Tunable terahertz absorption in Si/SiO2-graphene multilayers: disorder and magneto-optical effects

In this work we theoretically investigate the influence of disorder and external perpendicular magnetic field on terahertz (THz) absorption in graphene/SiC cap layers on top of one-dimensional photonic structures. We show that left-handed circularly polarized light absorption can be achieved up to 0.9 and even nearly perfect absorption at magnetic fields over 4 T. It is also demonstrated that multichannel absorption can be obtained, in a broad frequency range, by increasing the disorder strength in the layer thicknesses, outperforming the corresponding periodic structures. Altogether, our results reveal the potentialities of introducing disorder to not only enhance but also to tune absorption in photonic superlattices with graphene under the influence of an external magnetic field, allowing for applications such as THz circular polarization selective sensors and photodetectors. (C) 2020 Optical Society of America