Measurement and Modeling of Hyperfine- and Rotation-Induced State Mixing in Large Weakly Bound Sodium Dimers
Eite Tiesinga, Kevin Jones, Paul D. Lett, U Volz, Carl J. Williams, Paul S. Julienne
We present high-precision trap loss spectroscopy of excited Na_2 molecules obtained by the photoassociation of ultracold sodium atoms. Near the 3S+3P3/2 dissociation limit, hyperfine and rotational (Coriolis type) interactions cause significant mixing of states of different nominal Hund's case (c) symmetry resulting in a complex pattern of spectral lines. We construct a theoretical model of the large, slowly-rotating molecule starting from a long-range, atomic viewpoint. Interaction potentials are derived from the known long-range resonant dipole and van der Waalsforces between atoms, supplemented at short-range by the results of ab initio electronic structure calculations. Spin-dependent interactions coupling the various angular momenta - nuclear spin, electron spin, electron orbit and the mechanical rotation of the molecule as a whole - are derived from known atomic parameters. We avoid imposing approximate symmetries or coupling schemes and consequently include all non-adiabatic mixing of different degrees of freedom. Quantitative agreement between experiment and theory for both line positions and intensities is found. Specifically we observe and calculate mixing of levels of 0g-, 0u+, and 1g symmetry bound by
Physical Review A (Atomic, Molecular and Optical Physics)
, Jones, K.
, Lett, P.
, Volz, U.
, Williams, C.
and Julienne, P.
Measurement and Modeling of Hyperfine- and Rotation-Induced State Mixing in Large Weakly Bound Sodium Dimers, Physical Review A (Atomic, Molecular and Optical Physics)
(Accessed March 4, 2024)