Real-Time Propagation of the Reduced One-Electron Density Matrix in Atom-Centered Orbitals: Application to Multielectron Dynamics of Carbon Clusters Cn in the Strong Laser Pulses
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- 作者：Jin Sun ; Jie Liu ; WanZhen LiangYi Zhao
- 刊名：Journal of Physical Chemistry A
- 出版年：2008
- 出版时间：October 23, 2008
- 年：2008
- 卷：112
- 期：42
- 页码：10442-10447
- 全文大小：214K
- 年卷期：v.112,no.42(October 23, 2008)
- ISSN：1520-5215
文摘
We present a time-dependent density functional theory (TDDFT) study on the electron dynamics of small carbon clusters Cn (n = 9, 10) exposed to a linearly polarized (LP) or circularly polarized (CP) oscillating electric field of ultrafast laser with moderate laser intensity. The multielectron dynamics is described by propagating the reduced one-electron density matrix in real-time domain. The high harmonic generation (HHG) spectra of emission as well as the time evolution of atomic charges, dipole moments and dipole accelerations during harmonic generation are calculated. The microscopic structure−property correlation of carbon chains is characterized. It is found that the electron responses of Cn to the laser field oscillation become nonadiabatic as the field intensity is larger than 1.4 × 1013 W/cm2. The nonadiabatic multielectron effect is displayed by an explicit fluctuation on the induced atomic charges and the instantaneous dipole acceleration and by observing the additional peaks other than those predicted from the spectral selection rule in HHG spectra of Cn as well. The origin of these additional peaks is elucidated. The atomic charges of Cn in LP and CP laser pulses experience different type of oscillations as expected. In the linear structure C9, the atomic charges at the two ends experience larger amplitude oscillations than those near the chain center whereas the induced charges on each atom of C10 experience the equal amplitude oscillations in the CP laser pulse.