Vacancy-related color centers in two-dimensional silicon carbide monolayers

We examine vacancy defects in two-dimensional silicon carbide (2D-SiC) using density functional theory in order to explore their magneto-optical properties and their potential in quantum technologies. The defects include the silicon-vacancy (V$_{\text{Si}}$) and two antisite-vacancy pairs (V$_{\text{C}}$-C$_{\text{Si}}$ and V$_{\text{Si}}$-C$_{\text{Si}}$). We determine the characteristic hyperfine tensors and the fluorescence spectrum that are the key fingerprints of silicon-vacancy-related paramagnetic color centers in 2D-SiC and may be observed in electron paramagnetic resonance and photoluminescence experiments. In particular, we show that the V$_{\text{C}}$-C$_{\text{Si}}^-$ defect is promising candidate for a single-photon quantum emitter and qubit