The normal state gap and other strange properties of cuprate superconductors

Abstract
We summarise some of our recent work on the Normal State Gap(NSG) in hole-doped high T_c cuprates, including an empirical model for the density of states which appears to account for the effect of doping on the electronic entropy and spin susceptibility. Several features of our data such as the variations in entropy and thermoelectric power with hole content at room temperature are consistent with numerical studies of the t - J model. We note that the effect of doping on the the thermoelectric power is difficult to reconcile with the "stripes scenario". It is shown that the NSG strongly affects most superconducting properties, and, via a simple tunnelling picture, the out-of-plane resistivity and magnetoresistance in the normal state.