Bulk-edge correspondence in the Su-Schrieffer-Heeger chain
Zak Phase: π (Topological) | Gap: 0.800
The SSH chain alternates hopping amplitudes t₁ (intra-cell) and t₂ (inter-cell). When t₂ > t₁ the system is topological with Zak phase γ = π and protected edge states at zero energy. When t₁ > t₂ the Zak phase is 0 and no edge states exist. This is a paradigmatic example of bulk-edge correspondence in 1D.