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arXiv · 1309.6890

Comment on "Sudden change in quantum discord accompanying the transition from bound to free entanglement"

Swapan Rana·Preeti Parashar
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Abstract

In a recent article [http://dx.doi.org/10.1103/PhysRevA.87.022340, Phys. Rev. A 87, 022340 (2013)], Yan et al have studied geometric discord for a well known class of bound entangled states. Based on their calculation, they claim "It is found that there exists a nondynamic sudden change in quantum discord" for these states. In this Comment, we criticize their work by pointing out that what has been calculated is actually a bound, and not the exact value of discord. Since, generally, it is not possible to infer the exact value (or property) of a quantity just from its bound, we can not conclude about (exact) discord and its change. Thus, the above-mentioned conclusion can not be drawn from the calculations of the paper.

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Swapan Rana, Preeti Parashar. 2013-09-26. Comment on "Sudden change in quantum discord accompanying the transition from bound to free entanglement". https://doi.org/10.1103/physreva.88.036301

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