Enhancing Field‐Like Efficiency Via Interface Engineering with Sub‐Atomic Layer Ta Insertion

Abstract The prevailing research emphasis has been on reducing the critical switching current density ( J _c ) by enhancing the damping‐like efficiency ( β _DL ). However, recent studies have shown that the field‐like efficiency ( β _FL ) can also play a major role in reducing J _c . In this study, the central inversion asymmetry of Pt‐Co is significantly enhanced through interface engineering at the sub‐atomic layer of Ta, thereby inducing substantial alterations in the β _FL associated with the interface. The β _FL has shown a 123% increase, from −1.66 Oe/(MA cm ^{− 2} ) to ‐3.8 Oe/(MA cm ^{− 2} ). As a result, the multilayered Ta/Pt/Ta (0.3 nm insertion)/Co/Ta structure leads to a notable decrease in J _c , exceeding a remarkable 90% compared to the simpler Ta/Pt/Co/Ta structure, ultimately achieving a significantly low value of 2.7 MA cm ^{− 2} . These findings pave the way for the development of highly efficient and energy‐saving spin‐orbit torque (SOT)‐based spintronic devices, where further optimizations in interface engineering can unlock even greater potential in terms of reduced power consumption and enhanced performance.