A Magnetometer Based on a Spin Wave Interferometer

Area of Science:

• Condensed Matter Physics
• Materials Science
• Nanotechnology

Background:

• Spin waves are collective excitations in magnetic materials.
• Interferometry is a technique that exploits wave interference to make precise measurements.
• Magnetic field sensors are crucial for various scientific and technological applications.

Purpose of the Study:

• To develop a highly sensitive magnetic field sensor.
• To explore the use of spin wave interferometry for magnetic field detection.
• To characterize the performance of a Y3Fe2(FeO4)3 based spin wave interferometer.

Main Methods:

• Fabrication of a magnetic cross junction with micro-antennas.
• Excitation and detection of spin waves using micro-antennas.
• Measurement of inductive voltage and phase shifts under varying magnetic fields.

Main Results:

• The spin wave interferometer demonstrates high sensitivity to external magnetic fields.
• A change of over 40 dB per 1 Oe in inductive voltage was observed near destructive interference.
• A π-phase shift was achieved within a 1 Oe field change.

Conclusions:

• The developed spin wave interferometer is a promising platform for ultra-sensitive magnetic field sensing.
• The device operates at room temperature and shows potential for attotesla-level sensitivity.
• Further research into ferrite structures could lead to even more sensitive magnetic sensors.