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Entanglement generation by Fock-state filtration

K. J. Resch·J. L. O'Brien·T. J. Weinhold·K. Sanaka·A. G. White
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Abstract

We demonstrate a Fock-state filter which is capable of preferentially blocking single photons over photon pairs. The large conditional nonlinearities are based on higher-order quantum interference, using linear optics, an ancilla photon, and measurement. We demonstrate that the filter acts coherently by using it to convert unentangled photon pairs to a path-entangled state. We quantify the degree of entanglement by transforming the path information to polarisation information, applying quantum state tomography we measure a tangle of T=(20+/-9)%.

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K. J. Resch, J. L. O'Brien, T. J. Weinhold, K. Sanaka, A. G. White. 2006-08-07. Entanglement generation by Fock-state filtration. https://doi.org/10.1103/physrevlett.98.203602

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