Scattering From Graphene-Based Multilayered Spherical Structures

In this paper, modified Mie-Lorentz coefficients for graphene-based multilayered spherical structures are extracted. To this end, electromagnetic fields in each region of the solution domain are expanded in terms of vector spherical harmonics. By properly choosing the geometrical dimensions of the spheres, graphene coatings are considered as thin shells with the surface conductivities calculated by the Kubo formulas. Later, graphene surface currents are incorporated in the boundary conditions on tangential magnetic fields. The aforementioned procedure is conducted at the interface of two adjacent layers to relate the Mie coefficients of the successive layers recurrently. The validity of the extracted equations is verified by calculating the extinction cross section of various graphene-based multilayered spherical structures and comparing them with the results of finite element method. Possibility of tuning the graphene plasmonic resonances in multiple layers by varying graphene carrier doping density is discussed, as well. The potential application of our analysis is scattering shaping of graphene-based multilayered spherical configurations for cloaking, super-scattering, medical treatment, and tagging.