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arXiv · 1808.10222

Post-processing minimal joint observables

Teiko Heinosaari·Yui Kuramochi
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Abstract

A finite set of quantum observables (positive operator valued measures) is called compatible if these observables are marginals of a some observable, called a joint observable of them. For a given set of compatible observables, their joint observable is in general not unique and it is desirable to take a minimal joint observable in the post-processing order since a less informative observable disturbs less the system. We address the question of the minimality of finite-outcome joint observables and prove that any joint observable is lower bounded by a minimal joint observable in the post-processing order. We also give characterizations of the minimality of a joint observable that can be checked by finite-step algorithms and apply them to the case of non-commuting dichotomic qubit observables.

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Teiko Heinosaari, Yui Kuramochi. 2018-08-30. Post-processing minimal joint observables. https://doi.org/10.1088/1751-8121%2Faaf7bb

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