Surface and interface effects on a magnetic Chern insulator

International Conference on Strongly Correlated Electron Systems 2014

Ozawa, Ryo^1 ; Udagawa, Masafumi^1 ; Akagi, Yutaka^2 ; Motome, Yukitoshi^1

Department of Applied Physics, University of Tokyo, Bunkyo, Tokyo

113-8656, Japan^1

Okinawa Institute of Science and Technology, Onna, Okinawa

904-0412, Japan^2

关键词: Edge reconstruction;    Kondo lattice model;    Magnetic layers;    Magnetic orders;    Simple junction;    Surface and interfaces;    Topological insulators;    Triangular lattice;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/592/1/012130/pdf
DOI  :  10.1088/1742-6596/592/1/012130

来源: IOP

【 摘 要 】

Effects of an open surface on a magnetic Chern insulator are investigated in comparison with those of an interface to a capping magnetic layer. In magnets, an open surface often perturbs the magnetic order by a reconstruction of the magnetic moment directions near the surface. On the other hand, in topological insulators, it leads to the formation of topologically protected surface states. These two contrasting effects may coexist in magnetic Chern insulators, which give rise to nontrivial surface reconstruction. For instance, the chiral edge current is largely enhanced by the edge reconstruction in a two-dimensional magnetic Chern insulator realized in a quarter-filled Kondo lattice model on a triangular lattice. We here show that the edge reconstruction can be described semiquantitatively by a simple junction model between the bulk topological magnetic state and a ferromagnetic capping layer. We further clarify how the chiral edge current is affected by the magnetic structure in the capping layer. Our results indicate that the topological edge state can be controlled magnetically through the junctions.