Anomalous Thermal-Assisted Spin-Orbit Torque-Induced Magnetization Switching for Energy-Efficient Logic-in-Memory

Area of Science:

• Spintronics
• Materials Science
• Condensed Matter Physics

Background:

• Spin-orbit torque (SOT) is crucial for manipulating magnetism in spintronic devices.
• Reducing SOT switching current density (j_sw) is vital for low-power, high-endurance computing.
• Existing methods to lower j_sw are limited, primarily focusing on SOT source materials.

Purpose of the Study:

• To investigate anomalous thermal-assisted (TA) reduction of j_sw in engineered ferrimagnetic heterostructures.
• To explore the dependence of this TA reduction on material parameters, specifically Tb thickness (t_Tb).
• To demonstrate a novel SOT switching mechanism beyond conventional frameworks for potential device applications.

Main Methods:

• Fabrication of Pt/Co/Tb heterostructures with engineered ferrimagnetic interfaces.
• Experimental characterization of j_sw under varying temperatures and t_Tb.
• Theoretical simulations to elucidate the underlying physics of the observed TA reduction.
• Design and simulation of a logic-in-memory device utilizing the TA SOT switching.

Main Results:

• Achieved a significant, anomalous TA reduction in j_sw in Pt/Co/Tb heterostructures.
• Demonstrated that j_sw reduction is strongly dependent on t_Tb, with an optimal point at 3 nm.
• Observed a >17-fold reduction in j_sw with a 74 K temperature increase at the optimal t_Tb.
• Confirmed that the mechanism originates from a temperature-sensitive ferrimagnetic interface, distinct from conventional SOT.

Conclusions:

• Developed an effective strategy to reduce j_sw via TA effects in ferrimagnetic interfaces.
• The proposed mechanism offers an alternative to conventional SOT for energy-efficient spintronic devices.
• Demonstrated the potential of this TA SOT switching for multifunctional logic-in-memory applications.