Field-free and efficient nanosecond spin–orbit torque switching in optimized WTe₂/Fe₃GaTe₂ heterostructures

Spin–orbit torque (SOT) driven magnetization switching in all-van der Waals (vdW) heterostructures is a promising route toward next-generation, high-density spintronic memories. Improving switching efficiency and achieving nanosecond-scale operation are essential for practical applications. Here, we demonstrate room-temperature, field-free SOT magnetization switching in WTe₂/Fe₃GaTe₂ heterostructures, achieved through an optimized fabrication process. The device achieves a high switching ratio of 90% at a low current density on the order of 10 5 A/cm². Moreover, we demonstrate nanosecond-timescale magnetization switching while maintaining high switching ratio and energy efficiency. These results advance the viability of all-vdW heterostructures for energy-efficient, high-speed memory applications.