Electric-field control of atom-molecule Feshbach resonances        

We present our latest results on collisions between ²³Na³⁹K molecules and ³⁹K atoms, where we successfully observe Feshbach resonances between these scattering partners. For the first time in comparable systems, we demonstrate the ability to control the position of these resonances using electric fields. This allows us to investigate the electric field dependence of bound trimer states and assign specific quantum numbers to these states.

Our observations highlight a significant influence of the potassium atom on the molecule, despite the weak binding of the trimer state, which can be attributed to hindered rotation. These findings represent a new step in controlling atom-molecule interactions in ultracold gases and offer valuable insights into the behavior of molecular systems under external fields.