Nawareg Mohamed, Muhammad Sadiq, Horodecki Pawel, Bourennane Mohamed
Department of Physics, Stockholm University, S-10691 Stockholm, Sweden.
Institute of Theoretical Physics and Astrophysics, University of Gdańsk, PL-80-952 Gdansk, Poland.
Sci Adv. 2017 Sep 22;3(9):e1602485. doi: 10.1126/sciadv.1602485. eCollection 2017 Sep.
Entanglement is one of the most puzzling features of quantum theory and a principal resource for quantum information processing. It is well known that in classical information theory, the addition of two classical information resources will not lead to any extra advantages. On the contrary, in quantum information, a spectacular phenomenon of the superadditivity of two quantum information resources emerges. It shows that quantum entanglement, which was completely absent in any of the two resources separately, emerges as a result of combining them together. We present the first experimental demonstration of this quantum phenomenon with two photonic three-partite nondistillable entangled states shared between three parties Alice, Bob, and Charlie, where the entanglement was completely absent between Bob and Charlie.
量子纠缠是量子理论中最令人困惑的特征之一，也是量子信息处理的主要资源。众所周知，在经典信息论中，两个经典信息资源相加不会带来任何额外优势。相反，在量子信息中，出现了两个量子信息资源超可加性的惊人现象。这表明，两个资源各自单独都完全不存在的量子纠缠，是它们组合在一起的结果。我们利用三方（爱丽丝、鲍勃和查理）共享的两个光子三部分不可蒸馏纠缠态，首次通过实验证明了这种量子现象，其中鲍勃和查理之间完全不存在纠缠。
