Comment on 'High-field studies of superconducting fluctuations in high-T_c cuprates: Evidence for a small gap distinct from the large pseudogap'

摘要

By using high magnetic field data to estimate the background conductivity, Rullier-Albenque and coworkers have recently published [Phys. Rev. B 84,014522 (201 1)1 experimental evidence that the in-plane paraconductiv-ity in cuprates is almost independent of doping. In this Comment we also show that, in contrast with their claims, these useful data may be explained at a quantitative level in terms of the Gaussian-Ginzburg-Landau approach for layered superconductors, extended by Carballeira and coworkers to high reduced temperatures by introducing a total-energy cutoff [Phys. Rev. B 63, 144515 (2001)]. When combined, these two conclusions further suggest that the paraconductivity in cuprates is conventional, i.e., associated with fluctuating superconducting pairs above the mean-field critical temperature.