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Abstract

The method of the envelope Hamiltonian [K. Toyota, U. Saalmann, and J. M. Rost, New J. Phys. 17, 073005 (2015)] is applied to further study a detachment dynamics of a model negative ion in one dimension in the high-frequency regime. This method is based on the Floquet approach, but the time dependency of an envelope function is explicitly kept for arbitrary pulse durations. Therefore, it is capable of describing not only a photon absorption or emission, but also a nonadiabatic transition which is induced by the time-varying envelope of the pulse. It was shown that the envelope Hamiltonian accurately retrieves the results obtained by the time-dependent Schrodinger equation, and the underlying physics were well understood by the adiabatic approximation based on the envelope Hamiltonian. In this paper, we explore two more aspects of the detachment dynamics, which were not considered in our previous work. First, we determine the features of both a spatial and temporal interference of photoelectron wave packets in a photon-absorption process. We conclude that both of the interference mechanisms are universal in ionization dynamics in the high-frequency regime. Second, we extract a pulse duration which maximizes a yield of the nonadiabatic transition as a function of a pulse duration. It is shown that it becomes maximum when the pulse duration is comparable to a time scale of an electron.