Relaxation processes and coherent spin manipulations for triplet Si-C divacancies in silicon carbide enriched tenfold in the $^{13}$C isotope

Coherent spin manipulations of ensembles of color centers in the form of neutral V$_{\text{Si}}$-V$_{\text{C}}$ divacancies with the spin $S = 1$ in hexagonal silicon carbide 6H–SiC enriched in the $^{13}$C isotope ($12\%$) are studied in strong magnetic fields using electron spin echo and Rabi oscillation methods. Rabi oscillation experiments show that spin coherence is created in SiC with a tenfold increase in the content of the $^{13}$C isotope with a nuclear magnetic moment. The spin–lattice relaxation $T_1$ and spin–spin relaxation $T_2$ times are measured under conditions of optical alignment of spins at the temperature $T = 150$ K in a magnetic field of about $3 T$ and are $T_1 \sim 5$ ms and $T_2 \sim 15$ $\mu$s, respectively. The optical alignment of populations of spin levels makes it possible to manipulate electron and nuclear spins in the environment using optical, microwave, and radio-frequency radiation.