Bonn 2000 – wissenschaftliches Programm

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MO: Molekülphysik

MO III: HV III

MO III.1: Hauptvortrag

Dienstag, 4. April 2000, 11:40–12:20, HS VI

Cold molecules: experiments and prospects — •Pierre Pillet — Laboratoire Aime Cotton, CNRS II, Bat. 505, Campus d’Orsay, 91405 Orsay cedex, France

In contrast to atoms, laser cooling of molecules is very difficult because of the lack of a closed two-level scheme for recycling the population. The molecular photoassociation of cold atoms opens a promising alternative for the formation of cold molecules. In a photoassociation process, two colliding cold atoms absorb one photon to form a cold molecule in a ro-vibrational level of a molecular electronically excited state. Unfortunately, for most of the considered systems, photoassociated excited molecules dissociate after spontaneous emission. Long-range states below the first excited dissociation limits 6s+6p of the cesium dimer present configurations with Condon points at intermediate distances, offering efficient channels for the formation of ground state Cs2 molecules after spontaneous decay. Temperatures of the molecular cloud as low as 20 *K and formation rates of one cold molecule per micro-second have been measured. The properties of photoassociated long-range molecules, and the possibilities to trap cold molecules by using magnetic or laser-dipole traps, and the mechanisms to prepare them in a well defined ro-vibrational level of the ground-state will be developed. Further prospects will be discussed.