Do the Experimental Violations of Bell Inequalities Require a Non-Local Interpretation of Quantum Mechanics？

Edward S. Fry, Xinmei Qu, Marlan O. Scully

Catherine E Nisson

Einstein was never satisfied with quantum mechanics. He argued that quantum mechanics was incomplete for two main reasons; it violated the locality principle and the separability principle. The violation of separability is an unavoidable consequence of quantum interactions. Non-separability can be seen in quantum entanglement. Non-locality, however, is more controversial. Einstein and his associates published the EPR paper in order to argue for the incompleteness of quantum mechanics. Years later, John Bell formulated what became known as the Bell Inequalities in response to the EPR paper. The Bell Inequalities are seen as a major obstacle for quantum locality. I will argue that non-locality is not a necessary implication of the Bell Inequalities. The Bell Inequalities were developed using Bell’s locality requirement as a major premise. Bell’s locality requirement can be described in terms of two conditions, parameter independence and outcome independence. A violation of either condition will lead to a violation of the Bell inequalities. Parameter independence is not violated by the results of experimental quantum physics. So, it can be argued that violations of the Bell inequalities are caused by the violation of outcome independence. Such a violation of outcome independence does not imply non-locality if we accept some form of holism or non-separability. Thus, by including some form of holism or non-separability into our picture of the quantum realm we can develop a theory that does not conflict with locality. This paper will discuss different types of holism and non-separability and how they can be used to help understand quantum phenomena.

Agung Budiyono

De Muynck, W M

The discussion of the foundations of quantum mechanics is complicated by the fact that a number of different issues are closely entangled. Three of these issues are i) the interpretation of probability, ii) the choice between realist and empiricist interpretations of the mathematical formalism of quantum mechanics, iii) the distinction between measurement and preparation. It will be demonstrated that an interpretation of violation of Bell's inequality by quantum mechanics as evidence of non-locality of the quantum world is a consequence of a particular choice between these alternatives. Also a distinction must be drawn between two forms of realism, viz. a) realist interpretations of quantum mechanics, b) the possibility of hidden-variables (sub-quantum) theories.

Giovanni Di Giuseppe, F. De Martini, D. Boschi

Stéphane Le Corre

The aim of this study is to produce a simulation of EPR experiments violating the CHSH-Bell inequalities using physically interpretable objects (properties defined before measurement) and interactions (no supraliminal communication), without influence from any theory. It turns out that the proposed model systematically violates the CHSH-Bell inequalities reaching all the values ( 2 ≤ S ≤ 4 ) . Our simulation reproduces experimental entanglements with greater efficiency. This approach has at least two consequences. First, it demonstrates that violations of the CHSH-Bell inequalities are possible while still verifying the principles of realism and locality, but in a different sense from that of Bell’s theorem. Therefore, Bell’s theorem itself is not called into question, nor are the results of the EPR experiments. However, it is the deduction that leads to the current interpretation (often described as strange because it does not follow one of the principles of realism and locality as defined by Bell’s theorem) that is challenged. Second, it challenges real-world EPR experiments to exceed the efficiency rates of our simulation. Our idealization demonstrates that, between the efficiency rates required to confirm the violation of Bell’s inequalities and the efficiency rates of our idealization, the interpretation of experiments remains possible within a framework of “classical” physical principles (properties defined before measurement and no supraliminal communication). Confirming the strangeness of quantum mechanics would therefore require obtaining efficiency rates higher than those of Bell’s theorem.