Harnessing the Orbital Hall Effect for Energy-Efficient Magnetization Switching in the Room-Temperature van der Waals Ferromagnet Fe3GaTe2.

2D van der Waals (vdW) magnets provide new opportunities for spin-orbit torque magnetoresistive random-access memory (SOT-MRAM) due to their unique properties. Electrically manipulating the magnetization of vdW magnets is key to realizing 2D SOT-MRAM, whereas conventional spin Hall materials such as heavy metals and topological insulators suffer from limitations in torque efficiency and energy consumption. Although recent studies show that the orbital Hall conductivity in light metals greatly exceeds the spin Hall conductivity, direct experimental demonstrations that the orbital Hall effect (OHE) can induce more energy-efficient SOT switching than the spin Hall effect in vdW magnets remain scarce. Here, we utilize Cr as the orbital current source to efficiently manipulate the magnetization of the vdW ferromagnet Fe3GaTe2 at room temperature. In the Fe3GaTe2/Pt (1.5 nm)/Cr (4.5 nm) trilayer structure, the orbital current originating from Cr is converted into the spin current via Pt, which then exerts a torque on Fe3GaTe2. Compared with control samples using 6 nm Pt as the spin current source, the switching current density in OHE-based devices is reduced by ∼3.9 times, resulting in a ∼52% reduction in power consumption. This work presents the promising potential of harnessing orbital currents to realize energy-efficient 2D SOT-MRAM.