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Entropic uncertainty relations place nontrivial lower bounds to the sum of Shannon information entropies for noncommuting observables. Here we obtain a novel lower bound on the entropy sum for general pairs of observables in…

Quantum Physics · Physics 2009-11-13 Julio I. de Vicente , Jorge Sánchez-Ruiz

Uncertainty lower bounds for parameter estimations associated with a unitary family of mixed-state density matrices are obtained by embedding the space of density matrices in the Hilbert space of square-root density matrices. In the…

Quantum Physics · Physics 2021-10-20 Alex J. Belfield , Dorje C. Brody

We study entropic uncertainty relations by using stepwise linear functions and quadratic functions. Two kinds of improved uncertainty lower bounds are constructed: the state-independent one based on the lower bound of Shannon entropy and…

Quantum Physics · Physics 2018-11-14 Zhihua Chen , Zhihao Ma , Yunlong Xiao , Shao-Ming Fei

Conventional quantum uncertainty relations (URs) contain dispersions of two observables. Generalized URs are known which contain three or more dispersions. They are derived here starting with suitable generalized Cauchy inequalities. It is…

Quantum Physics · Physics 2007-05-23 M. I. Shirokov

A new lower boundary for the product of variances of two observables is obtained in the case, when these observables are entangled with the third one. This boundary can be higher than the Robertson--Schr\"odinger one. The special case of…

Quantum Physics · Physics 2017-11-13 V. V. Dodonov

Uncertainty relations are old, yet potentially rewarding to explore. By introducing a quantity called the uncertainty matrix, we provide a link between purity and observable incompatibility, and derive several stronger uncertainty relations…

Quantum Physics · Physics 2018-07-02 Chiranjib Mukhopadhyay , Arun Kumar Pati

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

Heisenberg-Robertson's uncertainty relation expresses a limitation in the possible preparations of the system by giving a lower bound to the product of the variances of two observables in terms of their commutator. Notably, it does not…

Quantum Physics · Physics 2015-01-07 Lorenzo Maccone , Arun K. Pati

We introduce a self-consistent theoretical framework associated with the Schwinger unitary operators whose basic mathematical rules embrace a new uncertainty principle that generalizes and strengthens the Massar-Spindel inequality. Among…

Quantum Physics · Physics 2013-06-28 Marcelo A. Marchiolli , Paulo E. M. F. Mendonca

The uncertainty relation of three quantities in quantum mechanics is estimated in terms of commutators. The Pauli matrices are used to find a contribution of third-order commutators. The resulting inequality refines the Heisenberg…

Quantum Physics · Physics 2025-01-30 Sergei P. Efimov

We formulate uncertainty relations for arbitrary finite number of incompatible observables. Based on the sum of variances of the observables, both Heisenberg-type and Schr\"{o}dinger-type uncertainty relations are provided. These new lower…

Quantum Physics · Physics 2016-08-23 Bin Chen , Ning-Ping Cao , Shao-Ming Fei , Gui-Lu Long

Uncertainty relations are pivotal in delineating the limits of simultaneous measurements for observables. In this paper, we derive four novel uncertainty and reverse uncertainty relations for the sum of variances of two incompatible…

Quantum Physics · Physics 2025-08-05 M. Y. Abd-Rabbou , Cong-Feng Qiao

Learning physical properties of a quantum system is essential for the developments of quantum technologies. However, Heisenberg's uncertainty principle constrains the potential knowledge one can simultaneously have about a system in quantum…

Quantum Physics · Physics 2022-05-25 Yunlong Xiao , Naihuan Jing , Bing Yu , Shao-Ming Fei , Xianqing Li-Jost

Characteristic uncertainty relations and their related squeezed states are briefly reviewed and compared in accordance with the generalizations of three equivalent definitions of the canonical coherent states. The standard SU(1,1) coherent…

Quantum Physics · Physics 2009-11-06 D. A. Trifonov

We construct a multi-observable uncertainty equality as well as an inequality based on the sum of standard deviations in the qubit system. The obtained equality indicates that the uncertainty relation can be expressed more accurately, and…

Quantum Physics · Physics 2020-06-08 Xiao Zheng , Shaoqiang Ma , Guofeng Zhang

We introduce two uncertainty relations based on the state-dependent norm of commutators, utilizing generalizations of the B\"ottcher-Wenzel inequality. The first relation is mathematically proven, while the second, tighter relation is…

Quantum Physics · Physics 2024-12-30 Aina Mayumi , Gen Kimura , Hiromichi Ohno , Dariusz Chruściński

A scheme for construction of uncertainty relations (UR) for n observables and m states is presented. Several lowest order UR are displayed and briefly discussed. For two states |\psi> and |\phi> and canonical observables the (entangled)…

Quantum Physics · Physics 2009-11-06 D. A. Trifonov

We analyze entropic uncertainty relations in a finite dimensional Hilbert space and derive several strong bounds for the sum of two entropies obtained in projective measurements with respect to any two orthogonal bases. We improve the…

Quantum Physics · Physics 2015-06-30 Łukasz Rudnicki , Zbigniew Puchała , Karol Życzkowski

The upper bound of the fine-grained uncertainty relation is different for classical physics, quantum physics and no-signaling theories with maximal nonlocality (supper quantum correlation), as was shown in the case of bipartite systems [J.…

Quantum Physics · Physics 2013-05-30 T. Pramanik , A. S. Majumdar

Number-phase uncertainty relations are formulated in terms of unified entropies which form a family of two-parametric extensions of the Shannon entropy. For two generalized measurements, unified-entropy uncertainty relations are given in…

Quantum Physics · Physics 2012-06-26 Alexey E. Rastegin