Journal Article

Efficient state transfer in an ultracold dense gas of heteronuclear molecules

Zirbel, J. J., Jin, D. S., Pe’er, A., Kotochigova, S., Ni, K.-K., Neyenhuis, B., Ye, J., Ospelkaus, S., Julienne, P. S.

2008

Overview

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 interactions 1 , and could find uses in quantum information science 2 and in precision measurements 3 , 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 40 K 87 Rb Feshbach molecules 6 , 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 association 8 , we achieve a transfer efficiency of 84%. Given favourable Franck–Condon factors 9 , 10 , the presented technique can be extended to access much more deeply bound vibrational levels and those exhibiting a significant dipole moment.

• Publisher: Nature Publishing Group UK,Nature Publishing Group
• Subject: Atomic / Atoms & subatomic particles / Classical and Continuum Physics / Complex Systems / Condensed Matter Physics / Dipole moments / Energy levels / Gases / letter / Mathematical and Computational Physics / Molecular / Molecules / Optical and Plasma Physics / Physics / Physics and Astronomy / Quantum phenomena / Theoretical