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Updated: Jan 9, 2026

Cooling an Optically Trapped Ultracold Fermi Gas by Periodical Driving
Published on: March 30, 2017
Spectroscopy and Ground-State Transfer of Ultracold Bosonic ^{39}K^{133}Cs Molecules
Krzysztof P Zamarski1, Charly Beulenkamp1, Yi Zeng1
1Universität Innsbruck, Institut für Experimentalphysik und Zentrum für Quantenphysik, Technikerstraße 25, 6020 Innsbruck, Austria.
Abstract:
We report the creation of ultracold samples of ^{39}K^{133}Cs molecules in their rovibrational ground state. By investigating potentially suitable excited states using one- and two-photon spectroscopy, we have identified a pathway to the ground state via an exceptionally narrow intermediate state. Using stimulated Raman adiabatic passage, we create trapped samples of up to 3500 molecules at temperatures of 1 μK with one-way efficiencies of 71%. The lifetime of these samples is limited by a near-universal two-body loss process, which could shed new light on similar loss mechanisms in other molecular species. Our results are a step toward establishing an alternative molecular species as a platform for the study of bosonic and fermionic quantum matter with strong dipolar interactions.
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