GHZ protocols enhance frequency metrology despite spontaneous decay

authored by: Timm Kielinski, Piet O. Schmidt, Klemens Hammerer
Abstract: The use of correlated states and measurements promises improvements in the accuracy of frequency metrology and the stability of atomic clocks. However, developing strategies robust against dominant noise processes remains challenging. We address the issue of decoherence due to spontaneous decay and show that Greenberger-Horne-Zeilinger (GHZ) states, in conjunction with a correlated measurement and nonlinear estimation strategy, achieve gains comparable to fundamental bounds for ensembles of up to 40 atoms. This result is surprising since GHZ states do not provide any enhancement under dephasing noise compared to the standard quantum limit of uncorrelated states. The gain arises from a veto signal, which allows for the detection and mitigation of errors caused by spontaneous emission events. Through comprehensive Monte-Carlo simulations of atomic clocks, we demonstrate the robustness of the GHZ protocol.
Organisation(s): Institute of Theoretical Physics
Institute of Quantum Optics
External Organisation(s): National Metrology Institute of Germany (PTB)
Type: Article
Journal: Science advances
Volume: 10
No. of pages: 13
ISSN: 2375-2548
Publication date: 10.2024
Publication status: Published
Peer reviewed: Yes
ASJC Scopus subject areas: General
Electronic version(s): https://doi.org/10.48550/arXiv.2406.11639 (Access: Open)
https://doi.org/10.1126/sciadv.adr1439 (Access: Open)

BibTeX

@article{36f1725331db4ccfbedf6002e9a48461,
title = "GHZ protocols enhance frequency metrology despite spontaneous decay",
abstract = " The use of correlated states and measurements promises improvements in the accuracy of frequency metrology and the stability of atomic clocks. However, developing strategies robust against dominant noise processes remains challenging. We address the issue of decoherence due to spontaneous decay and show that Greenberger-Horne-Zeilinger (GHZ) states, in conjunction with a correlated measurement and nonlinear estimation strategy, achieve gains comparable to fundamental bounds for ensembles of up to 40 atoms. This result is surprising since GHZ states do not provide any enhancement under dephasing noise compared to the standard quantum limit of uncorrelated states. The gain arises from a veto signal, which allows for the detection and mitigation of errors caused by spontaneous emission events. Through comprehensive Monte-Carlo simulations of atomic clocks, we demonstrate the robustness of the GHZ protocol. ",
keywords = "quant-ph, physics.atom-ph",
author = "Timm Kielinski and Schmidt, {Piet O.} and Klemens Hammerer",
note = "Publisher Copyright: Copyright {\textcopyright} 2024 The Authors, some rights reserved;",
year = "2024",
month = oct,
doi = "10.48550/arXiv.2406.11639",
language = "English",
volume = "10",
journal = "Science advances",
issn = "2375-2548",
publisher = "American Association for the Advancement of Science",
number = "43",
}