The negatively charged nitrogen-vacancy defect in diamond was a leading candidate to realize solid-state qubits and ultrasensitive magnetometers in ambient conditions. A new interpretation of some of the properties of the center was presented. It was shown that the double peak in the absorption phonon sidebands might correspond to the local a1 and e vibration modes of the defect that had very similar energies, and that tunnelling of nitrogen atoms in the vacancy did not occur as had been previously suggested.
An Ab Initio Study of Local Vibration Modes of the Nitrogen-Vacancy Center in Diamond. A.Gali, T.Simon, J.E.Lowther: New Journal of Physics, 2011, 13, 025016