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We propose an experimentally accessible scheme to determine lower bounds on the quantum Fisher information (QFI), which ascertains multipartite entanglement or usefulness for quantum metrology. The scheme is based on comparing the…

Quantum Physics · Physics 2016-03-14 Florian Fröwis , Pavel Sekatski , Wolfgang Dür

We derive upper bounds on the quantum Fisher information in interferometry with $N$ subsystems, e.g. two-level atoms or Gaussian modes, in the presence of arbitrarily correlated Gaussian dephasing including independent and collective…

Quantum Physics · Physics 2014-03-06 Katarzyna Macieszczak

We derive a new variational principle for the quantum Fisher information leading to a simple iterative alternating algorithm, the convergence of which is proved. The case of a fixed measurement, i.e. the classical Fisher information, is…

Quantum Physics · Physics 2013-12-06 Katarzyna Macieszczak

We propose a critical dissipaive quantum metrology schemes for single parameter estimation which are based on a quantum probe consisting of coherently driven ensemble of $N$ spin-1/2 particles under the effect of squeezed, collective spin…

Quantum Physics · Physics 2023-08-16 Venelin P. Pavlov , Diego Porras , Peter A. Ivanov

We prove an extended convexity for quantum Fisher information of a mixed state with a given convex decomposition. This convexity introduces a bound which has two parts: i. classical part associated to the Fisher information of the…

Quantum Physics · Physics 2015-04-09 S. Alipour , A. T. Rezakhani

The interplay of quantum and thermal fluctuations in the vicinity of a quantum critical point characterizes the physics of strongly correlated systems. Here we investigate this interplay from a quantum information perspective presenting the…

Strongly Correlated Electrons · Physics 2018-10-30 Marco Gabbrielli , Augusto Smerzi , Luca Pezzè

In estimating an unknown parameter of a quantum state the quantum Fisher information (QFI) is a pivotal quantity, which depends on the state and its derivate with respect to the unknown parameter. We prove the continuity property for the…

Quantum Physics · Physics 2019-09-16 A. T. Rezakhani , M. Hassani , S. Alipour

The minimum achievable statistical uncertainty in the estimation of physical parameters is determined by the quantum Fisher information. Its computation for noisy systems is still a challenging problem. Using a variational approach, we…

Quantum Physics · Physics 2012-11-21 B. M. Escher , L. Davidovich , N. Zagury , R. L. de Matos Filho

Quantum Fisher information (QFI) is a novel measure of multipartite quantum entanglement that can be measured in inelastic neutron scattering experiments on quantum magnets. In this work, we demonstrate that the QFI can be used to…

Strongly Correlated Electrons · Physics 2025-10-17 Chengkang Zhou , Zhengbang Zhou , Félix Desrochers , Yong Baek Kim , Zi Yang Meng

We show that spin squeezing implies pairwise entanglement for arbitrary symmetric multiqubit states. If the squeezing parameter is less than or equal to 1, we demonstrate a quantitative relation between the squeezing parameter and the…

Quantum Physics · Physics 2009-11-10 Xiaoguang Wang , Barry C. Sanders

The characterization of entanglement is a central problem for the study of quantum many-body dynamics. Here, we propose the quantum Fisher information as a useful tool for the study of multipartite-entanglement dynamics in many-body…

Statistical Mechanics · Physics 2019-02-27 Karol Gietka , Jan Chwedeńczuk , Tomasz Wasak , Francesco Piazza

Quantum Fisher information (QFI) is a measure of multipartite quantum entanglement that can be obtained from inelastic neutron scattering data on quantum magnets. In this work, we demonstrate that the QFI can distinguish an unconventional…

Strongly Correlated Electrons · Physics 2026-03-23 Zhengbang Zhou , Chengkang Zhou , Menghan Song , Yong Baek Kim , Zi Yang Meng

Quantum Fisher information places the fundamental limit to the accuracy of estimating an unknown parameter. Here we shall provide the quantum Fisher information an operational meaning: a mixed state can be so prepared that a given…

Quantum Physics · Physics 2013-02-22 Sixia Yu

We show that the two-axis counter twisting interaction squeezes a coherent spin state into three states of interest in quantum information, namely, the twin-Fock state, the equally-weighted superposition state, and the state that achieves…

Quantum Physics · Physics 2015-01-07 Emi Yukawa , Gerard Milburn , Masahito Ueda , Kae Nemoto

This paper deals with the problem of estimating the coupling constant $\theta$ of a mixing quantum Markov chain. For a repeated measurement on the chain's output we show that the outcomes' time average has an asymptotically normal…

Quantum Physics · Physics 2011-06-23 Madalin Guta

In this work, we study temperature sensing with finite-sized strongly correlated systems exhibiting quantum phase transitions. We use the quantum Fisher information (QFI) approach to quantify the sensitivity in the temperature estimation,…

Quantum mechanics gives a new breakthrough to the field of parameter estimation. In the realm of quantum metrology, the precision of parameter estimation is limited by the quantum Fisher information. We introduce the measures of partial…

Quantum Physics · Physics 2024-11-14 Dong-Ping Xuan , Zhong-Xi Shen , Wen Zhou , Hua Nan , Shao-Ming Fei , Zhi-Xi Wang

The quantum Fisher information matrix provides us with a tool to determine the precision, in any multiparametric estimation protocol, through quantum Cram\'er-Rao bound. In this work, we study simultaneous and individual estimation…

Quantum Physics · Physics 2019-04-17 L. Bakmou , A. Slaoui , M. Daoud , R. Ahl Laamara

In the adiabatic perturbation theory, Berry curvature is related to the generalized force, and the quantum metric tensor is linked with energy fluctuation. While the former is tested with numerous numerical results and experimental…

Quantum Physics · Physics 2023-01-25 Xingyu Zhang , Xiao-Ming Lu , Jing Liu , Wenkui Ding , Xiaoguang Wang

We use extensive numerical simulations based on matrix product state methods to study the quantum dynamics of spin chains with strong on-site disorder and power-law decaying ($1/r^\alpha$) interactions. We focus on two spin-$1/2$…

Disordered Systems and Neural Networks · Physics 2019-03-19 A. Safavi-Naini , M. L. Wall , O. L. Acevedo , A. M. Rey , R. M. Nandkishore