Room temperature field-free switching of CoFeB/MgO heterostructure based on large-scale few-layer WTe2

Spin-orbit-torque (SOT)-driven perpendicular magnetization switching has attracted great attention for designing energy-efficient, high-density, and thermal-stable storage devices. As field-free deterministic switching of perpendicular magnetization is not allowed in conventional heavy metals or topological insulators where spin polarization is limited to the in-plane direction, transition metal dichalcogenides (TMDs) emerge as current spin platforms due to their low-crystal symmetries. However, present studies using TMDs are restricted to mechanically exfoliated samples with micron sizes and to low-temperature operation, which impede their practical applications. Here, based on large-scale, chemical vapor deposition (CVD)-grown, few-layer WTe2 thin films, the field-free switching at room temperature of the CoFeB/MgO heterostructure with perpendicular magnetic anisotropy is experimentally realized owing to unconventional SOTs in WTe2. Furthermore, we employ micromagnetic simulations to explore magnetization dynamics in the out-of-plane polarized spin’s presence. This work paves the way for constructing all-electrical, low-power spintronic devices based on two-dimensional TMDs.