Non-reciprocal gyrotropy in graphene: New phenomena and applications

The non-reciprocal gyrotropic properties of magnetically biased graphene are presented and subsequent potential applications are proposed. Graphene exhibits strong Faraday rotation at microwave frequencies. The amount of rotation can be controlled by both an applied static magnetic field, which controls the cyclotron resonance frequency, and an applied static electric field, which tunes the chemical potential of the material. As an application of Faraday rotation, we present, beyond recently reported non-reciprocal components, a waveguide setup for the extraction of the conductivity tensor of graphene. Moreover, it is shown that a graphene strip supports surface magneto-plasmon modes, each of which propagates along one of its edges, at THz frequencies. Exploiting this effect, a non-reciprocal phase shifter can be realized by placing a conducting plate along one side of the strip.