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Introducing Quantum Discord

Harold Ollivier·Wojciech H. Zurek
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Abstract

Two classically identical expressions for the mutual information generally differ when the two systems involved are quantum. We investigate this difference -- quantum discord -- and show that it can be used as a criterion for the classicality of the correlations. We also show that quantum discord can be used for describing the selection of the preferred, effectively classical, pointer states.

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Harold Ollivier, Wojciech H. Zurek. 2001-05-16. Introducing Quantum Discord. https://doi.org/10.1103/physrevlett.88.017901

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