Dynamical mean field theory of small polaron transport

TL;DR

This paper uses Dynamical Mean Field Theory to analyze small-polaron transport in the Holstein model, revealing a temperature-dependent crossover from activated to coherent motion and proposing a new interpolation formula.

Contribution

It provides a unified, nonperturbative analysis of small-polaron transport, highlighting discrepancies with standard formulas and offering a new scaling approach in the nonadiabatic regime.

Findings

Discrepancies with standard polaronic formulas

Crossover from activated to coherent motion

Proposed interpolation formula for resistivity

Abstract

We present a unified view of the transport properties of small-polarons in the Holstein model at low carrier densities, based on the Dynamical Mean Field Theory. The nonperturbative nature of the approach allows us to study the crossover from classical activated motion at high temperatures to coherent motion at low temperatures. Large quantitative discrepancies from the standard polaronic formulae are found. The scaling properties of the resistivity are analysed, and a simple interpolation formula is proposed in the nonadiabatic regime.