TDGW+BSE第一性原理计算方法发展

激子是凝聚态体系中一种常见的准粒子，激子从高能量到低能量的弛豫、迁移、寿命以及与其他准粒子相互作用的动力学过程是影响凝聚态体系宏观性质的重要因素。在第一性原理计算领域，GW+BSE是人们常用的用来计算激子性质的方法，然而这种方法只能得到激子的静态电子结构。对于激子的含时动力学演化却无能为力。我们计划在经典路径近似的基础上，发展实时的含时GW+BSE (time dependent GW+BSE) 方法，并结合面跳跃方法来研究材料体系的激子动力学，并进一步考虑自旋轨道耦合效应我们将以激子效应显著的二维过渡金属硫族化物为原型材料，研究激子的产生、弛豫、湮灭、自旋翻转、电荷转移等过程。我们期待通过本项目的执行，开启利用第一性原理计算研究激子动力学的新领域。

An exciton is a quasiparticle formed by an electron and a hole, which interact through the Coulomb interaction.It generally describes optically excited states in insulators, semiconductors, and liquids. The dynamics of excitons, including the hot exciton relaxation and electron-hole recombination, play crucial roles in the energy transfer processes for sustainable energy generation. Calculating the electronic structure of excited states in solids requires many-body perturbation theory approaches such as green’s function based many-body perturbation and Bethe-Salpeter equation (GW+BSE). The goal of this research is to develop the ab initio time-dependent GW+BSE (TDGW+BSE) method based on the classical path approximation (CPA) and surface hopping scheme in nonadiabatic molecular dynamics (NAMD). The spin-orbit coupling (SOC) will be included in order to investigate spin dynamics of the electron/hole in the exciton. We expect the proposed TDGW+BSE method will become an important tool to investigate the ultrafast exciton dynamics in condensed matter systems.