Optical Charge Conversion of the SnV Defect in Diamond

Isolated color centers in wide-band-gap materials like diamond have shown promise in quantum information science (QIS) as single-photon emitters and qubits. While the nitrogen-vacancy (NV) defect in diamond has received substantial attention, many potential QIS defects exist, including the group-IV-vacancy defects. Due to the presence of donors in diamond like substitutional nitrogen, these defects typically occur in the negative charge state as spin-½ defects which may limit their applications. The neutral group-IV defects, however, are spin triplets like the NV^- defect. While SiV defects have been prepared in the neutral state, to date, other group-IV defects like the SnV defect have not. Here, we use density-functional-theory calculations to study the optical charge conversion of the SnV defect from the negative to the neutral charge state. We find a deep UV transition with a reasonably strong transition rate that can ionize an electron from the defect into the conduction bands. Furthermore, we study competing processes including deep-valence-band absorption, further conversion to the positive charge state, and band-edge recombination to characterize the robustness of the desired conversion.