Temperature Dependence of the Penetration Depth of LaFePO from Scanning SQUID Susceptometry

ORAL

Abstract

We use a scanning SQUID susceptometer to measure locally the temperature dependence of the penetration depth of the superconductor LaFePO. We observe a linear temperature dependence down to 850 mK, with a slope that varies with position on the sample. This is in contrast to recent measurements on the related iron arsenide family of superconductors, which indicate fully-gapped superconductivity. We also report on our ability to measure T$_c$ locally, and observe local regions with weak superconductivity at temperatures well above the dominant T$_c$.

–

Authors

  • Cliffird Hicks

    • Geballe Laboratory for Advanced Materials, Stanford University, Stanford, California, 94305, USA
    • Geballe Laboratory for Advanced Materials, Stanford University

  • Thomas Lippman

    • Geballe Laboratory for Advanced Materials, Stanford University, Stanford, California, 94305, USA
    • Geballe Laboratory for Advanced Materials, Stanford University

  • Martin Huber

    • Departments of Physics and Electrical Engineering, University of Colorado at Boulder

  • James Analytis

    • Geballe Laboratory for Advanced Materials, Stanford University

  • Jiun-Haw Chu

    • Geballe Laboratory for Advanced Materials, Stanford University

  • Ian Fisher

    • Geballe Laboratory for Advanced Materials, Stanford University

  • Kathryn Moler

    • Geballe Laboratory for Advanced Materials, Stanford University