Substrate-induced bianisotropy in the metasurfaces

The plasmonic hot spot caused by the incident electric field in the metal nanoparticle when extended to the highly-refractive substrate produces the resonant magnetic polarization in the structure. The effect is reciprocal – the external magnetic field produces the resonant electric polarization. The array of small electric scatterers in presence of the semiconductor substrate becomes bi-anisotropic. The effect is important for the proper theoretical and experimental electromagnetic characterization of metasurfaces (without this characterization the design of electromagnetic metasurfaces for practical applications is impossible). This work was supported by the project NANOMETA of the Finnish Academy.