Resonance shifts and spill-out effects in self-consistent hydrodynamic nanoplasmonics
Resonance shifts and spill-out effects in self-consistent hydrodynamic nanoplasmonics
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DOI：
10.1038/ncomms8132
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发表时间：
2015-05-01
影响因子：
16.6
通讯作者：
Wubs, Martijn
中科院分区：
文献类型：
--
作者：
Toscano, Giuseppe;Straubel, Jakob;Wubs, Martijn
采用硬壁边界条件的标准流体力学Drude模型可以对贵金属纳米粒子的光学响应进行精确的定量预测。然而，它是不太准确的其他金属纳米系统，由于电子密度溢出在自由空间中的表面效应不能忽略。在这里，我们解决的基本问题是否在等离子体表面效应的描述一定需要一个完全量子力学从头算方法。本文提出了一个自洽的流体动力学模型（SC-HDM），在该模型中，可以确定非均匀电子气的基态和激发态性质。用这种方法，我们能够解释的Na和Ag纳米线和纳米球的尺寸依赖的表面共振位移。我们得到的结果与实验和更先进的量子方法符合得很好。的SC-HDM给出了准确的结果与适度的计算工作量，并可以应用到任意nanoplasmonic系统的尺寸大得多的从头算方法访问。
The standard hydrodynamic Drude model with hard-wall boundary conditions can give accurate quantitative predictions for the optical response of noble-metal nanoparticles. However, it is less accurate for other metallic nanosystems, where surface effects due to electron density spill-out in free space cannot be neglected. Here we address the fundamental question whether the description of surface effects in plasmonics necessarily requires a fully quantum-mechanical ab initio approach. We present a self-consistent hydrodynamic model (SC-HDM), where both the ground state and the excited state properties of an inhomogeneous electron gas can be determined. With this method we are able to explain the size-dependent surface resonance shifts of Na and Ag nanowires and nanospheres. The results we obtain are in good agreement with experiments and more advanced quantum methods. The SC-HDM gives accurate results with modest computational effort, and can be applied to arbitrary nanoplasmonic systems of much larger sizes than accessible with ab initio methods.