Theoretical analysis of the role of complex transition dipole phase in XUV transient-absorption probing of charge migration
Theoretical analysis of the role of complex transition dipole phase in XUV transient-absorption probing of charge migration
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DOI：
10.1364/oe.451129
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发表时间：
2022-02-14
期刊：
影响因子：
3.8
通讯作者：
Leone, Stephen R.
中科院分区：
文献类型：
--
作者：
Kobayashi, Yuki;Neumark, Daniel M.;Leone, Stephen R.
从理论上研究了复偶极相位在阿秒探测电荷迁移中的作用。碘溴乙炔离子（ICCBr+）被认为是一个例子，其中一个可以探测电荷迁移通过访问两个碘和溴端的分子与不同的光谱窗口的极紫外（XUV）脉冲。瞬态吸收的解析表达式表明，特定位点的电荷迁移的信息被编码在复杂的相位交叉偶极产品的XUV跃迁之间的I-4d和Br-3d光谱窗口。对ICCBr+的量子化学从头计算表明，在I-4d和Br-3d瞬态吸收光谱窗口之间存在一个恒定的π相位差，与精细结构的能量分裂无关。瞬态吸收光谱模拟与多状态模型，包括复杂的偶极相位，和正确的结果重建的电荷迁移动力学通过量子拍在两个元素的光谱窗口，表现出异相振荡。(C)2022 Optica出版集团根据Optica开放获取出版协议的条款
We theoretically investigate the role of complex dipole phase in the attosecond probing of charge migration. The iodobromoacetylene ion (ICCBr+) is considered as an example, in which one can probe charge migration by accessing both the iodine and bromine ends of the molecule with different spectral windows of an extreme-ultraviolet (XUV) pulse. The analytical expression for transient absorption shows that the site-specific information of charge migration is encoded in the complex phase of cross dipole products for XUV transitions between the I-4d and Br-3d spectral windows. Ab-initio quantum chemistry calculations on ICCBr+ reveal that there is a constant pi phase difference between the I-4d and Br-3d transient-absorption spectral windows, irrespective of the fine-structure energy splittings. Transient absorption spectra are simulated with a multistate model including the complex dipole phase, and the results correctly reconstruct the charge-migration dynamics via the quantum beats in the two element spectral windows, exhibiting out-of-phase oscillations. (C) 2022 Optica Publishing Group under the terms of the Optica Open Access Publishing Agreement