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Cooling an Optically Trapped Ultracold Fermi Gas by Periodical Driving
Published on: March 30, 2017
Observation of a strong atom-dimer attraction in a mass-imbalanced Fermi-Fermi mixture
Michael Jag1, Matteo Zaccanti2, Marko Cetina3
1Institut für Quantenoptik und Quanteninformation (IQOQI), Österreichische Akademie der Wissenschaften, 6020 Innsbruck, Austria and Institut für Experimentalphysik, Universität Innsbruck, 6020 Innsbruck, Austria.
Abstract:
We investigate a mixture of ultracold fermionic K40 atoms and weakly bound Li6K40 dimers on the repulsive side of a heteronuclear atomic Feshbach resonance. By radio-frequency spectroscopy we demonstrate that the normally repulsive atom-dimer interaction is turned into a strong attraction. The phenomenon can be understood as a three-body effect in which two heavy K40 fermions exchange the light Li6 atom, leading to attraction in odd partial-wave channels (mainly p wave). Our observations show that mass imbalance in a fermionic system can profoundly change the character of interactions as compared to the well-established mass-balanced case.
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