Study of plasmon resonance in a gold nanorod with an LC circuit model

Abstract

Gold nanorod has generated great research interest due to its tunable longitudinal plasmon resonance. However, little progress has been made in the understanding of the effect. A major reason is that, except for the metallic spheres and ellipsoids, the interaction between light and nanoparticles is generally insoluble. In this paper, a new scheme has been proposed to study the plasmon resonance of gold nanorod, in which the nanorod is modeled as an LC circuit with an inductance and a capacitance. The obtained resonance wavelength is dependent on not only aspect ratio but also rod radius, suggesting the importance of self-inductance and the breakdown of linear scaling. Moreover, the cross sections for light scattering and absorption have been deduced analytically, giving rise to a Lorentzian line-shape for the extinction spectrum. The result provides us with new insight into the phenomenon.

Localized Surface Plasmon Resonances: Noble Metal Nanoparticle Interaction with Rare-Earth Ions

“…Nevertheless, numerical results suggest that, even when the aspect ratio is fixed and the retardation effect is weak, the position of longitudinal resonance can still depend strongly with the aspect ratio [29,30] . Using the model of Cheng -ping Huang et al [31], we can write:…”

Interactions of Nanorod Particles in the Strong Coupling Regime

“…is the ac resistance or impedance [48]). Noticing that each nanorod (carrying opposite charges on the opposite sides) can be regarded as an electric dipole with its dipole moment p ql ≈ , we have…”

Spectral properties of Au–ZnTe plasmonic nanorods

“…Applying the approach of Ref. [23] to obtain the equivalent values of circuit elements, we find L s 10.1 fH (inductance of sphere), C fs 2.78 aF(fringe capacitance of sphere), C r 293.6 fF(capacitance of rod), C fr 6.67 aF (fringe capacitance of rod), and the total values for the LCR circuit would be L ∼ 10.1 fH, C ∼ 11.1 aF, and R ∼ 233.4 Ω. This is a bandpass filter with a Q factor of 7.78 and fractional bandwidth of 0.1288, centered at a frequency corresponding to a 630 nm light.…”

“…We use the finite element method (FEM) to explore the best design for such a nanostructure array. This composite structure can also be modeled as a metamaterial composed of distinct nanocircuit elements [22,23], which means that each nanostructure element can be represented by a nanoresistor, nanocapacitor, or nanoinductor, or a combination of them. Therefore, one can intuitively study the effects of design parameters simply by studying the circuit elements.…”