title: Demonstration of a stable atom-photon entanglement source for quantum repeaters.
abstract: We demonstrate a novel way to efficiently create a robust entanglement between an atomic and a photonic qubit. A single laser beam is used to excite one atomic ensemble and two different modes of Raman fields are collected to generate the atom-photon entanglement. With the help of built-in quantum memory, the entanglement still exists after 20.5 micros storage time which is further proved by the violation of Clauser-Horne-Shimony-Holt type Bell's inequality. The entanglement procedure can serve as a building block for a novel robust quantum repeater architecture [Zhao, Phys. Rev. Lett. 98, 240502 (2007)10.1103/PhysRevLett.98.240502] and can be extended to generate high-dimensional atom-photon entanglements.
authors.affiliation: Physikalisches Institut, Ruprecht-Karls-Universität Heidelberg, Philosophenweg 12, 69120 Heidelberg, Germany.
authors.forename: Shuai
authors.initials: S
authors.lastname: Chen
authors.forename: Yu-Ao
authors.initials: YA
authors.lastname: Chen
authors.forename: Bo
authors.initials: B
authors.lastname: Zhao
authors.forename: Zhen-Sheng
authors.initials: ZS
authors.lastname: Yuan
authors.forename: Jörg
authors.initials: J
authors.lastname: Schmiedmayer
authors.forename: Jian-Wei
authors.initials: JW
authors.lastname: Pan