Fig. 4
Characterizations of chiral edge states at the interfaces between a Floquet Chern insulator and normal insulators. a Schematic of the super-cell geometry with a Floquet Chern insulator placed in between two Floquet normal insulators. The Floquet Chern insulator is the same setup as the right panel of Fig. 3d. All regions are driven at the same frequency Ω3, and the associated gap Chern number for the Floquet insulator is Cg = 1. Further details of the super-cell setup can be found in Supplementary Note 7. b The dispersion along kx axis shows two types of modes: bulk bands in the normal and Chern insulator regions (yellow) and uni-directional chiral edge states at the top and bottom interfaces (red and blue). c Chiral edge states are absent in the projected dispersion when all regions are driven at frequency Ω1 before the topological phase transition. d Comparison among the mode profiles of a bulk state (black), the chiral edge states localized at the top interface traveling to the left (red) and at the bottom interface traveling to the right (blue)
