Quantitative assessment of the universal thermopower in the Hubbard model

As primarily an electronic observable, the room-temperature thermopower \(S\) in cuprates provides possibilities for a quantitative assessment of the Hubbard model. Using determinant quantum Monte Carlo, we demonstrate agreement between Hubbard model calculations and experimentally measured room-temperature \(S\) across multiple cuprate families, both qualitatively in terms of the doping dependence and quantitatively in terms of magnitude. We observe an upturn in \(S\) with decreasing temperatures, which possesses a slope comparable to that observed experimentally in cuprates. From our calculations, the doping at which \(S\) changes sign occurs in close proximity to a vanishing temperature dependence of the chemical potential at fixed density. Our results emphasize the importance of interaction effects in the systematic assessment of the thermopower \(S\) in cuprates.