Selective excitation of coupled CO vibrations on a dissipative Cu(100) surface by shaped infrared laser pulses.
Selective excitation of coupled CO vibrations on a dissipative Cu(100) surface by shaped infrared laser pulses.
复制标题
通过整形红外激光脉冲选择性激发耗散 Cu(100) 表面上的耦合 CO 振动。
DOI：
10.1063/1.2916710
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发表时间：
2008
期刊：
影响因子：
--
通讯作者：
P. Saalfrank
中科院分区：
文献类型：
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作者：
J. Tremblay;Stephanie Beyvers;P. Saalfrank
在之前的一篇论文中[Beyvers et al.， J. Chem.][物理学报，124,234706(2006)]，研究了通过形红外脉冲对吸附在耗散Cu（100）表面上的CO分子的各种振动模式进行模式和状态选择性激发的可能性。采用仅拉伸坐标的降维模型来实现。这个模型现在被扩展到包括旋转模式。首先，我们对吸附CO分子的束缚态进行了全维分析；即，通过对角化包含Tully等人的半经验势的六维哈密顿量得到六维特征态。真空吸尘器。科学。抛光工艺。A 11, 1914(1993)]。这是通过使用基于完全再正交化的耦合两项Lanczos算法的收缩迭代特征求解器来实现的。本文还计算了降维子系统特征向量，并将其用于研究开放系统在密度矩阵形式下存在耗散时分子的选择性激发。在密度矩阵传播中，包含多达四个自由度，即r （C-O距离），Z（分子-表面距离），以及phi和theta（分子轴相对于表面的方位角和极性）。利用最优控制理论对短强激光脉冲进行合理设计和进一步细化，再次以模式和状态选择激励为目标。同时研究了红外激光诱导解吸。在计算中，将先前的双模（r，Z）偶极子表面扩展到包含角依赖性，并改进了分子与表面电子自由度耦合的模型。
In a previous paper [Beyvers et al., J. Chem. Phys. 124, 234706 (2006)], the possibility to mode and state selectively excite various vibrational modes of a CO molecule adsorbed on a dissipative Cu(100) surface by shaped IR pulses was examined. Reduced-dimensionality models with stretching-only coordinates were employed to do so. This model is now extended with the goal to include rotational modes. First, we present an analysis of the bound states of the adsorbed CO molecule in full dimension; i.e., six-dimensional eigenstates are obtained by diagonalizing the six-dimensional Hamiltonian containing the semiempirical potential of Tully et al. [J. Vac. Sci. Technol. A 11, 1914 (1993)]. This is achieved by using a contracted iterative eigensolver based on the coupled two-term Lanczos algorithm with full reorthogonalization. Reduced-dimension subsystem eigenvectors are also computed and then used to study the selective excitation of the molecule in the presence of dissipation within the density matrix formalism for open systems. In the density matrix propagations, up to four degrees of freedom were included, namely, r (the C-O distance), Z (the molecule-surface distance), and phi and theta (the azimuthal and polar angles of the molecular axis with respect to the surface). Short, intense laser pulses are rationally engineered and further refined with optimal control theory, again with the goal for mode and state selective excitation. Also, IR-laser induced desorption is studied. For the calculations, the previous two-mode (r,Z) dipole surface is extended to include the angular dependence and the model for the coupling of the molecule to the surface electronic degrees of freedom is refined.