title: Generation of narrow-band hyperentangled nondegenerate paired photons.
abstract: We report the generation of nondegenerate narrow-bandwidth paired photons with time-frequency and polarization entanglements from laser cooled atoms. We observe the two-photon interference caused by Rabi splitting with a coherence time of about 30 ns and a visibility of 81.8% which verifies the time-frequency entanglement of the paired photons. The polarization entanglement is confirmed by polarization correlation measurements which exhibit a visibility of 89.5% and characterized by quantum-state tomography with a fidelity of 90.8%. Taking into account the transmission losses and duty cycle, we estimate that the system generates hyperentangled paired photons into opposing single-mode fibers at a rate of 320 pairs per second.
authors.affiliation: Department of Physics, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, China.
authors.forename: Hui
authors.initials: H
authors.lastname: Yan
authors.forename: Shanchao
authors.initials: S
authors.lastname: Zhang
authors.forename: J F
authors.initials: JF
authors.lastname: Chen
authors.forename: M M T
authors.initials: MM
authors.lastname: Loy
authors.forename: G K L
authors.initials: GK
authors.lastname: Wong
authors.forename: Shengwang
authors.initials: S
authors.lastname: Du