This paper investigates the CO2 defect in silicon (C-center) for quantum technology applications. The authors calculated the electronic structure, spin interactions, and optical transitions of the defect using density functional theory (DFT) and other computational methods. Key findings include the determination of zero-phonon line (ZPL) energy, spin-spin and spin-orbit coupling parameters, and hyperfine interaction values. The results suggest the C-center as a promising single-photon source and potential platform for quantum computing, enabled by optical readout of the spin state in its triplet excited state.

P. Udvarhelyi