Direct observation of bimolecular reactions of ultracold KRb molecules

In this study, we took the contrasting approach of prolonging the lifetime of an intermediate by preparing reactant molecules in their lowest rovibronic quantum state at ultralow temperatures, thereby markedly reducing the number of exit channels accessible upon their mutual collision. Using ionization spectroscopy and velocity-map imaging of a trapped gas of potassium-rubidium (KRb) molecules at a temperature of 500 nanokelvin, we directly observed reactants, intermediates, and products of the reaction 40K87Rb + 40K87Rb -> K2Rb2* -> K2 + Rb2. Beyond observation of a long-lived, energy-rich intermediate complex, this technique opens the door to further studies of quantum-state–resolved reaction dynamics in the ultracold regime.

Source: ScienceNOW - November 27, 2019 Category: Science Authors: Hu, M.- G., Liu, Y., Grimes, D. D., Lin, Y.- W., Gheorghe, A. H., Vexiau, R., Bouloufa-Maafa, N., Dulieu, O., Rosenband, T., Ni, K.- K. Tags: Chemistry, Physics reports Source Type: news