GdN thin film: Chern insulating state on square lattice
Date of Issue2015-11-10
School of Materials Science and Engineering
Institute of Advanced Studies
Using first-principles calculations, we predict a Chern insulating phase in thin films of the ferromagnetic semimetal GdN. In contrast to previously proposed Chern insulator candidates, which mostly rely on honeycomb lattices, this system affords a great chance to realize the quantum anomalous Hall effect on a square lattice without either a magnetic substrate or transition metal doping, making synthesis easier. The band inversion between the 5d orbitals of Gd and 2p orbitals of N is verified by first-principles calculations based on density functional theory, and the band gap can be as large as 100 meV within the GdN trilayer. With a further increase of film thickness, the band gap tends to close and the metallic bulk property becomes obvious.
Materials Science and Engineering
Physical Review B
© 2015 American Physical Society. This paper was published in Physical Review B and is made available as an electronic reprint (preprint) with permission of American Physical Society. The published version is available at: [http://dx.doi.org/10.1103/PhysRevB.92.201303]. One print or electronic copy may be made for personal use only. Systematic or multiple reproduction, distribution to multiple locations via electronic or other means, duplication of any material in this paper for a fee or for commercial purposes, or modification of the content of the paper is prohibited and is subject to penalties under law.