Two types of superconducting pairs in stripe-ordered La2-xBaxCuO4 (x=1/8): Evidence from resistivity measurements

Recent angle-resolved c-axis resistivity measurements of the stripe-ordered La2-xBaxCuO4 (LBCO) with x = 1/8 revealed an unexpected dependence on the direction of the in-plane magnetic field. We argue that these and other available data for the c-axis transport point to the existence of superconducting pairs of two different types in the x = 1/8 LBCO below the stripe ordering temperature. The pairs of one type carry finite momentum and are confined to the Cu-O planes; the pairs of other type (probably the conventional d wave with zero momentum) propagate along narrow conducting channels traversing the sample in the c-axis direction. The evidence for this comes from the observed exponential temperature dependence of the c-axis resistivity rho c(T ) which we attribute to the thermally excited slips of the superconducting phase and flux flows. We present a simple theory to fit the observed z/2-periodic dependence of rho c on the direction of the in-plane magnetic field and the other data.