Measuring entanglement entropy in a quantum many-body system
Measuring entanglement entropy in a quantum many-body system
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DOI：
10.1038/nature15750
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发表时间：
2015-12-03
期刊：
影响因子：
64.8
通讯作者：
Greiner, Markus
中科院分区：
文献类型：
--
作者：
Islam, Rajibul;Ma, Ruichao;Greiner, Markus
纠缠是量子力学最耐人寻味的特征之一。它描述了量子对象之间的非局域关联，是量子信息科学的核心。从凝聚态到量子引力，人们正在不同的领域对纠缠进行研究。然而，测量纠缠仍然是一个挑战。这在相互作用的离域粒子系统中尤其如此，对于这些系统，空间纠缠的直接实验测量一直难以捉摸。在这里，我们使用多体孪生的量子干涉来测量这样一个巡回粒子系统中的纠缠。利用我们对光学晶格中超冷玻色子原子的单点分辨控制，我们制备了两个完全相同的多体态副本，并对它们进行了干涉。这使我们能够直接测量量子纯度、Renyi纠缠熵和互信息。这些实验为利用纠缠来表征强关联多体系统的量子相和动力学特性铺平了道路。
Entanglement is one of the most intriguing features of quantum mechanics. It describes non-local correlations between quantum objects, and is at the heart of quantum information sciences. Entanglement is now being studied in diverse fields ranging from condensed matter to quantum gravity. However, measuring entanglement remains a challenge. This is especially so in systems of interacting delocalized particles, for which a direct experimental measurement of spatial entanglement has been elusive. Here, we measure entanglement in such a system of itinerant particles using quantum interference of many-body twins. Making use of our single-site-resolved control of ultracold bosonic atoms in optical lattices, we prepare two identical copies of a many-body state and interfere them. This enables us to directly measure quantum purity, Renyi entanglement entropy, and mutual information. These experiments pave the way for using entanglement to characterize quantum phases and dynamics of strongly correlated many-body systems.