Atomic Cascade Experiments.

Nelson Frederick Beeler, Franklyn Mansfield Branley

Susana F. Huelga, Miguel Ferrero, Emilio Santos

Bell's inequalities cannot be violated in atomic-cascade experiments, even with ideal apparatus, due to the three-body character of the atomic decay. Here we propose a new experiment that would block this loophole by means of a suitable selection of an ensemble of photon pairs. A threshold value for the quantum efficiency is found which may allow the discrimination between quantum mechanics and local-hidden-variables theories. Experimental requirements for performing such a test are discussed.

Angel L. Sanz, J. L. Sánchez‐Gómez

We compute the probability, P , that the second photon of an atomic-cascade experiment, performed to test Bell inequalities, undergoes rescattering. In the case of the experiments of Aspect et al. , we find P ≃ 0.1; hence, the possibility that photon rescattering be a "loophole" in the experimental refutation of local hidden-variable theories is ruled out.

Trevor W. Marshall

A theoretical model is presented for a singlephoton interference experiment in a beam -splitter using the second photon in a cascade transition of a threelevel atomic system.A clear anticorrelation effect is found in the coincidences of photons on the two sides of the beam splitter that can only be explained by quantum theory of light .A qualitative comparison is made with an earlier singlephoton interference experiment available in literature.

Philip George Burke, B L Moiseiwitsch