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For a pair of observables, they are called "incompatible", if and only if the commutator between them does not vanish, which represents one of the key features in quantum mechanics. The question is, how can we characterize the…

Quantum Physics · Physics 2019-10-02 Yunlong Xiao , Cheng Guo , Fei Meng , Naihuan Jing , Man-Hong Yung

In a real expert system, one may have unreliable, unconfident, conflicting estimates of the value for a particular parameter. It is important for decision making that the information present in this aggregate somehow find its way into use.…

Artificial Intelligence · Computer Science 2013-04-15 Henry Hamburger

We derive two quantum uncertainty relations for position and momentum coarse-grained measurements. Building on previous results, we first improve the lower bound for uncertainty relations using the Renyi entropy, particularly in the case of…

Quantum Physics · Physics 2012-11-06 Łukasz Rudnicki , Stephen P. Walborn , Fabricio Toscano

As a foundation of modern physics, uncertainty relations describe an ultimate limit for the measurement uncertainty of incompatible observables. Traditionally, uncertain relations are formulated by mathematical bounds for a specific state.…

Quantum Physics · Physics 2019-09-18 Jie Xie , Songtao Huang , Li Zhou , Aonan Zhang , Huichao Xu , Man-Hong Yung , Nengkun Yu , Lijian Zhang

Historically, the element of uncertainty in quantum mechanics has been expressed through mathematical identities called uncertainty relations, a great many of which continue to be discovered. These relations use diverse measures to quantify…

Quantum Physics · Physics 2016-03-16 Varun Narasimhachar , Alireza Poostindouz , Gilad Gour

A tight information-theoretic measurement uncertainty relation is experimentally tested with neutron spin-1/2 qubits. The noise associated to the measurement of an observable is defined via conditional Shannon entropies and a tradeoff…

Quantum Physics · Physics 2019-02-12 Bülent Demirel , Stephan Sponar , Alastair A. Abbott , Cyril Branciard , Yuji Hasegawa

Heisenberg's measurement uncertainty relations (MUR) of two quantum observables are essential for contemporary researches in quantum foundations and quantum information science. Going beyond, here we report the first experimental test of…

Quantum Physics · Physics 2022-11-24 Ya-Li Mao , Hu Chen , Chang Niu , Zheng-Da Li , Sixia Yu , Jingyun Fan

We show that the uncertainty relation as expressed in the Robertson-Schrodinger generalized form can be used to detect the mixedness of three-level quantum systems in terms of measureable expectation values of suitably chosen observables…

Quantum Physics · Physics 2013-03-14 S. Mal , T. Pramanik , A. S. Majumdar

The concept of quantum coherence, including various ways to quantify the degree of coherence with respect to the prescribed basis, is currently the subject of active research. The complementarity of quantum coherence in different bases was…

Quantum Physics · Physics 2017-09-08 Alexey E. Rastegin

Joint, or simultaneous, measurements of non-commuting observables are possible within quantum mechanics, if one accepts an increase in the variances of the jointly measured observables. In this paper, we discuss joint measurements of a spin…

Quantum Physics · Physics 2009-11-11 Erika Andersson , Stephen M. Barnett , Alain Aspect

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

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 uncertainty relation, as one of the fundamental principles of quantum physics, captures the incompatibility of noncommuting observables in the preparation of quantum states. In this work, we derive two strong and universal uncertainty…

Quantum Physics · Physics 2019-04-10 Zhi-Xin Chen , Hui Wang , Jun-Li Li , Qiu-Cheng Song , Cong-Feng Qiao

The notion of incompatibility of measurements in quantum theory is in stark contrast with the corresponding classical perspective, where all physical observables are jointly measurable. It is of interest to examine if the results of two or…

Quantum Physics · Physics 2015-01-29 H. S. Karthik , A. R. Usha Devi , A. K. Rajagopal

The uncertainty principle sets a bound on our ability to predict the measurement outcomes of two incompatible observables which are measured on a quantum particle simultaneously. In quantum information theory, the uncertainty principle can…

Quantum Physics · Physics 2019-12-03 H. Dolatkhah , S. Haseli , S. Salimi , A. s. Khorashad

The problem of characterising the accuracy of, and disturbance caused by a joint measurement of position and momentum is investigated. In a previous paper the problem was discussed in the context of the unbiased measurements considered by…

Quantum Physics · Physics 2007-05-23 D. M. Appleby

We investigate the uncertainty associated with a joint quantum measurement of two components of spin of a spin-1/2 particle and quantify this in terms of entropy. We consider two entropic quantities: the joint entropy and the sum of the…

Quantum Physics · Physics 2015-05-13 Thomas Brougham , Erika Andersson , Stephen M Barnett

Constructive techniques to establish state-independent uncertainty relations for the sum of variances of arbitrary two observables are presented. We investigate the range of simultaneously attainable pairs of variances, which can be applied…

Quantum Physics · Physics 2019-04-26 Konrad Szymański , Karol Życzkowski

We investigate the problem of jointly testing a pair of composite hypotheses and, depending on the test result, estimating a random parameter under distributional uncertainties. Specifically, it is assumed that the distribution of the data…

Signal Processing · Electrical Eng. & Systems 2026-04-27 Dominik Reinhard , Michael Fauß , Abdelhak M. Zoubir

We describe a setup for obtaining uncertainty relations for arbitrary pairs of observables related by Fourier transform. The physical examples discussed here are standard position and momentum, number and angle, finite qudit systems, and…

Quantum Physics · Physics 2016-01-18 Reinhard F. Werner
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