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Related papers: Multiparameter quantum estimation with a uniformly…

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We establish the multiparameter quantum Cram\'er-Rao bound for simultaneously estimating the centroid, the separation, and the relative intensities of two incoherent optical point sources using alinear imaging system. For equally bright…

Quantum Physics · Physics 2017-12-13 J. Rehacek , Z. Hradil , B. Stoklasa , M. Paur , J. Grover , A. Krzic , L. L. Sanchez-Soto

For decoherence processes induced by weak interactions with the environment, a general quantum channel with one noise parameter has been formulated. This channel is called low-noise channel and very useful for investigating the parameter…

Quantum Physics · Physics 2009-11-13 Masahiro Hotta , Tokishiro Karasawa

We develop a localized particle detector model formulated as a massive quantum field on Minkowski spacetime with the spatial origin excised. To render the problem well-posed at the puncture, we impose boundary conditions at the excised…

High Energy Physics - Theory · Physics 2026-02-12 Victor Hugo M. Ramos , João Paulo M. Pitelli , João C. A. Barata

We obtained an exact solution for a uniformly accelerated Unruh-DeWitt detector interacting with a massless scalar field in (3+1) dimensions which enables us to study the entire evolution of the total system, from the initial transient to…

General Relativity and Quantum Cosmology · Physics 2008-11-26 Shih-Yuin Lin , B. L. Hu

The power of quantum sensing rests on its ultimate precision limit, quantified by the quantum Cramer-Rao bound (QCRB), which can surpass classical bounds. In multi-parameter estimation, the QCRB is not always saturated as the quantum nature…

Quantum Physics · Physics 2024-05-24 Changhao Li , Mo Chen , Paola Cappellaro

The widely used quantum Cramer-Rao bound (QCRB) sets a lower bound for the mean square error of unbiased estimators in quantum parameter estimation, however, in general QCRB is only tight in the asymptotical limit. With a limited number of…

Quantum Physics · Physics 2016-09-07 Jing Liu , Haidong Yuan

We introduce quantum parameter estimation with the encoding being via a quantum measurement. We quantify the precision for estimating parameters characterizing a general two-outcome qubit measurement, considering two cases: when the…

Quantum Physics · Physics 2025-12-12 Shuva Mondal , Priya Ghosh , Ujjwal Sen

In this paper, we investigate the quantum correlations and coherence of two accelerating Unruh-deWitt detectors coupled to a scalar field in 3 + 1 Minkowski space-time. We show that the entanglement is completely destroyed in the limit of…

Quantum Physics · Physics 2022-11-29 S. Bhuvaneswari , R. Muthuganesan , R. Radha

The aim of the channel estimation is to estimate the parameters encoded in a quantum channel. For this aim, it is allowed to choose the input state as well as the measurement to get the outcome. Various precision bounds are known for the…

Quantum Physics · Physics 2024-11-21 Masahito Hayashi , Yingkai Ouyang

The symmetric logarithmic derivative Cram\'er-Rao bound (SLDCRB) provides a fundamental limit to the minimum variance with which a set of unknown parameters can be estimated in an unbiased manner. It is known that the SLDCRB can be…

Quantum Physics · Physics 2024-04-03 Lorcan O. Conlon , Jun Suzuki , Ping Koy Lam , Syed M. Assad

Mixed-resolution architectures, combining high-resolution (analog) data with coarsely quantized (e.g., 1-bit) data, are widely employed in emerging communication and radar systems to reduce hardware costs and power consumption. However, the…

Signal Processing · Electrical Eng. & Systems 2025-08-29 Yaniv Mazor , Tirza Routtenberg

Precision and accuracy, as two crucial criteria for quantum metrology, have previously lacked rigorous definitions and distinctions. In this paper, we provide a unified definition of precision and accuracy from the perspective of…

Quantum Physics · Physics 2025-07-15 Cong-Gang Song , Qing-yu Cai

We examine the Unruh-DeWitt particle detector coupled to a scalar field in an arbitrary Hadamard state in four-dimensional curved spacetime. Using smooth switching functions to turn on and off the interaction, we obtain a regulator-free…

General Relativity and Quantum Cosmology · Physics 2014-11-18 Jorma Louko , Alejandro Satz

Many results in the quantum metrology literature use the Cram\'er-Rao bound and the Fisher information to compare different quantum estimation strategies. However, there are several assumptions that go into the construction of these tools,…

Quantum Physics · Physics 2018-01-31 Jesús Rubio , Paul Knott , Jacob Dunningham

I propose a physical measurement scheme on multiple independent and identically distributed quantum objects to approach the Holevo--Nagaoka bound for quantum multiparameter estimation. The scheme entails a physical interaction of the…

Quantum Physics · Physics 2026-03-27 Mankei Tsang

The theoretical foundation of quantum sensing is rooted in the Cram\'er-Rao formalism, which establishes quantitative precision bounds for a given quantum probe. In many practical scenarios, where more than one parameter is unknown, the…

Quantum Physics · Physics 2025-12-05 George Mihailescu , Saubhik Sarkar , Abolfazl Bayat , Steve Campbell , Andrew K. Mitchell

The optimal quantum measurements for estimating different unknown parameters in a parameterized quantum state are usually incompatible with each other. Traditional approaches to addressing the measurement incompatibility issue, such as the…

Quantum Physics · Physics 2026-02-03 Sisi Zhou , Senrui Chen

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

In a quantum sense, vacuum is not an empty void but full of virtual particles (fields). It may have long-range properties, be altered, and even undergo phase transitions. It is suggested that long-range properties of a quantum vacuum may be…

High Energy Physics - Theory · Physics 2022-09-28 Shijing Cheng , Wenting Zhou , Hongwei Yu

The main contribution of this paper is to derive an explicit expression for the fundamental precision bound, the Holevo bound, for estimating any two-parameter family of qubit mixed-states in terms of quantum versions of Fisher information.…

Quantum Physics · Physics 2016-05-04 Jun Suzuki