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A universally valid Heisenberg uncertainty relation is proposed by combining the universally valid error-disturbance uncertainty relation of Ozawa with the relation of Robertson. This form of the uncertainty relation, which is defined with…

Quantum Physics · Physics 2015-06-05 Kazuo Fujikawa

A general theory of preparational uncertainty relations for a quantum particle in one spatial dimension is developed. We derive conditions which determine whether a given smooth function of the particle's variances and its covariance is…

Quantum Physics · Physics 2016-10-18 Spiros Kechrimparis , Stefan Weigert

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

Introductory courses on quantum mechanics usually include lectures on uncertainty relations, typically the inequality derived by Robertson and, perhaps, other statements. For the benefit of the lecturers, we present a unified approach --…

Quantum Physics · Physics 2023-12-18 Berthold-Georg Englert

The quantum rotor represents, after the harmonic oscillator, the next obvious quantum system to study the complementary pair of variables: the angular momentum and the unitary shift operator in angular momentum. Proper quantification of…

Quantum Physics · Physics 2024-08-13 Ladislav Mišta , Matouš Mišta , Zdeněk Hradil

Fluctuation theorems are fundamental results in non-equilibrium thermodynamics. Considering the fluctuation theorem with respect to the entropy production and an observable, we derive a new thermodynamic uncertainty relation which also…

Statistical Mechanics · Physics 2022-02-02 Gianluca Francica

We consider particles prepared by the von Neumann-L\"uders projection. For those particles the standard deviation of the momentum is discussed. We show that infinite standard deviations are not exceptions but rather typical. A necessary and…

Quantum Physics · Physics 2010-06-29 Thomas Schürmann , Ingo Hoffmann

Uncertainty relation lies at the heart of quantum mechanics, characterizing the incompatibility of non-commuting observables in the preparation of quantum states. An important question is how to improve the lower bound of uncertainty…

Quantum Physics · Physics 2017-05-25 Qiu-Cheng Song , Jun-Li Li , Guang-Xiong Peng , Cong-Feng Qiao

The uncertainty relation is a distinguishing feature of quantum theory, characterizing the incompatibility of noncommuting observables in the preparation of quantum states. Recently, many uncertainty relations were proposed with improved…

Quantum Physics · Physics 2017-12-25 Zhi-Xin Chen , Jun-Li Li , Qiu-Cheng Song , Hui Wang , S. M. Zangi , Cong-Feng Qiao

Uncertainty principle plays a vital role in quantum physics. The Wigner-Yanase skew information characterizes the uncertainty of an observable with respect to the measured state. We generalize the uncertainty relations for two quantum…

Quantum Physics · Physics 2021-09-06 Qing-Hua Zhang , Jing-Feng Wu , Shao-Ming Fei

We re-derive the Schr\"{o}dinger-Robertson uncertainty principle for the position and momentum of a quantum particle. Our derivation does not directly employ commutation relations, but works by reduction to an eigenvalue problem related to…

Quantum Physics · Physics 2012-11-15 A. Mandilara , N. J. Cerf

Thermodynamic uncertainty principles make up one of the few rare anchors in the largely uncharted waters of nonequilibrium systems, the fluctuation theorems being the more familiar. In this work we aim to trace the uncertainties of…

Statistical Mechanics · Physics 2022-08-02 Hang Dong , Daniel Reiche , Jen-Tsung Hsiang , Bei-Lok Hu

The Heisenberg uncertainty relation, which links the uncertainties of the position and momentum of a particle, has an important footprint on the quantum behavior of a physical system. Analogous to this principle, we propose that…

Quantum Physics · Physics 2026-02-18 Pratik Sathe , Luis Pedro García-Pintos , Francesco Caravelli

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

Uncertainty relations based on quantum coherence is an important problem in quantum information science. We discuss uncertainty relations for averaged unified ($\alpha$,$\beta$)-relative entropy of coherence under mutually unbiased…

Quantum Physics · Physics 2026-04-08 Baolong Cheng , Zhaoqi Wu

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

"\textit{The noise is the signal}"[R. Landauer, Nature \textbf{392}, 658 (1998)] emphasizes the rich information content encoded in fluctuations. This paper assesses the dynamical role of fluctuations of a quantum system driven far from…

Quantum Physics · Physics 2015-03-10 Yi-Jen Chen , Stefan Pabst , Zheng Li , Oriol Vendrell , Robin Santra

Sharp uncertainty relations restricting the values of variances in the position space and in the momentum (wavevector) space are derived. They have the same form $\Delta r\Delta k\ge 5/2$ in the classical theory of light beams, in the…

Quantum Physics · Physics 2026-05-29 Iwo Bialynicki-Birula , Zofia Bialynicka-Birula

We rederive uncertainty relations for the angular position and momentum of a particle on a circle by employing the exponential of the angle instead of the angle itself, which leads to circular variance as a natural measure of resolution.…

Quantum Physics · Physics 2008-07-25 J. Rehacek , Z. Bouchal , R. Celechovsky , Z. Hradil , L. L. Sanchez-Soto

We report a universal improvement to the standard Robertson--Schr\"odinger uncertainty relation. Our result shows that the Robertson--Schr\"odinger lower bound can be supplemented by a new noncommutativity-induced term. This term represents…

Quantum Physics · Physics 2026-05-19 Gen Kimura , Aina Mayumi , Hiromichi Ohno , Jaeha Lee , Dariusz Chruściński