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arXiv · 1105.1303

Nernst effect beyond the relaxation-time approximation

D. I. Pikulin·Chang-Yu Hou·C. W. J. Beenakker
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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.

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D. I. Pikulin, Chang-Yu Hou, C. W. J. Beenakker. 2011-05-06. Nernst effect beyond the relaxation-time approximation. https://doi.org/10.1103/physrevb.84.035133

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