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

Spin-orbit torque (SOT) is widely considered as an effective route to manipulate magnetic order in spintronic devices. The low power consumption and long endurance demands from future computer architectures urgently require a reduction of the critical SOT switching current density, j sw . However, except for searching for a SOT source with a high-spin Hall angle, few efficient mechanisms to reduce j sw have been proposed. In this work, we achieved an anomalous thermal-assisted (TA) j sw reduction in a Pt/Co/Tb heterostructure through engineering a ferrimagnetic Co/Tb interface. This j sw reduction tendency is demonstrated to be strongly dependent on the thickness of Tb, t Tb . When t Tb reaches an optimal point (3 nm), a 74 K temperature increase will reduce j sw by more than an order of magnitude (17 times). Comparison experiments and theoretical simulations indicate that this anomalous TA reduction behavior goes beyond the conventional SOT framework and originates from the temperature-sensitive ferrimagnetic interface. We further propose a multifunctional logic-in-memory device, where six different Boolean logic gates can be implemented, to demonstrate the application potential and energy efficiency of this TA SOT switching mechanism. Our work provides an effective alternative to reduce j sw in SOT devices and may inspire future spintronic memory, logic, and high-frequency devices.