Effect of mechanical stress on the splitting of spin sublevels in 4H-SiC

The effect of static mechanical strain on the splitting of spin sublevels of color centers based on spin $3/2$ silicon vacancies in silicon carbide at room temperature has been shown. The deformed heterointerface of the AlN/4H-SiC structure has been studied. Stresses near the heterointerface have been determined using confocal Raman spectroscopy. The spin–strain coupling constants ${\Xi} = (-0.1 \pm 0.25)$ GHz/strain and ${\Xi'} = (-0.8 \pm 0.1)$ GHz/strain for the V2 center in 4H-SiC have been experimentally determined for the first time using the optically detected magnetic resonance method. The results obtained can be used to control spin states in SiC by means of the controlled piezoelectric strain in AlN and to estimate the fine-structure parameter $D$ of spin centers using Raman scattering. Such an estimate makes it possible to forecast magnetometric parameters of nanosensors based on SiC nanocrystals.