Laser excitation of angular Rydberg wavepackets

We consider the dynamics of the formation df high angular momentum Rydberg states in a hydrogen by laser excitation. The Schrodinger equation is solved by expanding the wavefunction in spherical /n, l, m] states. Results obtained by expansions over a large and a small number of basis functions are compared in order to identify the main excitation dynamics. The final population is studied by simpler models and the survival of only odd angular momentum in the long-time limit states can be explained within an analytical model. From this model it is shown that the survival of odd high-l states originates from symmetry properties of the time development operator and that the population of even I states may occur with ultra-short laser pulses.