Charge quantization via winding number in a dimerized chain
The Su-Schrieffer-Heeger (SSH) model on a finite chain hosts zero-energy edge states when v < w (topological phase). A Thouless pump slowly varies the hopping amplitudes around the parameter space in a closed loop, transferring exactly one quantum of charge per cycle — quantized by the Chern number (winding number of the Bloch Hamiltonian).