Room Temperature Coherent Spin Alignment of Silicon Vacancies in4H- and6H-SiC

We report the realization of the optically induced inverse population of the ground-state spin sublevels of the silicon vacancies (${V}_{\mathrm{Si}}$) in silicon carbide (SiC) at room temperature. The data show that the probed silicon vacancy spin ensemble can be prepared in a coherent superposition of the spin states. Rabi nutations persist for more than $80\text{ }\text{ }\ensuremath{\mu}\mathrm{s}$. Two opposite schemes of the optical alignment of the populations between the ground-state spin sublevels of the silicon vacancy upon illumination with unpolarized light are realized in $4H$- and $6H$-SiC at room temperature. These altogether make the silicon vacancy in SiC a very favorable defect for spintronics, quantum information processing, and magnetometry.