Zero-field ODMR and relaxation of Si-vacancy centers in 6H-SiC

Abstract

Silicon vacancies in silicon carbide (SiC) have been proposed as interesting candidates for quantum technology applications such as quantum sensing and quantum repeaters. SiC exists in many polytypes with different plane stacking sequences, and in each polytype, the vacancies can occupy a variety of different lattice sites. In this work, we focus on the three important charged silicon vacancies in the 6H-SiC polytype. We record the photoluminescence and continuous-wave optically detected magnetic resonance (ODMR) spectra at different radio-frequency power levels and different temperatures. We individually select the zero-phonon lines of the different silicon vacancies at low temperatures and record the corresponding ODMR spectra. ODMR allows us to correlate optical and magnetic resonance spectra and thereby separate signals from V1 and V3. The results also explain the observed sign change of the ODMR signal as a function of temperature.