Temperature induced topological transition in semiconductor metamaterial

We propose new type of temaperature tunable metamaterial based on semiconductor superlattice for THz applications. We have shown that temperature activation of donors in semiconductor metamaterial results in drastic changes of the dielectric function in terahertz region. We have analyzed that the shape and topology of equal frequency contours depending on the external temperature. It was shown that transition from elliptical to hyperbolic regime, so called “topological transition”, can be observed at room temperature.