We report the comprehensive comparative analysis of the upper critical magnetic fields μ0Hc2(0) obtained within Ginzburg-Landau and Werthamer-Helfand-Hohenberg theories for optimally-doped YBa2Cu3O7−δ thin films. For different orientations of the magnetic field, our calculations give 638 and 153 T for μ0Hc2(0), H || ab and μ0Hc2(0), H || c, respectively, when using Hc2(0). For the first time, the temperature dependences of coherence lengths ξab(T) and ξc(T) within proposed theories were determined using 50 and 90% criteria of the normal state resistivity value ρN. The Ginzburg-Landau 0.9ρN approach gives ξab(0)=11.8 A, and ξc(0)=3.0 A which are in a good agreement with literature data. The implications of very short coherence lengths in HTSCs are discussed.
@article{arxiv.2209.14668,
title = {Temperature dependence of upper critical fields and coherence lengths for optimally-doped $YBa_2Cu_3O_{7-\delta}$ thin films},
author = {E. V. Petrenko and L. V. Omelchenko and A. V. Terekhov and Yu. A. Kolesnichenko and K. Rogacki and D. M. Sergeyev and A. L. Solovjov},
journal= {arXiv preprint arXiv:2209.14668},
year = {2022}
}