Zhongyue Zhang and Yiping Zhao 2008 J. Phys.: Condens. Matter 20 345223 doi:10.1088/0953-8984/20/34/345223
Zhongyue Zhang and Yiping Zhao
Show affiliationsThe extinction spectra and E field distribution of a U-shaped nanostructure have been calculated using the discrete dipole approximation method, and compared to those of the parallel-nanorod structure. For a parallel-nanorod structure, when light propagates with its E field perpendicular to the nanorod axis only transverse plasmon modes are excited. Under the same condition for a U-shaped nanostructure, because the bottom nanorod builds a path for the electrons oscillations, longitudinal mode plasmon oscillations can also occur along the vertical nanorods. A U-shaped nanostructure has more hot spots than a parallel-nanorod structure; and at the longitudinal mode incidence, the E field enhancements are much larger than those of the parallel-nanorod structure. The longitudinal mode plasmon peaks red shift linearly with increase in the height, and decay exponentially with increasing nanorod radius. When the separation between two vertical nanorods increases, the longitudinal mode plasmon peaks first blue shift and then red shift linearly. These results could be used to engineer U-shaped nanostructures for specific plasmonic applications.
78.67.Bf Nanocrystals and nanoparticles
73.22.Lp Collective excitations
Issue 34 (27 August 2008)
Received 23 April 2008, in final form 14 June 2008
Published 6 August 2008
Zhongyue Zhang and Yiping Zhao 2008 J. Phys.: Condens. Matter 20 345223
B A Samuel et al 2007 Nanotechnology 18 115704
Raj K Dash et al 2007 Nanotechnology 18 475711
Adam Brandenburger and Noson Yanofsky 2008 J. Phys. A: Math. Theor. 41 425302
Juan Maldacena and Liat Maoz JHEP02(2004)053
Evgeny Kh. Akhmedov et al JHEP06(2008)072
L Robertsson et al 2005 Metrologia 42 04003
F Altarelli et al 2008 J. Phys.: Conf. Ser. 95 012013
L Robertsson et al 2005 Metrologia 42 04004
N Mufti et al 2009 J. Phys.: Condens. Matter 21 452203