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

Area of Science:

• Condensed Matter Physics
• Quantum Sensing
• Materials Science

Background:

• Detecting superconducting behavior at high pressures using magnetic phase transitions is crucial but challenging due to small sample volumes in diamond anvil cells.
• Nitrogen vacancy centers in diamond have been used for in situ detection, but their complex spectra hinder interpretation.

Purpose of the Study:

• To investigate silicon vacancy defects in 4H-silicon carbide as an alternative quantum sensor for high-pressure magnetic measurements.
• To overcome the limitations of nitrogen vacancy centers by utilizing defects with simpler spectral properties.

Main Methods:

• Studied the optical and spin properties of implanted silicon vacancy defects in 4H-silicon carbide.
• Utilized the single-axis and temperature-independent zero-field splitting properties of these defects for quantum sensing.
• Applied the technique for in situ detection of magnetic phase transitions under high pressure.

Main Results:

• Successfully observed the magnetic phase transition of Nd2Fe14B at approximately 7 GPa.
• Mapped the critical temperature-pressure phase diagram of the superconductor YBa2Cu3O6.6.
• Demonstrated the viability of silicon vacancy defects as robust quantum sensors.

Conclusions:

• Silicon vacancy defects in 4H-silicon carbide provide a promising platform for in situ magnetic detection at high pressures.
• This technique offers advantages over existing methods due to simpler spectral interpretation.
• The findings pave the way for advanced studies of materials under extreme conditions.