Theoretical Understanding of the Dynamics of Silicon-Vacancy Color Center Dynamics in Nanodiamonds

Diamond-based color centers have emerged for a variety of applications in quantum communication, quantum photonics, and biological sciences, etc. Optical color center of SiV formed by one silicon atom sited in the middle of two vacancies shows great promise as a single-photon source. Unlike the NV center, which can be improved sufficiently for quantum applications by high-temperature annealing to mobilize only vacancies, SiV center may become unstable in diamond lattice under annealing. Upon annealing to temperatures up to 800 °C, both SiVs and vacancies would become mobile to the surface of diamond. It is unclear during the annealing process whether SiV or vacancy impurity migration dominates and the relative time-scale of the two processes. In this talk, we are going to present our studies to unravel this problem, focusing on the theoretical calculations. An AOM-modulated laser heating and annealing in a diamond anvil cell has been used. The fluorescent intensities of SiV center before and after the annealing were measured using fluorescent spectroscopy. ab initio DFT calculations were used to quantify the dynamics of two impurities. Both experimental and theoretical results suggest that SiV centers can be stabilized associated with the crystalline quality during the production of artificial SiV photonic centers.