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MM: Fachverband Metall- und Materialphysik
MM 21: Transport in Materials: Diffusion, Conduction of Charge or Heat I
MM 21.1: Talk
Tuesday, March 19, 2024, 10:15–10:30, C 264
Transport and diffusion in the two-dimensional Hubbard model — •Martin Ulaga1, Jernej Mravlje1,2, Peter Prelovšek1, and Jure Kokalj3,1 — 1Insitute "Jožef Stefan", Ljubljana, Slovenija — 2Faculty of mathematics of physics, University of Ljubljana, Ljubljana, Slovenija — 3Faculty of civil and geotedic engineering, University of Ljubljana, Ljubljana, Slovenija
We study transport coefficients and diffusion constants in the square lattice Hubbard model by using the finite-temperature Lanczos method and Nernst-Einstein relations. Notably, we observe a strong, non-monotonic temperature dependence in heat conductivity that violates the Mott-Ioffe-Regel limit across a wide range of parameter space, mirroring the behavior of charge conductivity. These findings are particularly significant for experiments on cold-atomic gases, as well as on cuprates. We comment on the experimental implications of our results for thermal conductivity in the Mott-insulating regime and the Lorenz ratio in the doped Mott insulator.
Keywords: Hubbard model; strong correlations; Lorenz ratio; bad metal