Ground State Scattering Lengths for Potassium Isotopes Determined by Double-Resonance Photoassociative Spectroscopy of Ultracold 39K

Published

November 1, 2000

Author(s)

Haonan Wang, A N. Nikolov, J R. Ensher, P L. Gould, E E. Eyler, W C. Stwalley, J P. Burke, J L. Bohn, C H. Greene, Eite Tiesinga, Carl J. Williams, Paul S. Julienne

Abstract

We use double-resonance photoassociative spectroscopy of ultracold ³⁹K atoms to precisely determine the triplet a³Σ scattering length for the various isotopes of potassium. Photoassociation of free ³⁹K atoms to the pure long-range 0 (v' = O, J' = 2) level is followed by stimulated emission to high-lying levels of the a³Σ potential. The binding energies of levels within 5 GHz below the lowest ground-state 4s_1/2 (fa =1) + 4s_1/2 (fb =1) hyperfine asymptote are measured by both trap loss and ionization detection. The locations of these near-threshold hyperfine-coupled molecular levels allow us to constrain the triplet potential and thereby determine the triplet scattering length. The result for ³⁹K, aτ = -33 + 5 ao (1 ao=0.0529177 nm), is a factor of 5 improvement over previous determinations and establishes that a large ³⁹K Bose-Einstein condensate will not be stable.

Citation

Physical Review A (Atomic, Molecular and Optical Physics)

Pub Type

Journals

Keywords

Bose Einstein condensates, photoassociative spectroscopy, scattering lengths

Citation

Wang, H. , Nikolov, A. , Ensher, J. , Gould, P. , Eyler, E. , Stwalley, W. , Burke, J. , Bohn, J. , Greene, C. , Tiesinga, E. , Williams, C. and Julienne, P. (2000), Ground State Scattering Lengths for Potassium Isotopes Determined by Double-Resonance Photoassociative Spectroscopy of Ultracold ³⁹K, Physical Review A (Atomic, Molecular and Optical Physics) (Accessed October 12, 2025)