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arXiv · 2107.10863

Multiple-phase quantum interferometry -- real and apparent gains of measuring all the phases simultaneously

Wojciech Gorecki·Rafal Demkowicz-Dobrzanski
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Abstract

We characterize operationally meaningful quantum gains in a paradigmatic model of lossless multiple-phase interferometry and stress insufficiency of the analysis based solely on the concept of quantum Fisher information. We show that the advantage of the optimal simultaneous estimation scheme amounts to a constant factor improvement when compared with schemes where each phase is estimated separately -- contrary to a widely cited results claiming a better precision scaling in terms of the number of phases involved.

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Wojciech Gorecki, Rafal Demkowicz-Dobrzanski. 2022-01-04. Multiple-phase quantum interferometry -- real and apparent gains of measuring all the phases simultaneously. https://doi.org/10.1103/physrevlett.128.040504

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