Detection of microwave spin pumping using the inverse spin Hall effect

Area of Science:

• Condensed Matter Physics
• Materials Science
• Spintronics

Background:

• Spin pumping generates pure spin currents from precessing magnetization.
• Inverse spin Hall effect converts spin currents into measurable charge currents.
• Direct electrical detection of spin pumping is crucial for spintronics applications.

Purpose of the Study:

• To electrically detect the dynamical component of spin-pumping current.
• To utilize inverse spin Hall effect for sensitive detection of magnetization dynamics.
• To develop a novel method for studying spin dynamics in magnetic insulators.

Main Methods:

• Experiments performed on Yttrium Iron Garnet (YIG)|Platinum (Pt) bilayer.
• Utilized ferromagnetic resonance (FMR) with parametric excitation at half the microwave frequency.
• Employed inverse spin Hall effect (ISHE) for electrical signal detection.
• Used a spectrum analyzer for direct microwave voltage detection.

Main Results:

• Successfully detected the microwave component of the inverse spin Hall effect voltage.
• Measured signals up to 30 μV for small precession angles (a few degrees).
• Demonstrated direct electrical detection of spin-pumping current, free from eddy currents.

Conclusions:

• The developed method allows direct electrical detection of spin-pumping currents.
• This technique offers a sensitive and efficient way to study magnetization dynamics.
• Applicable to a wide frequency range, advancing spintronic device research.