论文标题
电子筛选效果在电子光谱中的鲁棒性：v $ _2 $ o $ _5 $的示例
Robustness of electronic screening effects in electron spectroscopies: example of V$_2$O$_5$
论文作者
论文摘要
在批量和低维扩展系统中，电子云对激发的筛选是控制光谱特性的关键特征。广泛使用的计算方法，尤其是在多体扰动理论的框架中，例如GW近似和所得的近似伯特 - 盐方程，是根据筛选的库仑相互作用而明确提出的。在目前的工作中，我们探讨了筛选在吸收和电子能量损失光谱中的影响，集中在局部扭曲对筛选的影响并阐明各种光谱中所得的变化。使用分层的氧化物V $ _2 $ o $ _5 $作为原型材料，我们显示了局部畸变影响筛选的方式，以及在哪种方式上改变筛选影响电子能量损失和吸收光谱，包括激子。我们强调取消在频谱中产生多体效应的结构修饰非常稳定，而带状结构发生重大变化，激发的性质也可能受到影响。这产生了有关结构 - 企业关系的洞察力，这些关系对于使用V $ _2 $ o $ _5 $作为储能材料至关重要，更一般而言，可以用来优化复杂材料中电子光谱的分析和计算。
In bulk and low-dimensional extended systems, the screening of excitations by the electron cloud is a key feature governing spectroscopic properties. Widely used computational approaches, especially in the framework of many-body perturbation theory, such as the GW approximation and the resulting approximate Bethe-Salpeter equation, are explicitly formulated in terms of the screened Coulomb interaction. In the present work we explore the effect of screening in absorption and electron energy loss spectroscopy, concentrating on the effect of local distortions on the screening and elucidating the resulting changes in the various spectra. Using the layered bulk oxide V$_2$O$_5$ as prototype material, we show in which way local distortions affect the screening, and in which way changes in the screening impact electron energy loss and absorption spectra including excitons. We highlight cancellations that make many-body effects in the spectra very robust with respect to structural modifications, while the band structure undergoes significant changes and the nature of the excitations may also be affected. This yields insight concerning the structure-properties relations that are crucial for the use of V$_2$O$_5$ as energy storage material, and more generally, that may be used to optimize the analysis and the calculation of electronic spectra in complex materials.
