A spin-orbit torque switching scheme with collinear magnetic easy axis and current configuration

Area of Science:

• Condensed Matter Physics
• Materials Science
• Nanotechnology

Background:

• Spin-orbit torque (SOT) enables magnetization switching in heavy-metal/ferromagnet nanostructures using in-plane currents.
• Existing research primarily utilizes device geometries where the nanomagnet's easy axis is perpendicular to the current (z or y axes).

Purpose of the Study:

• To introduce and investigate a novel device geometry for SOT-driven magnetization switching.
• To explore the physics of SOT switching in a configuration where the easy axis is collinear with the current (x axis).

Main Methods:

• Fabrication of a three-terminal device based on a Ta/CoFeB/MgO stack.
• Experimental demonstration of magnetization switching driven by spin-orbit torque.
• Comparative analysis of switching behavior across different device geometries.

Main Results:

• Successful demonstration of magnetization switching in a geometry with the easy axis collinear with the current.
• Identification of spin-orbit torque originating from Ta with a negative spin Hall angle.
• Highlighting previously unobserved mechanisms governing SOT switching in this new configuration.

Conclusions:

• The study presents a new device geometry for spin-orbit torque applications.
• This work expands the understanding of SOT switching physics.
• The findings offer new possibilities for spintronics device development.