A study of adiabatic population transfer for the production of heavy Rydberg systems

We present recent progress towards the production of heavy Rydberg systems within alkali metal dimers using STIRAP to effect vibrational state transfer followed by excitation with a pulsed UV laser. We have calculated the efficiency of adiabatic population transfer in a 2-level system and investigated its dependence on the temporal profile of the perturbation. We show that the optimal profile for adiabatic following results in a significantly lower probability of a non-adiabatic transition than that predicted by applying the Landau-Zener formula. We have also determined the relationship between population-loss and beam profile for a 3-level system undergoing a STIRAP process. These theoretical predictions will be compared with results from a molecular beam experiment within which lithium dimers cross beams from a pair of diode lasers tuned to the $A ^1\Sigma_u^+$ - $X ^1\Sigma_g^+$ transition.