRevLett.132.100201.
Quantum theory features several phenomena which can be considered as resources for information processing tasks. Some of these effects, such as entanglement, arise in a nonlocal scenario, where a quantum state is distributed between different parties. Other phenomena, such as contextuality, can be observed if quantum states are prepared and then subjected to sequences of measurements. We use robust remote state preparation to connect the nonlocal and sequential scenarios and provide an intimate connection between different resources: We prove that entanglement in a nonlocal scenario can arise only if there is preparation and measurement contextuality in the corresponding sequential scenario and that the absence of entanglement implies the absence of contextuality. As a direct consequence, our result allows us to translate any inequality for testing preparation and measurement contextuality into an entanglement test; in addition, entanglement witnesses can be used to design novel contextuality inequalities.
量子理论具有若干可被视为信息处理任务资源的现象。其中一些效应，比如纠缠，出现在非局域情形中，即量子态在不同方之间分布。其他现象，比如背景相关性，如果制备量子态然后对其进行一系列测量就可以观察到。我们使用稳健的远程态制备来连接非局域和序列情形，并提供不同资源之间的紧密联系：我们证明，仅当在相应的序列情形中存在制备和测量背景相关性时，非局域情形中的纠缠才会出现，并且不存在纠缠意味着不存在背景相关性。直接的结果是，我们的结果使我们能够将任何用于检验制备和测量背景相关性的不等式转化为一个纠缠检验；此外，纠缠见证可用于设计新的背景相关性不等式。
