Candidate for laser cooling of a negative ion: observations of bound-bound transitions in La(-)

C W Walter; N D Gibson; D J Matyas; C Crocker; K A Dungan; B R Matola; J Rohlén

doi:10.1103/PhysRevLett.113.063001

Candidate for laser cooling of a negative ion: observations of bound-bound transitions in La(-)

Phys Rev Lett. 2014 Aug 8;113(6):063001. doi: 10.1103/PhysRevLett.113.063001. Epub 2014 Aug 5.

Authors

C W Walter¹, N D Gibson¹, D J Matyas¹, C Crocker¹, K A Dungan¹, B R Matola¹, J Rohlén²

Affiliations

¹ Department of Physics and Astronomy, Denison University, Granville, Ohio 43023, USA.
² Department of Physics, University of Gothenburg, SE-412 96 Gothenburg, Sweden.

PMID: 25148321
DOI: 10.1103/PhysRevLett.113.063001

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.