Motivated by the recent acoustically driven spin resonance studies applied to silicon vacancy centers in silicon carbide, we theoretically investigate the spin–strain interaction characterized by the defect spin-3/2 quadrupole components coupled to strain fields. Considering the C_3v symmetry of the vacancy site beyond the spherical approximation, we clarify the effect of a deviation from the spherical symmetry on spin resonance transition rate, which can be changed by rotating a static magnetic field. The ratios of spin–strain coupling parameters can be evaluated from the anisotropic field-direction dependence of the transition rate using a standing or traveling surface acoustic wave. We also discuss the effect of the propagation direction of the acoustic wave tilted from the crystallographic mirror plane reflecting the C_3v symmetry. The results presented here reveal the quadrupole properties inherent in spin-3/2 states and will promote the realization of the acoustically driven strain control of spin.

中文翻译：

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碳化硅中具有 C3[math] 位对称性的自旋 3/2 Si 空位的自旋声共振理论

受最近应用于碳化硅中硅空位中心的声驱动自旋共振研究的启发，我们从理论上研究了以与应变​​场耦合的缺陷自旋 3/2 四极分量为特征的自旋应变相互作用。考虑到空位位置的C _{3 v}对称性超出球形近似，我们阐明了偏离球形对称性对自旋共振跃迁率的影响，可以通过旋转静磁场来改变自旋共振跃迁率。自旋应变耦合参数的比率可以使用驻波或行波表面声波根据转变率的各向异性场方向依赖性来评估。我们还讨论了从反映C _{3 v}对称性的晶体镜面倾斜的声波传播方向的影响。这里提出的结果揭示了自旋 3/2 态固有的四极特性，并将促进声驱动自旋应变控制的实现。