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

TL;DR

This paper demonstrates the use of silicon vacancy centers in silicon carbide as a stable, high-pressure magnetic sensor capable of detecting phase transitions in materials like Nd2Fe14B and YBa2Cu3O6.6.

Contribution

It introduces a novel application of silicon vacancy centers in SiC for in-situ magnetic detection under high pressures, overcoming limitations of previous NV center methods.

Findings

Detected magnetic phase transition of Nd2Fe14B at 7 GPa

Mapped the phase diagram of YBa2Cu3O6.6

Silicon vacancy centers are temperature-independent and single-axis

Abstract

Pressure-induced magnetic phase transition is attracting interest due to its ability to detect superconducting behaviour at high pressures in diamond anvil cells. However, detection of the local sample magnetic properties is a great challenge due to the small sample chamber volume. Recently, optically detected magnetic resonance (ODMR) of nitrogen vacancy (NV) centers in diamond have been used for in-situ pressure-induced phase transition detection. However, owing to their four orientation axes and temperature-dependent zero-field-splitting, interpreting the observed ODMR spectra of NV centers remain challenging. Here, we study the optical and spin properties of implanted silicon vacancy defects in 4H-SiC, which is 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 YBa2Cu3O6.6. These results highlight the potential of silicon vacancy-based quantum sensors for in-situ magnetic detection at high pressures.