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

arXiv:quant-ph/0010023 · Physical Review Letters

Incompatibility of Macroscopic Local Realism with Quantum Mechanics in Measurements with Macroscopic Uncertainties

M. D. Reid

Published Mar 27, 2000• 24 citations
arXivHTMLPDF

Abstract

We show that quantum mechanics predicts a contradiction with local hidden variable theories for photon number measurements which have limited resolving power, to the point of imposing an uncertainty in the photon number result which is macroscopic in absolute terms. We show how this can be interpreted as a failure of a new premise, macroscopic local realism.

DOI
10.1103/physrevlett.84.2765

Related papers

New Tests of Macroscopic Local Realism using Continuous Variable Measurements

M. D. Reid

We show that quantum mechanics predicts an Einstein-Podolsky-Rosen paradox (EPR), and also a contradiction with local hidden variable theories, for photon number measurements which have limited resolving power, to the point of imposing an uncertainty in the photon number result which is macroscopic in absolute terms. We show how this can be interpreted as a failure of a new, very strong premise, called macroscopic local realism. We link this premise to the Schrodinger-cat paradox. Our proposed experiments ensure all fields incident on each measurement apparatus are macroscopic. We show that an alternative measurement scheme corresponds to balanced homodyne detection of quadrature phase amplitudes. The implication is that where either EPR correlations or failure of local realism is predicted for continuous variable (quadrature phase amplitude) measurements, one can perform a modified experiment which would lead to conclusions about the much stronger premise of macroscopic local realism.

arXiv:quant-ph/0101050•Jan 12, 2001•0 citations

Violations of Bell inequalities for measurements with macroscopic uncertainties: What it means to violate macroscopic local realism

M. D. Reid

We suggest a method to test the premise of ``macroscopic local realism'' that is sufficient to derive Bell inequalities when measurements of photon numbers are only accurate to an uncertainty of order n photons, where n is macroscopic. Macroscopic local realism is only sufficient to imply, in the context of the original Einstein-Podolsky-Rosen argument, fuzzy ``elements of reality'' that have a macroscopic indeterminacy. We show therefore how the violation of local realism in the presence of macroscopic uncertainties implies the failure of macroscopic local realism. Quantum states violating this macroscopic local realism are presented.

arXiv:quant-ph/0009016•Physical Review A•Jul 18, 2000•14 citations

Macroscopic local realism incompatible with quantum mechanics: failure of local realism where measurements give macroscopic uncertainties

Reid

Quantum Electronics and Laser Science Conference•Jan 1, 2000•0 citations

Macroscopic elements of reality and the Einstein - Podolsky - Rosen paradox

M. D. Reid

We consider a new version of the Einstein - Podolsky - Rosen (EPR) paradox in which the measurements have limited accuracy, so that a photon number is specified only to plus or minus a macroscopic number of photons. In our example the minimum quantum uncertainty product for the two relevant conjugate quantities is itself a macroscopic photon number. This new version of the EPR situation is stronger than the original microscopic versions, which were based on the validity, now disproved by Bell experiments, of `local realism' at a microscopic level. The new version is based on the validity of `macroscopic local realism', which has to date not been questioned.

Quantum and Semiclassical Optics Journal of the European Optical Society Part B•Jun 1, 1997•9 citations

Reality and Non-Reality of Physical Variables(Issues in the Philosophy of Quantum Mechanics (2))

Hisato Shirai

Quantum mechanics is widely believed to be inconsistent with local realism because J.S. Bell proved the contradiction between quantum mechanics and the hidden variable theories based on reality and locality of matter. As described herein, the relation between quantum mechanics and local realism is discussed. This paper presents the question of whether any version of local realism is contradicted by quantum mechanics. The answer is negative. An interpretation is proposed by which the contradiction is explained using physical variables of two types: (1) physical variables of the first type, such as positions and angles (i.e. coordinates), are realistic variables and always possess definite values independently of measurements; (2) those of the second type, such as momenta, angular momenta, and spins (i.e., conserved quantities), are non-realistic variables, which possess no value before measurement. Value definiteness of the first type provides a reliable basis to physical reality of matter, and non-reality of the second type might solve the problem of inconsistency between quantum mechanics and local realism.

