Ionization of an atom with different initial angular momenta in an intense circular polarized laser field

Abstract

Abstract We theoretically investigate the ionization process of the interaction between a strong circular polarized laser pulse and an atom, whose initial state has different orbital angular momenta. When the rotation direction of the laser vector field is opposite to that of the bound state, the ionization probability is significantly higher than the co-rotating case, in which the laser vector field is in the rotational direction of the bound electron. Especially, with the increase of the incident laser’s wavelength, the ionization probability is enhanced for the co-rotating case, and it is on the contrary in the counter-rotating case. By analyzing electronic trajectories in both cases, it is demonstrated that, the difference of variations of the ionization probability with the laser’s wavelength can be attributed to that of durations from the electron passing through the exit of the over-the-barrier potential, which is formed by the atom potential and the laser field.