Probing cosmic string spacetime through parameter estimation

Ying Yang; Jiliang Jing; Zehua Tian

doi:10.1140/epjc/s10052-022-10628-y

2022 Impact factor 4.4

Particles and Fields

Open Access

Eur. Phys. J. C (2022) 82: 688
https://doi.org/10.1140/epjc/s10052-022-10628-y

Regular Article - Theoretical Physics

Probing cosmic string spacetime through parameter estimation

Ying Yang¹^a, Jiliang Jing² and Zehua Tian³^c

¹ Department of Physics, Key Laboratory of Intelligent Sensors and Advanced Sensor Materials, Hunan University of Science and Technology, 411201, Xiangtan, Hunan, People’s Republic of China
² Department of Physics, Key Laboratory of Low Dimensional Quantum Structures and Quantum Control of Ministry of Education, and Synergetic Innovation Center for Quantum Effects and Applications, Hunan Normal University, 410081, Changsha, Hunan, People’s Republic of China
³ CAS Key Laboratory of Microscale Magnetic Resonance and Department of Modern Physics, University of Science and Technology of China, 230026, Hefei, People’s Republic of China

^a yingyanghnust@163.com
^c tianzh@ustc.edu.cn

Received: 28 March 2022
Accepted: 24 July 2022
Published online: 7 August 2022

Abstract

Quantum metrology studies the ultimate precision limit of physical quantities by using quantum strategy. In this paper we apply the quantum metrology technologies to the relativistic framework for estimating the deficit angle parameter of cosmic string spacetime. We use a two-level atom coupled to electromagnetic fields as the probe and derive its dynamical evolution by treating it as an open quantum system. We estimate the deficit angle parameter by calculating its quantum Fisher information(QFI). It is found that the quantum Fisher information depends on the deficit angle, evolution time, detector initial state, polarization direction, and its position. We then identify the optimal estimation strategies, i.e., maximize the quantum Fisher information via all the associated parameters, and therefore optimize the precision of estimation. Our results show that for different polarization cases the QFIs have different behaviors and different orders of magnitude, which may shed light on the exploration of cosmic string spacetime.

© The Author(s) 2022

Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. The images or other third party material in this article are included in the article’s Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit http://creativecommons.org/licenses/by/4.0/.