Generalization of the Franck-Condon model for phonon excitations by resonant inelastic x-ray scattering
Generalization of the Franck-Condon model for phonon excitations by resonant inelastic x-ray scattering
复制标题
共振非弹性 X 射线散射声子激发 Franck-Condon 模型的推广
DOI：
10.1103/physrevb.101.214307
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发表时间：
2020
影响因子：
3.7
通讯作者：
K. Gilmore
中科院分区：
文献类型：
--
作者：
A. Geondzhian;K. Gilmore
共振非弹性X射线散射（RIXS）越来越多地用于量化材料中的电子振动相互作用。在周期系统的情况下，这通常是通过将实验结果拟合到一个参数化的，但精确的分析解决方案的一个简单的霍尔斯坦哈密顿量，包括一个单一的电子能级线性耦合到一个单一的爱因斯坦振动模式。在这个标准的框架内工作，我们考虑这个模型的小概括的影响，即，引入第二个爱因斯坦振子，并允许激发态势能面的曲率不同于基态势能面。我们发现，发生在RIXS中间（激发）状态的动态显着改变RIXS最终状态中观察到的光谱特征的定量解释。这使得当多个声子模式活跃时使用单模模型变得复杂。在这种情况下，我们的广义模型原则上可以被替代，尽管我们发现精确的定量结果依赖于激发态势能面的知识，尽管这通常是未知的。
Resonant inelastic X-ray scattering (RIXS) is increasingly used to quantify vibronic interactions in materials. In the case of periodic systems, this is most often done through fitting experimental results to a parameterized, but exact analytical solution of a simple Holstein Hamiltonian that consists of a single electronic level coupled linearly to a single Einstein vibrational mode. Working within this standard framework, we consider the impact of minor generalizations of this model, namely, introducing a second Einstein oscillator, and allowing the curvature of the excited-state potential energy surface to differ from that of the ground-state potential energy surface. We find that dynamics occurring in the RIXS intermediate (excited) state considerably alter the quantitative interpretation of the spectral features observed in the RIXS final state. This complicates the use of the single mode model when multiple phonon modes are active. Our generalized model may in principle by substituted in this case, though we find that accurate quantitative results rely on knowledge of the excited-state potential energy surface, though this typically is not known.
影响因子：
16.6
作者：
Johnston S;Monney C;Bisogni V;Zhou KJ;Kraus R;Behr G;Strocov VN;Málek J;Drechsler SL;Geck J;Schmitt T;van den Brink J
通讯作者：
van den Brink J