MODEL OF C-AXIS TRANSPORT OF HIGH-T-C CUPRATES

We present a simple phenomenological model for the normal state c-axis transport of high-T-c cuprates, which provides a quantitative fit to the c-axis resistivity data of La2SrxCuO4, YBa2Cu3O6+x and Bi2Sr2CaCu2 O8. We attribute the normal-state low-temperature upturn in rho(c) to the suppression of planar density of states, measured in nuclear magne tic resonance Knight shifts experiments. We show that this model can b e derived from a framework of quasiparticle tunnelling between conduct ing layers. We suggest that the overall increase in optical conductivi ties at higher frequencies is consistent with phonon-assisted tunnelli ng contributions whose onset occurs at higher frequencies.