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Universal and phase covariant superbroadcasting for mixed qubit states

Francesco Buscemi·Giacomo Mauro D'Ariano·Chiara Macchiavello·Paolo Perinotti
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Abstract

We describe a general framework to study covariant symmetric broadcasting maps for mixed qubit states. We explicitly derive the optimal N to M superbroadcasting maps, achieving optimal purification of the single-site output copy, in both the universal and the phase covariant cases. We also study the bipartite entanglement properties of the superbroadcast states.

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Francesco Buscemi, Giacomo Mauro D'Ariano, Chiara Macchiavello, Paolo Perinotti. 2006-02-15. Universal and phase covariant superbroadcasting for mixed qubit states. https://doi.org/10.1103/physreva.74.042309

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