论文标题
半导体中的两光子吸收：多波段长度分析
Two-photon absorption in semiconductors: a multi-band length-gauge analysis
论文作者
论文摘要
处理直接隙半导体中光激发的最简单方法是将它们建模为两个波段系统：一个传导和一个价带。对于此类模型，已知特别简单的分析表达式存在于光学响应（例如多光子吸收系数）。在这里，我们表明通用多波段模型不需要更复杂的表达式。我们的长度规程分析基于在没有所有散射过程的情况下基于半导体Bloch方程。在评估中，我们将重点放在泵探针方案的两光子激发上，该方案可能是非分级和任意两极化的配置。该理论是通过将密集结合模型以及K.P理论描述的块状锌蓝色半导体描述的对石墨烯及其双层的应用来验证的。
The simplest approach to deal with light excitations in direct-gap semiconductors is to model them as a two-band system: one conduction and one valence band. For such models, particularly simple analytical expressions are known to exist for the optical response such as multi-photon absorption coefficients. Here we show that generic multi-band models do not require much more complicated expressions. Our length-gauge analysis is based on the semiconductors Bloch equations in the absence of all scattering processes. In the evaluation, we focus on two-photon excitation by a pump-probe scheme with possibly non-degenerate and arbitrarily polarized configurations. The theory is validated by application to graphene and its bilayer, described by a tight-binding model, as well as bulk Zincblende semiconductors described by k.p theory.
