Room temperature optically detected magnetic resonance experiments on spin 3/2 Silicon vacancies in 4H-SiC are reported. The $m_s=+1/2\leftrightarrow -1/2$ transition is accessed using a two microwave frequency excitation protocol. The ratio of the Rabi frequencies of the $+3/2\leftrightarrow +1/2$ and $+1/2\leftrightarrow -1/2$ transitions is measured to be $(0.901\pm 0.013)$. The deviation from $\sqrt{3}/2$ is attributed to small difference in g-factor for different magnetic dipole transitions. Whereas a spin-1/2 system is characterized by a single spin lifetime $T_1$, we experimentally demonstrate that the spin 3/2 system has three distinct relaxation modes that can be preferentially excited and detected. The measured relaxation times are $(0.410.02) T_{slow}=T_d= (3.30.5)T_{fast} $. This differs from the values of $ T_p/3 =T_d= 2T_f $ expected for pure dipole ($T_p$), quadrupole ($T_d$), and octupole ($T_f$) relaxation modes, respectively, and implies admixing of the slow dipole and fast octupole relaxation mod es.

中文翻译：

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4H-SiC中自旋32硅空位的弛豫动力学

报道了在4H-SiC中自旋3/2硅空位的室温光学检测磁共振实验。的${米}_s=+\mathrm{1个}/2\leftrightarrow -\mathrm{1个}/2$使用两个微波频率激励协议访问过渡。拉比频率与$+3/2\leftrightarrow +\mathrm{1个}/2$ 和 $+\mathrm{1个}/2\leftrightarrow -\mathrm{1个}/2$ 过渡被测量为 $（0.901\pm 0.013）$。与$\sqrt{3}/2$归因于不同磁偶极跃迁的g因子差异小。而自旋1/2系统的特征在于单次自旋寿命${Ť}_{\mathrm{1个}}$，我们实验证明自旋3/2系统具有三个不同的弛豫模式，可以优先激发和检测它们。测得的弛豫时间为$（0.410.02）T_ {slow} = T_d =（3.30.5）T_ {fast} $。这不同于纯偶极子的$ T_p / 3 = T_d = 2T_f $的值（${Ť}_p$），四极（${Ť}_d$）和八极（${Ť}_F$弛豫模式分别表示慢偶极弛豫模型和快速八极弛豫模型的混合。