First-principles simulations of the divacancy formation and annealing in 3C-SiC

The divacancy (VV) in silicon carbide (SiC) is a promising spin qubit candidate for quantum technology applications. However, the formation and annealing mechanisms of the VV in SiC remain poorly understood at the microscopic level, thus hindering its controlled fabrication, manipulation and integration. Here, we combine first principles molecular dynamics (FPMD) with enhanced sampling simulations and nudged elastic band calculations to investigate the energetics of the VV formation and migration in cubic SiC. We predict pathways for the VV formation and annealing, and identify the critical intermediate configurations required for the correct interpretation of atomic transformation processes. Moreover, we characterize the impact of charge transfer, spin-flip and charge states in determining preferred pathways.