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Related papers: Quantum metrology beyond the Quantum Cram\'er-Rao …

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We revisit the problem of estimating an unknown parameter of a pure quantum state, and investigate `null-measurement' strategies in which the experimenter aims to measure in a basis that contains a vector close to the true system state.…

Quantum Physics · Physics 2023-10-11 Federico Girotti , Alfred Godley , Mădălin Guţă

Quantum parameter estimation theory is an important component of quantum information theory and provides the statistical foundation that underpins important topics such as quantum system identification and quantum waveform estimation. When…

Quantum Physics · Physics 2024-12-24 Hendra I. Nurdin

The impact of measurement imperfections on quantum metrology protocols has not been approached in a systematic manner so far. In this work, we tackle this issue by generalising firstly the notion of quantum Fisher information to account for…

Quantum Physics · Physics 2022-11-21 Yink Loong Len , Tuvia Gefen , Alex Retzker , Jan Kołodyński

We carefully examine critical metrology and present an improved critical quantum metrology protocol which relies on quenching a system exhibiting a superradiant quantum phase transition beyond its critical point. We show that this approach…

Quantum Physics · Physics 2022-05-04 Karol Gietka , Lewis Ruks , Thomas Busch

Quantum measurements are not deterministic. For this reason quantum measurements are repeated for a number of shots on identically prepared systems. The uncertainty in each measurement depends on the number of shots and the expected outcome…

Quantum Physics · Physics 2025-03-12 Pieter Thijs Eendebak

One of the main quests in quantum metrology, and quantum parameter estimation in general, is to find out the highest achievable precision with given resources and design schemes that attain that precision. In this article we present a…

Quantum Physics · Physics 2016-05-23 Haidong Yuan , Chi-Hang Fred Fung

In probabilistic quantum metrology, one aims at finding weak measurements that concentrate the Fisher Information on the resulting quantum states, post-selected according to the weak outcomes. Though the Quantum Cram\'er-Rao bound itself…

Quantum Physics · Physics 2022-07-08 Massimo Frigerio , Stefano Olivares , Matteo G. A. Paris

The Cramer-Rao bound, satisfied by classical Fisher information, a key quantity in information theory, has been shown in different contexts to give rise to the Heisenberg uncertainty principle of quantum mechanics. In this paper, we show…

Quantum Physics · Physics 2022-11-23 Yakov Bloch , Eliahu Cohen

Quantum information science currently poses a troubling contradiction. It can be summarized as: (1) To factor efficiently, quantum computers must perform exponentially precise energy estimation. (2) Exponentially precise energy estimation…

General Physics · Physics 2025-03-17 Liam P. McGuinness

As one of the main pillars of quantum technologies, quantum metrology aims to improve measurement precision using techniques from quantum information. The two main strategies to achieve this are the preparation of nonclassical states and…

Quantum Physics · Physics 2025-09-16 Matteo Fadel , Noah Roux , Manuel Gessner

Maximizing the precision in estimating parameters in a quantum system subject to instrumentation constraints is cast as a convex optimization problem. We account for prior knowledge about the parameter range by developing a worst-case and…

Quantum Physics · Physics 2008-04-01 Robert L. Kosut

In quantum metrology, the parameter estimation accuracy is bounded by quantum Fisher information. In this paper, we present coherence measures in terms of (quantum) Fisher information by directly considering the post-selective non-unitary…

Quantum Physics · Physics 2023-07-06 Deng-hui Yu , Chang-shui Yu

We investigate the ultimate precision achievable in Gaussian quantum metrology. We derive general analytical expressions for the quantum Fisher information matrix and for the measurement compatibility condition, ensuring asymptotic…

Quantum Physics · Physics 2018-07-18 Rosanna Nichols , Pietro Liuzzo-Scorpo , Paul A. Knott , Gerardo Adesso

We describe a quantum limit to measurement of classical spacetimes. Specifically, we formulate a quantum Cramer-Rao lower bound for estimating the single parameter in any one-parameter family of spacetime metrics. We employ the locally…

Quantum Physics · Physics 2017-11-15 T. G. Downes , J. R. van Meter , E. Knill , G. J. Milburn , C. M. Caves

Quantum metrology is the science that aims to achieve precision measurements by making use of quantum principles. Attribute to the well-developed techniques of manipulating and detecting cold atoms, cold atomic systems provide an excellent…

Quantum Physics · Physics 2017-08-23 Jiahao Huang , Shuyuan Wu , Honghua Zhong , Chaohong Lee

A central challenge in quantum metrology is identifying optimal measurements that saturate the quantum Cramer-Rao bound under realistic constraints, e.g., local measurements. We show that symmetries of the probe state provide a general…

Quantum Physics · Physics 2026-03-10 Jia-Xuan Liu , Hai-Long Shi , Chunfeng Wu , Sixia Yu

Quantum metrology comprises a set of techniques and protocols that utilize quantum features for parameter estimation which can in principle outperform any procedure based on classical physics. We formulate the quantum metrology in terms of…

Quantum Physics · Physics 2021-05-17 Chungwei Lin , Yanting Ma , Dries Sels

The estimation of multiple parameters is a ubiquitous requirement in many quantum metrology applications. However, achieving the ultimate precision limit, i.e. the quantum Cram\'er-Rao bound, becomes challenging in these scenarios compared…

Quantum Physics · Physics 2024-11-25 Ben Wang , Kaimin Zheng , Qian Xie , Aonan Zhang , Liang Xu , Lijian Zhang

Quantum-enhanced (i.e., higher performance by quantum effects than any classical methods) mean value estimation of observables is a fundamental task in various quantum technologies; in particular, it is an essential subroutine in quantum…

Quantum Physics · Physics 2024-09-11 Kaito Wada , Kazuma Fukuchi , Naoki Yamamoto

Quantum mechanics offers the possibility of unconditionally secure communication between multiple remote parties. Security proofs for such protocols typically rely on bounding the capacity of the quantum channel in use. In a similar manner,…