Quantum Control of Atom-Ion Charge Exchange via Light-Induced Conical Intersections

Conical intersections are crossing points or lines betweentwoor more adiabatic electronic potential energy surfaces in the multidimensionalcoordinate space of colliding atoms and molecules. Conical intersectionsand corresponding nonadiabatic coupling can greatly affect moleculardynamics and chemical properties. In this paper, we predict significantor measurable nonadiabatic effects in an ultracold atom-ioncharge-exchange reaction in the presence of laser-induced conicalintersections (LICIs). We investigate the fundamental physics of theseLICIs on molecular reactivity under unique conditions: those of relativelylow laser intensity of 10(8) W/cm(2) and ultracoldtemperatures below 1 mK. We predict irregular interference effectsin the charge-exchange rate coefficients between K and Ca+ as functions of the laser frequency. These irregularities occurin our system due to the presence of two LICIs. To further elucidatethe role of the LICIs on the reaction dynamics, we compare these ratecoefficients with those computed for a system where the CIs have beenremoved. In the laser frequency window, where conicalinteractions are present, the difference in rate coefficients canbe as large as 1 x 10(-9) cm(3)/s.

Automated summary

Conical intersections have a significant impact on molecular dynamics and chemical properties. In this paper, we predict nonadiabatic effects in an ultracold atom-ion charge-exchange reaction induced by laser-induced conical intersections. The interference effects in charge-exchange rate coefficients between K and Ca+ are irregular due to the presence of two licis.