Direct electronic measurement of the spin Hall effect

Area of Science:

• Condensed Matter Physics
• Materials Science
• Nanotechnology

Background:

• Spin-based electronics (spintronics) faces challenges in generating, manipulating, and detecting spin-polarized electrons in nanostructures.
• Spin-orbit coupling, which links electron spin to momentum, is a key phenomenon for spintronics applications.
• The spin Hall effect, a consequence of spin-orbit coupling, predicts spin current generation perpendicular to an electric field.

Purpose of the Study:

• To electrically measure the spin Hall effect in a diffusive metallic conductor.
• To demonstrate a method for spin detection without relying on magnetic materials.
• To explore opportunities for developing integrated spintronics devices.

Main Methods:

• Fabrication of devices using a ferromagnetic electrode and a tunnel barrier to inject spin-polarized current.
• Electrical measurement of the induced voltage resulting from the spin Hall effect.
• Utilizing the conversion of injected spin current into charge imbalance via spin-orbit coupling.

Main Results:

• Observed an induced voltage solely from the spin Hall effect's conversion of spin current to charge imbalance.
• The induced voltage was proportional to the spin component perpendicular to the spin current and voltage probe plane.
• Demonstrated electrical detection of spin polarization in a diffusive metallic conductor.

Conclusions:

• The spin Hall effect can be electrically detected in metallic conductors, offering an alternative to optical methods.
• This approach enables efficient spin detection without requiring magnetic materials, paving the way for novel spintronics.
• Potential for developing spintronics devices that combine information processing and data storage functionalities.