Complex-scaling generalized pseudospectral method for quasienergy resonance states in two-center systems: Application to the Floquet study of charge resonance enhanced multiphoton ionization of molecular ions in intense low-frequency laser fields
Complex-scaling generalized pseudospectral method for quasienergy resonance states in two-center systems: Application to the Floquet study of charge resonance enhanced multiphoton ionization of molecular ions in intense low-frequency laser fields
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DOI：
10.1103/physreva.63.013414
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发表时间：
2001-01-01
影响因子：
2.9
通讯作者：
Chu, SI
中科院分区：
文献类型：
--
作者：
Chu, X;Chu, SI
本文提出了一种复杂标度广义伪谱方法，用于精确和有效地处理双中心分子体系的共振态，该方法涉及在长球面坐标系下哈密顿量的最优非均匀网格离散化。该程序应用于强低频（1064nm）激光场中分子离子多光子电离的首次收敛非厄米Floquet研究。我们探索了H-2（+）在一些临界核间距离上电离增强的潜在机制。观察到复合准能态的几个特征。对这些准能态性质和动力学行为的详细分析表明，电离增强主要是由于1 σ (g)和1 σ (u)态与激发态在某些特定核间距离上的电荷共振增强的多光子共振的影响。这些“临界”距离取决于分子电子结构的细节以及研究中使用的激光频率和强度。
Ne present a complex-scaling generalized pseudospectral method for accurate and efficient treatment of resonance states in two-center molecular systems: involving optimal nonuniform grid discretization of the Hamiltonian in prolate spheroidal coordinates. The procedure is applied to the first converged non-Hermitian Floquet study of multiphoton ionization of molecular ions in intense low-frequency (1064 nm) laser fields. Ne explore the underlying mechanism responsible for the ionization enhancement of H-2(+) at some critical internuclear distances. Several features of the complex quasienergy states are observed. A detailed analysis of the nature and dynamical behavior of these quasienergy states reveals that the ionization enhancement is mainly due to the effect of charge-resonance-enhanced multiphoton resonances of the 1 sigma (g) and 1 sigma (u) states with excited electronic states at some particular internuclear distances. These "critical" distances depend on the details of molecular electronic structure and the laser frequency and intensity used in the study.