Field-free spin-orbit torque switching in interlayer exchange coupled Co/Ta/CoTb

Area of Science:

• Spintronics
• Materials Science
• Condensed Matter Physics

Background:

• Spin-orbit torque (SOT) devices are crucial for advanced memory and computing.
• Field-free SOT switching is essential for energy-efficient spintronic devices.
• T-type magnetic configurations offer unique properties for device applications.

Purpose of the Study:

• To investigate a T-type field-free spin-orbit torque device with coupled in-plane and perpendicular magnetic layers.
• To explore current-induced magnetization switching and domain wall motion.
• To demonstrate the device's potential for spintronic memory and neuromorphic computing.

Main Methods:

• Fabrication of a Co/Ta/CoTb heterostructure with a non-magnetic Ta spacer.
• Characterization of interlayer exchange coupling (IEC) and its effect on magnetization.
• Magneto-optic Kerr effect (MOKE) measurements for domain wall motion analysis.
• Investigation of anomalous Hall resistance for synaptic plasticity demonstration.

Main Results:

• Deterministic current-induced magnetization switching of the perpendicular CoTb layer was achieved via in-plane effective field from IEC.
• Field-driven and current-driven asymmetric domain wall motion were observed and characterized.
• Multistate synaptic plasticity functionality was demonstrated, correlating anomalous Hall resistance with current pulses.

Conclusions:

• The T-type SOT device enables efficient magnetization switching and domain wall motion.
• The device exhibits potential for implementing multistate synaptic plasticity.
• This research highlights the device's promise for next-generation spintronic memory and neuromorphic computing.