Giant THz Faraday rotation with stacked magnetized graphene

Abstract

It has been recently discovered that strong magnetoplasmonic effects exist on graphene and may open a new avenue for many novel THz non-reciprocal devices. The magnetoplasmonic response of two-dimensional graphene strongly depends on the electromagnetic properties of the surrounding medium. We develop a modified transmission line analog formulation to investigate the Faraday and Kerr rotation associated with multi-sheet magnetized graphene embedded in the layered medium. The formulation utilizes a junction transformer to model anisotropic conductive sheets at the interfaces and is highly numerically efficient and stable. It is also demonstrated for the first time that a multiple heterojunctions conjugated photonic crystal with graphene embedded at the interfaces will significantly enhance the magneto-optical effect of the system. 15.3° Faraday angle under 0.25 T low static bias magnetic field is achieved at 15 THz with a high transmittance, which enables the design of accessible high-performance non-reciprocal devices in the high THz frequency regime. The proposed formulation and design principle may lay the foundation for future THz graphene-based plasmonic devices.