ESTEEM3 Project (H2020)

Part of EU Open Research Repository
Published July 23, 2021 | Version v1
Journal article Open

Optical conductivity and superconductivity in highly overdoped La2−xCaxCuO4 thin films

Authors/Creators

  • 1. Max Planck Institute for Solid State Research
  • 2. Cornell University

Description

We have used atomic layer-by-layer oxide molecular beam epitaxy to grow epitaxial thin films of La2−xCaxCuO4 with x up to 0.5, greatly exceeding the solubility limit of Ca in bulk systems (x∼0.12). A comparison of the optical conductivity measured by spectroscopic ellipsometry to prior predictions from dynamical mean-field theory demonstrates that the hole concentration p is approximately equal to x. We find superconductivity with Tc of 15 to 20 K up to the highest doping levels and attribute the unusual stability of superconductivity in La2−xCaxCuO4 to the nearly identical radii of La and Ca ions, which minimizes the impact of structural disorder. We conclude that careful disorder management can greatly extend the “superconducting dome” in the phase diagram of the cuprates.

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Optical conductivity and superconductivity in highly overdoped La2−xCaxCuO4 thin films.pdf

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Additional details

Funding

European Commission
ESTEEM3 - Enabling Science and Technology through European Electron Microscopy 823717