Efficient state transfer in an ultracold dense gas of heteronuclear molecules

Abstract

A rich internal structure and long-range interactions between them make molecules with non-vanishing dipole moments interesting for many applications. An experiment demonstrating the efficient transfer of loosely bound heteronuclear molecules into more deeply bound energy levels indicates a route towards producing dense ensembles of cold polar molecules. Polar molecules have bright prospects for novel quantum gases with long-range and anisotropic interactions1, and could find uses in quantum information science2 and in precision measurements3,4,5. However, high-density clouds of ultracold polar molecules have so far not been produced. Here, we report a key step towards this goal. We start from an ultracold dense gas of loosely bound 40K87Rb Feshbach molecules6,7 with typical binding energies of a few hundred kilohertz, and coherently transfer these molecules in a single transfer step into a vibrational level of the ground-state molecular potential bound by more than 10 GHz. Starting with a single initial state prepared with Feshbach association8, we achieve a transfer efficiency of 84%. Given favourable Franck–Condon factors9,10, the presented technique can be extended to access much more deeply bound vibrational levels and those exhibiting a significant dipole moment.

Cite this article

Ospelkaus, S., Pe’er, A., Ni, KK. et al. Efficient state transfer in an ultracold dense gas of heteronuclear molecules. Nature Phys 4, 622–626 (2008). https://doi.org/10.1038/nphys997

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