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

Abstract

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.

Heat-Assisted Magnetization Switching in Flexible Spin–Orbit Torque Devices

“…Here, the θ SH of our system is determined as well as the value of H x , so that the change in I c could be mainly attributed to the variation of H k . The decrease in H k with temperature in Figure e verifies the conclusion that I c decreases with an increase in temperature, and this phenomenon has been discussed in several reports. − …”

“…This suggests that magnetization reversal occurs step by step in many small domains, each with a different deterministic J c . Therefore, we can achieve multistate magnetoresistance by adjusting the amplitude and width of the current pulses, promising possible application in multistate storage or other logic devices. ,, …”

Ferrimagnetic Dynamics Induced by Spin‐Orbit Torques

“…Since temperature varies on the same timescale as the magnetization switching, the net magnetization and angular momentum are dynamical quantities. Therefore, one or both compensation temperatures may be reached and overcome during the switching, [140,141] and assessing the importance of the two compensation points is challenging.…”

Non-volatile reconfigurable spin logic functions in a two-channel Hall bar by spin–orbit torque-based magnetic domains and directional read current

“…In particular, SOT-based reconfigurable logic devices are expected to provide solutions for ultralow-power, high-speed, high-density, and non-volatile systems. These devices can also perform multiple logic operations in a single device frame, enhancing their efficiency compared to conventional logic devices 21 – 29 . For example, numerous studies of spin-based reconfigurable logic devices have also reported successful logic operations using skyrmion dynamics, magnetic tunnel junctions, and chirality-based vortex domain walls 30 – 34 .…”