Concurrence of Stochastic 1-Qubit Maps

Meik Hellmund; Armin Uhlmann

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arXiv · 0802.2092

Concurrence of Stochastic 1-Qubit Maps

Meik Hellmund·Armin Uhlmann

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Abstract

Explicit expressions for the concurrence of all positive and trace-preserving ("stochastic") 1-qubit maps are presented. By a new method we find the relevant convex roof pattern. We conclude that two component optimal decompositions always exist. Our results can be transferred to $2 \times n$-quantum systems providing the concurrence for all rank two density operators as well as a lower bound for their entanglement of formation.

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Meik Hellmund, Armin Uhlmann. 2008-12-04. Concurrence of Stochastic 1-Qubit Maps. https://arxiv.org/abs/0802.2092

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