【文章介绍】构建光与原子存储器的宽带空间轨道角动量模式接口

　　携带轨道角动量的涡旋光场与原子之间复杂的相互作用一直以来是量子光学和量子信息领域之间最有趣的现象之一。为了建立一个通用的高维量子通信网络，需要制备高维空间模式光场以及解决量子接口之间空间带宽不匹配的问题。这里我们介绍了一种光与原子存储器间的宽带空间模式接口。我们通过利用携带轨道角动量的两束泵浦光场分别对原子进行读写操作，使得光与存储器之间的空间轨道角动量模式分布有一个明显的展宽。利用这种空间模式展宽，我们实现了高维轨道角动量纠缠以及验证了高量子数轨道角动量纠缠。因此，我们这种能够操控轨道角动量模式分布的技术对于建立高维量子通信网络是有重要意义。

图一实验装置图

图二空间模式拓展分布以及高维轨道角动量纠缠验证

本文已被CommunicationsPhysics 在线发表，博士生董明新和丁冬生教授为文章共同第一作者。

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Abstract

The complex interactions between orbital angular momentum(OAM) of light and atoms are particularly intriguing in the areas of quantumoptics and quantum information. Building a versatile high-dimensional quantumnetwork needs broad spiral-bandwidth for preparing higher-quanta OAM mode andresolving the bandwidth mismatch in spatial space. Here, we demonstrate a broadspiral-bandwidth quantum-interface between photon and memory. Through twisted fields of the writing and reading, the correlated OAMdistribution between photon and memory is significantlybroadened. This broad spiral-bandwidth quantum-interface could be spanned inmultiplexing regime and could work in high-quanta scenario with capability of |l|=30, and we demonstrate the entanglementwithin 2-D subspace with a fidelity of 80.5 ± 4.8% for high l. Suchstate-of-the-art technology to freely control the spatial distribution of OAMmemory is very helpful to construct high-dimensional quantum networks andprovides a benchmark in the field of actively developing methods toengineer OAM single photon from matters.

URL： https://www.nature.com/articles/s42005-019-0201-1