Magneto-thermoelectric studies of high temperature superconductors

The electrical resistivity and Seebeck effect probe the charge carrier currents caused by electric and temperature gradients. A magnetic field additionally superimposed on a superconducting sample allows one to observe phenomena called excess electrical resistivity, excess thermoelectric power Nernst effect and excess electrothermal conductivity. These parameters supply some consistent information on the kinetics of vortices and of quasi particle scattering in the mixed state. We stress apparently different behaviors for the various effects. We emphasize that more relevance should be put on sorting out the various dissipation mechanisms, like quasi particle scattering vortex motion dissipation and superconductivity fluctuations. Several cases of Bi-based superconductors are reviewed with the aim of defining further lines of investigation