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arXiv 1006.2649cond-mat.mtrl-sci
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固体二阶非线性光学的从头计算:基于含时密度泛函理论的二次谐波产生光谱

Ab Initio Second-Order Nonlinear Optics in Solids: Second-Harmonic Generation Spectroscopy from Time-Dependent Density-Functional Theory

Eleonora Luppi, Hannes Hübener, Valérie Véniard

摘要:

我们详细介绍了从头计算理论的制定,我们已经开发的宏观二阶极化率$χ^{(2)}$的计算。我们发现一个一般表达式$χ^{(2)}$适用于任何领域,包含从头算之间的关系的\textit{microscopic}和\textit{macroscopic}制定的二阶响应。我们考虑了长波长极限,并在含时密度泛函理论框架下发展了我们的理论。这使我们能够直接包括多体效应,如晶体局域场和激子效应。本文从$χ^{(2)}$的独立粒子近似出发,计算了立方半导体SiC、AlAs和GaAs的二次谐波产生谱,并考虑了准粒子效应(通过剪刀算符)、晶体局域场和激子效应。特别是,我们考虑两种不同类型的内核:ALDA和“远程”内核。我们发现很好的协议与其他理论计算和文献中提出的实验,非常准确的描述多体相互作用的重要性。

英文摘要:

We present in detail the formulation of the ab initio theory we have developed for the calculation of the macroscopic second-order susceptibility $χ^{(2)}$. We find a general expression for $χ^{(2)}$ valid for any fields, containing the ab initio relation between the \textit{microscopic} and \textit{macroscopic} formulation of the second-order responses. We consider the long wavelength limit and we develop our theory in the Time-Dependent Density-Functional Theory framework. This allows us to include straightforwardly many-body effects such as crystal local-field and excitonic effects. We compute the Second-Harmonic Generation spectra for the cubic semiconductors SiC, AlAs and GaAs and starting from the Independent-Particle Approximation for $χ^{(2)}$, we include quasiparticle effects via the scissors operator, crystal local-field and excitonic effects. In particular, we consider two different types of kernels: the ALDA and the "long-range" kernel. We find good agreement with other theoretical calculations and experiments presented in literature, showing the importance of very accurate description of the many-body interactions.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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