Electron–Nuclear Interactions of NV Defects in an Isotopically Purified 6H-28SiC Crystal

NV^– defects in silicon carbide (SiC) are emerging as a competitive alternative to NV^– centers in diamond due to advanced industrial-scale SiC production methods. We present a study of the ground-state electron–nuclear coupling of negatively charged nitrogen-vacancy NV^– centers in a 6H-SiC crystal by electron paramagnetic resonance and electron–nuclear double resonance techniques. The hyperfine and nuclear quadrupole interaction tensors have been precisely determined. The hyperfine coupling is found to be predominantly characterized by an isotropic contact Fermi part a_iso = −1.125(2) MHz and a negligibly small dipole–dipole part b < 50 kHz. The nuclear quadrupole interaction is characterized by a coupling constant C_q = 2.530(3) MHz. The spin density distribution of the NV_k2k1^– center was calculated using density functional theory, and the theoretical electron–nuclear interaction values align well with experimental results. All established parameters are crucial for implementing NV^– defects in SiC for quantum magnetometry, other sensing applications, and as robust qubits.