Laboratory of Quantum Engineering and Quantum Materials, School of Physics and Telecommunication Engineering, South China Normal University, Guangzhou 510006, China.
Department of Physics, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, China.
Phys Rev Lett. 2014 Jun 20;112(24):243602. doi: 10.1103/PhysRevLett.112.243602.
We demonstrate an efficient experimental scheme for producing polarization-entangled photon pairs from spontaneous four-wave mixing (SFWM) in a laser-cooled (85)Rb atomic ensemble, with a bandwidth (as low as 0.8 MHz) much narrower than the rubidium atomic natural linewidth. By stabilizing the relative phase between the two SFWM paths in a Mach-Zehnder interferometer configuration, we are able to produce all four Bell states. These subnatural-linewidth photon pairs with polarization entanglement are ideal quantum information carriers for connecting remote atomic quantum nodes via efficient light-matter interaction in a photon-atom quantum network.
我们展示了一种从激光冷却的（85）Rb 原子系综中的自发四波混频（SFWM）中产生偏振纠缠光子对的有效实验方案，其带宽（低至 0.8MHz）远小于铷原子的自然线宽。通过在马赫-曾德尔干涉仪配置中稳定两个 SFWM 路径之间的相对相位，我们能够产生所有四个贝尔态。这些具有偏振纠缠的亚自然线宽光子对是通过光子-原子量子网络中的有效光物质相互作用连接远程原子量子节点的理想量子信息载体。
