Theory of laser enhancement of ultracold reactions: The fermion-boson population transfer by adiabatic passage of Li-6+(LiLi)-Li-6-Li-7(T-r=1 mK)- (LiLi)-Li-6-Li-6+Li-7(T-p=1 mK)

摘要

We present a new theory of population transfer by adiabatic passage. This theory relates laser catalysis to adiabatic passage, enhancing chemical reactions with the freedom to choose the translational energies of the reactants and products separately. The process, A+BC <->((h) over bar omega p)ABC(*)(v)<->((h) over bar omega s)AB+C, involves two laser fields that are slowly varying so the process is adiabatic, and sufficiently intense so the population of the intermediate bound complex (ABC) is minimized. We apply this theory to the collinear exchange reaction Li-6+Li-7(2)(T-r)<->((h) over bar omega p)((LiLiLi)-Li-6-Li-7-Li-7)(*)<->(LiLi)-Li-(h) over bar omega s6-Li-7(T-p)+Li-7. We show that at translational energies T-p=T-r=1 mK with a narrow energy bandwidth of delta(E)=0.01 mK, we can obtain nearly total (>= 98%) population transfer from the reactant to the product states. This can be done with a pump laser and a Stokes laser in an "intuitive" sequence (t(p)