Anomalous dependence of ionization probability and electron angular distributions on orientation of molecular axis in photoionization of : effect of two-center interference

Abstract

A theoretical and computational study of photoionization of the one-electron molecular ion initially in the 1σ u state is performed. The laser pulse is linearly polarized with the carrier wavelength in the extreme ultraviolet and soft x-ray regions. The electron wave function is obtained by solving the time-dependent Schrödinger equation with the help of the generalized pseudospectral method. The dependence of the total ionization probability and photoelectron spectra on the orientation of the molecular axis is analyzed. Within the wavelength interval 6 to 23 nm, anomalous behavior of the ionization probability is found, where it increases with the angle between the polarization vector of the external field and the molecular axis and reaches a maximum at the perpendicular orientation of the molecule. The phenomenon is explained as resulting from the two-center interference in the wave function of the emitted electron.