Investigations of local-realism and the quantum phase

Alexander Afriat, F. Selleri

Moamer Hasanovic

This chapter investigates quantum entanglement and teleportation, challenging local realism by demonstrating quantum mechanics' inconsistency with locality and realism. It begins with Einstein's skepticism towards entanglement and introduces Bell's theorem as a framework to test local realism, showing how quantum systems violate Bell's inequality. The chapter details experiments with entangled photon pairs, highlighting their non-local correlations and probabilistic nature, and contrasts these with classical correlations. It explains quantum teleportation, its process, and applications in quantum networks, concluding with the operational principles of an entanglement generator and its role in secure quantum communication.

Gary Bruno Schmid, Rudolf M. Dünki

It has been experimentally confirmed that quantum physical phenomena can violate the Information Bell Inequalities. A violation of the one or the other of these Information Bell Inequalites is equivalent to a violation of local realism meaning that either objectivity or locality, or both, do not hold for the phenomena under investigation. We propose (1) an experimental design for carrying out classical measurements in the absence of ontological complementarity; (2) a rational way to extract epistemologically complementary (pseudocomplementary) data from it; (3) a statistical approach which can reject stochastic and/or suspected violations of local realism in measurements of such data.

J. W. de Roever, Martin Streng

Reinhard K. Erdmann, Michael L. Fanto, Corey J. Peters +3 more

Experimental measurements of entangled photons have enabled effective probing of foundational principles of physical law, Quantum Mechanics (QM) in particular. When it was noted that QM is non-local and precludes certain real properties, change in the description of basic phenomena was required. Bell's Inequality work clarified this conflict with Local-Realistic descriptions but left open whether locality, realism, or both should be abandoned. More recent investigations consider models that maintain forms of non-local realism as alternatives to QM. Problems with those are illustrated here, and support a non-local QM description of entangled photons having non-determinate properties.