Possible mechanism of eemiconductive temperature dependence of c-axis resistivity in the normal state of high-T_c superconductors: Renormalization effect of fermi surface by antiferromagnetic spin fluctuations

We propose a mechanism of the semiconductive temperature dependence of the c-axis resistivity (ρ_c) in the normal state of high-T_c 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 ρ_c, ρ_c 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 (ρ_ab) which decreases with decreasing temperature. Thus, the present mechanism can explain the semiconductive temperature dependence of ρ_c satisfying the metallic behavior of ρ_ab.