title: Deterministically Entangling Two Remote Atomic Ensembles via Light-Atom Mixed Entanglement Swapping.
abstract: Entanglement of two distant macroscopic objects is a key element for implementing large-scale quantum networks consisting of quantum channels and quantum nodes. Entanglement swapping can entangle two spatially separated quantum systems without direct interaction. Here we propose a scheme of deterministically entangling two remote atomic ensembles via continuous-variable entanglement swapping between two independent quantum systems involving light and atoms. Each of two stationary atomic ensembles placed at two remote nodes in a quantum network is prepared to a mixed entangled state of light and atoms respectively. Then, the entanglement swapping is unconditionally implemented between the two prepared quantum systems by means of the balanced homodyne detection of light and the feedback of the measured results. Finally, the established entanglement between two macroscopic atomic ensembles is verified by the inseparability criterion of correlation variances between two anti-Stokes optical beams respectively coming from the two atomic ensembles.
authors.affiliation: State Key Laboratory of Quantum Optics and Quantum Optics Devices, Institute of Opto-Electronics, Shanxi University, Taiyuan, 030006, People's Republic of China.
authors.forename: Yanhong
authors.initials: Y
authors.lastname: Liu
authors.affiliation: State Key Laboratory of Quantum Optics and Quantum Optics Devices, Institute of Opto-Electronics, Shanxi University, Taiyuan, 030006, People's Republic of China.|Collaborative Innovation Center of Extreme Optics, Shanxi University, Taiyuan, 030006, People's Republic of China.
authors.forename: Zhihui
authors.initials: Z
authors.lastname: Yan
authors.affiliation: State Key Laboratory of Quantum Optics and Quantum Optics Devices, Institute of Opto-Electronics, Shanxi University, Taiyuan, 030006, People's Republic of China.|Collaborative Innovation Center of Extreme Optics, Shanxi University, Taiyuan, 030006, People's Republic of China.
authors.forename: Xiaojun
authors.initials: X
authors.lastname: Jia
authors.affiliation: State Key Laboratory of Quantum Optics and Quantum Optics Devices, Institute of Opto-Electronics, Shanxi University, Taiyuan, 030006, People's Republic of China.|Collaborative Innovation Center of Extreme Optics, Shanxi University, Taiyuan, 030006, People's Republic of China.
authors.forename: Changde
authors.initials: C
authors.lastname: Xie