Open AccessMagnetic-field enhancement in gold nanosandwiches
Author(s) -
Tavakol Pakizeh,
Mohammad Sadegh Abrishamian,
Nosrat Granpayeh,
А. К. Дмитриев,
Mikael Käll
Publication year - 2006
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.14.008240
Subject(s) - finite difference time domain method , metamaterial , optics , plasmon , excitation , negative refraction , magnetic field , magnetic dipole , dipole , discrete dipole approximation , surface plasmon , resonance (particle physics) , refraction , physics , materials science , atomic physics , scattering , quantum mechanics
Using dispersive finite-difference time-domain (D-FDTD) simulations, we show that a pair of gold nanodisks stacked in a 'sandwich'-like (end-fire) configuration produces a large enhancement of the magnetic field when irradiated with a plane optical wave, if the distance between the nanodisks is optically small. The effect, which can be rationalized in terms of a magnetic dipole resonance, is due the excitation of a hybridized asymmetric plasmon mode, in which the induced electrical dipoles in the two disks oscillate out-of-phase. The strong magnetic response, together with the simple morphology, suggests that Au nanosandwiches are suitable elementary building blocks for optical metamaterials that exhibit negative refraction.