Faraday rotation by artificial electric gyrotropy in a transparent slot-ring metamaterial structure

A non-reciprocal metamaterial structure composed of a 2D periodic array of slot ring resonators including each a semiconductor-based isolator is introduced and experimentally shown to produce Faraday rotation. In contrast to previously reported non-reciprocal metastructures, which were of microstrip type and were limited to the reflection mode, the proposed slot line type structure is transparent, as the wave can pass through the slots, and therefore it operates in the transmission mode. The metamaterial exhibits the same response as a magnetically biased ferrite or plasma, but without the need of a biasing static magnetic field.