Abstract
We propose a mechanism of the semiconductive temperature dependence of the c-axis resistivity (ρc) in the normal state of high-Tc superconductors. We show that antiferromagnetic spin fluctuations in the CuO2-layer affect the temperature dependence of the Fermi surface shape and that they decrease (increase) the conductive carrier density (band mass) in the c-direction. Thus, when this effect dominates the temperature dependence of ρc, ρc increases at low temperatures. On the other hand, in the in-plane direction, the AF spin fluctuations do not affect the carrier density while they decrease the so-called k-mass at low temperatures. As a consequence, taking into account the damping rate which is caused by the electron-electron interaction, we obtain the in-plane resistivity (ρab) which decreases with decreasing temperature. Thus, the present mechanism can explain the semiconductive temperature dependence of ρc satisfying the metallic behavior of ρab.
