Nernst effect beyond the relaxation-time approximation
Other Condensed Matter
2011-08-08 v1
Abstract
Motivated by recent interest in the Nernst effect in cuprate superconductors, we calculate this magneto-thermo-electric effect for an arbitrary (anisotropic) quasiparticle dispersion relation and elastic scattering rate. The exact solution of the linearized Boltzmann equation is compared with the commonly used relaxation-time approximation. We find qualitative deficiencies of this approximation, to the extent that it can get the sign wrong of the Nernst coefficient. Ziman's improvement of the relaxation-time approximation, which becomes exact when the Fermi surface is isotropic, also cannot capture the combined effects of anisotropy in dispersion and scattering.
Cite
@article{arxiv.1105.1303,
title = {Nernst effect beyond the relaxation-time approximation},
author = {D. I. Pikulin and Chang-Yu Hou and C. W. J. Beenakker},
journal= {arXiv preprint arXiv:1105.1303},
year = {2011}
}