Room-Temperature and Tunable Tunneling Magnetoresistance in Fe 3 GaTe 2 -Based 2D van der Waals Heterojunctions.

Magnetic tunnel junctions (MTJs) based on van der Waals (vdW) heterostructures with sharp and clean interfaces on the atomic scale are essential for the application of next-generation spintronics. However, the lack of room-temperature intrinsic ferromagnetic crystals with perpendicular magnetic anisotropy has greatly hindered the development of vertical MTJs. The discovery of room-temperature intrinsic ferromagnetic two-dimensional (2D) crystal Fe 3 GaTe 2 has solved the problem and greatly facilitated the realization of practical spintronic devices. Here, we demonstrate a room-temperature MTJ based on a Fe 3 GaTe 2 /WS 2 /Fe 3 GaTe 2 heterostructure for the first time. The tunneling magnetoresistance (TMR) ratio is up to 213% with a high spin polarization of 72% at 10 K, the highest ever reported in Fe 3 GaTe 2 -based MTJs up to now. A tunneling spin-valve signal robustly persists at room temperature (300 K) with a bias current down to 10 nA. Moreover, the spin polarization can be modulated by bias current and the TMR shows a sign reversal at a large bias current. Our work sheds light on the potential application of low-energy consumption in all-2D vdW spintronics and offers alternative routes for the electronic control of spintronic devices.