Fig. 3
a Energy band structure of RuS4 monolayer with SOC. b Magnified plot of electronic band structure along the X–Γ direction, with VB, CB, and SOC-induced gap labeled. c 3D landscapes of VB and CB with SOC. d Schematic representation of the supercell used to model the open boundary conditions. Shaded regions are used to illustrate the edge cells. e Electronic band structures of RuS4 [30 × 1 × 1] nanoribbon. The helical edge states are denoted by the red circles
