Réduction du bruit de polarisation et intrication quantique en variables continues avec un nuage d'atomes froids

Abstract : We have studied the quantum fluctuations of the electromagnetic field after the interaction with cold atoms placed inside an optical cavity. Near the resonance, the atomic ensemble behaves as a non linear medium an account of the saturation of the optical transition. When the incoming light is linearly polarized, the saturation is responsible for a Kerr effect on the mean field and a crossed Kerr effect on the vacuum orthogonal mode. Both effects modify the quantum fluctuations of the light. At the output of the cavity, we observed squeezing on both the mean field mode and the orthogonal vacuum mode.
First, we interpreted the vacuum squeezing in terms of polarization squeezing. The fluctuations of the polarization have been characterized by measuring the quantum Stokes parameters.
Then we studied the quantum correlations produced by the system. These correlations have been estimated using a recent non-separability criterion for continous variables. We demonstrated that the modes polarized at °45° (with respect to the mean field) are quadrature entangled. Last, we mapped these quantum correlations onto the fluctuations of the Stokes parameters associated with two spatially separated beams and achieved polarization entanglement.
Complete list of metadatas

https://tel.archives-ouvertes.fr/tel-00004876
Contributor : Vincent Josse <>
Submitted on : Thursday, February 19, 2004 - 2:12:26 PM
Last modification on : Monday, June 17, 2019 - 2:42:04 PM
Long-term archiving on : Friday, April 2, 2010 - 7:58:49 PM

Identifiers

  • HAL Id : tel-00004876, version 1

Citation

Vincent Josse. Réduction du bruit de polarisation et intrication quantique en variables continues avec un nuage d'atomes froids. Physique Atomique [physics.atom-ph]. Université Pierre et Marie Curie - Paris VI, 2003. Français. ⟨tel-00004876⟩

Share

Metrics

Record views

507

Files downloads

979