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Extremal covariant quantum operations and POVM's

Giacomo Mauro D'Ariano
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Abstract

We consider the convex sets of QO's (quantum operations) and POVM's (positive operator valued measures) which are covariant under a general finite-dimensional unitary representation of a group. We derive necessary and sufficient conditions for extremality, and give general bounds for ranks of the extremal POVM's and QO's. Results are illustrated on the basis of simple examples.

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Giacomo Mauro D'Ariano. 2004-05-31. Extremal covariant quantum operations and POVM's. https://arxiv.org/abs/quant-ph/0310024

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