Su-Schrieffer-Heeger Model

The model describes a half-filled one-dimensional lattice, with two sites per unit cell, A and B. The tight-binding Hamiltonian in a chain with N sites can be written as By periodic boundary condition, we can obtain Therefore, the Hamiltonian becomes The eigenvectors of the Hamiltonian are where Therefore, the Berry connections are So we can obtain the Berry's phase We can consider two cases If v>w, then tanφ is finite value.

It means that the range of φ is -π/2<φ<π/2. Therefore, it does not enc...