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arXiv · 2003.07889

On the Alberti-Uhlmann Condition for Unital Channels

Sagnik Chakraborty·Dariusz Chruściński·Gniewomir Sarbicki·Frederik vom Ende
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Abstract

We address the problem of existence of completely positive trace preserving (CPTP) maps between two sets of density matrices. We refine the result of Alberti and Uhlmann and derive a necessary and sufficient condition for the existence of a unital channel between two pairs of qubit states which ultimately boils down to three simple inequalities.

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Sagnik Chakraborty, Dariusz Chruściński, Gniewomir Sarbicki, Frederik vom Ende. 2020-03-17. On the Alberti-Uhlmann Condition for Unital Channels. https://doi.org/10.22331/q-2020-11-08-360

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