Fig. 5: Gigantic intrinsic spin-orbit torque in Fe₃GeTe₂.

a Increasing current induced substantial reduction of coercive field. b Large coercivity reduction after Joule heating’s contribution subtracted off. c Spin-orbit torque (SOT) magnitude extracted from coercivity reduction for devices of varying thickness. The net SOT magnitude (blue points) shows no noticeable thickness dependence, with device thickness ranging from 6 to 40 nm. d SHG schematic on bulk Fe_2.8GeTe₂. e, f SHG response for the PP mode e shows a prominent three-fold petal, while for the SS mode f is nearly zero. It shows that inversion symmetry has been broken, mainly along the out-of-plane direction. g Comparison of SOT magnitude of different systems, where the ME/SOT coefficient is about 100 times larger than that of conventional heavy metals. h A novel type of magnetic memory has been demonstrated based on the gigantic intrinsic SOT. The switching current density and power dissipation are around 400 and 4000 times reduced compared to the conventional Pt/Co devices. i Eight multi-level states controlled nonvolatilely by tiny currents, corresponding to 3 bits in a single-device magnetic memory. (Fig. 5a–c is reproduced from Fig. 2a, Fig. S4f, and Fig. 3e respectively in Ref. ¹⁷; Fig. 5d–f is reproduced from Fig. 1a–c in Ref. ¹⁹; Fig. 5g is reproduced from Fig. 3f in Ref. ¹⁷, and Fig. 5h, i is reproduced from Fig. 3d and Fig. 5c respectively in ref. ²⁰).