Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Log inSign up
Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Blog
Job Board
Q3AS

© 2026 Aqora Quantum S.A.S.

TermsPrivacyLegal Notice

Journal of Physics A Mathematical and General

Minimal uncertainty and maximal information for quantum position and momentum

Paul Busch, PEKKA J. LAHTI

Published Mar 11, 1987• 9 citations
Publisher

Abstract

In view of the recently proposed entropic uncertainty relations several characterisations of 'maximal information' and 'minimal uncertainty' are compared and applied to position and momentum. It is argued that a sufficiently refined entropic uncertainty relation might require the general concept of POV observables as used in stochastic quantum mechanics.

DOI
10.1088/0305-4470/20/4/024

Related papers

Position-momentum uncertainty relations in the presence of quantum memory

Fabian Furrer, Mario Berta, Marco Tomamichel +2 more

A prominent formulation of the uncertainty principle identifies the fundamental quantum feature that no particle may be prepared with certain outcomes for both position and momentum measurements. Often the statistical uncertainties are thereby measured in terms of entropies providing a clear operational interpretation in information theory and cryptography. Recently, entropic uncertainty relations have been used to show that the uncertainty can be reduced in the presence of entanglement and to prove security of quantum cryptographic tasks. However, much of this recent progress has been focused on observables with only a finite number of outcomes not including Heisenberg’s original setting of position and momentum observables. Here, we show entropic uncertainty relations for general observables with discrete but infinite or continuous spectrum that take into account the power of an entangled observer. As an illustration, we evaluate the uncertainty relations for position and momentum measurements, which is operationally significant in that it implies security of a quantum key distribution scheme based on homodyne detection of squeezed Gaussian states.

arXiv:1308.4527•Journal of Mathematical Physics•Dec 1, 2014•67 citations

Quantum observables: Compatibility versus commutativity and maximal information

Paul Busch, Thomas P. Schonbek, Franklin E. Schroeck

Two different approaches to a characterization of the degree of (in)compatibility of quantum observables are investigated. First, recent examples of the (partial) commutativity of spectral measures of incompatible observables are proved to be generic. The analysis is extended to the case of compatible or incompatible unsharp, or stochastic observables, leading to a general criterion for commutativity of position and momentum effects. Further, a recently proposed information theoretic quantification of the (in)compatibility of noncommuting observables is generalized, and the relation between ‘‘maximal information,’’ ‘‘minimal uncertainty,’’ partial commutativity, and strict correlation is further clarified. Both approaches are illustrated in a number of examples.

Journal of Mathematical Physics•Dec 1, 1987•23 citations

A note on entropic uncertainty relations of position and momentum

Thomas Schürmann

We consider two entropic uncertainty relations of position and momentum recently discussed in the literature. By a suitable rescaling of one of them, we obtain a smooth interpolation for both high-resolution and low-resolution measurements, respectively. Because our interpolation has never been mentioned in the literature before, we propose it as a candidate for an improved entropic uncertainty relation of position and momentum. Up to now, we have neither been able to falsify nor prove the new inequality. In our opinion, it is a challenge to do either one.

•Jan 1, 2012•2 citations

Entropic uncertainty minimum for angle and angular momentum

Alison M. Yao, Thomas Brougham, Electra Eleftheriadou +2 more

Uncertainty relations are key components in the understanding of the nature of quantum mechanics. In particular, entropic relations are preferred in the study of angular position and angular momentum states. We propose a new form of angle–angular momentum state that provides, for all practical purposes, a lower bound on the entropic uncertainty relation, , for any given angular uncertainty, thus improving upon previous bounds. We establish this by comparing this sum with the absolute minimum value determined by a global numerical search. These states are convenient to work with both analytically and experimentally, which suggests that they may be of use for quantum information purposes.

Journal of Optics•Sep 23, 2014•1 citation

Entropic uncertainty relations for the infinite well

Vladimír Majerník, Lukáš Richterek

We calculate the entropic and standard uncertainty relations for the position and momentum of the infinite potential well as functions of its quantum states. We show that the entropic uncertainty relations express more adequately the uncertainty principle than the standard ones which use the dispersions as measures of the uncertainties for two non-commuting observables.

Journal of Physics A Mathematical and General•Feb 21, 1997•53 citations

Uncertainty related to position and momentum localization of a quantum state

Łukasz Rudnicki

This paper presents the uncertainty related to position and momentum localization of a quantum state in terms of entropic uncertainty relations. We slightly improve the inequality given in [Phys. Rev. A 74, 052101 (2006)] and introduce a new entropic measure with corresponding uncertainty relation.

arXiv:1010.3269•Oct 15, 2010•7 citations
In view of the recently proposed entropic uncertainty relations several characterisations of 'maximal information' and 'minimal uncertainty' are compared and applied to position and momentum. It is argued that a sufficiently refined entropic uncertainty relation might require the general concept of POV observables as used in stochastic quantum mechanics.
A prominent formulation of the uncertainty principle identifies the fundamental quantum feature that no particle may be prepared with certain outcomes for both position and momentum measurements. Often the statistical uncertainties are thereby measured in terms of entropies providing a clear operational interpretation in information theory and cryptography. Recently, entropic uncertainty relations have been used to show that the uncertainty can be reduced in the presence of entanglement and to prove security of quantum cryptographic tasks. However, much of this recent progress has been focused on observables with only a finite number of outcomes not including Heisenberg’s original setting of position and momentum observables. Here, we show entropic uncertainty relations for general observables with discrete but infinite or continuous spectrum that take into account the power of an entangled observer. As an illustration, we evaluate the uncertainty relations for position and momentum measurements, which is operationally significant in that it implies security of a quantum key distribution scheme based on homodyne detection of squeezed Gaussian states.
Two different approaches to a characterization of the degree of (in)compatibility of quantum observables are investigated. First, recent examples of the (partial) commutativity of spectral measures of incompatible observables are proved to be generic. The analysis is extended to the case of compatible or incompatible unsharp, or stochastic observables, leading to a general criterion for commutativity of position and momentum effects. Further, a recently proposed information theoretic quantification of the (in)compatibility of noncommuting observables is generalized, and the relation between ‘‘maximal information,’’ ‘‘minimal uncertainty,’’ partial commutativity, and strict correlation is further clarified. Both approaches are illustrated in a number of examples.
We consider two entropic uncertainty relations of position and momentum recently discussed in the literature. By a suitable rescaling of one of them, we obtain a smooth interpolation for both high-resolution and low-resolution measurements, respectively. Because our interpolation has never been mentioned in the literature before, we propose it as a candidate for an improved entropic uncertainty relation of position and momentum. Up to now, we have neither been able to falsify nor prove the new inequality. In our opinion, it is a challenge to do either one.
Uncertainty relations are key components in the understanding of the nature of quantum mechanics. In particular, entropic relations are preferred in the study of angular position and angular momentum states. We propose a new form of angle–angular momentum state that provides, for all practical purposes, a lower bound on the entropic uncertainty relation, , for any given angular uncertainty, thus improving upon previous bounds. We establish this by comparing this sum with the absolute minimum value determined by a global numerical search. These states are convenient to work with both analytically and experimentally, which suggests that they may be of use for quantum information purposes.