Field-free spin-orbit torque-induced switching of perpendicular magnetization at room temperature in WTe₂/ferromagnet heterostructures

Spin-orbit torque provides an efficient way to achieve switching of perpendicular magnetization, which is essential for designing energy-efficient spintronic devices. An in-plane antidamping torque combined with an out-of-plane antidamping torque can often deterministically switch perpendicular magnetization without an external magnetic field. Encouragingly, field-free perpendicular magnetization switching of a two-dimensional (2D) material WTe2/ferromagnet bilayer has been reported recently, but the working temperature (< 200 K) is quite below room temperature. Here, we demonstrate field-free perpendicular magnetization switching in the Pt/Co/Pt/WTe2 multilayer films at room temperature, which is mainly attributed to the out-of-plane antidamping torque originating from the WTe2 layer. In addition, current-induced perpendicular magnetization switching at zero magnetic field is also accomplished in the [Co/Pt](2)/WTe2 multilayer film with a very large perpendicular magnetic anisotropic field (similar to 13 600 Oe), which is very useful for practical applications. This work offers a potential way to develop spintronic devices based on 2D materials at room temperature.