Terahertz excitons in monolithically integrated carbon nanostructures

At present, mobile networks and emerging wireless technologies (internet of things etc.) require broadband channels to exchange rapidly a huge amount of data. The usage of frequencies from 0.1 to 10 THz has potential to increase the state-of-the-art high speeds by 2 orders of magnitude. However, despite the latest advancements in THz technology, we still lack proper materials to realize suitable THz photonic components. This project aims to understand principles of designing THz devices based on carbon nanostructures integrated into a monolithic flexible and durable substrate. The route to harnessing THz radiation for compact devices is seen in the usage of carbon nanostructures as building blocks for detectors, emitters etc. Such carbon nanostructures, as nanotubes and graphene nanoribbons, exhibit unique electronic and optical properties that make them very promising candidates for THz components. However, carbon nanotube and nanoribbon monolithic on-chip integration is challenging because it may results in significant change of their intrinsic properties after an embedment into a substrate. We propose to investigate with first principles and theoretical methods the successful routes of such integration and calculate electronic and optical properties of the integrated structures. We shall model such systems with 2D graphene superlattices. In these structures, quasi-metallic and dielectric regions can be alternated, for instance, either by selective hydrogenation of graphene or by embedment of boron nitride regions. The project will focus on (i) spin-orbit interactions and the topological edge states at interfaces; (ii) topological singularities in optical matrix element and (iii) excitonic effects. This project has a significant impact in THz technology and wireless communications. Its success can lead to the realization of ultrafast wireless networks for multi-user environment. The potential benefits can ensure EU leadership in the global telecom market.