Ab initio calculation of spin-orbit coupling for an NV center in diamond exhibiting dynamic Jahn-Teller effect

Point defects in solids may realize solid state quantum bits. The spin-orbit coupling in these point defects plays a key role in the magneto-optical properties that determine the conditions of quantum bit operation. However, experimental data and methods do not directly yield these highly important data, particularly for such complex systems where the dynamic Jahn-Teller (DJT) effect damps the spin-orbit interaction. Here, we show for an exemplary quantum bit, the nitrogen-vacancy (NV) center in diamond, that ab initio supercell density functional theory provides a quantitative prediction for the spin-orbit coupling damped by DJT. We show that DJT is responsible for the multiple intersystem crossing rates of the NV center at cryogenic temperatures. Our results pave the way toward optimizing solid state quantum bits for quantum information processing and metrology applications.