Small-q electron-phonon scattering and linear dc resistivity in high-T_c oxides

TL;DR

This paper investigates how small-q electron-phonon scattering influences the linear temperature dependence of DC resistivity in high-T_c oxides, highlighting the roles of band structure and phonon processes.

Contribution

It demonstrates that forward scattering and band undulations can lead to significant transport effects and explains the origin of linear resistivity at low temperatures in high-T_c oxides.

Findings

Small-q electron-phonon scattering can significantly affect resistivity.

Extended van-Hove singularities enhance acoustic phonon contributions.

Linear T resistivity persists down to 10 K despite optical phonon scattering.

Abstract

We examine the effect on the DC resistivity of small-q electron-phonon scattering, in a system with the electronic topology of the high-T_c oxides. Despite the fact that the scattering is dominantly forward, its contribution to the transport can be significant due to ``ondulations'' of the bands in the flat region and to the umpklapp process. When the extended van-Hove singularities are sufficiently close to $E_F$ the acoustic branch of the phonons contribute significantly to the transport. In that case one can obtain linear $T$ dependent resistivity down to temperatures as low as 10 K, even if electrons are scattered also by optical phonons of about 500 K as reported by Raman measurements.