Resistivity saturation revisited: results from a dynamical mean field theory

TL;DR

This paper uses dynamical mean field theory to analyze high-temperature resistivity in strongly coupled electron-phonon systems, challenging the traditional notion of resistivity saturation and highlighting a breakdown of the Migdal approximation at high scattering rates.

Contribution

It demonstrates that resistivity does not truly saturate at high temperatures but instead undergoes a change in behavior due to the breakdown of the Migdal approximation, revising previous interpretations.

Findings

Resistivity does not saturate at high temperatures.

A change in temperature dependence occurs when scattering becomes very strong.

Breakdown of the Migdal approximation explains the observed behavior.

Abstract

We use the dynamical mean field method to study the high-temperature resistivity of electrons strongly coupled to phonons. The results reproduce the qualtiative behavior of the temperature and disorder dependence of the resistivity of the 'A-15' materials, which is commonly described in terms of saturation, but imply that the resistivity does not saturate. Rather, a change in temperature dependence occurs when the scattering becomes strong enough to cause a breakdown of the Migdal approximation.