"Sub-microKelvin chemistry with ultracold molecules"
Recent tools developed for cooling atoms and molecules allow certain classes of molecules to be prepared at sub-microKelvin temperatures. This has enabled the exploration of chemistry in the ultracold regime. After 10 years of work using loss rates to reveal the long-range physics that determines how the reactants approach each other, including the role of quantum statistics, we recently gained the capability of direct detection of products. In particular, we combined ionization detection and ion velocity map imaging within a potassium-rubidium (KRb) quantum gas apparatus. It allowed us to detect all relevant species in the intriguing 4-center reaction KRb + KRb -> K2Rb2* -> K2+Rb2, including the surprising detection of the intermediate complex. We found this complex to be long-lived (of order one microsecond), which we further took advantage of to control the product formation rate by an external light source. The new capability of detecting reaction products rather than merely reactant loss opens new opportunities for reaction studies.
Ming-Guang Hu is a Postdoctoral research fellow at Harvard University. He conducted research on ultracold atoms and Bose-Einstein condensate. His current work focuses on the creation of ultracold molecules and their application to the study of chemistry in the ultracold regime. His favorite atomic species are potassium and rubidium.