Quantum interference in the femtosecond photoionization spectra of NaI molecules

This study investigates femtosecond pump-probe photoionization of NaI molecules by solving the time-dependent Schrodinger equation through the wave packet approach. The photoelectron spectra arc presented to analyze the dynamic information of the internal wave packet. Quantum interference is observed in the photoelectron kinetic energy spectrum at a certain time delay of the probe field. The interference signals are weak but cover a wide range of energy. This finding is consistent with the interfering process of forward and returned wave packets at short internuclear distances of the repulsive potential.