Article pubs.acs.org/JPCC
Equivalent Permittivity and Permeability and Multiple Fano Resonances for Nonlocal Metallic Nanowires Y. Huang and L. Gao* Jiangsu Key Laboratory of Thin Films, School of Physical Science and Technology, Soochow University, Suzhou 215006, China ABSTRACT: Equivalent permittivity and permeability for metallic nanowires with spatial dispersion are derived analytically. The extinction cross section based on the local full-wave theory with our equivalent permittivity and permeability is found to be in agreement with the one based on the nonlocal full-wave theory. When the electromagnetic wave is incident on the nanocylinder with nonlocal permittivity, multiple Fano resonances exist because of the interference of different longitudinal modes with the dipole moments, and the nonlocal nanocylinder can be designed to yield an abrupt transition between full transparency and strong scattering. Interestingly, both the frequencies at which the transparency and strong scattering occur can be described well by the equivalent permittivity. Our study may be helpful in the design of optical nanoswitches and nanomemories. finite element method (FEM)14 were proposed for nanostructures with arbitrary shapes. More recently, some transformation optics procedures involving the nonlocality were proposed.3,15 Because the nonlocality arises from the quantum effects in the metal’s conduction electrons, the recently proposed full quantum treatment16−19 seems to be a good method for nanostructures a few nanometers in size. Nevertheless, theoretical results based on the semiclassical nonlocal treatment20 still are in good agreement with experimental results even for separations of
