SSH Model — Topological Band Theory & Edge States

Su-Schrieffer-Heeger (SSH) model: 1D chain with alternating hoppings t₁ (intra-cell) and t₂ (inter-cell). Topological phase: t₁ < t₂ → Zak phase = π, protected edge states appear in gap. Trivial phase: t₁ > t₂ → Zak phase = 0, no edge states.

t₁ (intra): 0.3 t₂ (inter): 1.0 Chain N: 30

Phase: — | Zak phase: — | Gap Δ = 2|t₁ − t₂|: —