论文标题
使用广义的Kohn-Sham实时TDDFT模拟固体中Attosend瞬时软X射线吸收
Simulation of attosecond transient soft X-ray absorption in solids using generalized Kohn-Sham real-time TDDFT
论文作者
论文摘要
时间依赖性密度功能理论（TDDFT）对瞬态核心水平光谱镜的模拟需要对价值和核心电子激发的平衡处理。为此，在广义的Kohn-Sham方案中，通过调整范围分离的混合交换相关功能提供了一种计算有效的方法，可以通过缓解多个长度级别的定位误差来同时提高TDDFT的价准确性和TDDFT的核心激发能量。在这项工作范围内分离的杂种功能与实时TDDFT的速度 - 规格一起使用，以模拟原型固体系统中的静态X射线以及瞬态软X射线近边缘吸收光谱，单层六边形乙酰基硝基胺氮气，兴奋性效果很重要。在静态情况下，计算出的软X射线吸收边缘能和线形与实验非常吻合。通过泵脉冲激发激发后，显示了软X射线探针光谱，显示出种群引起的漂白和瞬时能量转移的特征。因此，这项工作中概述的方法说明了一种实用手段，用于模拟TDDFT框架内的固体中的ATTSENT时间分辨核心水平光谱。
Time-dependent density functional theory (TDDFT) simulations of transient core-level spectroscopies require a balanced treatment of both valence- and core-electron excitations. To this end, tuned range-separated hybrid exchange-correlation functionals within the generalized Kohn-Sham scheme offer a computationally efficient means of simultaneously improving the accuracy of valence and core excitation energies in TDDFT by mitigating delocalization errors across multiple length-scales. In this work range-separated hybrid functionals are employed in conjunction with the velocity-gauge formulation of real-time TDDFT to simulate static as well as transient soft X-ray near-edge absorption spectra in a prototypical solid-state system, monolayer hexagonal boron nitride, where excitonic effects are important. In the static case, computed soft X-ray absorption edge energies and line shapes are seen to be in good agreement with experiment. Following laser excitation by a pump pulse, soft X-ray probe spectra are shown to exhibit characteristic features of population induced bleaching and transient energy shifts of exciton peaks. The methods outlined in this work therefore illustrate a practical means for simulating attosecond time-resolved core-level spectra in solids within a TDDFT framework.
