核心电离诱导的阿秒电荷迁移：相对论实时含时密度泛函理论视角
Attosecond Charge Migration Induced by Core-Level Ionization: A Relativistic Real-Time Time-Dependent Density Functional Theory Perspective
AI总结：
本研究通过相对论实时含时密度泛函理论，揭示核心电离诱导电荷迁移中相对论效应由价轨道敏感性决定，而非仅重原子核心电离，并观察到相对论印记的延迟出现。
AI中文摘要：
分子系统中由核心电离诱导的电荷迁移已被广泛研究，但相对论效应对此类动力学的影响从相对论理论角度而言仍相对未被探索。这一问题尤为重要，因为核心轨道表现出强烈的标量相对论和自旋-轨道印记，且这些效应在重元素系统中进一步增强，其中相对论特征也改变价轨道。为解决此问题，我们构建了四分量Dirac-Coulomb和两分量原子平均场精确两分量（以及非相对论）哈密顿量方法，用于在实时含时密度泛函理论框架内研究电荷迁移。时间依赖的诱导电偶极矩被用作特征电荷迁移时间尺度的标记。我们将该方法应用于亚硝基苯（N 1s电子移除）、碘乙炔（I 2p电子移除）和卤间化合物系列（I 2p、Cl 2p电子移除）。对于碘乙炔，电荷迁移时间尺度对哈密顿量的选择相对不敏感，但表现出微弱的相对论相位和振幅修正。然而，若据此得出相对论效应通常不重要的结论将具有误导性。在卤间化合物系统中，我们观察到相对论与非相对论动力学之间的显著偏差。这些结果表明，核心电离诱导的电荷迁移中的相对论特征并非仅由重原子核心电离决定，而是由驱动核心空穴屏蔽和电荷再分布的价轨道流形的相对论敏感性所决定。此外，在所有系统中一致地，我们观察到相对论印记出现的延迟。
英文摘要：
Core-ionization induced charge migration in molecular systems has been widely studied, but the influence of relativistic effects on such dynamics remains relatively unexplored from a relativistic theory perspective. This issue is particularly important because core orbitals exhibit strong scalar-relativistic and spin-orbit imprints, and these effects are further enhanced in heavy-element systems, where relativistic signatures also alter the valence orbitals. To address this, we formulate four-component Dirac-Coulomb and two-component atomic mean-field exact two-component (and non-relativistic) Hamiltonian approaches for studying charge migration within real-time time-dependent density functional theory. The time-dependent induced electric dipole moment is used as a marker of the characteristic charge-migration time scales. We apply the method to nitrosobenzene (N $1s$ electron removal), iodoacetylene (I $2p$ electron removal) and interhalogen series (I $2p$, Cl $2p$ electron removal). For iodoacetylene, the charge migration timescale is relatively insensitive to the choice of Hamiltonian but they show weak relativistic phase and amplitude modifications. However, it would be misleading to conclude that relativistic effects are generally unimportant. In interhalogen systems, we observe significant deviations between relativistic and non-relativistic dynamics. These results demonstrate that relativistic signatures in core-ionization-induced charge migration are not determined by heavy-atom core ionization alone, but by the relativistic sensitivity of the valence orbital manifold that drives core-hole screening and charge redistribution. Moreover, consistently across all systems, we observe a delay in the emergence of the relativistic imprints.
