Highly Retrievable Spin-Wave–Photon Entanglement Source

作者：Sheng-Jun Yang, Xu-Jie Wang, Jun Li, Jun Rui, Xiao‐Hui Bao, Jian-Wei Pan · 发表于：Physical Review Letters · 年份：2015 · DOI：10.1103/physrevlett.114.210501 · 被引用次数：49 · 研究领域：Quantum Information and Cryptography、Quantum optics and atomic interactions、Atomic and Subatomic Physics Research

Entanglement between a single photon and a quantum memory forms the building blocks for a quantum repeater and quantum network. Previous entanglement sources are typically with low retrieval efficiency, which limits future larger-scale applications. Here, we report a source of highly retrievable spin-wave-photon entanglement. Polarization entanglement is created through interaction of a single photon with an ensemble of atoms inside a low-finesse ring cavity. The cavity is engineered to be resonant for dual spin-wave modes, which thus enables efficient retrieval of the spin-wave qubit. An intrinsic retrieval efficiency up to 76(4)% has been observed. Such a highly retrievable atom-photon entanglement source will be very useful in future larger-scale quantum repeater and quantum network applications.