Figure 7: 3D SPT model with 
symmetry.
symmetry.From: Symmetry-protected topological phases from decorated domain walls
Lattice model: each cube hosts a Z2 variable Ï„ (big black dot) and each vertex hosts a 
variable σ (small green dot) (a) a cube and the vertices around it (b) a vertex and the cubes around it. Shaded surfaces represent Z2 domain walls.
