Pseudogap in Pb-doped Bi2201 Studied by the Out-of-Plane Resistivity in Magnetic Fields up to 40 T

摘要

We determine the onset temperature of the pseudogap corresponding to the precursor of the superconductivity by measuring the out-of-plane resistivity (rho)_(c) of Bi_(1.74)Pb_(0.38)Sr_(1.88)CuO_(6+delta) in magnetic fields up to 40 T. It has been found that the semiconducting upturn of (rho)_(c)(T) below T~(*) is suppressed by the application of magnetic fields up to 40 T at low temperatures below T~(**) which is lower than T~(*). That is, with decreasing temperature, the magnetic-field insensitive pseudogap is formed below T~(*), and then the magnetic-field sensitive one participates below T~(**). These results have confirmed that the pseudogap corresponding to the precursor of the superconductivity is formed below T~(**).