Rotational dynamics and transitions between ?-type doubling of NO induced by an intense two-color laser field

We numerically investigate the rotational dynamics of NO in the electronic ground X-2 pi state induced by an intense two-color laser field (10 TW/cm(2)) as a function of pulse duration (0.3-25 ps). In the short pulse duration of less than 12 ps, rotational Raman excitation is effectively induced and results in molecular orientation. On the contrary, when the pulse duration is longer than 15 ps, the rotational excitation is suppressed. In addition to the rotational excitation, we find that transitions between lambda-type doubling are induced. Significantly, the maximum coherent wave packet between lambda-type doubling in J = 0.5 is generated using the pulse duration of 19.8 ps. The wave packet changes to the eigenstates of lambda = +1 or -1 alternatively, where lambda is the projection of the electronic orbital angular momentum on the N-O axis, which is regarded as the unidirectional rotation of an unpaired 2 pi electron around the N-O axis in a space-fixed frame as well as in a molecule-fixed frame. The experimental method to observe the alternation of the rotational direction of the electron around the N-O axis is proposed.

Automated summary

The rotational dynamics of NO in the electronic ground X-2 pi state is numerically investigated using an intense two-color laser field, with different pulse durations leading to either rotational Raman excitation or suppression of rotational excitation. In addition, transitions between lambda-type doubling are induced, with the generation of a coherent wave packet between lambda-type doubling in J = 0.5 at a specific pulse duration. The alternation of the rotational direction of the electron around the N-O axis is proposed to be observed experimentally.