Normal-state and superconducting anisotropy in the doped topological insulator Sr<sub>0.1</sub>Bi<sub>2</sub>Se<sub>3</sub>

ORAL

Abstract

The topological insulator Bi2Se3 becomes superconducting when doped with Cu, Nb (Tc~3.5 K) or Sr (Tc~3.0K); these materials are candidate topological superconductors. We observe twofold in-plane anisotropy in Hc2 in Sr0.1Bi2Se3 via magnetotransport and thermodynamic measurements despite the trigonal crystal structure. We show that the direction of current does not affect the axis of anisotropy and that the normal state electronic and magnetic properties are isotropic in the basal plane. Synchrotron x-ray diffraction shows no distortions from the ideal crystal structure. We conclude that the anisotropy arises from the superconducting gap structure itself, consistent with the recently proposed odd-parity nematic superconducting state characterized by a nodal gap of Eu symmetry.

*This work was supported by the U.S. Department of Energy, Office of Science, Basic Energy Sciences, Materials Sciences and Engineering Division. KW acknowledges support through an Early Postdoc Mobility Fellowship of the Swiss National Science Foundation.

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Presenters

  • Matthew Smylie

    • Argonne Natl Lab
    • Materials Science Division, Argonne National Laboratory

Authors

  • Matthew Smylie

    • Argonne Natl Lab
    • Materials Science Division, Argonne National Laboratory

  • Kristin Willa

    • Argonne Natl Lab
    • Materials Science Division, Argonne National Laboratory

  • Helmut claus

    • Materials Science Division, Argonne National laboratory
    • Argonne Natl Lab

  • Alexei Koshelev

    • Materials Science Division, Argonne National Laboratory
    • Argonne National Laboratory
    • Materials Science Division, Argonne National laboratory
    • Argonne Natl Lab

  • Kok Wee Song

    • Argonne Natl Lab
    • Materials Science Division, Argonne National Laboratory

  • Ulrich Welp

    • Materials Science Division, Argonne National laboratory
    • Argonne Natl Lab
    • Argonne National Laboratory
    • Materials Science Division, Argonne National Laboratory
    • Material Science Division, Argonne National Laboratory

  • Wai-Kwong Kwok

    • Argonne National Lab.
    • Materials Science Division, Argonne National laboratory
    • Argonne Natl Lab
    • Argonne National Laboratory
    • Materials Science Division, Argonne National Laboratory
    • Materials Science Division, Argonne National Lab
    • Material Science Division, Argonne National Laboratory

  • Zahirul Islam

    • Argonne Natl Lab
    • X-ray Science Division, Argonne National Laboratory
    • Advanced Photon Source, Argonne National Laboratory
    • Argonne National Laboratory

  • John Schneeloch

    • Brookhaven National Laboratory
    • Brookhaven Natl Lab
    • Condensed Matter Physics and Materials Science Department, Brookhaven National Laboratory
    • Brookhaven National Lab

  • Ruidan Zhong

    • Brookhaven National Laboratory
    • Brookhaven National Labs
    • Brookhaven Natl Lab
    • Brookhaven National Lab
    • Condensed Matter Physics and Materials Science Department, Brookhaven National Laboratory

  • Genda Gu

    • Brookhaven National Laboratory
    • Brookhaven National Labs
    • Condensed Matter Physics and Materials Science Division, Brookhaven National Laboratory
    • Condensed Matter Physics and Material Science Department, Brookhaven National Laboratory
    • Condensed Matter &materials Science, Brookhaven Natl Lab
    • Brookhaven Natl Lab
    • Condensed Matter Physics and Materials Science, Brookhaven National Laboratory
    • Brookhaven Natl. Lab
    • Brookhaven National Lab
    • Condensed Matter Physics and Materials Science Department, Brookhaven National Laboratory
    • brookhaven national laboratory