I want to understand how the symmetry of defects play the role in the quantum applicaitons. Because, implementation of nano-photonics structures in the vicinity of spin-based quantum systems usually severely compromises spin and optical stability and coherence. so we are looking for new systems that are decoupled from detrimental interactions by a high degree of symmetry. For example, the negatively charged silicon vacancy defect in diamond shows very high optical stability due to inversion symmetry at low strain