Validity of time-dependent trial states for the Holstein polaron

Abstract

Validity of three time-dependent trial states of the Holstein Hamiltonian, namely the D₂, Merrifield and Ansätze has been examined in detail with regards to their deviations from the exact solution to the time-dependent Schrödinger equation. Linear absorption spectra are also calculated as an additional indicator of the Ansatz validity. It is found that the Ansatz is the most accurate trial state of the three, and all Ansätze fail to provide an adequate description of system dynamics in the weak-coupling regime.