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Related papers: Quantum metrology at level anti-crossing

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It is a general fact that the coupling constant of an interacting many-body Hamiltonian do not correspond to any observable and one has to infer its value by an indirect measurement. For this purpose, quantum systems at criticality can be…

Quantum Physics · Physics 2009-11-13 Carmen Invernizzi , Michael Korbman , Lorenzo Campos Venuti , Matteo G. A Paris

Phase estimation protocols provide a fundamental benchmark for the field of quantum metrology. The latter represents one of the most relevant applications of quantum theory, potentially enabling the capability of measuring unknown physical…

We construct optimal measurements, achieving the ultimate precision predicted by quantum theory, for the simultaneous estimation of centroid, separation, and relative intensities of two incoherent point sources using a linear optical…

Quantum Physics · Physics 2018-07-04 J. Rehacek , Z. Hradil , D. Koutny , J. Grover , A. Krzic , L. L. Sanchez-Soto

Quantum Metrology is one of the most promising application of quantum technologies. The aim of this research field is the estimation of unknown parameters exploiting quantum resources, whose application can lead to enhanced performances…

Quantum Physics · Physics 2020-03-13 Emanuele Polino , Mauro Valeri , Nicolò Spagnolo , Fabio Sciarrino

A fundamental challenge in multiparameter quantum estimation arises from the incompatibility of optimal measurements for different parameters, leading to intricate precision trade-offs that obscure the understanding of ultimate quantum…

Quantum Physics · Physics 2026-05-25 Lingna Wang , Hongzhen Chen , Haidong Yuan

We investigate quantum parameter estimation based on linear and Kerr-type nonlinear controls in an open quantum system, and consider the dissipation rate as an unknown parameter. We show that while the precision of parameter estimation is…

Quantum Physics · Physics 2017-12-12 Beili Gong , Wei Cui

Optimal measurements for quantum multiparameter estimation are complicated by the uncertainty principle. Generally, there is a trade-off between the precision with which different parameters can be simultaneously estimated. The task of…

Quantum Physics · Physics 2025-11-20 Simon K. Yung , C. M. Yung , Lorcán O. Conlon , Syed M. Assad

Estimating extensive combinations of local parameters in distributed quantum systems is a central problem in quantum sensing, with applications ranging from magnetometry to timekeeping. While optimal strategies are known for sensing…

Continuous-time measurements are instrumental for a multitude of tasks in quantum engineering and quantum control, including the estimation of dynamical parameters of open quantum systems monitored through the environment. However, such…

Quantum Physics · Physics 2023-04-12 Alfred Godley , Madalin Guta

This is a tutorial aimed at illustrating some recent developments in quantum parameter estimation beyond the Cram\`er-Rao bound, as well as their applications in quantum metrology. Our starting point is the observation that there are…

Quantum Physics · Physics 2020-03-06 Luigi Seveso , Matteo G. A. Paris

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

Using quantum systems as sensors or probes has been shown to greatly improve the precision of parameter estimation by exploiting unique quantum features such as entanglement. A major task in quantum sensing is to design the optimal…

Quantum Physics · Physics 2024-06-24 Jessica Bavaresco , Patryk Lipka-Bartosik , Pavel Sekatski , Mohammad Mehboudi

We consider the problem of a state determination for a two-level quantum system which can be in one of two nonorthogonal mixed states. It is proved that for the two independent identical systems the optimal combined measurement (which…

Quantum Physics · Physics 2007-05-23 A. E. Allahverdyan , D. B. Saakian

Quantum sensors are among the most promising quantum technologies, allowing to attain the ultimate precision limit for parameter estimation. In order to achieve this, it is required to fully control and optimize what constitutes the…

Quantum Physics · Physics 2020-05-19 Ilaria Gianani , Marco G. Genoni , Marco Barbieri

We investigate critical quantum metrology,that is the estimation of parameters in many-body systems close to a quantum critical point, through the lens of Bayesian inference theory. We first derive a no-go result stating that any…

Quantum Physics · Physics 2023-10-31 Raffaele Salvia , Mohammad Mehboudi , Martí Perarnau-Llobet

The quest for precision in parameter estimation is a fundamental task in different scientific areas. The relevance of this problem thus provided the motivation to develop methods for the application of quantum resources to estimation…

Quantum Physics · Physics 2024-06-18 Valeria Cimini , Emanuele Polino , Mauro Valeri , Nicolò Spagnolo , Fabio Sciarrino

Quantum phase estimation is fundamental to advancing quantum science and technology. While much of the research has concentrated on estimating a single phase, the simultaneous estimation of multiple phases can yield significantly enhanced…

Quantum Physics · Physics 2025-03-21 Marco Barbieri , Ilaria Gianani , Aaron Z. Goldberg , Luis L. Sánchez-Soto

Adaptive feedback schemes are promising for quantum-enhanced measurements yet are complicated to design. Machine learning can autonomously generate algorithms in a classical setting. Here we adapt machine learning for quantum information…

Quantum Physics · Physics 2010-02-25 Alexander Hentschel , Barry C. Sanders

Quantum metrology seeks to leverage the richness of quantum systems for making better measurements than are possible using only classical resources in order to gain a ``quantum advantage''. Quantum metrology schemes must also be resilient…

Critical quantum metrology relies on the extreme sensitivity of a system's eigenstates near the critical point of a quantum phase transition to Hamiltonian perturbations. This means that these eigenstates are extremely sensitive to all the…

Quantum Physics · Physics 2025-06-12 George Mihailescu , Steve Campbell , Karol Gietka