Simultaneous enhancements of perpendicular magnetic anisotropy and spin-orbit torque through two-dimensional-like Gd insertion
摘要
High density and low-power consumption are critically important for the development of spin-orbit-torque magnetic random-access memory (SOT-MRAM) towards applications. High density requires high anisotropy energy for thermal stability at small feature size, while low power consumption demands high SOT efficiency. In this work, through the insertion of a two-dimensional-like gadolinium at the β-W/CoFeB interface, the perpendicular magnetic anisotropy (PMA) is greatly enhanced by 472%, while the SOT conductivity is simultaneously improved by more than double. The two-dimensional-like (2D) Gd stimulates the orbital hybridization with Co, resulting in the promotion of interfacial PMA. The significant mismatch of work function between Gd and neighboring layers positions Gd as an interfacial electron-leakage mediator. This leakage effect, along with the Rashba-Edelstein effect, stimulates the injection of spin current into CoFeB, which substantially improves the SOT efficiency. These findings establish rare-earth elements as multifunctional spin regulators, providing a paradigm of interfacial design for high-density and high-performance spintronic hierarchy.