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Bipartite subspaces having no LOCC-distinguishable bases

John Watrous
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Abstract

It is proved that there exist subspaces of bipartite tensor product spaces that have no orthonormal bases that can be perfectly distinguished by means of LOCC protocols. A corollary of this fact is that there exist quantum channels having sub-optimal classical capacity even when the receiver may communicate classically with a third party that represents the channel's environment.

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John Watrous. 2005-03-18. Bipartite subspaces having no LOCC-distinguishable bases. https://doi.org/10.1103/physrevlett.95.080505

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