Open AccessFano-like resonance in symmetry-broken gold nanotube dimer
Author(s) -
DaJian Wu,
Shumin Jiang,
Ying Cheng,
Xiaojun Liu
Publication year - 2012
Publication title -
optics express
Language(s) - Uncategorized
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.20.026559
Subject(s) - nanotube , fano resonance , dimer , molecular physics , materials science , condensed matter physics , plasmon , electric field , resonance (particle physics) , surface plasmon resonance , dipole , scattering , carbon nanotube , physics , optics , atomic physics , nanotechnology , nuclear magnetic resonance , optoelectronics , nanoparticle , quantum mechanics
The influences of the symmetry-breaking on the plasmon resonance couplings in the isolated gold nanotube and the gold nanotube dimer have been investigated by means of the finite element method. It is found that the core offset of gold nanotubes leads to the red-shifts of the low energy modes and the enhanced near-field on the thin shell side of the symmetry-broken gold nanotube (SBGNT). In the weak coupling model of the SBGNT dimer, the interference of the bonding octupole mode of the dimer with the dipole modes causes a strong Fano-like resonance in scattering spectrum. The Fano dip shows a red-shift and becomes deep with the increase of the offset-value. In the strong coupling model of the SBGNT dimer, the coupling between two SBGNTs induces giant electric field enhancement at the gap of the dimer, which is much larger than that in the symmetry gold nanotube dimer. The SBGNT with larger offset-value exhibits stronger near-field at the "hot spot".