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Related papers: Optimal quantum parameter estimation of two intera…

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We analyze decoherence-free (DF) quantum information in the presence of an arbitrary non-nearest-neighbor bath-induced system Hamiltonian using a Markovian master equation. We show that the most appropriate encoding for N qubits is probably…

Quantum Physics · Physics 2008-06-25 Peter G. Brooke , James D. Cresser , Manas K. Patra

In this article we derive a measure of quantumness in quantum multi-parameter estimation problems. We can show that the ratio between the mean Uhlmann Curvature and the Fisher Information provides a figure of merit which estimates the…

Quantum Physics · Physics 2020-01-01 Angelo Carollo , Bernardo Spagnolo , Alexander A. Dubkov , Davide Valenti

The application of quantum estimation theory to the problem of imaging two incoherent point sources has recently led to new insights and better measurements for incoherent imaging and spectroscopy. To establish a more general limit beyond…

Quantum Physics · Physics 2019-01-09 Mankei Tsang

Quantum probing is the art of exploiting simple quantum systems interacting with a complex environment to extract precise information about some environmental parameters, e.g. the temperature of the environment or its spectral density. Here…

Quantum Physics · Physics 2020-08-26 Dario Tamascelli , Claudia Benedetti , Heinz-Peter Breuer , Matteo G. A. Paris

We revisit the problem of thermalization process for an Unruh-DeWitt (UDW) detector in de Sitter space. We derive the full dynamics of the detector in the context of open quantum system, neither using Markovian or RWA approximations. We…

High Energy Physics - Theory · Physics 2025-06-09 Langxuan Chen , Jun Feng

We study the precision of parameter estimation for dephasing model under squeezed environment. We analytically calculate the dephasing factor $\gamma(t)$ and obtain the analytic quantum Fisher information (QFI) for the amplitude parameter…

Quantum Physics · Physics 2018-02-27 Shao-xiong Wu , Chang-shui Yu

Real quantum systems couple to their environment and lose their intrinsic quantum nature through the process known as decoherence. Here we present a method for minimizing decoherence by making it energetically unfavorable. We present a…

Quantum Physics · Physics 2009-11-06 D. Bacon , K. R. Brown , K. B. Whaley

We derive ultimate precision bounds for estimating parameters encoded in \emph{time-dependent} Hamiltonians in the presence of general Markovian noise, allowing for arbitrary adaptive protocols with fast controls and noiseless ancillas.…

Quantum Physics · Physics 2026-05-19 Luca Previdi , Francesco Albarelli

It is difficult to evaluate the precision of quantum measurements because it is not possible to conduct a second reference measurement on the same physical system to compare the measurement outcome with a more accurate value of the measured…

Quantum Physics · Physics 2021-02-10 Holger F. Hofmann

In the last years, a relationship has been established between the quantum Fisher information (QFI) and quantum entanglement. In the case of two-qubit systems, all pure entangled states can be made useful for sub-shot-noise interferometry…

Quantum Physics · Physics 2019-11-11 Stefano Scali , Roberto Franzosi

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

The quantum Fisher information (QFI) is a fundamental quantity of interest in many areas from quantum metrology to quantum information theory. It can in particular be used as a witness to establish the degree of multi-particle entanglement…

Quantum Physics · Physics 2023-01-26 Aniket Rath , Cyril Branciard , Anna Minguzzi , Benoît Vermersch

A quantum measurement is Fisher symmetric if it provides uniform and maximal information on all parameters that characterize the quantum state of interest. Using (complex projective) 2-designs, we construct measurements on a pair of…

Quantum Physics · Physics 2018-01-25 Huangjun Zhu , Masahito Hayashi

We propose a scheme for parameter estimation with the steady states of non-Hermitian spin chains. The parameters to be estimated are encoded in the system via the external magnetic field that imposed on the first site of the chain. We…

Quantum Physics · Physics 2022-06-07 Huiqin Zhang , Jiasen Jin

We show that in presence of a local and uncorrelated dephasing noise, quantum advantage can be obtained in the Fisher information-based lower bound of the minimum uncertainty in estimating parameters of the system Hamiltonian. The quantum…

Quantum Physics · Physics 2024-05-27 Aparajita Bhattacharyya , Ahana Ghoshal , Ujjwal Sen

Quantum illumination leverages entangled lights to detect the presence of low-reflectivity objects within a thermal environment. In a related vein, quantum parameter estimation utilizes nonclassical probes to precisely determine unknown…

Quantum Physics · Physics 2025-06-18 Wei Zhong , Dong-Qing Wang , Wen-Yi Zhu , Lan Zhou , Ming-Ming Du , Yu-Bo Sheng

We examine the effect of multilevels on decoherence and dephasing properties of a quantum system consisting of a non-ideal two level subspace, identified as the qubit and a finite set of higher energy levels above this qubit subspace. The…

Mesoscale and Nanoscale Physics · Physics 2007-05-23 T. Hakioglu , K. Savran

In this manuscript, we investigate the effect of the white and color noise on a accelerated two-qubit system, where different initial state setting are considered. The behavior of the survival amount of entanglement is quantified for this…

Quantum Physics · Physics 2019-07-02 F. Ebrahim , N. Metwally

We study optimal quantum sensing of multiple physical parameters using repeated measurements. In this scenario, the Fisher information framework sets the fundamental limits on sensing performance, yet the optimal states and corresponding…

Quantum Physics · Physics 2024-04-23 Denis V. Vasilyev , Athreya Shankar , Raphael Kaubruegger , Peter Zoller

We show how to verify the metrological usefulness of quantum states based on the expectation values of an arbitrarily chosen set of observables. In particular, we estimate the quantum Fisher information as a figure of merit of metrological…

Quantum Physics · Physics 2017-04-25 Iagoba Apellaniz , Matthias Kleinmann , Otfried Gühne , Geza Toth
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