Broadband microwave detection using electron spins in a hybrid diamond-magnet sensor chip

Area of Science:

• Quantum Science and Technology
• Condensed Matter Physics
• Materials Science

Background:

• Quantum sensing leverages quantum phenomena for high-resolution measurements.
• Diamond electron spins are effective magnetic field sensors but have limited microwave frequency bandwidth.
• Existing sensors struggle with sensitivity across a wide range of microwave frequencies.

Purpose of the Study:

• To develop a broadband microwave detection technique using diamond spins.
• To overcome the narrow bandwidth limitations of current diamond-based sensors.
• To enable high-fidelity spin control and material characterization over gigahertz bandwidths.

Main Methods:

• Interfacing diamond electron spins with a thin-film magnet.
• Utilizing a pump field to convert microwave signals to sensor-spin frequencies via non-linear spin-wave dynamics.
• Employing two complementary conversion protocols for sensing and spin control.

Main Results:

• Achieved gigahertz bandwidth for microwave detection and spin control.
• Demonstrated characterization of spin-wave bands several gigahertz above the sensor-spin frequency.
• Enabled pump-tunable, hybrid diamond-magnet sensor operation.

Conclusions:

• The hybrid diamond-magnet sensor chip enables broadband microwave detection.
• This technology facilitates spin-based gigahertz material characterization at low magnetic bias fields.
• Opens new avenues for quantum sensing and material analysis.