Superconducting phase boundaries and gap symmetry of the candidate topological superconductor In<sub>0.8</sub>Pb<sub>0.2</sub>Te

ORAL

Abstract

The family of (Sn,In,Pb)Te compounds is expected to contain members which are topological superconductors. Recently, it was observed that the solubility limit of Pb in In1-xPbxTe can be substantially raised via high-pressure synthesis, forming a cubic NaCl-type structure with an enhancement of Tc from ~3 K to ~5 K. We present the superconducting phase diagram of the x = 0.2 member (Tc ~4.7 K), finding lower and upper critical fields of 3.2 mT and 2.12 T, respectively. We report on a full superconducting gap as deduced from penetration depth measurements using the TDO technique at temperatures as low as ~450 mK, eliminating a nodal, odd-parity topological superconducting state as a possibility.

*Sample characterization at Argonne National Laboratory was supported by the U. S. Department of Energy, Office of Science, Basic Energy Sciences, Materials Science and Engineering Division. Crystal synthesis was supported by Grant-in-Aid from the Ministry of Education, Culture, Sports, Science, and Technology (MEXT) under Grants No. 18K03540 and 19H01852.

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Presenters

  • Jared Z Dans

    • Hofstra University

Authors

  • Jared Z Dans

    • Hofstra University

  • Matthew P Smylie

    • Hofstra University

  • Kaya Kobayashi

    • Department of Physics, Okayama University
    • Okayama Univ

  • Kaya Kobayashi

    • Department of Physics, Okayama University
    • Okayama Univ

  • Kaya Kobayashi

    • Department of Physics, Okayama University
    • Okayama Univ

  • Ramakanta Chapai

    • Argonne National Laboratory
    • Louisiana State University

  • Wai-Kwong K Kwok

    • Argonne National Laboratory
    • Materials Sciences Division, Argonne National Laboratory, Argonne, Illinois 60439

  • Ulrich Welp

    • Argonne National Laboratory
    • Materials Sciences Division, Argonne National Laboratory, Argonne, Illinois 60439