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We construct uncertainty relation for arbitrary finite dimensional PT invariant non-Hermitian quantum systems within a special inner product framework. This construction is led by good observables which are a more general class of…

Quantum Physics · Physics 2023-04-11 Namrata Shukla , Ranjan Modak , Bhabani Prasad Mandal

The metric-adjusted skew information establishes a connection between the geometrical formulation of quantum statistics and the measures of quantum information. We study uncertainty relations in product and summation forms of…

Quantum Physics · Physics 2022-04-04 Xiaoyu Ma , Qing-Hua Zhang , Shao-Ming Fei

We have introduced a measure of Gaussian quantum correlations based on quantum Fisher information. For bipartite Gaussian states the minimum quantum Fisher information due to local unitary evolution on one of the parties reliably quantifies…

Quantum Physics · Physics 2014-06-20 Manabendra N. Bera

The assumption that an ensemble of classical particles is subject to nonclassical momentum fluctuations, with the fluctuation uncertainty fully determined by the position uncertainty, has been shown to lead from the classical equations of…

General Relativity and Quantum Cosmology · Physics 2008-11-26 Michael J. W. Hall

In recent proposals for achieving optical super-resolution, variants of the Quantum Fisher Information (QFI) quantify the attainable precision. We find that claims about a strong enhancement of the resolution resulting from coherence…

Quantum Physics · Physics 2019-11-14 Zdeněk Hradil , Jaroslav Řeháček , Luis Sánchez-Soto , Berthold-Georg Englert

Uncertainty relations in quantum mechanics express bounds on our ability to simultaneously obtain knowledge about expectation values of non-commuting observables of a quantum system. They quantify trade-offs in accuracy between…

Quantum Physics · Physics 2020-03-16 Ilya Kull , Philippe Allard Guérin , Frank Verstraete

In this work we study various notions of uncertainty for angular momentum in the spin-s representation of SU(2). We characterize the "uncertainty regions'' given by all vectors, whose components are specified by the variances of the three…

Quantum Physics · Physics 2015-10-05 Lars Dammeier , René Schwonnek , Reinhard F. Werner

This paper is concerned with two questions in the decoherent histories approach to quantum mechanics: the emergence of approximate classical predictability, and the fluctuations about it necessitated by the uncertainty principle. We…

General Relativity and Quantum Cosmology · Physics 2009-10-22 J. J. Halliwell

Quantum metrology concerns improving the estimation of an unknown parameter using an optimal measurement scheme on the quantum system. More the optimality of the measurement, the better will be the improvement in sensing the value of the…

Quantum Physics · Physics 2025-07-30 H. S. Karthik

We provide a unified and strengthened framework for the product form and the sum form variance-based uncertainty relations by constructing a unified uncertainty relation. In the unified framework, we deduce that the uncertainties of the…

Quantum Physics · Physics 2020-02-24 Xiao Zheng , Shao-Qiang Ma , Guo-Feng Zhang , Heng Fan , Wu-Ming Liu

The uncertainty relation is a fundamental concept in quantum theory, plays a pivotal role in various quantum information processing tasks. In this study, we explore the additive uncertainty relation pertaining to two or more observables, in…

Quantum Physics · Physics 2024-04-30 Lin Zhang , Dade Wu , Ming-Jing Zhao , Hua Nan

The effect of the quantum feedback on the tightness of the variance-based uncertainty, the possibility of using quantum feedback to prepare the state with a better tightness, and the relationship between the tightness of the uncertainty and…

Quantum Physics · Physics 2017-02-16 Xiao Zheng , Guo-Feng Zhang

The optimal phase estimation strategy is derived when partial a priori knowledge on the estimated phase is available. The structure of the optimal measurements, estimators and the optimal probe states is analyzed. The results fill the gap…

Quantum Physics · Physics 2013-05-29 Rafal Demkowicz-Dobrzanski

We propose a new generalised formalism for estimating the quantum phase uncertainty of pure and mixed continuous-variable quantum states and compare this with the phase uncertainty given by the quantum Fisher information. In order to…

Quantum Physics · Physics 2014-04-02 Jaewoo Joo , Jacob A. Dunningham , Daniel K. L. Oi , Timothy P. Spiller

Quantum Fisher information (QFI) and skew information (SI) plays a key role in the quantum resource theory. Understanding these measures in the physical system has practical significance in the state parameter estimation and quantum…

Quantum Physics · Physics 2021-11-17 R. Muthuganesan , V. K. Chandrasekar

It is known that the variance and entropy of quantum observables decompose into intrinsically quantum and classical contributions. Here a general method of constructing quantum-classical decompositions of resources such as uncertainty is…

Quantum Physics · Physics 2023-07-07 Michael J. W. Hall

We examine a system in which an impurity qubit is immersed in a quasi-two-dimensional dipolar Bose-Einstein condensate whose collective excitations act as a depasing reservoir for the qubit. The relative dipole-dipole interaction strength…

Quantum Physics · Physics 2024-12-02 Ji-Bing Yuan , Hai-Fei Liu , Ya-Ju Song , Shi-Qing Tang , Xin-Wen Wang , Le-Man Kuang

The development and improvement of analytical methods for evaluating nonclassical correlations is one of the most important tasks in quantum information science. In this paper, we investigate a mixed spin-$(1/2,S)$ system with an arbitrary…

Quantum Physics · Physics 2025-06-06 Saeed Haddadi , Elena I. Kuznetsova , M. A. Yurischev

We study sum uncertainty relations for arbitrary finite $N$ quantum mechanical observables. Some uncertainty inequalities are presented by using skew information introduced by Wigner and Yanase. These uncertainty inequalities are nontrivial…

Quantum Physics · Physics 2016-06-07 Bin Chen , Shao-Ming Fei , Gui-Lu Long

Quantum metrology leverages quantum effects such as squeezing, entanglement, and other quantum correlations to boost precision in parameter estimation by saturating quantum Cramer Rao bound, which can be achieved by optimizing quantum…

Quantum Physics · Physics 2024-12-03 A. Naimy , A. Slaoui , A. Ali , H. El Hadfi , R. Ahl Laamara , S. Al-Kuwari