Fluctuation and Noise Letters

PROBING BELL'S INEQUALITY WITH CLASSICAL SYSTEMS

David K. Ferry

Published Aug 23, 2010• 5 citations

Abstract

From the early days of quantum mechanics, there has been a discussion on the concept of reality, exemplified by the EPR paradox. To many, the idea of the paradox and the possibility of local hidden variables was dismissed by the Bell inequality. Yet, there remains considerable evidence that this inequality can be violated even by classical systems, so that experiments showing quantum behavior and the violation of the inequality must be questioned. Here, we demonstrate that classical optical polarization experiments can be shown to violate the Bell inequality. Hence, such experiments cannot be used to distinguish between classical and quantum theories.

DOI: 10.1142/s0219477510000307

Related papers

Bell's Inequality: Excluding Local Realism from a Physical Theory of Nature

Jack H. Berg, Fredrik Brange

An overview of the history of Bell’s inequality is given, beginning with the so-called EPR paradox originally put forward by Einstein, Podolsky and Rosen and the impossibility proof of von Neumann. Bell’s inequality, which ultimately shifted the discussion from arguments based on philosophically introduced postulates to the domain of experimental physics, is presented together with experimental attempts from the early 1970s to 2010s to violate this inequality. We introduce three historical loopholes in the experimental schemes which have prevented experimentalists from being able to fully disprove the possibility of a hidden-variables description of nature. Recent experimental data indicate that all the main loopholes are now closed for photons (albeit not simultaneously in one experiment). Besides the class of stochastic local realism that have been tested experimentally, some other possible classical interpretations are mentioned.

Jan 1, 20130 citations

Experimental Counterexample to Bell’s Locality Criterion

Ghenadie N. Mardari

The EPR paradox was caused by the provision that quantum variables must have pre-existing values. This type of "hidden property realism" was later falsified by Bell's Theorem. Accordingly, the physical basis for action-at-a-distance between entangled quanta was removed. Yet, modern interpretations present Bell's inequality as a Locality Criterion, as if Bell violations can only happen at the quantum level, and only with remote interactions. This is a questionable practice, considering that classical joint measurements also violate such inequalities for mutually exclusive wave properties. In particular, consecutive measurements of polarization produce the same coefficients of correlation as parallel measurements with entangled quanta, yet they are explicitly local. Furthermore, it is possible to combine parallel and consecutive measurements of Type I polarization-entangled photons in a single experiment, conclusively showing that quantum Bell violations can be local. Surprisingly, classical phenomena also require nonlocal interpretations if pre-existing properties are taken for granted. Hence, the solution is to reject the models with pre-existing properties for both classical and quantum wave-like phenomena.

EntropyNov 29, 20226 citations

NOISE AND BELL'S INEQUALITY

David K. Ferry, László B. Kish

To many, the idea of the EPR paradox and the possibility of local hidden variables were dismissed by the Bell inequality, although the central points of this argument have been around since the advent of quantum mechanics. Yet, there remains considerable evidence that this inequality can be violated even by classical systems. The question really is whether or not strongly correlated classical fields will also violate Bell's inequality. In a previous paper, it was shown that this was the case. Here, we ask the question as to just how much correlation in the classical waves is required to violate the inequality.

arXiv:1008.0667Fluctuation and Noise LettersAug 23, 20101 citation

The EPR paradox, Bell’s inequality, and the question of locality

Guy Blaylock

Most physicists agree that the Einstein–Podolsky–Rosen–Bell paradox exemplifies much of the strange behavior of quantum mechanics, but argument persists about what assumptions underlie the paradox. To clarify what the debate is about, we employ a simple and well-known thought experiment involving two correlated photons to help us focus on the logical assumptions needed to construct the EPR and Bell arguments. The view presented in this paper is that the minimal assumptions behind Bell’s inequality are locality and counterfactual definiteness but not scientific realism, determinism, or hidden variables as are often suggested. We further examine the resulting constraints on physical theory with an illustration from the many-worlds interpretation of quantum mechanics—an interpretation that we argue is deterministic, local, and realist but that nonetheless violates the Bell inequality.

arXiv:0902.3827American Journal of PhysicsDec 14, 200959 citations

Do Quantum Measurements Reveal Pre-existing Properties?

Ghenadie N. Mardari

The EPR paradox was caused by the provision that quantum variables must have pre-existing values. This type of “hidden property realism” was later falsified by Bell’s Theorem. Yet, modern interpretations of quantum entanglement still insist on the reality of pre-existing properties, whether explicitly or implicitly. Instead, they treat Bell’s inequality as a Locality Criterion. This is a questionable practice, considering that classical joint measurements also violate such inequalities for mutually exclusive wave properties. In particular, consecutive measurements of polarization produce the same coefficients of correlation as parallel measurements with polarization-entangled quanta, yet they are explicitly local. Nonetheless, they also require nonlocal interpretations if pre-existing properties are taken for granted. The solution is to reject the models with pre-existing properties for both classical and quantum wave-like phenomena.

Nov 7, 20220 citations

Bell's Theorem and Inequalities, with Experimental Considerations

Niclas Hoglund, Olof H. Jacobson

Bell's theorem is an important milestone in the development of quantum mechanics. It draws a line between concepts such as realism and locality on the one hand and quantum mechanics on the other. Experimentally veried violations of Bell inequalities can yield important information about what assumptions can be made about physical reality. Experiments have been conducted for over 40 years, but have left loopholes open in their executions. It is of great interest to close these loopholes, and in order to do so, further experiments are needed. The objective of this project is to investigate the underlying, previous work in the eld and to formulate a proposal for a new experiment. To do this, the derivations of the original Bell inequality and the CHSH inequality are presented along with previously conducted experiments. Also presented is the EPR paradox from which sprung the original Bell inequality.

Jan 1, 20133 citations