Theory of laser enhancement and suppression of cold reactions: The fermion-boson 6Li+7Li2↔hω06Li7Li+7Li radiative collision.

We present a nonperturbative time-dependent quantum mechanical theory of the laser catalysis and control of a bifurcating A+BC↔^hω₀ABC^*(v)↔^hω₀AB+C reaction, with ABC^*(v) denoting an intermediate, electronically excited, complex of ABC in the vth vibrational state. We apply this theory to the low collision energy fermion-boson light-induced exchange reaction, ⁶Li(²S)+⁷Li₂(³Σ_u⁺)↔^hω₀(⁶Li⁷Li⁷Li)^*↔^hω₀6Li⁷Li(³Σ⁺)+⁷Li(²S). We show that at very low collision energies and energetically narrow (∼0.01 cm^-1) initial reactant wave packets, it is possible to tune the yield of the exchange reaction from 0 to near-unity (yield >=99%) values. Controllability is somewhat reduced at collisions involving energetically wider (∼1 cm^-1) initial reactant wave packets. At these energetic bandwidths, the radiative reactive control, although still impressive, is limited to the 0%–76% reactive-probabilities range. [ABSTRACT FROM AUTHOR]