Faraday Rotation and Circular Dichroism Spectra of Gold and Silver Nanoparticle Aggregates

Abstract

We study the magneto-optical response of noble metal nanoparticle clusters. We consider the interaction between the light-induced dipoles of particles. In the presence of a magnetic field, the simplest achiral cluster, a dimer, exhibits circular dichroism (CD). The CD of a dimer depends on the directions of the magnetic field and the light wave vector. The CD of a populous cluster weakly depends on the magnetic field. Upon scattering from the cluster, an incident linearly polarized light with polarization azimuth $\phi$, becomes elliptically polarized. The polarization azimuth rotation and ellipticity angle variation are sinusoidal functions of $2\phi$. The anisotropy and the chirality of the cluster control the amplitude and offset of these sinusoidal functions. The Faraday rotation and Faraday ellipticity are also sinusoidal functions of $2\phi$. Near the surface plasmon frequency, Faraday rotation and Faraday ellipticity increase.

References in corpus (2)

• DNA-based Self-Assembly of Chiral Plasmonic Nanostructures with Tailored Optical Response
• Circular dichroism in planar nonchiral plasmonic metamaterials

Cited by in corpus (2)

• Effects of interband transitions on Faraday rotation in metallic nanoparticles
• Subwavelength plasmonic chain for magneto-optics enhancement