Probing and controlling chemical reactions at sub-microkelvin temperatures

Advances in AMO physics techniques led to the creation of ultracold samples of molecules and opened opportunities to explore chemistry in the ultralow temperature regime. While many prior studies investigated how long-range forces influence ultracold reactions, we extend the exploration into the short-range where the particle rearrangment takes place. To this end, we developed an experimental apparatus that combines production of state-controlled ultracold molecules with highly efficient and universal ion-based detection. This allowed us to probe the exchange reaction between ultracold KRb molecules, and eventually gain control over its various aspects. In this talk, I will describe the identification of an unusually long-lived intermediate complex, steering the reaction pathway with light, and controlling the quantum state occupation of the reaction products via an external magnetic field. Finally, I will present our recent results on a complete pair-correlated map of the product quantum state distribution. I will compare our result to the celebrated statistical theory, and test one of its central tenets: in an energy-rich intermediate complex, is there a complete redistribution of energy prior to its dissociation?