Theory of Broad Resistive Transition in High Temperature Superconductors under Magnetic Field

Abstract

We further develop the theory of renormalized superconducting fluctuations in a strong field, taking account of layer structure in high temperature superconductors and renormalization of fluctuations of higher Landau levels, both of which we neglected in our previous works. Performing detailed comparisons with recent resistivity data for bulk single crystal samples of YBCO and BSCCO, we find that the resulting expressions of fluctuation conductivities quantitatively explain the broadening of resistive transition for both cases of the field perpendicular and parallel to current. In particular, the single expression for the case I ⊥ B can cover not only the broad transition region but also the flux flow region observed at lower temperature.