Single-polaron properties in the one-dimensional Holstein and SSH models

We study the single-polaron properties of the one-dimensional Holstein and SSH model. The dynamical coherent potential approximation (under the Hartree approximation) is applied to compute the polaron dispersion, the quasi-particle residue, and the polaron?s Green?s functions. We compare our calculated results in comparison with those by the self-consistent Born approximation plus higher-order diagrams.