S.N. Pisharody and R.R. Jones
Abstract:The time-dependent survival probabilities of autoionizing 4pNd wavepackets in calcium have been measured. Femtosecond laser pulses induce sequential isolated-core excitations (ICE) of singly-excited 4sNd radial wavepackets to create and probe the non-stationary doubly-excited states. Stair-step, rather than exponential, decay of the wavepackets is observed. Moreover, we have shown that the autoionization lifetime can be varied by a factor of five by adjusting the relative phases of the constituent eigenstates in the packet. The stair-step decay structure and its dependence on the wavepacket phase is interpreted using an intuitive time-domain picture. The experimental results are in excellent agreement with a K-matrix based, 28-channel quantum defect theory (QDT) calculation as well as with an approximate 2-channel formulation.
Status: Published Phys. Rev. A ,65, 033418 (March 2002).