Molecular photoelectron momentum and angular distributions of N₂ molecules by ultrashort attosecond laser pulses

The ultrafast photoionization dynamics of N₂ molecules by x-ray/XUV laser pulses is investigated. The molecular frame photoelectron momentum distributions (MF-PMDs) and the molecular frame photoelectron angular distributions (MF-PADs) are obtained by numerically solving 2D time-dependent Schrödinger equations within the single-electron approximation (SEA) frame. The results show that the molecular photoionization diffraction appears in 5 nm laser fields. However, when the laser wavelength is 30 nm, the molecular photoionization diffraction disappears and the MF-PMDs show four-lobe pattern. The ultrafast photoionization model can be employed to describe the MF-PMDs and MF-PADs of N₂ molecules.