--- _id: '1039' abstract: - lang: eng text: 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. acknowledgement: " 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.\r\n" article_processing_charge: No author: - first_name: Johann G full_name: Danzl, Johann G id: 42EFD3B6-F248-11E8-B48F-1D18A9856A87 last_name: Danzl orcid: 0000-0001-8559-3973 - first_name: Elmar full_name: Haller, Elmar last_name: Haller - first_name: Mattias full_name: Gustavsson, Mattias last_name: Gustavsson - first_name: Manfred full_name: Mark, Manfred last_name: Mark - first_name: Russell full_name: Hart, Russell last_name: Hart - first_name: Nadia full_name: Bouloufa, Nadia last_name: Bouloufa - first_name: Olivier full_name: Dulieu, Olivier last_name: Dulieu - first_name: Helmut full_name: Ritsch, Helmut last_name: Ritsch - first_name: Hanns full_name: Nägerl, Hanns last_name: Nägerl citation: ama: Danzl JG, Haller E, Gustavsson M, et al. Quantum gas of deeply bound ground state molecules. Science. 2008;321(5892):1062-1066. doi:10.1126/science.1159909 apa: Danzl, J. G., Haller, E., Gustavsson, M., Mark, M., Hart, R., Bouloufa, N., … Nägerl, H. (2008). Quantum gas of deeply bound ground state molecules. Science. American Association for the Advancement of Science. https://doi.org/10.1126/science.1159909 chicago: Danzl, Johann G, Elmar Haller, Mattias Gustavsson, Manfred Mark, Russell Hart, Nadia Bouloufa, Olivier Dulieu, Helmut Ritsch, and Hanns Nägerl. “Quantum Gas of Deeply Bound Ground State Molecules.” Science. American Association for the Advancement of Science, 2008. https://doi.org/10.1126/science.1159909. ieee: J. G. Danzl et al., “Quantum gas of deeply bound ground state molecules,” Science, vol. 321, no. 5892. American Association for the Advancement of Science, pp. 1062–1066, 2008. ista: Danzl JG, Haller E, Gustavsson M, Mark M, Hart R, Bouloufa N, Dulieu O, Ritsch H, Nägerl H. 2008. Quantum gas of deeply bound ground state molecules. Science. 321(5892), 1062–1066. mla: Danzl, Johann G., et al. “Quantum Gas of Deeply Bound Ground State Molecules.” Science, vol. 321, no. 5892, American Association for the Advancement of Science, 2008, pp. 1062–66, doi:10.1126/science.1159909. short: J.G. Danzl, E. Haller, M. Gustavsson, M. Mark, R. Hart, N. Bouloufa, O. Dulieu, H. Ritsch, H. Nägerl, Science 321 (2008) 1062–1066. date_created: 2018-12-11T11:49:49Z date_published: 2008-08-22T00:00:00Z date_updated: 2021-01-12T06:47:50Z day: '22' doi: 10.1126/science.1159909 extern: '1' external_id: arxiv: - '0806.2284' intvolume: ' 321' issue: '5892' language: - iso: eng main_file_link: - open_access: '1' url: https://arxiv.org/abs/0806.2284 month: '08' oa: 1 oa_version: None page: 1062 - 1066 publication: Science publication_status: published publisher: American Association for the Advancement of Science publist_id: '6351' status: public title: Quantum gas of deeply bound ground state molecules type: journal_article user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87 volume: 321 year: '2008' ...