High-throughput computational search for group-IV-related quantum defects as spin-photon interfaces in 4H-SiC

Optically active paramagnetic point defects in host semiconductors hold significant potential for integration into quantum technologies. However, the identification of a suitable candidate from the vast search space of numerous structural configurations, along with charge and spin states of defects, even within a single host, is extremely challenging. Here, we have developed a high-throughput approach based on first-principles calculations to screen group-IV-related promising quantum defects in 4H-SiC. We have systematically selected 13 quantum defects based on desired thermodynamic, electronic, and optical screening criteria. This strategy successfully identifies seven novel group-IV-related defects with single photon emission within the telecommunication and mid-infrared window, with a zero phonon line energy exceeding 0.4 eV. Two SnSiVC defects have favorable emission for silica fiber-based optical communication, while the remaining group-IV defects hold promise for fluoride fiber-based and free space communication. These quantum defects possess a strong transition dipole moment surpassing 5 Debye and exhibit zero-field splitting within the microwave range, and hence are potential for quantum sensing and spin-photon interfaces.