High temperature transport in a Hubbard model with screened Coulomb interactions

We demonstrate that the Hubbard model with screened Coulomb interactions can be treated perturbatively in the hopping parameter t at temperatures and interaction strengths T, U >>t. This allows high temperature transport to be studied using classical Monte Carlo methods. Performing a Monte Carlo simulation, we map out the phase diagram for this two-dimensional electron system as a function of doping and T/U. It exhibits multiple signatures of non-Fermi liquid behavior, including linear-in-temperature resistivity across a large range of temperatures and a Lorentz ratio which fails to obey the Wiedemann-Franz law. We compare the transport and thermodynamic properties of our model to those measured experimentally in various strongly correlated materials.