On the Munn-Silbey approach to polaron transport with off-diagonal coupling

TL;DR

This paper improves the Munn-Silbey approach for modeling polaron transport by incorporating off-diagonal coupling and a numerically exact evaluation, revealing detailed temperature-dependent transport behaviors.

Contribution

It introduces a refined method with self-consistent transformation coefficients and momentum dependence, enhancing accuracy over previous models.

Findings

Transport properties show significant corrections compared to earlier results.

Distinct band-like and hopping-like transport features are observed.

Results cover a wide temperature range with improved precision.

Abstract

Improved results using a method similar to the Munn-Silbey approach have been obtained on the temperature dependence of transport properties of an extended Holstein model incorporating simultaneous diagonal and off-diagonal exciton-phonon coupling. The Hamiltonian is partially diagonalized by a canonical transformation, and optimal transformation coefficients are determined in a self-consistent manner. Calculated transport properties exhibit substantial corrections on those obtained previously by Munn and Silbey for a wide range of temperatures thanks to a numerically exact evaluation and an added momentum-dependence of the transformation matrix. Results on the diffusion coefficient in the moderate and weak coupling regime show distinct band-like and hopping-like transport features as a function of temperature.