Mechanistic Insights into Geometric Phase Effects in the Ultracold O + OH Reaction*

The quantum-enhanced geometric phase (GP) effects in ultracold reaction systems have attracted much recent attention owing to its potential application in controlling ultracold chemistry. We performed the time-dependent wave packet (TDWP) dynamical calculations for the ultracold O + OH reaction with the inclusion of the GP. The calculation illustrates that the TDWP method accurately describes experimentally relevent ultracold reaction systems containing a conical intersection (CI). More interestingly, the scattering wave functions provided by the TDWP method reveal explicitly the nature of the quantum interference between the direct and looping reaction pathways around the CI, and thus confirms the dynamical origin of the GP effects in the reaction for the first time. We will discuss how the ultracold O + OH reaction proceeds under the control of the GP. These findings indicate that quantum control techniques such as an optical lattice trap or the initial state orientation should be effective in controlling the reactivity.