Modulation of Fano resonances in symmetry-broken gold-SiO_2-gold nanotube dimers  

作　　者：WU DaJian YU HaiQun JIANG ShuMin WU XueWei LIU XiaoJun 

机构地区：[1]School of Physics and Technology,Nanjing Normal University [2]Faculty of Science,Jiangsu University [3]School of Physics,Nanjing University

出　　处：《Science China(Physics,Mechanics & Astronomy)》2014年第6期1063-1067,共5页中国科学：物理学、力学、天文学（英文版）

基　　金：supported by the National Basic Research Program of China(Grant No.2012CB921504);the National Natural Science Foundation of China(Grant Nos.11174113,11204129 and 11274171);the Research Fund for the Doctoral Program of Higher Education of China(RFDP)(Grant Nos.20120091110001 and 20130091130004);Qing Lan Project of Jiangsu Province

摘　　要：Fano resonances in the symmetry-broken gold-SiO2-gold(BGSG)nanotubes and the associated dimers have been investigated based on the finite element method.In the BGSG nanotube,the symmetry breaking induced the interactions of the inner gold core and outer gold nanoshell plasmons of all multipolar orders and hence the red-shifts of the plasmon resonance modes and the enhanced quadrupole mode peaks were observed.The interference of the quadrupole mode peak with the subradiant dipole mode caused a Fano-dip in the scattering spectrum.By increasing the core offset-value in the BGSG nanotube,the Fano dip with low energy showed a red-shift and became deeper.Unexpectedly the plasmon coupling between a GSG nanotube and a BGSG nanotube can lead to two strong Fano dips in the scattering spectra of the dimer.It was further noted that the thin side of the BGSG nanotube located at two sides of the dimer gap can lead to the strong near-field coupling between two BGSG nanotubes and hence a deeper and broader Fano dip.Fano resonances in the symmetry-broken gold-SiO2-gold （BGSG） nanotubes and the associated dimers have been investigated based on the finite element method. In the BGSG nanotube, the symmetry breaking induced the interactions of the inner gold core and outer gold nanoshell plasmons of all multipolar orders and hence the red-shifts of the plasmon resonance modes and the enhanced quadrupole mode peaks were observed. The interference of the quadrupole mode peak with the subradiant dipole mode caused a Fano-dip in the scattering spectrum. By increasing the core offset-value in the BGSG nanotube, the Fano dip with low energy showed a red-shift and became deeper. Unexpectedly the plasmon coupling between a GSG nanotube and a BGSG nanotube can lead to two strong Fano dips in the scattering spectra of the dimer. It was further noted that the thin side of the BGSG nanotube located at two sides of the dimer gap can lead to the strong near-field coupling between two BGSG nano- tubes and hence a deeper and broader Fano dip.

关 键 词：Fano resonance three-layered gold nanotube DIMER finite element methods 

分 类 号：TB383.1[一般工业技术—材料科学与工程]