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

by Abhisek Samanta, Itay Mangel, Amit Keren, Daniel P. Arovas, Assa Auerbach

This Submission thread is now published as

Submission summary

Authors (as registered SciPost users): Assa Auerbach
Submission information
Preprint Link: scipost_202405_00002v1  (pdf)
Date accepted: 2024-05-13
Date submitted: 2024-05-02 07:39
Submitted by: Auerbach, Assa
Submitted to: SciPost Physics
Ontological classification
Academic field: Physics
  • Condensed Matter Physics - Experiment
  • Condensed Matter Physics - Theory
  • Condensed Matter Physics - Computational
  • Statistical and Soft Matter Physics
Approaches: Theoretical, Experimental, Computational, Phenomenological


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 $\alpha$ 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 $T_{\rm c}$, and the out of-plane stiffness appears to vanish below $T_{\rm c}$ by a temperature shift of order $\alpha L_a/\xi^\parallel$, where $L_a/\xi^\parallel$ is the sample's width over coherence length. Including the effects of layer-correlated disorder, the measured temperature shifts can be fit by $\alpha=4.1\times 10^{-5}$ near $T_{\rm c}$, which is significantly lower than its previously measured value near zero temperature.

Author indications on fulfilling journal expectations

  • Provide a novel and synergetic link between different research areas.
  • Open a new pathway in an existing or a new research direction, with clear potential for multi-pronged follow-up work
  • Detail a groundbreaking theoretical/experimental/computational discovery
  • Present a breakthrough on a previously-identified and long-standing research stumbling block

Author comments upon resubmission

We accept the Referees suggestions. In the resubmitted manuscript we provide more details on sample preparation by adding the paragraph below. In single crystal growth it is costumery to provide the furnace power rather than temperature since there is no thermometer in the sample. The doping is set by the initial powder sociometric ratios. We also spell out the exact chemical formula used in each part of the manuscript and removed the acronym LSCO from the manuscript.

List of changes

1. In the Section 2 (experiments) we added the pragraph;

La$_{2-x}$Sr$_{x}$CuO$_4$ is known to grow in large single crystals allowing significant size reductions. Therefore, a powder of different doping is prepared from stoichiometric ratios of 99.99\% pure CuO, La$_2$O$_3$, and SrCO$_3$ to make feed and seed rods. This powder is turned into a single crystal using an image furnace with four elliptic mirrors focusing 300~W halogen lamps. The growth was stabilised over 100~h without any change of the lamp 59\% power. Growth rate of 1.0~mm/h, down-ward translation of 0.15~mm/h, and rotation in opposite directions of 15~rmp were used. The emerging crystals looked like Fig.~1 of Ref [15]. After the growth, the crystals were annealed in Argon environment at $T = 850$~C for 120~hr to release internal stress. Finally, the crystals were oriented with a Laue camera, and cut into rings with a femtosecond laser cutter.

2. We added Reference:
[15] C. Marin, T. Charvolin, D. Braithwaite, R. Calemczuk, Properties of a large La1.92Sr0.08CuO4+d single crystal grown by the travelling-solvent floating-zone method, Physica C 320 1999 197–205

3. Changed LSCO to full chemical formula.

Published as SciPost Phys. 16, 148 (2024)

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