English

Specific temperature dependence of pseudogap in YBa$_2$Cu$_3$O$_{7-\delta}$ nanolayers

Superconductivity 2018-04-18 v1

Abstract

The pseudogap (PG) derived from the analysis of the excess conductivity σ(T)\sigma'(T) in superlattices and double-layer films of YBa2Cu3O7δYBa_2Cu_3O_{7-\delta}-PrBa2Cu3O7δPrBa_2Cu_3O_{7-\delta}(YBCO-PrBCO), prepared by pulsed laser deposition, is studied for the first time. The σ(T)\sigma'(T) analysis has been performed within the local-pair (LP) model based on the assumption of the paired fermion (LPs) formation in the cuprate high-TcT_c superconductors (cuprates) below the representative temperature TTcT^*\gg T_c resulting in the PG opening. Within the model, the temperature dependencies of the PG, Δ(T)\Delta^*(T), for the samples with different number of the PrBCO layers (NPrN_{Pr}) were analyzed in the whole temperature range from TT^* down to TcT_c. Near TcT_c, excess conductivity was found to be perfectly described by the Aslamasov-Larkin and Hikami-Larkin (Maki-Thompson term) fluctuation theories, suggesting the presence of superconducting fluctuations in a relatively large (up to 15 K) temperature range above TcT_c. All sample parameters were found to change with increase of NPrN_{Pr}, finally resulting in the appearance of the pronounced maximum of Δ(T)\Delta^*(T) at high temperatures. The result is most likely due to increasing influence of the intrinsic magnetism of PrBCO (μPr4μB\mu_{Pr}\approx 4\,\mu_B) and suggests the possibility to search in that way the change of interplay between the superconductivity and magnetism in cuprates.

Keywords

Cite

@article{arxiv.1804.06119,
  title  = {Specific temperature dependence of pseudogap in YBa$_2$Cu$_3$O$_{7-\delta}$ nanolayers},
  author = {A. L. Solovjov and L. V. Omelchenko and V. B. Stepanov and R. V. Vovk and H. -U. Habermeier and H. Lochmajer and P. Przysłupski and K. Rogacki},
  journal= {arXiv preprint arXiv:1804.06119},
  year   = {2018}
}

Comments

11 pages, 12 figures