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

Abstract

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.

Keywords

• spin-optical property
• spin initialization
• spin polarization
• electron − paramagnetic resonance
• silicon carbide
• nv⁻ center