Local criticality and marginal Fermi liquid behavior in a translationally invariant solvable model II : Transport and beyond

One of the hallmarks of bad metal behavior in many strongly-correlated materials is the existence of a broad range of temperatures, upto a low crossover scale, over which the resistivity shows striking deviation from Fermi liquid behavior without any apparent sign of saturation. In this work, we consider the transport properties of a large class of translationally invariant models of strongly-correlated metals with on-site, multi-orbital interactions of the Sachdev-Ye-Kitaev form in the limit when the number of orbitals is taken to be large. In a generalized version of the model with multiple bands, we discuss the transport properties of the marginal and non-Fermi liquid metals and find no evidence of a `Planckian-bound' on the transport scattering rates. We also draw connections to many-body quantum chaos.