Spectrum of Feshbach resonances in NaLi $+$ Na collisions

Abstract

Collisional resonances of molecules can offer a deeper understanding of interaction potentials and collision complexes, and allow control of chemical reactions. Here, we experimentally map out the spectrum of Feshbach resonances in collisions between ultracold triplet ro-vibrational ground-state NaLi molecules and Na atoms over a range of 1400 G. Preparation of the spin-stretched state puts the system initially into the non-reactive quartet potential. A total of 25 resonances are observed, in agreement with quantum-chemistry calculations using a coupled-channels approach. Although the theory cannot predict the positions of resonances, it can account for several experimental findings and provide unprecedented insight into the nature and couplings of ultracold, strongly interacting complexes. Previous work has addressed only weakly bound complexes. We show that the main coupling mechanism results from spin-rotation and spin-spin couplings in combination with the anisotropic atom-molecule interaction, and that the collisional complexes which support the resonances have a size of 30-40 $a_0$. This study illustrates the potential of a combined experimental and theoretical approach.

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Cited by in corpus (14)

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• Ab initio calculation of the spectrum of Feshbach resonances in NaLi + Na collisions
• Magnetic Feshbach resonances in ultracold atom-molecule collisions
• Mass Ratio Dependence of Three-Body Resonance Lifetimes in 1D and 3D
• Feshbach Resonances in Cold Collisions: Benchmarking State of the Art ab initio Potential Energy Surfaces
• Ultracold molecular collisions in magnetic fields: Efficient incorporation of hyperfine structure in the total rotational angular momentum representation
• Multichannel quantum defect theory with a frame transformation for ultracold atom-molecule collisions in magnetic fields
• Broad Feshbach resonance with a large background scattering length in a fermionic atom-molecule mixture
• Rigorous quantum calculations for atom-molecule chemical reactions in electric fields: from single to multiple partial wave regimes
• Spin-polarized alkali-metal trimers revisited
• CaF+CaF interactions in the ground and excited electronic states: implications for collisional losses
• Formation of ultracold triatomic molecules by electric microwave association
• Stabilization of three-body resonances to bound states in a continuum
• Universality and threshold laws for collision lifetimes at ultralow temperatures