Magnetization of Topological Surface States of Topological Insulators by Two-dimensional Ferromagnetism

Yusheng Hou, Ruqian Wu

Published 2018-02-20Version 1

Magnetization of the topological surface states of topological insulators is critical to designing and creating next-generation innovative and novel spintronic devices. Here we discover through density functional calculations that the emerging two-dimensional (2D) ferromagnetism discovered in the insulating monolayer CrI3 by recent experiments [B. Huang et al., Nature (London) 546, 270 (2017)] can magnetize the topological surface states of the prototypical three-dimensional (3D) topological insulator Bi2Se3 by building van der Waals (vdW) heterostructures CrI3/Bi2Se3/CrI3. Excitingly, such heterostructures with six and more quintuple layers of Bi2Se3 are the long-term sought Chern insulators. Moreover, the band gaps of these Chern insulators are noticeably increased by reducing their vdW gaps. Our work demonstrates contacting 3D topological insulators with the emerging 2D ferromagnetism is a highly promising frontier to realize the high-temperature quantum anomalous Hall effect experimentally in the future.