The Su-Schrieffer-Heeger chain is the simplest 1D topological insulator. Edge states appear when the inter-cell hopping dominates — protected by topology.
0.50
1.20
14
Topological (w > v)
The winding number W=0 (trivial) or W=1 (topological) counts how many times h(k) winds around the origin as k goes from 0 to 2π.