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arXiv · 1311.1671

Maximally discordant separable two qubit $X$ states

Swapan Rana·Preeti Parashar
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Abstract

In a recent article S. Gharibian [\href{http://dx.doi.org/10.1103/PhysRevA.86.042106}{Phys. Rev. A {\bf 86}, 042106 (2012)}] has conjectured that no two qubit separable state of rank greater than two could be maximally non classical (defined to be those which have normalized geometric discord $1/4$) and asked for an analytic proof. In this work we prove analytically that among the subclass of $X$ states, there is a unique (up to local unitary equivalence) maximal separable state of rank two. Partial progress has been made towards the general problem and some necessary conditions have been derived.

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Swapan Rana, Preeti Parashar. 2013-11-07. Maximally discordant separable two qubit $X$ states. https://doi.org/10.1007/s11128-014-0865-0

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