Quasiparticle energies and optical excitations of 3C-SiC divacancy from GW and GW plus Bethe-Salpeter equation calculations

The authors study the divacancy in 3C-SiC, a promising system for quantum information or sensing applications, using large-scale GW plus Bethe-Salpeter equation simulations of nearly 1000 atoms. Notably, in contrast to the widely studied diamond NV center, low-energy excitonic states of 3C-SiC divacancy show substantial characters of transitions from localized defect states to continuum states. Some defect states that contribute to the low-energy excitations significantly hybridize with conduction bands. This work quantitatively determines the quasiparticle energies of defect states and zero-phonon line energy, emphasizing the importance of frontier conduction bands on the low-energy excitons of 3C-SiC divacancy.