The relation between the scaling behavior of thermopower and the band structure in high-T_c superconductors

We measured thermopower of La-doped Bi2201 polycrystalline samples and found that the experimental results can be scaled on a master curve by adequately assuming a doping dependent scaling temperature similarly as has been reported for other cuprate superconductors. However, the choice of the scaling temperature was not unique, indicating that the scaling temperature does not necessarily coincide with the pseudogap temperature as was claimed in the earlier reports. We also calculated thermopower curves based on the reported electronic structure of an overdoped Bi2201 crystal and by assuming a rigid band picture. Although the opening of the pseudogap was not accounted for in these calculations, we found that it is possible to scale the calculated curves by the same procedure that was applied to the experimental results.