  Recently, vacancy-related spin defects in silicon carbide (SiC) have been
demonstrated to be potentially suitable for versatile quantum interface
building and scalable quantum network construction. Significant efforts have
been undertaken to identify spin systems in SiC and to extend their quantum
capabilities using large-scale growth and advanced nanofabrication methods.
Here we demonstrated a type of spin defect in the 4H polytype of SiC generated
via hydrogen ion implantation with high-temperature post-annealing, which is
different from any known defects. These spin defects can be optically addressed
and coherently controlled even at room temperature, and their fluorescence
spectrum and optically detected magnetic resonance spectra are different from
those of any previously discovered defects. Moreover, the generation of these
defects can be well controlled by optimizing the annealing temperature after
implantation. These defects demonstrate high thermal stability with coherently
controlled electron spins, facilitating their application in quantum sensing
and masers under harsh conditions.
