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arXiv · 2011.03809

The PPT$^2$ conjecture holds for all Choi-type maps

Satvik Singh·Ion Nechita
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Abstract

We prove that the PPT$^2$ conjecture holds for linear maps between matrix algebras which are covariant under the action of the diagonal unitary group. Many salient examples, like the Choi-type maps, depolarizing maps, dephasing maps, amplitude damping maps, and mixtures thereof, lie in this class. Our proof relies on a generalization of the matrix-theoretic notion of factor width for pairwise completely positive matrices, and a complete characterization in the case of factor width two.

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Satvik Singh, Ion Nechita. 2020-11-07. The PPT$^2$ conjecture holds for all Choi-type maps. https://doi.org/10.1007/s00023-022-01166-0

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