Published March 2024 | Version Published
Journal Article Open

Enhanced Estimation of Quantum Properties with Common Randomized Measurements

Abstract

We present a technique for enhancing the estimation of quantum state properties by incorporating approximate prior knowledge about the quantum state. This consists in performing randomized measurements on a quantum processor and comparing the results with those obtained from a classical computer that stores an approximation of the quantum state. We provide unbiased estimators for expectation values of multicopy observables and present performance guarantees in terms of variance bounds that depend on the prior knowledge accuracy. We demonstrate the effectiveness of our approach through experimental and numerical examples detecting mixed-state entanglement, and estimating polynomial approximations of the von Neumann entropy and state fidelities.

Copyright and License

Published by the American Physical Society under the terms of the Creative Commons Attribution 4.0 International license. Further distribution of this work must maintain attribution to the author(s) and the published article's title, journal citation, and DOI.

Acknowledgement

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Additional details

Funding

Agence Nationale de la Recherche
ANR-20-CE47-0005
Agence Nationale de la Recherche
ANR-22-PETQ-0007
Agence Nationale de la Recherche
ANR-22-PETQ-0004
FWF Austrian Science Fund
P 3259
Agence Nationale de la Recherche
ANR-10-LABX-51-01
California Institute of Technology
Summer Undergraduate Research Fellowship
United States Department of Energy
DE-NA0003525
United States Department of Energy
DE-SC0020290
National Science Foundation
PHY-1733907
German National Academy of Sciences Leopoldina
LPDS 2021-02
California Institute of Technology
Walter Burke Institute for Theoretical Physics

Caltech Custom Metadata

Caltech groups
Institute for Quantum Information and Matter, Walter Burke Institute for Theoretical Physics, AWS Center for Quantum Computing