Magnetic-field-assisted transmission of THz waves through a graphene layer combined with a periodically perforated metallic film

摘要

We consider a graphene sheet encapsulated in a two-dimensional metallicgrating and a substrate ($\mathrm{Al_{2}O_{3}}$) and subjected to an externalmagnetic field (in Faraday configuration). The grating consists of a thinperfectly conducting metal film perforated with a 2D periodic array of squareholes. According to our calculations, significant changes in the spectra of theFaraday rotation angle of the transmitted wave and of the magnetic circulardichroism should be expected in this situation compared to bare graphene. Weexplain this enhancement by the excitation of graphene magnetoplasmons thataccompanies the transmission of the electromagnetic wave through the structure.The results can be interesting for applications in THz photonics, such asswitchable rotating polarizer and optical isolator.