Terahertz topological photonic integrated circuits for 6G and beyond: A Perspective

The development of terahertz integrated circuits is vital for realizing sixth-generation (6G) wireless communication, high-speed on-chip interconnects, high-resolution imaging, on-chip biosensors, and fingerprint chemical detection. Nonetheless, the existing terahertz on-chip devices suffer from reflection, and scattering losses at sharp bends or defects. Recently discovered topological phases of light endow the photonics devices with extraordinary properties, such as reflectionless propagation and robustness against impurities or defects, which is vital for terahertz integrated devices. Leveraging the robustness of topological edge states combined with a low-loss silicon platform is poised to offer a remarkable performance of the terahertz devices providing a breakthrough in the field of terahertz integrated circuits and high-speed interconnects. In this Perspective, we present a brief outlook of various terahertz functional devices enabled by a photonic topological insulator that will pave the path for augmentation of complementary metal oxide semiconductor compatible terahertz technologies, essential for accelerating the vision of 6G communication and beyond to enable ubiquitous connectivity and massive digital cloning of physical and biological worlds.