Formation of ultracold $^{39}$K$^{133}$Cs Feshbach molecules
Quantum Gases
2025-09-29 v2 Atomic Physics
Abstract
We report the creation of an ultracold gas of bosonic KCs molecules. We first demonstrate a cooling strategy relying on sympathetic cooling of Cs to produce an ultracold mixture. From this mixture, weakly bound molecules are formed using a Feshbach resonance at 361.7 G. The molecular gas contains molecules with a lifetime of about 130 ms, limited by two-body decay. We perform Feshbach spectroscopy to observe several new interspecies resonances and characterize the bound state used for magnetoassociation. Finally, we fit the combined results to obtain improved K-Cs interaction potentials. This provides a good starting point for the creation of ultracold samples of ground-state KCs molecules.
Keywords
Cite
@article{arxiv.2506.16520,
title = {Formation of ultracold $^{39}$K$^{133}$Cs Feshbach molecules},
author = {Charly Beulenkamp and Krzysztof P. Zamarski and Robert C. Bird and C. Ruth Le Sueur and Jeremy M. Hutson and Manuele Landini and Hanns-Christoph Nägerl},
journal= {arXiv preprint arXiv:2506.16520},
year = {2025}
}