Highly responsive ground state of PbTaSe$_2$: structural phase transition and evolution of superconductivity under pressure

ORAL

Abstract

Thermodynamic and transport studies of PbTaSe$_2$ under pressure suggest existence of two superconducting phases with the phase boundary at $\sim 0.25$ GPa at low temperatures that is defined by a very steep, first order, structural, phase transition. The structural phase transition line extends to $\sim 425$ K at ambient pressure as evidenced by transmission electron microscopy and x-ray diffraction at elevated temperatures. The new, high temperature / high pressure phase has similar crystal structure and slightly lower unit cell volume. The details of this new structute were identified based on first-principles total energy calculations.

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Authors

  • Serguei Budko

    • Iowa State Univ Ames Laboratory
    • Iowa State Univ
    • $^A$Ames Laboratory US DOE, $^B$Department of Physics and Astronomy, $^C$Department of Chemistry, Iowa State University, Ames, Iowa 50011, USA.
    • Ames Laboratory US DOE, and Department of Physics and Astronomy, Iowa State University, Ames, IA 50011, USA
    • Ames Laboratory, Dept. of Physics, ISU, Dept. of Physics, Washington University, St. Louis, ICQM, School of Physics, Peking University
    • Ames Laboratory and Dept. of Phys. and Astro., Iowa State University
    • Iowa State Univ and Ames Laboratory

  • U. S. Kaluarachchi

    • Ames Laboratory, Dept. of Physics, ISU, Dept. of Physics, Washington University, St. Louis, ICQM, School of Physics, Peking University

  • Y. Deng

    • Ames Laboratory, Dept. of Physics, ISU, Dept. of Physics, Washington University, St. Louis, ICQM, School of Physics, Peking University

  • M. F. Besser

    • Ames Laboratory, Dept. of Physics, ISU, Dept. of Physics, Washington University, St. Louis, ICQM, School of Physics, Peking University

  • K. Sun

    • Ames Laboratory, Dept. of Physics, ISU, Dept. of Physics, Washington University, St. Louis, ICQM, School of Physics, Peking University

  • L. Zhou

    • Ames Laboratory, Dept. of Physics, ISU, Dept. of Physics, Washington University, St. Louis, ICQM, School of Physics, Peking University

  • M. C. Nguyen

    • Ames Laboratory, Dept. of Physics, ISU, Dept. of Physics, Washington University, St. Louis, ICQM, School of Physics, Peking University

  • C. Zhang

    • Ames Laboratory, Dept. of Physics, ISU, Dept. of Physics, Washington University, St. Louis, ICQM, School of Physics, Peking University

  • J. S. Schilling

    • Ames Laboratory, Dept. of Physics, ISU, Dept. of Physics, Washington University, St. Louis, ICQM, School of Physics, Peking University

  • M. J. Kramer

    • Ames Laboratory, Dept. of Physics, ISU, Dept. of Physics, Washington University, St. Louis, ICQM, School of Physics, Peking University

  • S. Jia

    • Ames Laboratory, Dept. of Physics, ISU, Dept. of Physics, Washington University, St. Louis, ICQM, School of Physics, Peking University

  • C. Z. Wang

    • Ames Laboratory, Dept. of Physics, ISU, Dept. of Physics, Washington University, St. Louis, ICQM, School of Physics, Peking University

  • K. M. Ho

    • Ames Laboratory, Dept. of Physics, ISU, Dept. of Physics, Washington University, St. Louis, ICQM, School of Physics, Peking University

  • P. C. Canfield

    • Ames Laboratory, Dept. of Physics, ISU, Dept. of Physics, Washington University, St. Louis, ICQM, School of Physics, Peking University