Controlled state-to-state atom-exchange reaction in an ultracold atom–dimer mixture

• Published in: Nature physics 2017-07, Vol.13 (7), p.699-703
• Main Authors: Rui, Jun, Yang, Huan, Liu, Lan, Zhang, De-Chao, Liu, Ya-Xiong, Nan, Jue, Chen, Yu-Ao, Zhao, Bo, Pan, Jian-Wei
• Format: Article
• Language: English
• Subjects: 639/766/36/1120; 639/766/36/1125; 639/766/94; Atomic; Atoms & subatomic particles; Chemical reactions; Classical and Continuum Physics; Complex Systems; Condensed Matter Physics; Exchanging; Kondo effect; Magnetic fields; Mathematical and Computational Physics; Molecular; Molecules; Optical and Plasma Physics; Physics; Reaction products; Temperature effects; Theoretical; Ultracold atoms
• ISSN: 1745-2473; 1745-2481
• DOI: 10.1038/nphys4095

Ultracold molecules offer remarkable opportunities for the study of chemical reactions close to zero temperature. Although significant progress has been achieved in exploring ultracold bimolecular reactions, the investigations are usually limited to measurements of the overall loss rates of the reactants. Detection of the reaction products will improve our understanding of the reaction mechanism and provide a unique opportunity to study the state-to-state reaction dynamics. Here we report on the direct observation of an exoergic atom-exchange reaction in an ultracold atom–dimer mixture. Both the atom and molecule products are observed and the state-to-state reaction rate coefficient is measured. By changing the magnetic field, the reaction can be switched on or off, and the rate coefficient can be controlled. The observed atom-exchange reaction is an effective spin-exchange interaction between the dimer and the atom and may be exploited to study the Kondo effect with ultracold atoms. Products from ultracold atom–dimer exothermic reactions can be directly observed by controlling the energy released during the process, bringing the study of chemical dynamics to the quantum level.