Topological terahertz circuits using semiconductors

摘要

Topological insulator-based devices can transport electrons/photons at the surfaces of materials without any back reflections, even in the presence of obstacles. Topological properties have recently been investigated using non-reciprocal materials, such as gyromagnetics, or using biani-sotropy. However, these effects usually saturate at the optical frequencies and limit our ability to scale down the devices. In order to implement topological devices that we introduce in this paper for the terahertz range, we show that the semiconductors can be utilized via their cyclotron resonance in combination with small magnetic fields. We propose two terahertz operating devices such as the topological tunable power splitter and the topological circulator. This work opens up the perspectives in designing the terahertz integrated devices and circuits with high functionality.