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arXiv · 1901.08848

Comment on "Optimal convex approximations of quantum states"

Xiao-Bin Liang·Bo Li·Shao-Ming Fei
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Abstract

In a recent paper, M. F. Sacchi [Phys. Rev. A 96, 042325 (2017)] addressed the general problem of approximating an unavailable quantum state by the convex mixing of different available states. For the case of qubit mixed states, we show that the analytical solutions in some cases are invalid. In this Comment, we present complete analytical solutions for the optimal convex approximation. Our solutions can be viewed as correcting and supplementing the results in the aforementioned paper.

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Xiao-Bin Liang, Bo Li, Shao-Ming Fei. 2019-01-25. Comment on "Optimal convex approximations of quantum states". https://doi.org/10.1103/physreva.99.016301

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