L'effet Hanbury Brown et Twiss pour les atomes froids

M. Schellekens

Published Jan 1, 2007• 1 citation

Abstract

This thesis deals with the measurement of the quantum intensity correlations in gases of métastable Helium. The measurement has been performed on thermal gases of bosonic 4He and fermionic 3He, as well as on Bose-Einstein condensates. In 1956, Robert Hanbury Brown et Richard Twiss measured the correlation between photons emitted from a single thermal source. The consequently demonstrated that the photons emitted by such a source tend to arrive grouped on a detector. This bunching characterises bosons from a non-coherent source. Fermions show an anti-bunching behaviour in the same conditions. By using metastable Helium atoms, that can be detected individually through the use of micro-channel plates, we have been able to show a similar bunching of bosons 4He from thermal sources around the microkelvin. As expected, the coherence of the Bose-Einstein condensates did not produce a particular correlation. The measurement on thermal gases of fermionic 3He has demonstrated the anti-bunching. Particular effort has been employed in describing the micro-channel plates based delay-line detector, the key to the experiment.

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