Temperature dependence of the C 13 hyperfine structure of the negatively charged nitrogen-vacancy center in diamond

The nitrogen-vacancy (NV) center is a well utilized system for quantum technology, in particular quantum sensing and microscopy. Fully employing the NV center's capabilities for metrology requires a strong understanding of the behavior of the NV center with respect to changing temperature. Here, we probe the NV electronic spin density as the surrounding crystal temperature changes from 10 K to 700 K by examining the hyperfine interactions with a nearest-neighbor 13C. These results are corroborated with ab initio calculations and demonstrate that the change in hyperfine interaction is small and dominated by a change in the hybridization of the orbitals constituting the spin density, thus indicating that the defect and local crystal geometry is returning towards an undistorted structure at higher temperature.This work was supported by funding from the Australian Research Council (Projects No. DP140103862 and No. DE170100169). M.S.J.B. acknowledges support from the DAAD-GO8 joint research cooperative scheme and theRobert and Helen Crompton award