Abstract
Using Floquet-Bloch theory, we propose to realize chiral topological phases in two-dimensional (2D) hexagonal FeX2 (X = Cl, Br, I) monolayers under irradiation of circularly polarized light. Such 2D FeX2 monolayers are predicted to be dynamically stable and exhibit both ferromagnetic and semiconducting properties. To capture the full topological physics of the magnetic semiconductor under periodic driving, we adopt ab initio Wannier-based tight-binding methods for the Floquet-Bloch bands, with the light-induced bandgap closings and openings being obtained as the light field strength increases. The calculations of slabs with open boundaries show the existence of chiral edge states. Interestingly, the topological transitions with branches of chiral edge states changing from zero to one and from one to two by tuning the light amplitude are obtained, showing that the topological Floquet phase of high Chern number can be induced in the present Floquet-Bloch systems.
| Original language | English |
|---|---|
| Article number | 192404 |
| Journal | Applied Physics Letters |
| Volume | 116 |
| Issue number | 19 |
| DOIs | |
| State | Published - May 11 2020 |
Funding
This work was supported by the Ministry of Science and Technology of China (MOST) (Grant No. 2016YFA0301604), the National Natural Science Foundation of China (NSFC) (Nos. 11574008, 11761161003, 11825401, and 11921005), the Strategic Priority Research Program of Chinese Academy of Science (Grant No. XDB28000000), the Fonds voor Wetenschappelijk Onderzoek (FWO-Vl), and the FLAG-ERA Project TRANS 2D TMD. The computational resources and services used in this work were provided by the VSC (Flemish Supercomputer Center), funded by the Research Foundation-Flanders (FWO) and the Flemish Government— Department EWI—and the National Supercomputing Center in Tianjin, funded by the Collaborative Innovation Center of Quantum Matter. This research also used resources of the Compute and Data Environment for Science (CADES) at the Oak Ridge National Laboratory, which was supported by the Office of Science of the U.S. Department of Energy under Contract No. DE-AC05-00OR22725. X.K. and L.L. also acknowledge the work conducted at the Center for Nanophase Materials Sciences, which is a U.S. Department of Energy Office of Science User Facility.
| Funders | Funder number |
|---|---|
| CADES | |
| Data Environment for Science | |
| FWO-Vl | |
| Flemish Government— Department EWI | |
| Flemish Supercomputer Center | |
| Research Foundation-Flanders | |
| VSC | |
| U.S. Department of Energy | DE-AC05-00OR22725 |
| Office of Science | |
| National Natural Science Foundation of China | |
| Chinese Academy of Sciences | XDB28000000 |
| Ministry of Science and Technology of the People's Republic of China | 2016YFA0301604 |
| Fonds Wetenschappelijk Onderzoek | |
| National Supercomputing Center of Tianjin |