论文标题
来自密度响应的零的时间依赖性密度功能理论的激子效应
Excitonic effects in time-dependent density functional theory from zeros of the density response
论文作者
论文摘要
我们表明，可以通过其杆子来感知半导体和绝缘子动力学XC内核的分析结构，这些磁极在系统的物理相关频率上标记了离散集体激发的反相运动的物理相关频率：如果激发了集体模式，则集体模式相互平衡，使系统在全部或极弱的响应中表现出无关。该特性可用于构建动态XC内核的简单且实际相关的近似，以进行时间依赖性密度功能理论（TDDFT）。这样的内核具有简单的分析结构，能够复制单层半导体和块状固体的吸收光谱的显性激发特征，并有助于在TDDFT的有效实时计算中，对未来使用的潜力很高。
We show that the analytic structure of the dynamical xc kernels of semiconductors and insulators can be sensed in terms of its poles which mark physically relevant frequencies of the system where the counter-phase motion of discrete collective excitations occurs: if excited, the collective modes counterbalance each other, making the system to exhibit none at all or extremely weak density response. This property can be employed to construct simple and practically relevant approximations of the dynamical xc kernel for time-dependent density functional theory (TDDFT). Such kernels have simple analytic structure, are able to reproduce dominant excitonic features of the absorption spectra of monolayer semiconductors and bulk solids, and promise high potential for future uses in efficient real-time calculations with TDDFT.
