title: Thermopower and Entropy: Lessons from Sr_{2}RuO_{4}.
abstract: We calculate the in-plane Seebeck coefficient of Sr_{2}RuO_{4} within a framework combining electronic structure and dynamical mean-field theory. We show that its temperature dependence can be interpreted using entropic considerations based on the Kelvin formula and that it provides a meaningful probe of the crossover out of the Fermi liquid regime into an incoherent metal. This crossover proceeds in two stages: The entropy of spin degrees of freedom is released around room temperature, while orbital degrees of freedom remain quenched up to much higher temperatures. This is confirmed by a direct calculation of the corresponding susceptibilities and is a hallmark of "Hund's metals." We also calculate the c-axis thermopower and predict that it exceeds substantially the in-plane one at high temperature, a peculiar behavior which originates from an interlayer "hole-filtering" mechanism.
authors.affiliation: Jožef Stefan Institute, Jamova 39, Ljubljana, Slovenia.
authors.forename: Jernej
authors.initials: J
authors.lastname: Mravlje
authors.affiliation: Collège de France, 11 place Marcelin Berthelot, 75005 Paris, France.|Centre de Physique Théorique, École Polytechnique, CNRS, 91128 Palaiseau Cedex, France.|DQMP, Université de Genève, 24 quai Ernest Ansermet, CH-1211 Genève, Switzerland.
authors.forename: Antoine
authors.initials: A
authors.lastname: Georges