The interference between two dissociating wave packets of the I2 molecule driven by femtosecond laser pulses is theoreticaly studied by using the time-dependent quantum wave packet method. Both the internuclear distan...The interference between two dissociating wave packets of the I2 molecule driven by femtosecond laser pulses is theoreticaly studied by using the time-dependent quantum wave packet method. Both the internuclear distance-and velocity-dependent density functions are calculated and discussed. It is demonstrated that the interference pattern is determined by the phase difference and the delay time between two pump pulses. With two identical pulses with a delay time of 305 fs and a FWHM of 20 fs, more interference fringes can be observed, while with two pump pulses with a delay time of 80 fs and a FWHM of 20 fs, only a few interference fringes can be observed.展开更多
The Autler-Townes （AT） splitting in femtosecond photoelectron spectrum of three-level Li2 molecules is theoretically investigated using time-dependent quantum wave packet method. With proper femtosecond laser pulses...The Autler-Townes （AT） splitting in femtosecond photoelectron spectrum of three-level Li2 molecules is theoretically investigated using time-dependent quantum wave packet method. With proper femtosecond laser pulses, three peaks of the AT splitting can be observed in the photoelectron spectrum. The AT splitting stems from rapid Rabi oscillation caused by intense ultrashort laser pluses. The effects of laser parameters on the molecular ionization dynamics are also discussed.展开更多
The effect of delay time on photoelectron spectra and state populations of a four-level ladder K2 molecule is investigated by a pump1–pump2–probe pulse via the time-dependent wave packet approach. The periodical mot...The effect of delay time on photoelectron spectra and state populations of a four-level ladder K2 molecule is investigated by a pump1–pump2–probe pulse via the time-dependent wave packet approach. The periodical motion of the wave packet leads to the periodical change of the photoelectron spectra. The Autler–Townes triple splitting appears at zero delay time, double splitting appears at nonzero delay time between pump1 and pump2 pulses, and no splitting appears at nonzero delay time between pump2 and probe pulses. The periodical change of the state populations with the delay time may be due to the coupling effect between the two pulses. It is found that the selectivity of the state populations may be attained by regulating the delay time. The results can provide an important basis for realizing the optical control of molecules experimentally.展开更多
Effect of laser fields on Na2 interaction potentials is studied by calculating the time-resolved photoelectron spectrum （TRPES） with the time-dependent wave-packet method. It is shown that the photoelectron spectrum...Effect of laser fields on Na2 interaction potentials is studied by calculating the time-resolved photoelectron spectrum （TRPES） with the time-dependent wave-packet method. It is shown that the photoelectron spectrum at different delay times reflects the population in different electronic states. We inspect the periodicity of vibrational motion in neutral states, and map the vibrational wave-packet propagation in corresponding internuclear coordinate.展开更多
We investigate Autler-Townes splitting in the photoelectron spectra of K2 molecule driven by pump-probe pulses via employing the time-dependent wave packet approach. It is found that the magnitude of Aulter-Townes spl...We investigate Autler-Townes splitting in the photoelectron spectra of K2 molecule driven by pump-probe pulses via employing the time-dependent wave packet approach. It is found that the magnitude of Aulter-Townes splitting varies with the wavelength of the intense laser pulse. In particular, the phenomenon of Aulter-Townes splitting vanishes for the far-off resonance of the pump pulse. Also, the split peaks of Autler Townes in the case of resonant pump pulse give us an approach to directly obtaining the transition dipole moment of a molecule.展开更多
Three-dimensional quantum mechanical calculations for vibrational predissociation of HeI2(B) van der Waals molecules are presented using the time-dependent wave packet technique within the golden rule approxima tion.T...Three-dimensional quantum mechanical calculations for vibrational predissociation of HeI2(B) van der Waals molecules are presented using the time-dependent wave packet technique within the golden rule approxima tion.The total and partial decay widths,lifetimes,rates and their dependence on initial vibrational states were obtained for HeI2 at low initial vibrational excited levels.Our calculations show that the calculated tota decay widths,lifetimes and rates agree well with those extrapolated from experimental data available The predicted total decay widths as a function of initial vibrational states exhibit highly nonlinear behavior.The very short propagation time (less.than 1 ps) required in the golden rule wave packet calculation is determined by the duration time of the final state inter-action between the fragments on the vibrationally deexcited adiabatic potential surface.The final state interaction between the fragments is shown to play an important role in determining the final rotational distribution This interpreta tion clearly explains the dynamical effect that the final rotational distribution shifts to the lower rotational energy levels as the initial vibrational quantum number v increases.展开更多
基金Project supported by the National Natural Science Foundation of China (Grant Nos 10674022 and 20633070)
文摘The interference between two dissociating wave packets of the I2 molecule driven by femtosecond laser pulses is theoreticaly studied by using the time-dependent quantum wave packet method. Both the internuclear distance-and velocity-dependent density functions are calculated and discussed. It is demonstrated that the interference pattern is determined by the phase difference and the delay time between two pump pulses. With two identical pulses with a delay time of 305 fs and a FWHM of 20 fs, more interference fringes can be observed, while with two pump pulses with a delay time of 80 fs and a FWHM of 20 fs, only a few interference fringes can be observed.
