Quantum-Spillover-Enhanced Surface-Plasmonic Absorption at the Interface of Silver and High-Index Dielectrics
Quantum-Spillover-Enhanced Surface-Plasmonic Absorption at the Interface of Silver and High-Index Dielectrics
复制标题
DOI：
10.1103/physrevlett.115.193901
复制
发表时间：
2015-11-03
影响因子：
8.6
通讯作者：
Fang, Nicholas X.
中科院分区：
文献类型：
--
作者：
Jin, Dafei;Hu, Qing;Fang, Nicholas X.
基于电子和光子光谱，我们证明了在银和高指数电介质的界面上有一个出乎意料的强表面等离子体吸收。实验测得的吸收带宽和吸收强度与经典理论有很大偏差。我们的密度泛函计算很好地预测了这种现象的发生。结果表明，由于这种界面的金属-介电功函数较低，导电电子可以表现出强烈的量子溢出效应，导致界面电子-空穴对的产生主导了表面等离子体的衰变。这一发现对于理解和设计利用贵金属和高指数电介质的量子纳米等离子体器件具有重要意义。
We demonstrate an unexpectedly strong surface-plasmonic absorption at the interface of silver and high-index dielectrics based on electron and photon spectroscopy. The measured bandwidth and intensity of absorption deviate significantly from the classical theory. Our density-functional calculation well predicts the occurrence of this phenomenon. It reveals that due to the low metal-to-dielectric work function at such interfaces, conduction electrons can display a drastic quantum spillover, causing the interfacial electron-hole pair production to dominate the decay of surface plasmons. This finding can be of fundamental importance in understanding and designing quantum nanoplasmonic devices that utilize noble metals and high-index dielectrics.