Polarizability of Radially Inhomogeneous Subwavelength Spheres
arXiv:1804.04629 · doi:10.1103/PhysRevApplied.10.054012
Abstract
In this work the polarizability of a subwavelength core-shell sphere is considered, where the shell exhibits a radially inhomogeneous permittivity profile. A mathematical treatment of the elec- trostatic polarizability is formulated in terms of the scattering potentials and the corresponding scattering amplitudes. As a result, a generalized expression of the polarizability is presented as a function of the radial inhomogeneity function. The extracted general model is applied for two particular cases, i.e., the well-known power-law profile and a new class of permittivity profiles that exhibit exponential radial dependence. The proposed analysis quantifies in a simple manner the inhomogeneity effects, allowing the direct implementation of naturally or artificially occurring permittivity inhomogeneities for a wide range of applications within and beyond the metamaterial paradigm. Furthermore, the described analysis open avenues towards the phenomenological and first-principles modeling of the electrodynamic scattering effects for graded-index plasmonic par- ticles at the nanoscale. Finally, such description can be readily used either for the benchmarking of novel computational methods incorporating inhomogeneous materials or for inverse scattering purposes.
arXiv comment21 pages, 4 figures
References in corpus (15)
- Achieving transparency with plasmonic coatings
- Emergence of macroscopic directed motion in populations of motile colloids
- Vacuum Rabi splitting in a plasmonic cavity at the single quantum emitter limit
- Light scattering and surface plasmons on small spherical particles
- Realizing strong light-matter interactions between single nanoparticle plasmons and molecular excitons at ambient conditions
- Plasmonic Luneburg and Eaton Lenses
- Losses in plasmonics: from mitigating energy dissipation to embracing loss-enabled functionalities
- Blueshift of the surface plasmon resonance in silver nanoparticles studied with EELS
- Nonlocal Response of Metallic Nanospheres Probed by Light, Electrons, and Atoms
- First-principles approach to dielectric response of graded spherical particles
- Optical meta-atom for localization of light with quantized energy
- Non-radiative decay of a dipole emitter close to a metallic nanoparticle: Importance of higher-order multipole contributions
- Relative merits of Phononics vs. Plasmonics: the energy balance approach
- Unveiling the scattering behavior of small spheres
- General Scattering Characteristics of Resonant Core-Shell Spheres