Skip to Main content Skip to Navigation

Mesures de champs au niveau du photon par interférométrie atomique

Abstract : Two neighbouring levels of a Rydberg atom coupled to a high quality-factor microwave cavity are an excellent tool for the study of matter - wave interactions at the most basic level. The system is so simple (a two-level atom coupled to a single mode of the field) that most phenomena can be described analytically. In this work we study dispersive effects of the non-resonant atom - cavity interaction. We have measured the linear dependence of the atomic energy level-shifts on the average photon number in the cavity. Light shifts induced by an average microwave field intensity weaker than a single photon have been observed. It has also been possible to measure the residual shift of one of the two levels of the atomic transition in the absence of an injected field: a Lamb shift due to a single mode of the field. A sensitive measurement of these energy shifts is performed by an interferometric method: the Ramsey separated oscillatory fields technique. Future experiments, in a situation of very weak field relaxation, are proposed. The quantum behavior of the field will then be dominant and it shall be possible to perform a Quantum Non-Demolition measurement of the photon number: since the interaction is non-resonant, the atoms can neither absorb nor emit photons in the cavity. The performed experiments demonstrate the sensitivity of the apparatus and set the stage for future non-demolition measurements and for the study of "mesoscopic" Schrödinger cat states of the field, on the boundary between classical and quantum worlds.
Complete list of metadatas

Cited literature [89 references]  Display  Hide  Download
Contributor : Jacques Dupont-Roc <>
Submitted on : Thursday, March 9, 2006 - 5:38:05 PM
Last modification on : Thursday, December 10, 2020 - 12:36:18 PM
Long-term archiving on: : Saturday, April 3, 2010 - 8:40:53 PM


  • HAL Id : tel-00011897, version 1


Paulo Nussenzveig. Mesures de champs au niveau du photon par interférométrie atomique. Physique Atomique [physics.atom-ph]. Université Pierre et Marie Curie - Paris VI, 1994. Français. ⟨tel-00011897⟩



Record views


Files downloads