Optical absorption and activated transport in polaronic systems

TL;DR

This paper provides exact calculations of optical and electrical conductivities in a one-dimensional polaronic system, revealing deviations from traditional theories and highlighting non-adiabatic effects across various interaction strengths.

Contribution

It introduces a refined computational method to accurately analyze optical response and transport in the Holstein model, extending understanding beyond standard small polaron approximations.

Findings

Exact optical and transport properties calculated for the Holstein model.

Identification of deviations from small polaron theory in intermediate coupling.

Discussion of non-adiabatic effects influencing transport behavior.

Abstract

We present exact results for the optical response in the one-dimensional Holstein model. In particular, by means of a refined kernel polynomial method, we calculate the ac and dc electrical conductivities at finite temperatures for a wide parameter range of electron phonon interaction. We analyze the deviations from the results of standard small polaron theory in the intermediate coupling regime and discuss non-adiabaticity effects in detail.