Chern number as quantized adiabatic transport
The Thouless pump (1983) is a 1D tight-binding chain with time-periodic hopping: H(φ) = Σ [t+δcos(φ+2πn/N)] c†_{n+1}c_n + Δsin(φ+2πn/N) c†_n c_n. As φ advances by 2π, the spectral flow — how many eigenvalues cross the Fermi level — equals the Chern number C=1, guaranteeing exactly one electron is transported per cycle. This is the 1D precursor to the quantum Hall effect.