Delve into the future of research at MiS with our preprint repository. Our scientists are making groundbreaking discoveries and sharing their latest findings before they are published. Explore repository to stay up-to-date on the newest developments and breakthroughs.
Comment on ``Optimal convex approximations of quantum states"
Xiao-Bin Liang, Bo Li and Shao-Ming Fei
In a recent paper, Massimiliano 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 the complete analytical solutions for the optimal convex approximation. Our solutions can be viewed as the supplement to the results in [Phy. Rev. A 96, 042325(2017)]