Dynamics of a One-Dimensional Holstein Polaron with the Hierarchical Equations of Motion Approach.

Dynamics of a one-dimensional Holstein molecular crystal model is investigated by making use of the hierarchical equations of motion (HEOM) introduced by Tanimura and Kubo [J. Phys. Soc. Jpn. 1989, 104, 101]. Our extended, numerically exact HEOM approach is capable of treating exciton-phonon coupling in a nonperturbative manner and is applicable to any temperature. It is revealed that strong exciton phonon coupling leads to excitonic localization, while a large exciton transfer integral facilitates exciton transport. Temperature effects on excitonic scattering have also been examined. A proof of concept, our work also serves as a benchmark for future comparisons with other numerical approaches to Holstein polaron dynamics.