Quantum gas of deeply bound ground state molecules Journal Article

Author(s): Danzl, Johannes G; Haller, Elmar; Gustavsson, Mattias K; Mark, Manfred J; Hart, Russell A; Bouloufa, Nadia; Dulieu, Olivier; Ritsch, Helmut; Nägerl, Hanns C
Article Title: Quantum gas of deeply bound ground state molecules
Abstract: Molecular cooling techniques face the hurdle of dissipating translational as well as internal energy in the presence of a rich electronic, vibrational, and rotational energy spectrum. In our experiment, we create a translationally ultracold, dense quantum gas of molecules bound by more than 1000 wave numbers in the electronic ground state. Specifically, we stimulate with 80% efficiency, a two-photon transfer of molecules associated on a Feshbach resonance from a Bose-Einstein condensate of cesium atoms. In the process, the initial loose, long-range electrostatic bond of the Feshbach molecule is coherently transformed into a tight chemical bond. We demonstrate coherence of the transfer in a Ramsey-type experiment and show that the molecular sample is not heated during the transfer. Our results show that the preparation of a quantum gas of molecules in specific rovibrational states is possible and that the creation of a Bose-Einstein condensate of molecules in their rovibronic ground state is within reach.
Journal Title: Science
Volume: 321
Issue 5892
ISSN: 0036-8075
Publisher: American Association for the Advancement of Science  
Date Published: 2008-08-22
Start Page: 1062
End Page: 1066
DOI: 10.1126/science.1159909
Notes: We thank the team of J. Hecker Denschlag, the LevT team in our group, and T. Bergeman for very helpful discussions and M. Prevedelli for technical assistance. We are indebted to R. Grimm for generous support and gratefully acknowledge funding by the Austrian Ministry of Science and Research (Bundesministerium für Wissenschaft und Forschung) and the Austrian Science Fund (Fonds zur Förderung der wissenschaftlichen Forschung) in the form of a START prize grant and by the European Science Foundation in the framework of the EuroQUAM collective research project QuDipMol.
Open access: yes (repository)