We present a study of the thermoelectric (Seebeck and Nernst) response in heavily overdoped, non-superconducting La1.67Sr0.33CuO4. In spite of the electron-like curvature of the Fermi surface, the Seebeck coefficient is positive at low temperatures. Such a feature, previously observed in copper, silver, gold and lithium, is caused by a non-trivial energy dependence of the scattering time. We argue that this feature implies a strong asymmetry between the lifetime of occupied and unoccupied states along the zone diagonals and such an electron-hole asymmetry impedes formation of Cooper pairs along the nodal direction in the superconducting ground state emerging at lower doping levels.
@article{arxiv.2101.10750,
title = {Positive Seebeck coefficient in highly doped La$_{2-x}$Sr$_x$CuO$_4$ ($x$=0.33); its origin and implication},
author = {Hao Jin and Alessandro Narduzzo and Minoru Nohara and Hidenori Takagi and Nigel Hussey and Kamran Behnia},
journal= {arXiv preprint arXiv:2101.10750},
year = {2021}
}