A team led by academician GUO Guangcan from the University of Science and Technology of China (USTC) of the Chinese Academy of Sciences (CAS) has made progress in high-pressure quantum precision measurement on silicon carbide color centers. For the first time, the researchers achieved in-situ magnetic detection under high pressure based on silicon-vacancy color centers in silicon carbide. The study was published online in Nature Materials.
The difficulty of in-situ high-resolution magnetic measurements hinders the investigation of high-pressure superconducting anti-magnetic behavior and magnetic phase transition behavior. Diamond NV center-based magnetic resonance technology has been adopted to address this problem. However, due to the four-axis nature of NV centers and the temperature dependence of their electron spin zero-field splitting, it is challenging to analyze and interpret the optically detected magnetic resonance spectra obtained from measurements.
In this study, the researchers characterized the optical and spin properties of silicon-vacancy color centers under high pressures, and discovered that their spectra exhibited a blue shift and that the spin zero-field splitting values varied little compared with those of diamond NV color centers. This discovery would be beneficial for measuring and analyzing optically detected magnetic resonance spectra under high pressures.
Besides, the researchers observed the pressure-induced magnetic phase transition of neodymium-iron-boron magnets at around 7 GPa using silicon-vacancy color centers, and measured the critical temperature-pressure phase diagram of yttrium barium copper oxide superconductors.
The findings advanced high-pressure in situ magnetic detection technology based on solid-state color center spins. Silicon carbide material processing technology is mature enough to allow for large-scale preparation. It has a significant price advantage compared to diamonds. This work provides an excellent quantum research platform for characterizing the high-pressure properties of magnetic materials, especially for room-temperature superconductors.
