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A symmetry analyser for non-destructive Bell state detection using EIT

S. D. Barrett·P. Kok·K. Nemoto·R. G. Beausoleil·W. J. Munro·T. P. Spiller
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Abstract

We describe a method to project photonic two-qubit states onto the symmetric and antisymmetric subspaces of their Hilbert space. This device utilizes an ancillary coherent state, together with a weak cross-Kerr non-linearity, generated, for example, by electromagnetically induced transparency. The symmetry analyzer is non-destructive, and works for small values of the cross-Kerr coupling. Furthermore, this device can be used to construct a non-destructive Bell state detector.

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S. D. Barrett, P. Kok, K. Nemoto, R. G. Beausoleil, W. J. Munro, T. P. Spiller. 2005-06-14. A symmetry analyser for non-destructive Bell state detection using EIT. https://doi.org/10.1103/physreva.71.060302

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