We produce an ultracold and dense sample of rovibronic ground state Cs(2) molecules close to the regime of quantum degeneracy, in a single hyperfine level, in the presence of an optical lattice. The molecules are individually trapped, in the motional ground state of an optical lattice well, with a lifetime of 8 s. For preparation, we start with a zero-temperature atomic Mott-insulator state with optimized double-site occupancy and efficiently associate weakly-bound dimer molecules on a Feshbach resonance. Despite extremely weak Franck-Condon wavefunction overlap, the molecules are subsequently transferred with >50% efficiency to the rovibronic ground state by a stimulated four-photon process. Our results present a crucial step towards the generation of Bose-Einstein condensates of ground-state molecules and, when suitably generalized to polar heteronuclear molecules such as RbCs, the realization of dipolar many-body quantum-gas phases in periodic potentials.
- lattice potentials
- quantum degeneracy
- Feshbach resonance
- optical lattice
Nägerl, H-C., Mark, M. J., Haller, E., Gustavsson, M., Hart, R., & Danzl, J. G. (2011). Ultracold and dense samples of ground-state molecules in lattice potentials. Journal of Physics Conference Series, 264, . https://doi.org/10.1088/1742-6596/264/1/012015