  Silicon carbide (SiC) hosts many interesting defects that can potentially
serve as qubits for a range of advanced quantum technologies. Some of them have
very interesting properties, making them potentially useful, e.g. as interfaces
between stationary and flying qubits. Here we present a detailed overview of
the relevant properties of the spins in silicon vacancies of the 6H-SiC
polytype. This includes the temperature-dependent photoluminescence, optically
detected magnetic resonance, and the relaxation times of the longitudinal and
transverse components of the spins, during free precession as well as under the
influence of different refocusing schemes.
