Silicon carbide for novel quantum technology devices

Silicon carbide (SiC) has recently been investigated as an alternative material to host deep optically active defects suitable for optical and spin quantum bits. This material presents a unique opportunity to realise more advanced quantum-based devices and sensors than currently possible. We will summarise key results revealing the role that defects have played in enabling optical and spin quantum measurements in this material such as single photon emission and optical spin control. The great advantage of SiC lies in its existing and well-developed device processing protocols and the possibilities to integrate these defects in a straightforward manner. There is particular current interest in nanomaterials and nanophotonics in SiC that could, once realised, introduce a new platform for quantum nanophotonics and in general for photonics. We will summarise SiC nanostructures exhibiting optical emission due to multiple polytypic bandgap engineering and deep defects. The combination of nanostructures and in-built paramagnetic defects in SiC could pave the way for future single-particle and single-defect quantum devices and related biomedical sensors with single-molecule sensitivity. We will review relevant classical devices in SiC (photonics crystal cavities, microdiscs) integrated with intrinsic defects. Finally, we will provide an outlook on future sensors that could arise from the integration of paramagnetic defects in SiC nanostructures and devices.