Fig. 5: Cross-relaxation spectroscopy.
a Energy levels of the \({{{{{{{{\rm{V}}}}}}}}}_{{{{{{{{\rm{B}}}}}}}}}^{-}\) spin triplet ground state (top panel) and of a paramagnetic impurity with S = 1/2 (bottom panel) as a function of a static magnetic field B. The two spin systems are brought in resonance for B = Bc ~ 62 mT. b T1 time of the \({{{{{{{{\rm{V}}}}}}}}}_{{{{{{{{\rm{B}}}}}}}}}^{-}\) spin defect in the h10BN crystal as a function of a magnetic field applied along the c-axis. The field amplitude is inferred by recording the Zeeman shift of the ESR frequency of the \({{{{{{{{\rm{V}}}}}}}}}_{{{{{{{{\rm{B}}}}}}}}}^{-}\) defect. The solid line is data fitting with a Gaussian function. The error bars correspond to the uncertainty of fitting the T1 decay curve with an exponential function.
