T-linear resistivity in models with local self-energy*

Bad metallic transport is commonly observed in strongly correlated systems. In particular, T-linear resistivity is of special theoretical interest in its connection to quantum criticality and superconductivity. Recently, T-linear resistivity have been explicitly found in several models with local self-energy yet relation between different mechanisms remain unclear. In this work, we discuss two models that demonstrate T-linearity: lattice-Sachdev-Ye-Kitaev model and the Hubbard model within the dynamical mean-field theory (DMFT). In the former, we find that T-scaling depends crucially on the details of both the infra-red- and ultra-violet-limits. In the latter, we study the Hubbard model within single-site DMFT, and show that transport quantities and compressibility are driven by atomic interactions down to temperatures of the order of the bandwidth. We also study the temperature dependence of the Lorentz ratio and Diffusivity and contrast different mechanisms of T-linear resistivity.