Yang Xihua, Zhou Yuanyuan, Xiao Min
Department of Physics, Shanghai University, Shanghai 200444, China.
Sci Rep. 2013 Dec 11;3:3479. doi: 10.1038/srep03479.
Quantum entanglement plays an essential role in quantum information processing and quantum networks. One of the commonly-used methods to generate multiple entangled fields is to employ polarizing beam splitters. However, nonclassical input light fields are required and the generated entangled fields are always degenerate in such case. Here, we present a proof-of-principle demonstration of an efficient and convenient way to entangle multiple light fields via electromagnetically induced transparency (EIT) in an atomic ensemble. The atomic spin wave, produced through EIT in the Λ-type atomic system, can be described by a Bose operator and can act as an entangler. With such an entangler, any desired number of nondegenerate narrow-band continuous-variable entangled fields, in principle, can be generated through stimulated Raman scattering processes. This scheme holds great promise for applications in scalable quantum communication and quantum networks. PACS: 42.50.Gy, 03.67.Bg, 42.50.Dv, 42.65.Lm.
量子纠缠在量子信息处理和量子网络中起着至关重要的作用。产生多个纠缠场的常用方法之一是使用偏振分束器。然而，在这种情况下需要非经典输入光场，并且所产生的纠缠场总是简并的。在此，我们展示了一种通过原子系综中的电磁诱导透明（EIT）来纠缠多个光场的高效便捷方法的原理验证演示。在Λ型原子系统中通过EIT产生的原子自旋波，可以用玻色算符来描述，并可作为一个纠缠器。利用这样一个纠缠器，原则上可以通过受激拉曼散射过程产生任意数量的非简并窄带连续变量纠缠场。该方案在可扩展量子通信和量子网络应用方面具有巨大潜力。物理评论快报分类号：42.50.Gy，03.67.Bg，42.50.Dv，42.65.Lm。
