“ Linear-in-T resistivity, violation of Mott-Ioffe-Regel criterion, and disobedience of Wiedemann-Franz law: Is this enough to accuse a metal of being ‘strange’ or ‘bad’?”
A large fraction of the theoretical community believe that transport in many strongly correlated materials manifests ‘obvious’ non-Fermi liquid behavior through their linear-in-T electrical resistivity, their violation of the Mott-Ioffe-Regel resistivity limit as well as the Wiedemann-Franz law. I will challenge this non-Fermi liquid dogma using quantitative arguments based on the Fermi liquid theory being applied to a non-intuitive regime of low carrier density. I will critically analyze experimental transport data in several materials to assess the widespread theoretical claim of exotic or strange or bad metallic behavior in many systems (e.g. cuprates, ruthenates), showing that, in fact, some (perhaps much) of the observed ‘strange’ or ‘bad’ behavior can be well-understood within the Fermi liquid paradigm of a strongly interacting electron system.