A resonance triggers chemical reactions between the coldest molecules

The rich energy structure of ultracold molecules (at -459 °F or -273 °C), gives rise to collisional dynamics where the state-of-the-art models are inadequate for describing collisional resonances. We have discovered a pronounced magnetically tuned resonance in collisions between two NaLi molecules, which enhances the chemical reaction rate by more than a factor of a hundred.