The Seebeck coefficient in correlated low dimensional organic metals

TL;DR

This paper investigates how inelastic electron-electron interactions affect the temperature dependence of the Seebeck coefficient in quasi-one-dimensional organic superconductors, revealing effects near quantum critical points.

Contribution

It introduces a theoretical framework combining Boltzmann equation solutions with renormalization group calculations to explain Seebeck coefficient behavior in correlated low-dimensional metals.

Findings

Seebeck coefficient is enhanced and can reverse sign near quantum critical points.

Electron-hole asymmetry arises from umklapp scattering influenced by Fermi surface nesting.

Results align qualitatively with experimental data on organic superconductors.

Abstract

We study the influence of inelastic electron-electron scattering on the temperature variation of the Seebeck coefficient in the normal phase of quasi-one-dimensional organic superconductors. The theory is based on the numerical solution of the semi-classical Boltzmann equation for which the collision integral equation is solved with the aid of the electronic umklapp scattering vertex calculated by the renormalization group method. We show that the one-loop renormalization group flow of momentum and temperature dependent umklapp scattering, in the presence of nesting alterations of the Fermi surface, introduce electron-hole asymmetry in the energy dependence of the anisotropic scattering time. This is responsible for the enhancement of the Seebeck coefficient with respect to the band $T$-linear prediction and even its sign reversal around the quantum critical point of the phase diagram, namely where the interplay between antiferromagnetism and superconductivity along with the strength of spin fluctuations are the strongest. Comparison of the results with available data on low dimensional organic superconductors is presented and critically discussed.