The role of molecular electron distribution in strong-field ionization and dissociation of heteronuclear molecules

Abstract A comparison study of double-ionization induced dissociation in strong laser fields between a homonuclear diatomic molecule, O 2 , and a heteronuclear diatomic molecule, NO, shows that two electrons can easily be removed from one O atom of O 2 to form a O 2+ +O, however, two electrons can hardly be removed from the O atom of NO to form a N+O 2+ . Instead, for NO, two electrons are preferentially removed from the N atom to form a N 2+ +O, even though the N atom requires higher ionization energy than the O atom. This indicates that atomic ionization energy does not play a significant role here. Our further study on the formation dynamics of the N 2+ +O channel shows that the initial electron distribution of the NO molecule plays an important role in influencing the strong-field ionization and dissociation of NO and this effect seems to commonly exist in heteronuclear molecules when interacting with strong laser fields.