Journal Article

Quantum Gas of Deeply Bound Ground State Molecules

Danzl, Johann G, Hart, Russell, Bouloufa, Nadia, Mark, Manfred J, Dulieu, Olivier, Gustavsson, Mattias, Ritsch, Helmut, Nägerl, Hanns-Christoph, Haller, Elmar

2008

Overview

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.

• Publisher: American Association for the Advancement of Science,The American Association for the Advancement of Science
• Subject: Atomic and molecular collision processes and interactions / Atomic and molecular physics / Atoms / Binding energy / Cesium / Classical and quantum physics: mechanics and fields / Energy / Exact sciences and technology / Gases / Ground state / Laser-modified scattering and reactions / Lasers / Magnetic fields / Matter waves / Molecular excitation / Molecular properties and interactions with photons / Molecules / Optical cooling of molecules; trapping / Particle physics / Photon interactions with molecules / Physics / Quantum theory / Scattering of atoms, molecules and ions / Temperature / translation (genetics) / Wave functions / Wavelengths