Electron scattering in time-dependent density functional theory
Electron scattering in time-dependent density functional theory
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DOI：
10.1140/epjb/e2018-90101-2
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发表时间：
2018-03
期刊：
影响因子：
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通讯作者：
L. Lacombe;Yasumitsu Suzuki;Kazuyuki Watanabe;N. Maitra
中科院分区：
文献类型：
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作者：
L. Lacombe;Yasumitsu Suzuki;Kazuyuki Watanabe;N. Maitra
最近显示[Suzuki等人，Phys. Rev. Lett.119，263401（2017）]，含时密度泛函理论（TDDFT）的精确交换相关势中的峰和谷结构对于准确捕获模型一维系统中电子散射的时间分辨动力学至关重要。今天使用的近似泛函错过了这些结构，因此低估了散射概率。动态可以根据初始Kohn-Sham状态的选择而显著变化，并且，通过明智的选择，最近提出的非绝热近似提供了接近目标的非常精确的动态，但这最终也无法准确地捕获反射。在这里，我们提供了更多的细节，使用电子He+的模型作为说明，在非弹性和弹性制度。在弹性的情况下，时间分辨的图片与时间无关的图片的散射，TDDFT的线性响应理论可以用来提取透射和反射系数进行对比。虽然确切的功能产生相同的散射概率时，以这种方式使用，因为它在时间分辨的图片，我们表明，目前可用的近似泛函不，即使当他们有正确的渐近行为。
It was recently shown [Suzuki et al., Phys. Rev. Lett.119, 263401 (2017)] that peak and valley structures in the exact exchange-correlation potential of time-dependent density functional theory (TDDFT) are crucial for accurately capturing time-resolved dynamics of electron scattering in a model one-dimensional system. Approximate functionals used today miss these structures and consequently underestimate the scattering probability. The dynamics can vary significantly depending on the choice of the initial Kohn-Sham state, and, with a judicious choice, a recently-proposed non-adiabatic approximation provides extremely accurate dynamics on approach to the target but this ultimately also fails to capture reflection accurately. Here we provide more details, using a model of electron-He+as illustration, in both the inelastic and elastic regimes. In the elastic case, the time-resolved picture is contrasted with the time-independent picture of scattering, where the linear response theory of TDDFT can be used to extract transmission and reflection coefficients. Although the exact functional yields identical scattering probabilities when used in this way as it does in the time-resolved picture, we show that the currently-available approximate functionals do not, even when they have the correct asymptotic behavior.