Universality of Schmidt decomposition and particle identity.
Universality of Schmidt decomposition and particle identity.
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DOI：
10.1038/srep44675
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发表时间：
2017-03-23
影响因子：
4.6
通讯作者：
Compagno G
中科院分区：
文献类型：
--
作者：
Sciara S;Lo Franco R;Compagno G
施密特分解是量子理论中广泛使用的一种工具，它在纠缠表征、测量理论和态净化等场景中对区分粒子起着关键作用。然而，它对完全相同的粒子的公式仍然存在争议，危及它在分析一般多体量子系统中的应用。在这里，我们用一种新开发的方法证明了一种普适的施密特分解，它允许忠实地量化由于粒子身份而产生的物理纠缠。我们发现它受到单粒子测量局域化和态重叠的影响。我们研究典型的两粒子系统，其中相同的量子比特和量子比特位于相同的位置或分开的位置。对于两个量子在同一位置的情况，我们证明了它们的纠缠行为不同于以前用不同方法得到的纠缠行为，并给出了物理解释。我们的结果可推广到多粒子系统，并为进一步发展利用粒子身份作为资源的量子信息处理开辟了道路。
Schmidt decomposition is a widely employed tool of quantum theory which plays a key role for distinguishable particles in scenarios such as entanglement characterization, theory of measurement and state purification. Yet, its formulation for identical particles remains controversial, jeopardizing its application to analyze general many-body quantum systems. Here we prove, using a newly developed approach, a universal Schmidt decomposition which allows faithful quantification of the physical entanglement due to the identity of particles. We find that it is affected by single-particle measurement localization and state overlap. We study paradigmatic two-particle systems where identical qubits and qutrits are located in the same place or in separated places. For the case of two qutrits in the same place, we show that their entanglement behavior, whose physical interpretation is given, differs from that obtained before by different methods. Our results are generalizable to multiparticle systems and open the way for further developments in quantum information processing exploiting particle identity as a resource.