The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics

, Volume 31, Issue 2, pp 165–177

The photoassociative spectroscopy, photoassociative molecule formation, and trapping of ultracold \(\mathsf{^{39}K^{85}Rb}\)

Authors

  • D. Wang
    • Department of PhysicsUniversity of Connecticut
  • J. Qi
    • Department of PhysicsUniversity of Connecticut
  • M. F. Stone
    • Department of PhysicsUniversity of Connecticut
  • O. Nikolayeva
    • Department of PhysicsUniversity of Latvia
  • B. Hattaway
    • Department of PhysicsUniversity of Connecticut
  • S. D. Gensemer
    • Department of PhysicsUniversity of Amsterdam
  • H. Wang
    • Electronics and Photonics LaboratoryThe Aerospace Corporation, M2-253
  • W. T. Zemke
    • Department of ChemistryWartburg College
  • P. L. Gould
    • Department of PhysicsUniversity of Connecticut
  • E. E. Eyler
    • Department of PhysicsUniversity of Connecticut
    • Department of PhysicsUniversity of Connecticut
Article

DOI: 10.1140/epjd/e2004-00162-7

Cite this article as:
Wang, D., Qi, J., Stone, M.F. et al. Eur. Phys. J. D (2004) 31: 165. doi:10.1140/epjd/e2004-00162-7

Abstract.

We have observed the photoassociative spectra of colliding ultracold 39K and 85Rb atoms to produce KRb* in all eight bound electronic states correlating with the 39K (4s) + 85Rb(5p1/2 and 5p3/2) asymptotes. These electronically excited KRb* ultracold molecules are detected after their radiative decay to the metastable triplet (a \(^{3}\Sigma^{ + })\) state and (in some cases) the singlet (X \(^{1}\Sigma^{ + })\) ground state. The triplet (a \(^{3}\Sigma^{ + })\) ultracold molecules are detected by two-photon ionization at 602.5 nm to form KRb + , followed by time-of-flight mass spectroscopy. We are able to assign a majority of the spectrum to three states (2(0 + ), 2(0-), 2(1)) in a lower triad of states with similar C6 values correlating to the K(4s) + Rb (5p1/2) asymptote; and to five states in an upper triad of three states (3(0 + ), 3(0-), 3(1)) and a dyad of two states (4(1), 1(2)), with one set of similar C6 values within the upper triad and a different set of similar C6 values within the dyad. We are also able to make connection with the short-range spectra of Kasahara et al. [J. Chem. Phys. 111, 8857 (1999)], identifying three of our levels as v = 61, 62 and 63 of the 1\(^{1}\Pi \sim \) 4(1) state they observed. We also argue that ultracold photoassociation to levels between the K(4s) + Rb (5p3/2) and K(4s) + Rb (5p1/2) asymptotes may be weakly or strongly predissociated and therefore difficult to observe by ionization of a \(^{3}\Sigma^{ + }\) (or X \(^{1}\Sigma^{ + })\) molecules; we do know from Kasahara et al. that levels of the 1\(^{1}\Pi \sim \) 4(1) and 2\(^{1}\Pi \sim \) 5(1) states in the intra-asymptote region are predissociated. A small fraction (\(\le \)1/3) of the triplet (a \(^{3}\Sigma^{ + })\) ultracold molecules formed are trapped in the weak magnetic field of our magneto-optical trap (MOT).

Copyright information

© Springer-Verlag Berlin/Heidelberg 2004