META 2021, META'12

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Dirac physics in metamaterials with nanoparticle clusters as meta-atoms
Vassilios Yannopapas

Last modified: 2012-01-03

Abstract


We report on the emergence of a Dirac point in the dispersion relation of a plasmonic metamaterial which is realized as a three-dimensional crystal (cubic or orthorhombic) whose lattice sites are decorated by aggregates of gold nanoparticles embedded in a high-index dielectric material [1]. The dispersion relation is obtained by a rigorous two-stage multiple-scattering method for light which also provides the transmittance from finite slabs of the metamaterial [2]. The Dirac-type dispersion lines of the photon modes are not a result of diffraction as in photonic crystals but due to subwavelength features and emerge from the gapless transition from a negative to a positive index band [3,4]. The Dirac point is manifested as a dip in the spectrum of light transmittance through a finite slab of the metamaterial; however, transmittance does not decrease diffusively but exponentially due to the inherent losses of gold in the given spectral regime.


Keywords


metamaterials; plasmonics; multiple-scattering;