Post-processing minimal joint observables



: Teiko Heinosaari, Yui Kuramochi

Publisher: IOP PUBLISHING LTD

: 2019

: Journal of Physics A: Mathematical and Theoretical

: JOURNAL OF PHYSICS A-MATHEMATICAL AND THEORETICAL

: J PHYS A-MATH THEOR

: ARTN 065301

: 52

: 6

: 22

: 1751-8113

: 1751-8121

DOI: https://doi.org/10.1088/1751-8121/aaf7bb(external)

: https://research.utu.fi/converis/portal/detail/Publication/39603613(external)


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 the system less. 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.

Last updated on 2024-26-11 at 17:51