Current-induced magnetization switching at charge-transferred interface between topological insulator (Bi,Sb)2Te3 and van der Waals ferromagnet Fe3GeTe2
Reika Fujimura, Ryutaro Yoshimi, Masataka Mogi, Atsushi Tsukazaki, Minoru Kawamura, Kei Takahashi, M. Kawasaki, Yoshinori Tokura
Abstract
Ferromagnetic two-dimensional van der Waals materials attract enormous interest as a platform to explore spin-related quantum phenomena, especially in conjunction with other quantum materials. Topological insulator is one such candidate to form the junction, because the spin-polarized nature of the surface or interface Dirac states enables the highly efficient spin-charge conversion. Here, we report the current-driven magnetization switching in the bilayer film of a van der Waals ferromagnetic semimetal Fe3GeTe2 (FGT) and a topological insulator (Bi1−xSbx)2Te3 (BST). We observed the current-induced magnetization switching via the Edelstein effect in a wide temperature range, whose threshold current density is as small as that reported for the heterostructure of FGT with a Pt layer. By analyzing the transport properties in heterostructures with different Fermi level (EF) positions in the BST layer, we found that the EF position of the charge-transferred interface Dirac states causes the significant variation of the threshold current density with a Bi/Sb ratio. The present result may promise spintronic phenomena in heterostructures of 2D van der Waals ferromagnets with topological insulators/semimetals.