A cold atomic ensemble suits well for optical quantum memories, and its entanglement with a single photon forms the building block for quantum networks that give promise for many revolutionary applications. Efficiency and lifetime are among the most important figures of merit for a memory. In this paper, we report the realization of entanglement between an atomic ensemble and a single-photon with subsecond lifetime and high efficiency. We engineer dual control modes in a ring cavity to create entanglement and make use of 3-dimensional optical lattice to prolong memory lifetime. The memory efficiency is 38% for 0.1 second storage. We verify the atom-photon entanglement after 1 second storage by testing the Bell inequality with a result of S=2.36±0.14.
@article{arxiv.2101.01988,
title = {Cavity-Enhanced Atom-Photon Entanglement with Subsecond Lifetime},
author = {Xu-Jie Wang and Sheng-Jun Yang and Peng-Fei Sun and Bo Jing and Jun Li and Ming-Ti Zhou and Xiao-Hui Bao and Jian-Wei Pan},
journal= {arXiv preprint arXiv:2101.01988},
year = {2021}
}