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Entanglement generation via phase-matched processes: different Bell states within the linewidth

G. Brida·M. V. Chekhova·M. Genovese·L. A. Krivitsky
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Abstract

It is shown, theoretically and experimentally, that at any type-II spontaneous parametric down-conversion (SPDC) phase matching, the decoherence-free singlet Bell state is always present within the natural bandwidth and can be filtered out by a proper spectral selection. Instead of the frequency selection, one can perform time selection of the two-photon time amplitude at the output of a dispersive fibre. Applications to quantum communication are outlined.

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G. Brida, M. V. Chekhova, M. Genovese, L. A. Krivitsky. 2007-02-09. Entanglement generation via phase-matched processes: different Bell states within the linewidth. https://arxiv.org/abs/quant-ph/0702090

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