Ionization channels of the molecular ion H^(+)_(2) for various initial vibrational states in intense laser field(80 fs,800 nm,I=6.8×10^(13) W/cm^(2))are theoretically investigated by numerically solving the time-dependent Schrödinger equation.The results confirm that the channels largely depend on the selection of initial vibrational states by analyzing the variations of peak locations in the nuclear initial kinetic-energy-release spectra.Furthermore,the selection of the ionization channels is sensitive to the wavelength of the laser pulse.In addition,time-dependent competition between direct multi-photon ionization and charge-resonance-enhanced ionization are is discussed.
We theoretically investigate the electron localization around two nuclei in harmonic emission from asymmetric molecular ion. The results show that the ionization process of electron localized around one nucleus competes with its transfer process to the other nucleus. By increasing the initial vibrational level, more electrons localized around the nucleus D+tend to transfer to the nucleus He2+so that the ionizations of electrons localized around the nucleus He2+increase. In this case, the difference in harmonic efficiency between He H2+and He D2+decreases while the difference in harmonic spectral structure increases. The evident minimum can be observed in the harmonic spectrum of He H2+compared with that in the spectral structure of He D2+, which is due to the strong interference of multiple recombination channels originating from two nuclei. Time-dependent nuclear probability density, electron-nuclear probability density, double-well model, and time-frequency maps are presented to explain the underlying mechanisms.
The isotopic effect on nuclear dynamics in Coulomb explosion for various initial vibrational states of H_(2)^(+) and HD+in intense laser(80 fs,800 nm,I=6.8×10^(13)W/cm^(2)) is theoretically investigated by numerically solving the time-dependent Schrodinger equation.The calculated results confirm that the effect we discussed by paying close attention to the comparative analysis of peak locations in the nuclear kinetic-energy-release spectra largely depends on the selection of the initial vibrational states.Furthermore,it is the special isotope effect case about the vibrational state v=5 that has been studied in depth.We also discuss the time-dependent spectrum atυ=7,which can reveal the difference in nuclear wavepacket motion between H_(2)^(+) and HD+in the time region in which charge-resonance enhanced ionization takes place.
