Observation of collectivity enhanced magnetoassociation of 6Li in the quantum degenerate regime

Naniyil, Vineetha; Zhou, Yijia; Simmonds, Guy; Cooper, Nathan; Li, Weibin; Hackermüller, Lucia

Abstract

The association process of Feshbach molecules is well described by a Landau-Zener (LZ) transition above the Fermi temperature, such that two-body physics dominates the dynamics. However, using 6Li atoms and the associated Feshbach resonance at B r = 834.1 G, we observe an enhancement of the atom-molecule coupling as the fermionic atoms reach degeneracy, demonstrating the importance of many-body coherence not captured by the conventional LZ model. In the experiment, we apply a linear association ramp ranging from adiabatic to non-equilibrium molecule association for various temperatures. We develop a theoretical model that explains the temperature dependence of the atom-molecule coupling. Furthermore, we characterize this dependence experimentally and extract the atom-molecule coupling coefficient as a function of temperature, finding qualitative agreement between our model and experimental results. In addition, we simulate the dynamics of molecular association during a nonlinear field ramp. We find that, in the non-equilibrium regime, molecular association efficiency can be enhanced by sweeping the magnetic field cubically with time. Accurate measurement of the atom-molecule coupling coefficient is important for both theoretical and experimental studies of molecular association and many-body collective dynamics.

Citation

Naniyil, V., Zhou, Y., Simmonds, G., Cooper, N., Li, W., & Hackermüller, L. (2022). Observation of collectivity enhanced magnetoassociation of 6Li in the quantum degenerate regime. New Journal of Physics, 24(11), Article 113005. https://doi.org/10.1088/1367-2630/ac9b81

• Journal Article Type: Article
• Acceptance Date: Oct 19, 2022
• Online Publication Date: Nov 3, 2022
• Publication Date: 2022-11
• Deposit Date: Dec 5, 2022
• Publicly Available Date: Dec 20, 2022
• Journal: New Journal of Physics
• Electronic ISSN: 1367-2630
• Publisher: IOP Publishing
• Peer Reviewed: Peer Reviewed
• Volume: 24
• Issue: 11
• Article Number: 113005
• DOI: https://doi.org/10.1088/1367-2630/ac9b81
• Keywords: General Physics and Astronomy
• Public URL: https://nottingham-repository.worktribe.com/output/13182018
• Publisher URL: https://iopscience.iop.org/article/10.1088/1367-2630/ac9b81