Fano Profiles Induced by Near-Field Coupling in Heterogeneous Dimers of Gold and Silver Nanoparticles
Fano Profiles Induced by Near-Field Coupling in Heterogeneous Dimers of Gold and Silver Nanoparticles
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DOI：
10.1103/physrevlett.101.197401
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发表时间：
2008-11-07
影响因子：
8.6
通讯作者：
Brevet, P. -F.
中科院分区：
文献类型：
--
作者：
Bachelier, G.;Russier-Antoine, I.;Brevet, P. -F.
从理论上研究了金和银球形纳米粒子之间的近场耦合。由于银纳米粒子的光谱局域表面等离子体共振和金纳米粒子的带间跃迁的连续谱之间的耦合，在金纳米粒子的吸收截面中观察到Fano分布。二聚体的内部特性（颗粒大小和距离），周围的介质（通过折射率），和外部激发（偏振和传播方向）的影响得到解决。特别是，它示出的近场耦合可以从弱到强的制度，通过旋转的偏振方向调谐，和Fano配置文件是敏感的阴影效应，即使对于小颗粒尺寸。
The near-field coupling between a gold and a silver spherical nanoparticle is investigated theoretically. Fano profiles are observed in the absorption cross section of the gold nanoparticle due to the coupling between the spectrally localized surface plasmon resonance of the silver nanoparticle and the continuum of interband transitions of the gold one. The effect of dimer internal characteristics (particle sizes and distance), surrounding medium (through the refractive index), and external excitation (polarization and propagation directions) are addressed. In particular, it is shown that the near-field coupling can be tuned from the weak to the strong regime by rotating the polarization direction, and that the Fano profiles are sensitive to the shadowing effect even for small particle sizes.