The 6th International Conference on Matter and Radiation at Extremes (ICMRE2023)

320 / 2023-05-10 15:04:01

Magnetic detection under high pressures using designed silicon vacancy centres in silicon carbide

High Pressure Physics and Materials Science > Functional materials and physics

Pressure-induced magnetic phase transitions are attracting interest as a means to detect superconducting behaviour at high pressures in diamond anvil cells, but determining the local magnetic properties of samples is a challenge due to the small volumes of sample chambers. Optically detected magnetic resonance of nitrogen vacancy centres in diamond has recently been used for the in situ detection of pressure-induced phase transitions. However, owing to their four orientation axes and temperature-dependent zero-field splitting, interpreting these optically detected magnetic resonance spectra remains challenging. Here we study the optical and spin properties of implanted silicon vacancy defects in 4H-silicon carbide that exhibit single-axis and temperature-independent zero-field splitting. Using this technique, we observe the magnetic phase transition of Nd₂Fe₁₄B at about 7 GPa and map the critical temperature–pressure phase diagram of the superconductor YBa₂Cu₃O_6.6.^[1,2]  These results highlight the potential of silicon vacancy-based quantum sensors for in situ magnetic detection at high pressures.