Toward a coherent ultracold chemistry: controlling ultracold collisions of NaLi molecules

The intricate nature of molecular systems, with their multitude of bound rovibrational states and long-range, direction-dependent interactions, has recently made them a hotspot for advancing quantum control techniques. Pioneering research has shed light on the unexpectedly rapid loss rates in stable molecular systems, paving the way for groundbreaking work in controlled chemical processes. A pivotal tool in this domain is the Feshbach resonance, which provides insights into collision complexes through the interaction between molecular bound states and scattering states. In this context, the fermionic molecule 23Na6Li stands out with its minimal singlet-triplet mixing, presenting an ideal candidate for exploring triplet ground states. This molecule is distinguished by its dual electric and magnetic dipole moments and its unusually low two-body scattering rate, aligning with universal predictions for cold collisions. Our latest investigations reveal how magnetic fields can modulate the collision rate between two reactive NaLi molecules. We have identified a narrow p-wave Feshbach resonance, which intensifies the collisional loss rate by two orders of magnitude beyond the expected p-wave background level, bringing it close to the 2D unitarity limit at its peak. This discovery not only advances our understanding of molecular interactions but also holds great promise for the strategic manipulation of chemical reactions at the quantum level.