Institute of Physics, Chinese Academy of Sciences, Beijing, China.
J Chem Phys. 2011 Apr 7;134(13):134702. doi: 10.1063/1.3575185.
A semiclassical model is developed to describe plasmon-electron coupling and electronic damping of surface plasmons. It is compared with the ab initio linear response calculations for metallic thin films in the jellium approximation and for a realistic crystalline Mg(0001) surface. The semiclassical model is able to reproduce the quantum oscillations of plasmon linewidth, which was obtained in the previous ab initio calculations. In addition, state-resolved analysis reveals the origin of these oscillations, which result from superposition of the short-period oscillations of individual electron-hole pair transitions. The semiclassical model is further applied to a crystalline Mg(0001) surface, where linewidth dispersion of the surface plasmon is calculated and shows good agreement with earlier ab initio calculation and experiment. Our results suggest that this semiclassical approach is quite promising for the quantitative description of plasmon-electron coupling and associated processes such as surface-enhanced Raman scattering, light emission, and fluorescence.
我们构建了一个半经典模型来描述等离激元-电子耦合和表面等离激元的电子阻尼。我们将该模型与在理想晶体 Mg(0001)表面的金属薄膜的紧束缚近似中的从头算线性响应计算进行了比较。半经典模型能够再现之前从头算中获得的等离激元线宽的量子振荡。此外，状态分辨分析揭示了这些振荡的起源，它们是由单个电子-空穴对跃迁的短周期振荡的叠加引起的。我们进一步将半经典模型应用于晶体 Mg(0001)表面，计算了表面等离激元的线宽色散，并与早期的从头算计算和实验结果吻合良好。我们的结果表明，这种半经典方法对于定量描述等离激元-电子耦合以及相关过程，如表面增强拉曼散射、发光和荧光等，非常有前景。
