Time-dependent density-functional approach for exciton binding energies
Time-dependent density-functional approach for exciton binding energies
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激子结合能的时间依赖性密度泛函方法
DOI：
10.1103/physrevb.79.233201
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发表时间：
2009
影响因子：
3.7
通讯作者：
C. Ullrich
中科院分区：
文献类型：
--
作者：
V. Turkowski;V. Turkowski;A. Leonardo;C. Ullrich
绝缘体和半导体中的光学过程，包括激子效应，可以用含时密度泛函理论（TDDFT）在原理上精确描述。从线性化的TDDFT半导体布洛赫方程的两带模型，我们推导出一个简单的形式计算激子结合能。这种形式主义导致了标准的Wannier方程的激子，具有由长程和动态交换相关（XC）效应确定的非局部有效的电子-空穴相互作用的推广。我们计算激子结合能在几个直接带隙半导体，使用交换只和模型XC内核。
Optical processes in insulators and semiconductors, including excitonic effects, can be described in principle exactly using time-dependent density-functional theory (TDDFT). Starting from a linearization of the TDDFT semiconductor Bloch equations in a two-band model, we derive a simple formalism for calculating excitonic binding energies. This formalism leads to a generalization of the standard Wannier equation for excitons, featuring a nonlocal effective electron-hole interaction determined by long-range and dynamical exchange-correlation (XC) effects. We calculate excitonic binding energies in several direct-gap semiconductors, using exchange-only and model XC kernels.