Theory of the absorption line shape in monolayers of transition metal dichalcogenides
Theory of the absorption line shape in monolayers of transition metal dichalcogenides
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DOI：
10.1103/physrevb.101.155304
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发表时间：
2020-04-16
影响因子：
3.7
通讯作者：
Reiter, D. E.
中科院分区：
文献类型：
--
作者：
Lengers, F.;Kuhn, T.;Reiter, D. E.
过渡金属二硫属化物单分子膜的线性吸收光谱显示出这些材料中异常强的激子-声子相互作用的显著特征。为了解释这种光信号中的激子和声子物理学，我们比较了不同的理论方法来计算使用的例子MoSe 2的吸收光谱。在本文中，我们推导出的运动方程的极化使用相关展开到第四玻恩近似或时间卷积主方程。我们表明，玻恩近似可能会成为问题时，没有足够高的顺序处理，特别是在高温下。相比之下，无时间卷积公式给出了令人惊讶的好结果，尽管它的简单性相比，高阶相关展开，因此提供了一个强大的工具来计算线性吸收光谱的线形在非常流行的单层材料。
The linear absorption spectra in monolayers of transition metal dichalcogenides show pronounced signatures of the exceptionally strong exciton-phonon interaction in these materials. To account for both exciton and phonon physics in such optical signals, we compare different theoretical methods to calculate the absorption spectra using the example of MoSe2. In this paper, we derive the equations of motion for the polarization either using a correlation expansion up to fourth Born approximation or a time convolutionless master equation. We show that the Born approximation might become problematic when not treated in high enough order, especially at high temperatures. In contrast, the time convolutionless formulation gives surprisingly good results despite its simplicity when compared to higher-order correlation expansion and therefore provides a powerful tool to calculate the line shape of linear absorption spectra in the very popular monolayer materials.