Influence of Photoexcitation Conditions on the Spin Polarization of Nitrogen-Vacancy Centers in Isotopically Enriched Silicon Carbide 6H-28 SiC

Spin defects in semiconductors are attracting interest as a material basis for quantum information and computing technologies. In this work, the spin properties of negatively − charged nitrogen-vacancy ( NV ) centers in a 6H-SiC silicon carbide crystal enriched with the 28 Si isotope were studied by high-frequency ( 94 GHz) electron paramagnetic resonance (EPR) − methods. Due to an optical excitation channel at the NV centers, it was possible to initialize the electron spin of the defect using a laser source, which led to a significant increase in the intensity of the recorded EPR signal. The dependences of the observed spin polarization were analyzed at different optical excitation wavelengths ( λ = 640 – 1064 nm), output power ( 0 – 500 mW), and temperature ( 50 – 300 K) of the crystal. The results obtained reveal the optimal experimental conditions for maximizing the efficiency of optical quantum energy transfer to − the spin system. This opens up new possibilities for using NV centers in 6H-SiC to create multi-qubit spin-photon interfaces operating in the infrared region.