Bell's theorem

(redirected from Bell inequality)

Bell's theorem

[′belz ‚thir·əm]
(quantum mechanics)
A theorem which states that any hidden variable that satisifies the condition of locality cannot possibly reproduce all the statistical predictions of quantum mechanics, and which places upper limits, for the predictions of any such theory, on the strength of correlations between measurements of spatially separated objects, whereas quantum mechanics predicts very strong correlations between such measurements.
References in periodicals archive ?
Loophole-free Bell inequality violation using electron spins separated by 1.
In addition to having introduced this concept, Bell also derived the very first Bell inequality with which he was capable of proving the nonlocality of the two-qubit state |[psi]) := 1/[square root 2] = (|01> - |10>) (Bell 1964).
Here, we comment on a couple of remarks: The first implication is restrictive in the sense that there exist entangled local states (states that do not violate any Bell inequality, in particular, the CHSH inequality), although useful for teleportation (Popescu 1994).
A Relevant Two Qubit Bell Inequality Inequivalent to the CHSH Inequality, Journal of Physics A: Mathematical and General, 37(5):1775, 2004 doi:10.
The Einstein-Podolsky-Rosen (EPR) paradox and Bell inequality in quantum theory is one of the examples examined by Jaynes in [11].
that the physical circumstance that explains both experimental and quantum mechanical violations of the Bell inequality is nothing more nor less than the nonseparability at the heart of the quantum mechanical interaction formalism' (Howard [1992], p.
In another paper I show that we can derive the Bell inequality from two independent assumptions--the separability principle and the locality principle .
If my derivation of the Bell inequality is sound, then the interpretation of the results of the Bell experiments is simple.
For this reason the EPR paper appears legitimate from a rational point of view, although in fact wrong from a physical point of view; indeed a separate theoretical tool, the Bell inequality [7], was necessary to evidence the inconsistency of the EPR attempt [8, 9] : the predictions of local realism on which is based the Bell inequality conflict with the results obtained in various experiments, e.
In principle one could not exclude that the wave function, from which is extracted all physical information allowed about the quantum systems, could actually contain hidden variables; indeed this chance, reasonably suspected in the famous EPR paper, has been excluded later thanks to a separate theoretical tool only, the Bell inequality.
One central element in Brown's defence turns on a novel interpretation of the experimental violations of the Bell inequality.
In this paper, I first discussed the intuitively compelling local realism assumptions needed to derive a Bell inequality.