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.