Pseudogap in Bi2Sr2CaCu2O8+δ studied by measuring anisotropic susceptibilities and out-of-plane transport

We find in the Bi2Sr2CaCu2O8+delta system that the characteristic temperatures T-chi* (below which the uniform susceptibilities chi (ab)(T) (H perpendicular to c) and chi (c)(T) (H // c) decrease) and T-rhoc* (below which the out-of-plane resistivity rho (c)(T) shows typical upturn) coincide for all doping levels. We attribute the T dependence of chi 's and rho (c) to the anomalous (pseudogapped) density-of-states (DOS) in high-T-c cuprates. In addition, an analysis of the anisotropy in the T dependence of chi 's shows that the high-temperature component (d chi /dT < 0) is also caused by a DOS effect.