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.Keywords: Silicon carbide deep defects, Paramagnetic properties, Optical-detected magnetic resonance, Single-photon sources
IntroductionThe most common and technologically advanced SiC polytypes are 4H-SiC and 6H-SiC with hexagonal structures and 3C-SiC with a zinc-blende crystal structure (cubic). High-quality © 2015 The Author(s). Licensee InTech. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.bulk single-crystal 3C-SiC can be grown epitaxially on different substrates, most notably on silicon. This has led to many exciting devices fabricated with this particular polytype [1]. SiC has a wide bandgap (2.4-3.2 eV depending on the polytype), a high thermal conductivity, the ability to sustain high electric fields before breakdown and the highest maximum current density, making it ideal for high-power electronics [2]. More recently, it has become a notable material in the field of quantum computing and spintronics as several of its intrinsic defects are associated with an electron spin that can be used as quantum bit [3,4]. To enhance solid-state quantum systems scalability, a fully integrated device with quantum control should be built; thus, quantum systems should be part of the material used to fabricate the final device. Other solid-state quantum systems fully integrated into a functional device [5][6][7] operate at cryogenic temperatures (4 K or below),...