Field‐Free Spin–Orbit Torque Switching of Perpendicular Magnetization by PtTe ₂ /WTe ₂ Bilayers at Sub‐ns Timescales

Abstract Spin‐orbit torque (SOT) has emerged as a promising alternative to spin‐transfer torque (STT) for ultrafast memory applications, addressing the challenges of nanosecond‐scale incubation delays and associated endurance issues inherent to STT. Despite significant progress, achieving field‐free switching of perpendicular magnetization with short current pulses, minimal incubation delay, and low energy consumption remains a critical obstacle for the practical realization of high‐speed SOT devices. Here, field‐free SOT switching is demonstrated at sub‐nanosecond timescales in a PtTe 2 /WTe 2 /CoFeB heterostructure that fulfills all above requirements. The unique combination of WTe 2 , with its low crystal symmetry, facilitates field‐free SOT switching at reduced current densities, while PtTe 2 , characterized by its high spin Hall conductivity, enhances energy efficiency. Moreover, the significant in‐plane spin Hall conductivity from PtTe 2 contributes to shortening the incubation delay. The results establish a promising path toward energy‐efficient, high‐speed SOT memory devices, offering a practical field‐free solution to meet the performance demands of next‐generation memory technologies.