TRANSPORT-PROPERTIES AND FLUCTUATIONS IN TYPE-II SUPERCONDUCTORS NEAR HC2

We study the flux-flow Hall effect and thermomagnetic transport near the upper critical field H(c2) in extreme type-II superconductors starting from a suitable generalization of the time-dependent Ginzburg-Landau equations. We explicitly incorporate the effects of backflow into the calculations of the local electric field and current, which leads to a current that is properly divergenceless. The Hall conductivity calculated from this current agrees with other mean-field calculations that assume a uniform applied electric field (the Schmid-Caroli-Maki solution), thereby vindicating these simplified treatments. We then use these results to calculate the transverse thermomagnetic effects (the Ettingshausen and Nernst effects). The effects of thermal fluctuations and nonlocal elasticity of the flux lattice are incorporated using a method recently developed by Vecris and Pelcovits [G. Vecris and R. A. Pelcovits, Phys. Rev. B 44, 2767 (1991)]. We find that the elastic fluctuations of the vortex lattice suppress the conductivities below their mean-field values. Our results, taken together with those of Vecris and Pelcovits, provide a rather complete description of the transport properties of the flux lattice state near H(c2), at least within the framework of time-dependent Ginzburg-Landau theory.