High-sensitivity silicon carbide divacancy-based temperature sensing

Color centers in silicon carbide have become potentially versatile quantum sensors. Particularly, wide temperature-range temperature sensing has been realized in recent years. However, the sensitivity is limited due to the short dephasing time T-2* of the color centers. In this work, we developed a high-sensitivity silicon carbide divacancy-based thermometer using the thermal Carr-Purcell-Meiboom-Gill (TCPMG) method. First, the zero-field splitting D of the PL6 divacancy as a function of temperature was measured with a linear slope of -99.7 kHz K-1. The coherence times of TCPMG pulses linearly increased with the pulse number and the longest coherence time was about 21 mu s, which was ten times higher than T-2*. The corresponding temperature-sensing sensitivity was 13.4 mK Hz(-1/2), which was about 15 times higher than previous results. Finally, we monitored the laboratory temperature variations for 24 hours using the TCMPG pulse. The experiments pave the way for the application of silicon carbide-based high-sensitivity thermometers in the semiconductor industry, biology, and materials sciences.