Electronic dynamics and quantum path control using [formula omitted] molecule in three-color laser fields

Abstract

The high-order harmonic generation (HHG) from a one-dimensional (1-D) model of H2 molecule is investigated in the three-color laser fields by numerically solving time-dependent Schrödinger equation (TDSE) in the Born-Oppenheimer Approximation (BOA) and Non-Born-Oppenheimer Approximation (NBOA) cases. The harmonic spectra are smooth with few modulations in the three-color laser fields. The semi-classical three-step model and the time-frequency analysis are employed to explain the HHG process. The nuclear and electronic probability density present the ionization and recombination process of the electron, which further explain the underlying physical mechanism of HHG. In addition, the electronic dynamics is demonstrated by the probability density distributions of the coupled electron nuclear wave packet. The isolated attosecond pulses with duration 75 as and 54 as are generated in the BOA and NBOA cases in the three-color laser fields, respectively.