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Related papers: Quantum estimation in an expanding spacetime

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The Heisenberg scaling is an ultimate precision limit of parameter estimation allowed by the principles of quantum mechanics, with no counterpart in the classical realm, and has been a long-pursued goal in quantum metrology. It has been…

Quantum Physics · Physics 2024-12-06 Jingyi Fan , Shengshi Pang

The goal of quantum metrology is to improve measurements' sensitivities by harnessing quantum resources. Metrologists often aim to maximize the quantum Fisher information, which bounds the measurement setup's sensitivity. In studies of…

We calculate the quantum Fisher information (QFI) for estimating, using a circular imaging aperture, the two-dimensional location of a point source against a uniformly bright disk of known center and radius in the ideal photon-counting…

Quantum Physics · Physics 2023-04-12 Sudhakar Prasad

We study the role of probe dimension in determining the bounds of precision and the level of incompatibility in multi-parameter quantum estimation problems. In particular, we focus on the paradigmatic case of unitary encoding generated by…

Quantum Physics · Physics 2024-03-13 Alessandro Candeloro , Zahra Pazhotan , Matteo G. A. Paris

We have introduced a measure of Gaussian quantum correlations based on quantum Fisher information. For bipartite Gaussian states the minimum quantum Fisher information due to local unitary evolution on one of the parties reliably quantifies…

Quantum Physics · Physics 2014-06-20 Manabendra N. Bera

By confining a Bose-Einstein condensate in a vertical lattice subjected to a gravitational potential, we analyze the quantum Fisher information to determine its scaling with respect to time, system size and particle number. Our results…

Quantum Physics · Physics 2026-05-08 Hassan Manshouri , Moslem Zarei , Mehdi Abdi , Yasser Omar , Sougato Bose , Abolfazl Bayat

The availability of scaling solutions in renormalisation group improved versions of cosmology are investigated in the high-energy limit. We adopt $f(R)$-type models of quantum gravity which display an interacting ultraviolet fixed point at…

General Relativity and Quantum Cosmology · Physics 2018-05-16 Kevin Falls , Daniel F. Litim , Kostas Nikolakopoulos , Christoph Rahmede

We show that quantification of the performance of quantum-enhanced measurement schemes based on the concept of quantum Fisher information yields asymptotically equivalent results as the rigorous Bayesian approach, provided generic…

Quantum Physics · Physics 2015-01-13 Marcin Jarzyna , Rafal Demkowicz-Dobrzanski

Tripartite interactions play a fundamental role in the quantum information processing and quantum technology. However, it is generally difficult to realize strong tripartite coupling. We investigate the estimation of a tripartite coupling…

Quantum Physics · Physics 2024-12-20 Dong Xie , Chunling Xu

We study the finite time response of an Unruh-DeWitt particle detector described by a qubit (two-level system) moving with uniform constant acceleration in maximally symmetric spacetimes. The $D$ dimensional massless fermionic response…

High Energy Physics - Theory · Physics 2023-12-04 Shahnewaz Ahmed , Mir Mehedi Faruk , Muktadir Rahman

We consider the problem of determining the spatial phase profile of a single-mode electromagnetic field. Our attention is on input states that are a statistical mixture of displaced and squeezed number states, a superset of Gaussian states.…

Optics · Physics 2024-07-09 Jacob Trzaska , Amit Ashok

Vacuum fluctuations of quantum fields provide an unavoidable environment for any quantum system coupled to it. We study the interplay between boundary conditions and acceleration in determining decoherence of a two-level Unruh-DeWitt…

General Relativity and Quantum Cosmology · Physics 2026-04-06 Harkirat Singh Sahota , Shagun Kaushal , Kinjalk Lochan

Unruh deWitt detectors are important constructs in studying the dynamics of quantum fields in any geometric background. Curvature also plays an important role in setting up the correlations of a quantum field in a given spacetime. For…

General Relativity and Quantum Cosmology · Physics 2022-12-22 Ankit Dhanuka , Kinjalk Lochan

Quantum Fisher information (QFI) of the reduced two-atom state is employed to capture the quantum criticality of the superradiant phase transition in the Dicke model in the infinite size and finite-$N$ systems respectively. The analytical…

Quantum Physics · Physics 2016-01-05 Yu-Yu Zhang , Xiang-You Chen

We tackle the issue of estimating dynamical parameters in quantum electrodynamics. We numerically compute the quantum Fisher information matrix (QFIM) of physical parameters in electron-muon and Compton scattering at tree level. In…

Quantum Physics · Physics 2025-09-08 Preslav Asenov , WenHan Zhang , Alessio Serafini

Precisely measuring molecular orientation is key to understanding how molecules organize and interact in soft matter, but the maximum theoretical limit of measurement precision has yet to be quantified. We use quantum estimation theory and…

Optics · Physics 2020-07-23 Oumeng Zhang , Matthew D. Lew

We propose a method to probe the thermal properties of quantum field theory (QFT) in an inflationary universe simulated by spin systems. Our previous work (arXiv:2410.07587) has demonstrated that QFT of Majorana fermions in an arbitrary…

High Energy Physics - Theory · Physics 2025-05-08 Shunichiro Kinoshita , Keiju Murata , Daisuke Yamamoto , Ryosuke Yoshii

We investigate the quantum radiation emitted by a uniformly accelerated Unruh-DeWitt detector in de Sitter spacetime. We find that there exists a non-vanishing quantum radiation at late times in the radiation zone of the conformally flat…

High Energy Physics - Theory · Physics 2018-12-05 Shumpei Yamaguchi , Rumi Tatsukawa , Shih-Yuin Lin , Kazuhiro Yamamoto

Quantum Fisher information is a key concept in the field of quantum metrology, which aims to enhance the parameter accuracy by using quantum resources. In this paper, utilizing a representation of quantum Fisher information for a general…

Quantum Physics · Physics 2015-07-14 Xiao-Xing Jing , Jing Liu , Heng-Na Xiong , Xiaoguang Wang

Entanglement is widely regarded as an essential resource for a number of tasks and can in some cases be quantified by figures of merit related to those tasks. In quantum metrology, this is showcased by the connections between the quantum…

Quantum Physics · Physics 2026-03-24 Shaowei Du , Shuheng Liu , Matteo Fadel , Giuseppe Vitagliano , Qiongyi He