Collisions of ultracold trapped cesium Feshbach molecules

by F. Ferlaino, S. Knoop, M. Berninger, M. Mark, H.-C. Nägerl, R. Grimm
Abstract:
We study collisions in an optically trapped, pure sample of ultracold Cs2 molecules in various internal states. The molecular gas is created by Feshbach association from a near-degenerate atomic gas, with adjustable temperatures in the nanokelvin range. We identify several narrow loss resonances, which point to the coupling to more complex molecular states and may be interpreted as Feshbach resonances in dimerdimer interactions. Moreover, in some molecular states we observe a surprising temperature dependence in collisional loss. This shows that the situation cannot be understood in terms of the usual simple threshold behavior for inelastic two-body collisions. We interpret this observation as further evidence for a more complex molecular structure beyond the well-understood dimer physics.
Reference:
Collisions of ultracold trapped cesium Feshbach molecules,
F. Ferlaino, S. Knoop, M. Berninger, M. Mark, H.-C. Nägerl, R. Grimm,
Laser Physics, 20, 23-31, 2010.
Bibtex Entry:
@article{CollisionCsFeshbach,
  title={Collisions of ultracold trapped cesium Feshbach molecules},
  author={Ferlaino, F. and Knoop, S. and Berninger, M. and Mark, M. and Nägerl, H.-C. and Grimm, R.},
  journal={Laser Physics},
  volume={20},
  number={1},
  issn={1054-660X},
  pages={23-31},
  year={2010},
  month = {Jan},
  abstract = {We study collisions in an optically trapped, pure sample of ultracold Cs2 molecules in various internal states. The molecular gas is created by Feshbach association from a near-degenerate atomic gas, with adjustable temperatures in the nanokelvin range. We identify several narrow loss resonances, which point to the coupling to more complex molecular states and may be interpreted as Feshbach resonances in dimerdimer interactions. Moreover, in some molecular states we observe a surprising temperature dependence in collisional loss. This shows that the situation cannot be understood in terms of the usual simple threshold behavior for inelastic two-body collisions. We interpret this observation as further evidence for a more complex molecular structure beyond the well-understood dimer physics.},
  publisher={SP MAIK Nauka/Interperiodica},
  doi={10.1134/S1054660X0917006X},
  url={http://dx.doi.org/10.1134/S1054660X0917006X},
  arxiv ={http://arxiv.org/abs/0904.0935}
}