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

Institute of Electronic Structure and Laser Foundation for Research and Technology, Hellas P.O. Box 1527, Heraklion Crete 71110, Greece

Received: 28 July 1997
Accepted: 17 March 1998

Abstract

We examine the effect on the dc resistivity of small- 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 "undulations” 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.