Effect of aspect ratio on the inter-surface plasmonic coupling of tubular gold nanoparticle
The Key Laboratory of Biomedical Information Engineering of Ministry of Education, School of Life Science and Technology, Xi'an Jiaotong University, Xi'an, 710049, P.R. China
2 Department of optical information science and technology, School of Science, Xi'an Jiaotong University, Xi'an, 710049, P.R. China
Corresponding author: a email@example.com
Revised: 1 December 2010
Published online: 1 March 2011
A theoretical study based on discrete dipole approximation (DDA) and coupling effect is presented on the tunable transverse surface plasmon resonance (SPR) in a gold nanotube with varying aspect ratio (AR). Because gold nanotube has the shape features from both rod and shell, both the AR and wall thickness can greatly affect the transverse SPR. It is observed that the maximum red shift can be obtained with small wall thickness and AR. By calculating the local field distribution, the physical mechanism of this multi shape factors controlled plasmon shifting has been illustrated by the coulombic interaction from the charges at the interfaces of gold nanotube. This study indicates that finding the surface charge distribution by calculating the local electric field can be used as an effective method to analyze the plasmonic characters in complicated metallic nanostructure.
© EDP Sciences, Società Italiana di Fisica, Springer-Verlag, 2011