论文标题
内在硅的温度依赖性介电函数：分析模型和原子表面电势
Temperature-dependent dielectric function of intrinsic silicon: Analytic models and atom-surface potentials
论文作者
论文摘要
单晶，内在硅的光学特性对于技术应用以及原子表面相互作用的基本研究而言。为了提高理解，探索能够在广泛频率和广泛的温度参数$t_Δ=（t-t_0）/t_0 $的范围内，探索能够适合实验确定的介电函数$ε（t_δ，ω）$的分析模型引起了极大的兴趣。在这里，我们发现硅介电函数拟合的方便功能形式涉及具有复杂，频率依赖性振幅参数的Lorentz-Dirac曲线，该曲线描述了辐射反应。我们将此功能形式应用于表达式$ [ε（t_δ，ω）-1]/[ε（t_δ，ω）+2] $，灵感来自Clausius -Mossotti关系。在一组非常有限的拟合参数的情况下，我们能够以极好的准确性表示（角度）频率范围$ 0 <ω<0.16 \，{\ rm a.u。} $和$ 0 <t_Δ<2.83 $，对应于温度范围$ 293 \ \ \ rm k k} $ k} $ k} $ n <t <t <t <t <1123 $。使用我们的方法，我们评估了短期$ C_3 $和远程$ C_4 $系数，用于氦原子与硅面的相互作用。为了验证我们的结果，我们将$ε（t_δ，ω）$的单独温度依赖性直接拟合与Lorentz-Dirac模型进行比较。
The optical properties of monocrystalline, intrinsic silicon are of interest for technological applications as well as fundamental studies of atom-surface interactions. For an enhanced understanding, it is of great interest to explore analytic models which are able to fit the experimentally determined dielectric function $ε(T_Δ, ω)$, over a wide range of frequencies and a wide range of the temperature parameter $T_Δ= (T-T_0)/T_0$, where $T_0 = 293\,{\rm K}$ represents room temperature. Here, we find that a convenient functional form for the fitting of the dielectric function of silicon involves a Lorentz-Dirac curve with a complex, frequency-dependent amplitude parameter, which describes radiation reaction. We apply this functional form to the expression $[ε(T_Δ, ω) -1]/[ ε(T_Δ, ω)+2]$, inspired by the Clausius-Mossotti relation. With a very limited set of fitting parameters, we are able to represent, to excellent accuracy, experimental data in the (angular) frequency range $0 < ω< 0.16 \, {\rm a.u.}$ and $0< T_Δ< 2.83$, corresponding to the temperature range $ 293\,{\rm K} < T < 1123\, {\rm K}$. Using our approach, we evaluate the short-range $C_3$ and the long-range $C_4$ coefficients for the interaction of helium atoms with the silicon surface. In order to validate our results, we compare to a separate temperature-dependent direct fit of $ε(T_Δ, ω)$ to the Lorentz-Dirac model.
