Electrical Manipulation of Antiferromagnetic Random‐Access Memory Device by the Interplay of Spin‐Orbit Torque and Spin‐Transfer Torque

Abstract

Abstract Antiferromagnets (AFM) hold significant promise as ideal candidates for high‐density and ultrafast memory applications. Electrical manipulation of exchange bias (EB) has emerged as an effective solution to integrate AFMs into magnetic memories as active elements. In particular, spin‐orbit torque antiferromagnetic random‐access memory (SOT‐ARAM) is recently been demonstrated by using an AFM/FM hybrid free layer, which can simultaneously satisfy field‐free switching and good device scalability. However, the switching current density of the exchange bias in SOT‐ARAM devices is still high, and novel functionalities are exploited in this device scheme. In this study, the all‐electrical manipulation of the ARAM devices through the interplay of SOT and spin‐transfer torque (STT) is reported, both in three‐terminal and two‐terminal configurations. The SOT current density achieves a 40% reduction thanks to the incorporation of the STT current. Macrospin simulations are performed to illustrate the underlying mechanism. Further, a majority gate that can be decomposed into reconfigurable AND/OR functionalities in a single ARAM device is demonstrated, with an operation speed as fast as 2 ns. The results can advance the development of high‐performance memories and in‐memory computing.

Keywords

• antiferromagnet
• exchange bias
• high‐performance memory
• reconfigurable logic
• spin‐orbit torque
• spin‐transfer torque