Sticky collisions of ultracold RbCs molecules

Gregory, Philip D.; Frye, Matthew D.; Blackmore, Jacob A.; Bridge, Elizabeth M.; Sawant, Rahul; Hutson, Jeremy M.; Cornish, Simon L.

Abstract

Understanding and controlling collisions is crucial to the burgeoning field of ultracold molecules. All experiments so far have observed fast loss of molecules from the trap. However, the dominant mechanism for collisional loss is not well understood when there are no allowed 2-body loss processes. Here we experimentally investigate collisional losses of nonreactive ultracold 87Rb133Cs molecules, and compare our findings with the sticky collision hypothesis that pairs of molecules form long-lived collision complexes. We demonstrate that loss of molecules occupying their rotational and hyperfine ground state is best described by second-order rate equations, consistent with the expectation for complex-mediated collisions, but that the rate is lower than the limit of universal loss. The loss is insensitive to magnetic field but increases for excited rotational states. We demonstrate that dipolar effects lead to significantly faster loss for an incoherent mixture of rotational states.

Citation

Gregory, P. D., Frye, M. D., Blackmore, J. A., Bridge, E. M., Sawant, R., Hutson, J. M., & Cornish, S. L. (2019). Sticky collisions of ultracold RbCs molecules. Nature Communications, 10(1), Article 3104. https://doi.org/10.1038/s41467-019-11033-y

• Journal Article Type: Article
• Acceptance Date: Jun 13, 2019
• Online Publication Date: Jul 15, 2019
• Publication Date: Jul 15, 2019
• Deposit Date: Jul 19, 2019
• Publicly Available Date: Jul 19, 2019
• Journal: Nature Communications
• Electronic ISSN: 2041-1723
• Publisher: Nature Research
• Peer Reviewed: Peer Reviewed
• Volume: 10
• Issue: 1
• Article Number: 3104
• DOI: https://doi.org/10.1038/s41467-019-11033-y
• Public URL: https://durham-repository.worktribe.com/output/1296931