A protocol for global multiphase estimation

Fuente: arXiv
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Main Authors: Chesi, Giovanni, Rubboli, Roberto, Riccardi, Alberto, Maccone, Lorenzo, Macchiavello, Chiara
Format: Preprint
Published: 2023
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author Chesi, Giovanni
Rubboli, Roberto
Riccardi, Alberto
Maccone, Lorenzo
Macchiavello, Chiara
author_facet Chesi, Giovanni
Rubboli, Roberto
Riccardi, Alberto
Maccone, Lorenzo
Macchiavello, Chiara
contents Global estimation strategies allow to extract information on a phase or a set of phases without any prior knowledge, which is, instead, required for local estimation strategies. We devise a global multiphase protocol based on Holevo's estimation theory and apply it to the case of digital estimation, i.e. we estimate the phases in terms of the mutual information between them and the corresponding estimators. In the single-phase scenario, the protocol encompasses two specific known optimal strategies. We extend them to the simultaneous estimation of two phases and evaluate their performance. Then, we retrieve the ultimate digital bound on precision when a generic number of phases is simultaneously estimated. We show that in the multiphase strategy there is only a constant quantum advantage with respect to a sequence of independent single-phase estimations. This extends a recent similar result, which settled a controversy on the search for the multiphase enhancement.
format Preprint
id arxiv_https___arxiv_org_abs_2301_07380
institution arXiv
publishDate 2023
record_format arxiv
spellingShingle A protocol for global multiphase estimation
Chesi, Giovanni
Rubboli, Roberto
Riccardi, Alberto
Maccone, Lorenzo
Macchiavello, Chiara
Quantum Physics
Global estimation strategies allow to extract information on a phase or a set of phases without any prior knowledge, which is, instead, required for local estimation strategies. We devise a global multiphase protocol based on Holevo's estimation theory and apply it to the case of digital estimation, i.e. we estimate the phases in terms of the mutual information between them and the corresponding estimators. In the single-phase scenario, the protocol encompasses two specific known optimal strategies. We extend them to the simultaneous estimation of two phases and evaluate their performance. Then, we retrieve the ultimate digital bound on precision when a generic number of phases is simultaneously estimated. We show that in the multiphase strategy there is only a constant quantum advantage with respect to a sequence of independent single-phase estimations. This extends a recent similar result, which settled a controversy on the search for the multiphase enhancement.
title A protocol for global multiphase estimation
topic Quantum Physics
url https://arxiv.org/abs/2301.07380