Optically detected magnetic resonance of silicon vacancies in 4H-SiC with different temperatures

Silicon vacancy (VSi) centers in silicon carbide have attracted attention because of their potential applications to quantum sensors (high-sensitivity magnetic field and temperature sensors). VSi centers are also expected to be used for magnetic sensors under harsh environments such as space and undergrounds, since they have structural stability and the potential of high-fidelity spin manipulation at high temperatures. To realize VSi based magnetic sensors operating at high temperature, understanding of optically detected magnetic resonance (ODMR) in the ground states of VSi centers, which is the basic principle of magnetic sensing, is crucial. In particular, the effects of temperature on the ODMR spectra are less well understood. Here, we demonstrate the potential of VSi magnetic sensors at high temperatures by showing the ODMR spectra with different temperatures. We also systematically investigate the effects of high energy electron irradiations on the ODMR spectra of formed VSi centers. The concentration of VSi centers increases with increasing electron irradiation dose, resulting in the enhancement of sensitivity, but the increase of undesired defects which might cause decoherence is also considered. Hence, the effects of electron irradiation dose should be clarified to obtain better sensitivity of VSi based magnetic sensors.The 4th International Forum on Quantum Metrology and Sensin