Annals of the Japan Association for Philosophy of Science•Jan 1, 2009•1 citation

Incompatibility between quantum mechanics and classical realism in the ‘‘strong’’ macroscopic limit

Dipankar Home, A. S. Majumdar

We consider a state of N correlated particles, each with spin j, in which the quantum expectation value of an operator A^ is evaluated. This is found to exceed a bound on A^ obtained from considerations of classical realism. It is indicated from numerical results that this contradiction between quantum mechanics and classical realism persists in the ``strong'' macroscopic limit, i.e., when the values of both N and j are arbitrarily increased. In this argument, the notion of classical realism embodies the twin assumptions of locality (no action at a distance) and noncontextuality (a measurement simply reveals the preexisting value of an observed quantity).

Physical Review A•Dec 1, 1995•32 citations
We show that quantum mechanics predicts a contradiction with local hidden variable theories for photon number measurements which have limited resolving power, to the point of imposing an uncertainty in the photon number result which is macroscopic in absolute terms. We show how this can be interpreted as a failure of a new premise, macroscopic local realism.
We show that quantum mechanics predicts an Einstein-Podolsky-Rosen paradox (EPR), and also a contradiction with local hidden variable theories, for photon number measurements which have limited resolving power, to the point of imposing an uncertainty in the photon number result which is macroscopic in absolute terms. We show how this can be interpreted as a failure of a new, very strong premise, called macroscopic local realism. We link this premise to the Schrodinger-cat paradox. Our proposed experiments ensure all fields incident on each measurement apparatus are macroscopic. We show that an alternative measurement scheme corresponds to balanced homodyne detection of quadrature phase amplitudes. The implication is that where either EPR correlations or failure of local realism is predicted for continuous variable (quadrature phase amplitude) measurements, one can perform a modified experiment which would lead to conclusions about the much stronger premise of macroscopic local realism.
We suggest a method to test the premise of ``macroscopic local realism'' that is sufficient to derive Bell inequalities when measurements of photon numbers are only accurate to an uncertainty of order n photons, where n is macroscopic. Macroscopic local realism is only sufficient to imply, in the context of the original Einstein-Podolsky-Rosen argument, fuzzy ``elements of reality'' that have a macroscopic indeterminacy. We show therefore how the violation of local realism in the presence of macroscopic uncertainties implies the failure of macroscopic local realism. Quantum states violating this macroscopic local realism are presented.
We consider a new version of the Einstein - Podolsky - Rosen (EPR) paradox in which the measurements have limited accuracy, so that a photon number is specified only to plus or minus a macroscopic number of photons. In our example the minimum quantum uncertainty product for the two relevant conjugate quantities is itself a macroscopic photon number. This new version of the EPR situation is stronger than the original microscopic versions, which were based on the validity, now disproved by Bell experiments, of `local realism' at a microscopic level. The new version is based on the validity of `macroscopic local realism', which has to date not been questioned.
Quantum mechanics is widely believed to be inconsistent with local realism because J.S. Bell proved the contradiction between quantum mechanics and the hidden variable theories based on reality and locality of matter. As described herein, the relation between quantum mechanics and local realism is discussed. This paper presents the question of whether any version of local realism is contradicted by quantum mechanics. The answer is negative. An interpretation is proposed by which the contradiction is explained using physical variables of two types: (1) physical variables of the first type, such as positions and angles (i.e. coordinates), are realistic variables and always possess definite values independently of measurements; (2) those of the second type, such as momenta, angular momenta, and spins (i.e., conserved quantities), are non-realistic variables, which possess no value before measurement. Value definiteness of the first type provides a reliable basis to physical reality of matter, and non-reality of the second type might solve the problem of inconsistency between quantum mechanics and local realism.
We consider a state of N correlated particles, each with spin j, in which the quantum expectation value of an operator A^ is evaluated. This is found to exceed a bound on A^ obtained from considerations of classical realism. It is indicated from numerical results that this contradiction between quantum mechanics and classical realism persists in the ``strong'' macroscopic limit, i.e., when the values of both N and j are arbitrarily increased. In this argument, the notion of classical realism embodies the twin assumptions of locality (no action at a distance) and noncontextuality (a measurement simply reveals the preexisting value of an observed quantity).