Towards State-Resolved Ultracold Chemical Reactions with KRb Molecules

Ultracold chemistry explores reactions where both the internal and external quantum states of molecules are important and ideally controlled. Ultracold collisions between pairs of $\mathrm{^{40}K^{87}Rb}$ molecules have been studied previously where evidence of bimolecular chemical reactions was observed as two-body losses of $\mathrm{^{40}K^{87}Rb}$. This reaction pathway is expected to yield products $\mathrm{^{40}K_{2}}$ and $\mathrm{^{87}Rb_{2}}$ with 10 $\mathrm{cm^{-1}}$ (14.4 K) excess energy. We will present our design and construction of a new apparatus that aims to directly map out the products and their quantum states. The apparatus combines ultracold gases of $\mathrm{K}$, $\mathrm{Rb}$, and $\mathrm{KRb}$ and REMPI (Resonance-Enhanced Multiphoton Ionization) detection capabilities. This apparatus will offer possibilities to study state-to-state chemistry, reversibility of chemical reactions, and controllable ultracold reactions.