title: Candidate for laser cooling of a negative ion: observations of bound-bound transitions in La(-).
abstract: Despite the tremendous advances in laser cooling of neutral atoms and positive ions, no negatively charged ion has been directly laser cooled. The negative ion of lanthanum, La(-), has been proposed as the best candidate for laser cooling of any atomic anion [ and , Phys. Rev. A 81, 032503 (2010)]. Tunable infrared laser photodetachment spectroscopy is used to measure the bound-state structure of La(-), revealing a spectrum of unprecedented richness with multiple bound-bound electric dipole transitions. The potential laser-cooling transition ((3)F(2)(e)→(3)D(1)(o)) is identified and its excitation energy is measured. The results confirm that La^{-} is a very promising negative ion for laser-cooling applications.
authors.affiliation: Department of Physics and Astronomy, Denison University, Granville, Ohio 43023, USA.
authors.forename: C W
authors.initials: CW
authors.lastname: Walter
authors.affiliation: Department of Physics and Astronomy, Denison University, Granville, Ohio 43023, USA.
authors.forename: N D
authors.initials: ND
authors.lastname: Gibson
authors.affiliation: Department of Physics and Astronomy, Denison University, Granville, Ohio 43023, USA.
authors.forename: D J
authors.initials: DJ
authors.lastname: Matyas
authors.affiliation: Department of Physics and Astronomy, Denison University, Granville, Ohio 43023, USA.
authors.forename: C
authors.initials: C
authors.lastname: Crocker
authors.affiliation: Department of Physics and Astronomy, Denison University, Granville, Ohio 43023, USA.
authors.forename: K A
authors.initials: KA
authors.lastname: Dungan
authors.affiliation: Department of Physics and Astronomy, Denison University, Granville, Ohio 43023, USA.
authors.forename: B R
authors.initials: BR
authors.lastname: Matola
authors.affiliation: Department of Physics, University of Gothenburg, SE-412 96 Gothenburg, Sweden.
authors.forename: J
authors.initials: J
authors.lastname: Rohlén