Fig. 4.

At $D=-0.3$ V/nm after topological transition, spin- and layer-resolved $\kappa$ wavefunction for the first topological band (A) and second topological band (B). Both the spin and layer are mixed in these two bands. And the first topological band is dominantly localized at the ${\mathrm{W}\mathrm{S}\mathrm{e}}_2$ layer spin-up channel, with sizeable component localized at the ${\mathrm{M}\mathrm{o}\mathrm{T}\mathrm{e}}_2$ layer spin-up channel.