https://doi.org/10.1140/epjc/s10052-025-14175-0
Regular Article - Theoretical Physics
Quantum correlations and metrological advantage among Unruh–DeWitt detectors in de Sitter spacetime
1
Laboratory of High Energy Physics and Condensed Matter, Department of Physics, Faculty of Sciences of Aïn Chock, Hassan II University, P.O. Box 5366, Maarif, 20100, Casablanca, Morocco
2
College of Science and Engineering, Qatar Center for Quantum Computing, Hamad Bin Khalifa University, Doha, Qatar
3
School of Physics, University of Chinese Academy of Science, Yuquan Road 19A, 100049, Beijing, China
4
Mathematics Department, Faculty of Science, Al-Azhar University, 11884, Nassr City, Egypt
a
samira.elghaayda-etu@etu.univh2c.ma
Received:
14
December
2024
Accepted:
11
April
2025
Published online:
23
April
2025
A long-standing debate on Gibbons–Hawking (GH) decoherence centers on its obscure thermal nature. In this work, we investigate the robustness of quantum Fisher information (QFI) and local quantum uncertainty (LQU) in the presence of GH decoherence, using free-falling Unruh–DeWitt (UDW) detectors in de Sitter spacetime (dS-ST). The UDW detectors interact with a massless scalar field in dS-ST and are modeled as open quantum systems, with the field serving as the environment, described by a master equation that outlines their evolution. Our analysis investigates the roles of energy spacing, GH temperature, initial state preparation, and various de Sitter-invariant vacuum sectors on the optimization of QFI and LQU. We find that the optimal values of QFI and LQU depend on the selected de Sitter-invariant vacuum sector and increase with larger energy spacing. Our findings reveal that QFI exhibits resilience to GH decoherence, maintaining a pronounced local peak across a broader range of parameters. This robustness can be further enhanced through strategic initial state preparation and increased energy spacing, resulting in a higher maximum QFI value even under significant environmental decoherence. Our results underscore the critical role of GH thermality in governing QFI and LQU, offering valuable insights for advances in relativistic quantum metrology (RQM).
© The Author(s) 2025
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Funded by SCOAP3.
