Observation of Feshbach resonances in ultracold ²³Na⁶Li+²³Na collisions

Understanding molecular collisions in the quantum regime is the holy grail of quantum chemistry. Unfortunately, the high rovibrational density-of-states usually makes the collision process computationally intractable. As the lightest bi-alkali molecule, NaLi features relatively low density-of states which makes it an ideal platform to test quantum-scattering calculations. Furthermore, the long lifetime of NaLi in the triplet manifold also enables studies of spin-dependent molecular collision. In this work, we studied the dependence of NaLi+Na collision on external magnetic field over 1400G range and identified atom-molecule Feshbach resonances. By going close to the resonances, we are able to change the loss coefficient by more than order of magnetude. The observation of atom-molecule Feshbach resonance paves the way to study trimer physics in the future.