Kadowaki-Woods and Kadowaki-Woods-like ratios in strongly correlated electron materials

In a Fermi liquid there are well established temperature dependences for the low temperature resistivity and the specific heat. The ratio of these temperature dependences, the Kadowaki-Woods ratio (KWR), has been found to be roughly constant within families of strongly correlated electron materials. A recently introduced related ratio [Jacko et al. Nature Phys. 5, 422 (2009)] that takes into account band structure effects, was found to be roughly constant over a wide range of families of strongly correlated electron materials. Previous theoretical work on these ratios has assumed that the electron self-energy is momentum independent. We relax this assumption and consider a variety of phenomenological forms of the self-energy that have been proposed for strongly correlated electron materials. This leads us to investigate ratios analogous to the KWR for a variety of proposed electron self-energies from both a theoretical and a phenomenological point of view. In particular, we collate experimental data from heavy fermion compounds that have non-Fermi liquid phenomenology and investigate the KW-like ratio for those compounds.