title: Giant helium dimers produced by photoassociation of ultracold metastable atoms.
abstract: We produce giant, purely long-range helium dimers by photoassociation of metastable helium atoms in a magnetically trapped, ultracold cloud. The photoassociation laser is detuned close to the atomic 2(3)S1-2(3)P0 line and produces strong heating of the sample when resonant with molecular bound states. The temperature of the cloud serves as an indicator of the molecular spectrum. We report good agreement between our spectroscopic measurements and our calculations of the five bound states belonging to a 0(+)(u) purely long-range potential well. These previously unobserved states have classical inner turning points of about 150a(0) and outer turning points as large as 1150a(0).
authors.affiliation: Ecole Normale Supérieure and Collège de France, Laboratoire Kastler Brossel, 24 rue Lhomond, 75231 Paris CEDEX 05, France.
authors.forename: J
authors.initials: J
authors.lastname: Léonard
authors.forename: M
authors.initials: M
authors.lastname: Walhout
authors.forename: A P
authors.initials: AP
authors.lastname: Mosk
authors.forename: T
authors.initials: T
authors.lastname: Müller
authors.forename: M
authors.initials: M
authors.lastname: Leduc
authors.forename: C
authors.initials: C
authors.lastname: Cohen-Tannoudji