English

The two critical temperatures conundrum in La$_{1.83}$Sr$_{0.17}$CuO$_4$

Superconductivity 2024-06-05 v6

Abstract

The in-plane and out-of-plane superconducting stiffness of LSCO rings appear to vanish at different transition temperatures, which contradicts thermodynamical expectation. In addition, we observe a surprisingly strong dependence of the out-of-plane stiffness transition on sample width. With evidence from Monte Carlo simulations, this effect is explained by very small ratio α\alpha of interplane over intraplane superconducting stiffnesses. For three dimensional rings of millimeter dimensions, a crossover from layered three dimensional to quasi one dimensional behavior occurs at temperatures near the thermodynamic transition temperature TcT_{\rm c}, and the out of-plane stiffness appears to vanish below TcT_{\rm c} by a temperature shift of order αLa/ξ\alpha L_a/\xi^\parallel, where La/ξL_a/\xi^\parallel is the sample's width over coherence length. Including the effects of layer-correlated disorder, the measured temperature shifts can be fit by α=4.1×105\alpha=4.1\times 10^{-5} near TcT_{\rm c}, which is significantly lower than its previously measured value near zero temperature.

Keywords

Cite

@article{arxiv.2308.15540,
  title  = {The two critical temperatures conundrum in La$_{1.83}$Sr$_{0.17}$CuO$_4$},
  author = {Abhisek Samanta and Itay Mangel and Amit Keren and Daniel P. Arovas and Assa Auerbach},
  journal= {arXiv preprint arXiv:2308.15540},
  year   = {2024}
}