基金Supported by the National Natural Science Foundation of China under Grant Nos 10374012 and 10674022.
文摘The Autler-Townes （AT） splitting in femtosecond photoelectron spectrum of three-level Li2 molecules is theoretically investigated using time-dependent quantum wave packet method. With proper femtosecond laser pulses, three peaks of the AT splitting can be observed in the photoelectron spectrum. The AT splitting stems from rapid Rabi oscillation caused by intense ultrashort laser pluses. The effects of laser parameters on the molecular ionization dynamics are also discussed.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.11704178 and 11764041)the Scientific Research Fund of Hunan Provincial Education Department,China(Grant No.15B204)
文摘The effect of delay time on photoelectron spectra and state populations of a four-level ladder K2 molecule is investigated by a pump1–pump2–probe pulse via the time-dependent wave packet approach. The periodical motion of the wave packet leads to the periodical change of the photoelectron spectra. The Autler–Townes triple splitting appears at zero delay time, double splitting appears at nonzero delay time between pump1 and pump2 pulses, and no splitting appears at nonzero delay time between pump2 and probe pulses. The periodical change of the state populations with the delay time may be due to the coupling effect between the two pulses. It is found that the selectivity of the state populations may be attained by regulating the delay time. The results can provide an important basis for realizing the optical control of molecules experimentally.
基金Supported by the National Natural Science Foundation of China under Grant No 10575017.
文摘Effect of laser fields on Na2 interaction potentials is studied by calculating the time-resolved photoelectron spectrum （TRPES） with the time-dependent wave-packet method. It is shown that the photoelectron spectrum at different delay times reflects the population in different electronic states. We inspect the periodicity of vibrational motion in neutral states, and map the vibrational wave-packet propagation in corresponding internuclear coordinate.
基金supported by the National Natural Science Foundation of China (Grant Nos.91021009 and 10874102)the Research Fund for the Doctoral Program of Higher Education,China (Grant No.200804220004)
文摘We investigate Autler-Townes splitting in the photoelectron spectra of K2 molecule driven by pump-probe pulses via employing the time-dependent wave packet approach. It is found that the magnitude of Aulter-Townes splitting varies with the wavelength of the intense laser pulse. In particular, the phenomenon of Aulter-Townes splitting vanishes for the far-off resonance of the pump pulse. Also, the split peaks of Autler Townes in the case of resonant pump pulse give us an approach to directly obtaining the transition dipole moment of a molecule.
文摘Three-dimensional quantum mechanical calculations for vibrational predissociation of HeI2(B) van der Waals molecules are presented using the time-dependent wave packet technique within the golden rule approxima tion.The total and partial decay widths,lifetimes,rates and their dependence on initial vibrational states were obtained for HeI2 at low initial vibrational excited levels.Our calculations show that the calculated tota decay widths,lifetimes and rates agree well with those extrapolated from experimental data available The predicted total decay widths as a function of initial vibrational states exhibit highly nonlinear behavior.The very short propagation time (less.than 1 ps) required in the golden rule wave packet calculation is determined by the duration time of the final state inter-action between the fragments on the vibrationally deexcited adiabatic potential surface.The final state interaction between the fragments is shown to play an important role in determining the final rotational distribution This interpreta tion clearly explains the dynamical effect that the final rotational distribution shifts to the lower rotational energy levels as the initial vibrational quantum number v increases.
