Photoassociation experiments with ultracold metastable helium
École Normale Supérieure and Collège de France,
Laboratoire Kastler Brossel, 24 rue Lhomond, 75231 Paris Cedex 05,
Corresponding author: a email@example.com
Published online: 26 October 2004
The present article gives a review of various photoassociation (PA) experiments performed at ENS with a gas of ultracold atoms of metastable helium in the 23S1 state, using a PA laser beam red-detuned from the 23S1–23P transitions. Molecular spectra close to the D2 atomic line (23SP2) are presented. All the measured lines are identified as a signature of molecular bound states having a strong (if not pure) quintet spin character at short interatomic distance. Close to the D0 atomic line (23SP0), giant helium dimers can be produced [see Phys. Rev. Lett. 91, 073203 (2003)]. A laser set-up improved recently allows us to measure very accurately the binding energy of the ro-vibrational ground state of the purely long-range potential and the agreement with the theory published previously is excellent. Finally, preliminary results on 2 photon PA spectroscopy are given.
PACS: 32.80.Pj – Optical cooling of atoms trapping / 33.20.Kf – Visible molecular spectra / 34.50.Gb – Electronic excitation and ionization of molecules / 34.20.Cf – Interatomic potentials and forces
© EDP Sciences, Società Italiana di Fisica, Springer-Verlag, 2004