论文标题
过渡金属二分法元素单层中吸收线形的理论
Theory of absorption lineshape in monolayers of transition metal dichalcogenides
论文作者
论文摘要
过渡金属二分法源的单层中的线性吸收光谱显示出明显的这些材料中异常强的激子相互作用的特征。为了说明这种光学信号中的激子和声子物理，我们使用$ \ mathrm {Mose_2} $的示例比较了不同的理论方法来计算吸收光谱。在本文中，我们使用相关扩展最高为第4次近似或无时间卷积的主方程来得出极化的运动方程。我们表明，如果没有足够高的顺序处理，尤其是在高温下，天生的近似可能会变得有问题。相比之下，尽管与高阶更正关系的扩展相比，尽管它很简单，但无卷积公式的效果令人惊讶地良好，因此提供了一种强大的工具来计算非常流行的单层材料中线性吸收光谱的线条。
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 $\mathrm{MoSe_2}$. In this paper, we derive the equations of motion for the polarization either using a correlation expansion up to 4th 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 corrrelation expansion and therefore provides a powerful tool to calculate the lineshape of linear absorption spectra in the very popular monolayer materials.
