We explored the possibility of realizing quantum anomalous Hall effect by placing heavy-element atomic layer on top of monolayer CrI3 with a natural cleavage surface and broken time-reversal symmetry. We showed that CrI3/X (X = Bi, Sb, or As) systems can open up a sizable bulk gap to harbour quantum anomalous Hall effect, e.g., CrI3/Bi is a natural magnetic insulator with a bulk gap of 30~meV, which can be further enlarged via strain engineering or adjusting spin orientations. We also found that the ferromagnetic properties (magnetic anisotropic energy and Curie temperature) of pristine CrI3 can be further improved due to the presence of heavy atomic layers, and the spin orientation can be utilized as a useful knob to tune the band structure and Fermi level of CrI3/Bi system. The topological nature, together with the enhanced ferromagnetism, can unlock new potential applications for CrI3-based materials in spintronics and electronics.
@article{arxiv.1907.03711,
title = {Quantum Anomalous Hall Effect by Coupling Heavy Atomic Layers with CrI$_{3}$},
author = {Majeed Ur Rehman and Xinlong Dong and Tao Hou and Zeyu Li and Shifei Qi and Zhenhua Qiao},
journal= {arXiv preprint arXiv:1907.03711},
year = {2019}
}