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Related papers: Quantum metrology at level anti-crossing

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We propose to use neural networks to estimate the rates of coherent and incoherent processes in quantum systems from continuous measurement records. In particular, we adapt an image recognition algorithm to recognize the patterns in…

Quantum Physics · Physics 2017-11-15 Eliska Greplova , Christian Kraglund Andersen , Klaus Mølmer

We investigate the limits of thermometry using quantum probes at thermal equilibrium within the Bayesian approach. We consider the possibility of engineering interactions between the probes in order to enhance their sensitivity, as well as…

A general scheme is presented for controlling quantum systems using evolution driven by non-selective von Neumann measurements, with or without an additional tailored electromagnetic field. As an example, a 2-level quantum system controlled…

Quantum Physics · Physics 2007-05-23 Alexander Pechen , Nikolai Il'in , Feng Shuang , Herschel Rabitz

Quantum theory allows the traversing of multiple channels in a superposition of different orders. When the order in which the channels are traversed is controlled by an auxiliary quantum system, various unknown parameters of the channels…

Quantum Physics · Physics 2023-09-27 A. Z. Goldberg , L. L. Sanchez-Soto , K. Heshami

In this thesis we focus on Gaussian quantum metrology in the phase-space formalism and its applications in quantum sensing and the estimation of space-time parameters. We derive new formulae for the optimal estimation of multiple parameters…

Quantum Physics · Physics 2016-10-13 Dominik Šafránek

We address the estimation of a one-parameter family of isometries taking one input into two output systems. This primarily allows us to consider imperfect estimation by accessing only one output system, i.e. through a quantum channel. Then,…

Quantum Physics · Physics 2019-03-14 Milajiguli Rexiti , Stefano Mancini

A scheme is proposed to estimate the system and environmental parameter, the detuning, temperature and the squeezing strength with a high precision by the two-level atom system. It hasn't been reported that the squeezing strength estimation…

Quantum Physics · Physics 2021-05-07 Mengmeng Luo , Wenxiao Liu , Yuetao Chen , Shaoyan Gao

We provide optimal measurement schemes for estimating relative parameters of the quantum state of a pair of spin systems. We prove that the optimal measurements are joint measurements on the pair of systems, meaning that they cannot be…

Quantum Physics · Physics 2007-05-23 Stephen D. Bartlett , Terry Rudolph , Robert W. Spekkens

Quantum metrology harnesses quantum entanglement to improve measurement precision beyond standard quantum limit. Although nonlinear interaction is essential for generating entanglement, during signal accumulation, it becomes detrimental and…

Quantum Physics · Physics 2026-02-06 Jihao Ma , Jiahao Huang , Chaohong Lee

Precision control of a quantum system requires accurate determination of the effective system Hamiltonian. We develop a method for estimating the Hamiltonian parameters for some unknown two-state system and providing uncertainty bounds on…

Preserving the precision of the parameter of interest in the presence of environmental decoherence is an important yet challenging task in dissipative quantum sensing. In this work, we study quantum metrology when the decoherence effect is…

Quantum Physics · Physics 2024-11-05 Jing Yang

Quantum metrology enhances measurement precision by utilising the properties of quantum physics. In interferometry, this is typically achieved by evolving highly-entangled quantum states before performing single-shot measurements to reveal…

Quantum Physics · Physics 2023-01-11 Kawthar Al Rasbi , Almut Beige , Lewis A. Clark

Quantum metrology offers the potential to surpass its classical counterpart, pushing the boundaries of measurement precision toward the ultimate Heisenberg limit. This enhanced precision is normally attained by utilizing large squeezed…

Squeezed light enables quantum-enhanced phase estimation, with crucial applications in both fundamental physics and emerging technologies. To fully exploit the advantage provided by this approach, estimation protocols must remain optimal…

Quantum Physics · Physics 2025-10-17 Giorgio Minati , Enrico Urbani , Nicolò Spagnolo , Valeria Cimini , Fabio Sciarrino

We propose a protocol to overcome the shot noise limit and reach the Heisenberg scaling limit for parameter estimation by using quantum optimal control and a time-reversal strategy. Exemplified through the phase estimation, which can play…

Quantum Physics · Physics 2023-12-25 Da-Wei Luo , Ting Yu

We present a review on quantum metrology and sensing, from its foundations to current applications. Highlights of the review include consideration of both frequentist and Bayesian approaches to parameter estimation; single as well as…

Quantum Physics · Physics 2026-05-27 Priya Ghosh , Tanoy Kanti Konar , Debraj Rakshit , Aditi Sen De , Ujjwal Sen

We present an efficient tensor-network based algorithm for finding the optimal adaptive quantum channel discrimination strategies inspired by recently developed numerical methods in quantum metrology to find the optimal adaptive channel…

Quantum Physics · Physics 2026-02-11 Stanisław Sieniawski , Rafał Demkowicz-Dobrzański

Quantum metrology aims to exploit quantum phenomena to overcome classical limitations in the estimation of relevant parameters. We consider a probe undergoing a phase shift $\varphi$ whose generator is randomly sampled according to a…

Quantum Physics · Physics 2017-06-07 Rozhin Yousefjani , Rosanna Nichols , Shahriar Salimi , Gerardo Adesso

Continuously monitored quantum systems are emerging as promising platforms for quantum metrology, where a central challenge is to identify measurement strategies that optimally extract information about unknown parameters encoded in the…

Quantum Physics · Physics 2026-02-11 Alejandro Vivas-Viaña , Carlos Sánchez Muñoz

We consider the estimation of an unknown parameter $\theta$ through a quantum probe at thermal equilibrium. The probe is assumed to be in a Gibbs state according to its Hamiltonian $H_\theta$, which is divided in a parameter-encoding term…

Quantum Physics · Physics 2026-01-23 Paolo Abiuso , Pavel Sekatski , John Calsamiglia , Martí Perarnau-Llobet