论文标题
第一原理的激子 - phonon相互作用和放松时间
Exciton-Phonon Interaction and Relaxation Times from First Principles
论文作者
论文摘要
电子 - phonon（$ e $ ph）相互作用是了解材料中电子动力学的关键，并且可以从第一原理进行准确建模。但是，当电子和孔形成库仑结合状态（激子）时，量化其相互作用和与声子的散射过程仍然是一个开放的挑战。在这里，我们显示了一种严格的方法，用于计算第一个原理的激子 - phonon（EX-PH）相互作用以及相关的激子动力学过程。从伯特 - 钙板方程式开始，我们得出了前ph矩阵元素和放松时间的表达式。我们将我们的方法应用于大量的六边形硝酸硼，为此，我们将前pH弛豫时间映射为激动剂动量和能量的函数，分析前pH散射过程的温度和声子模式依赖性，并准确地预测声音声子辅助的光致发光。这项工作中引入的方法是一般的，并提供了一个框架，用于研究各种材料中的激子动态。
Electron-phonon ($e$-ph) interactions are key to understanding the dynamics of electrons in materials, and can be modeled accurately from first-principles. However, when electrons and holes form Coulomb-bound states (excitons), quantifying their interactions and scattering processes with phonons remains an open challenge. Here we show a rigorous approach for computing exciton-phonon (ex-ph) interactions and the associated exciton dynamical processes from first principles. Starting from the ab initio Bethe-Salpeter equation, we derive expressions for the ex-ph matrix elements and relaxation times. We apply our method to bulk hexagonal boron nitride, for which we map the ex-ph relaxation times as a function of exciton momentum and energy, analyze the temperature and phonon-mode dependence of the ex-ph scattering processes, and accurately predict the phonon-assisted photoluminescence. The approach introduced in this work is general and provides a framework for investigating exciton dynamics in a wide range of materials.
