Generating entanglement with linear optics
Generating entanglement with linear optics
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DOI：
10.1103/physreva.96.043861
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发表时间：
2016-09
影响因子：
2.9
通讯作者：
Stasja Stanisic;N. Linden;A. Montanaro;P. Turner
中科院分区：
文献类型：
--
作者：
Stasja Stanisic;N. Linden;A. Montanaro;P. Turner
纠缠是线性光学量子计算的基本构建模块，因此了解如何详细生成纠缠对于光学架构非常重要。我们证明了在双轨编码中仅使用三个光子不能生成贝尔态，并为现有四个光子方案的最优性提供了强有力的数值证据。在每种输入模式下都有一个光子的设置中，我们发现单模式 Alice 和任意 Bob 之间可能发生纠缠的基本限制。我们研究并比较了其他设置，旨在表征比双轨编码更通用的设置中的纠缠。结果引起了人们对状态纠缠与后选择该状态的概率之间的权衡的关注，即使光子数量不断增加，这也可以给出令人惊讶的恒定纠缠界限。
Entanglement is the basic building block of linear optical quantum computation, and as such understanding how to generate it in detail is of great importance for optical architectures. We prove that Bell states cannot be generated using only three photons in the dual-rail encoding, and give strong numerical evidence for the optimality of the existing four photon schemes. In a setup with a single photon in each input mode, we find a fundamental limit on the possible entanglement between a single mode Alice and arbitrary Bob. We investigate and compare other setups aimed at characterizing entanglement in settings more general than dual-rail encoding. The results draw attention to the trade-off between the entanglement a state has and the probability of postselecting that state, which can give surprising constant bounds on entanglement even with increasing numbers of photons.