Observation of collectivity enhanced magnetoassociation of $^6$Li in the quantum degenerate regime
| Autor: | Naniyil, Vineetha, Zhou, Yijia, Simmonds, Guy, Cooper, Nathan, Li, Weibin, Hackermüller, Lucia |
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| Rok vydání: | 2021 |
| Předmět: | |
| Zdroj: | New J. Phys. 24 (2022) 113005 |
| Druh dokumentu: | Working Paper |
| DOI: | 10.1088/1367-2630/ac9b81 |
| Popis: | 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 $^6$Li 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. Comment: 18 pages, 6 figures |
| Databáze: | arXiv |
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