EVOLUTION OF RYDBERG ANGULAR-MOMENTUM WAVEPACKETS IN HALF-CYCLE PULSES

We study the redistribution of Rydberg states subject to half-cycle el ectromagnetic pulses as a function of the field strength and the durat ion of the pulses. It is found that the survival probability exhibits oscillations which are associated with the almost recurrent propagatio n of the electronic wavepacket in angular momentum space. The classica l and quantal origin of the different 'Stark beat' frequencies is disc ussed. The dependence of the beats on the shape of the pulse and effec ts due to a non-hydrogenic core are analysed. The momentum transferred by the field is identified as a fundamental variable for the excitati on function.