Quantum-path control and isolated-attosecond-pulse generation using H2+ molecules with moving nuclei in few-cycle laser pulses

We theoretically investigate the high-order harmonic generation (HHG) and isolated-attosecond-pulse generation from a full one-dimensional (1D) model of H${}_{2}$${}^{+}$ molecule in 3-fs, 800-nm laser pulses by using numerical solutions of the non-Born-Oppenheimer time-dependent Schr\"odinger equation (TDSE). The numerical results with moving nuclei and the static nuclei are demonstrated. The harmonic spectrum from the 22nd to the cutoff becomes smooth and fewer modulations and an isolated-attosecond pulse with duration 129 as is generated when we consider the nuclear motion. We investigate the emission time of harmonics in terms of the time-frequency analysis, which shows that, with moving nuclei, the long trajectory is suppressed, and the short trajectories is enhanced. We apply the nuclear and electronic probability density and the simulation of classical electron trajectory to illustrate the physical mechanism of HHG.