Semiclassical wave-packet propagation on potential surfaces coupled by ultrashort laser pulses

We demonstrate the applicability of the time-dependent semiclassical initia l-value formalism to the problem of population transfer between adiabatic p otential surfaces which are coupled through a pulsed laser field. Despite t he fact that solutions of highly nonlinear classical equations are entering the semiclassical expression, our results for ultrashort pulse excitation are in good agreement with full quantum solutions. Even in the case where t he Rosen-Zener approach to population transfer breaks down, the semiclassic al results are still close to the quantum ones. [S1050-2947(99)06609-3].