STM study of Quantum phase transition in LiFe<sub>1-x</sub>Co<sub>x</sub>As

ORAL

Abstract

We use scanning tunneling microscopy (STM) to image the electronic impact of Co atoms on the ground state of the LiFe1-xCoxAs system. We observe that impurities progressively suppress the global superconducting gap and introduce low energy states near the gap edge, with the superconductivity remaining in the strong-coupling limit. Unexpectedly, the fully opened gap evolves into a nodal state before the Cooper pair coherence is fully destroyed. Our systematic theoretical analysis shows that these new observations can be quantitatively understood by the nonmagnetic Born-limit scattering effect in a s±-wave superconductor, unveiling the driving force of the superconductor to metal quantum phase transition.

*Experimental and theoretical work at Princeton University was supported by the Gordon and Betty Moore Foundation (GBMF4547/ Hasan) and the United States Department of energy (US DOE) under the Basic Energy Sciences programme (Grant No. DOE/BES DEFG-02-05ER46200).

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Presenters

  • Daniel Multer

    • Princeton University
    • Department of Physics, Princeton University

Authors

  • Daniel Multer

    • Princeton University
    • Department of Physics, Princeton University

  • Jiaxin Yin

    • Princeton University
    • Laboratory for Topological Quantum Matter and Spectroscopy, Department of Physics, Princeton University
    • Department of Physics, Princeton University

  • Songtian Sonia Zhang

    • Princeton University

  • Guangyang Dai

    • Chinese Academy of Science

  • Yuanyuan Zhao

    • Nanjing University of Information Science and Technology

  • Andreas Kreisel

    • Universität Leipzig
    • Institute for Theoretical Physics, University of Leipzig
    • Institute for Theoretical Physics, Leipzig University
    • Institut für Theoretische Physik, Universität Leipzig
    • University of Leipzig

  • Gennevieve Macam

    • National Sun Yat-Sen University
    • National Sun Yat-sen University

  • Xianxin Wu

    • The department of Physics, Pennsylvania State University
    • Chinese Academy of Science
    • Julius-Maximilians University of Wuerzburg
    • Max Planck Institute for Solid State Physics

  • Hu Miao

    • Oak Ridge National Laboratory, USA
    • Brookhaven National Laboratory
    • Oak Ridge National Laboratory
    • Materials Science and Technology Division, Oak Ridge National Laboratory

  • Brian M Andersen

    • Niels Bohr Institute
    • University of Copenhagen
    • Niels Bohr Institute, University of Copenhagen

  • Nana Shumiya

    • Princeton University

  • Maksim Litskevich

    • Princeton University

  • Zijia Cheng

    • Princeton University
    • Department of Physics, Princeton University

  • Xian Yang

    • Princeton University
    • Department of Physics, Princeton University

  • Tyler Cochran

    • Princeton University
    • Laboratory for Topological Quantum Matter and Spectroscopy, Department of Physics, Princeton University
    • Department of Physics, Princeton University

  • Guoqing Chang

    • Princeton University
    • Laboratory for Topological Quantum Matter and Spectroscopy, Department of Physics, Princeton University
    • Nanyang Technological University
    • Department of Physics, Princeton University

  • Ilya Belopolski

    • Princeton University
    • Laboratory for Topological Quantum Matter and Spectroscopy, Department of Physics, Princeton University
    • Department of Physics, Princeton University
    • Center for Emergent Matter Science, RIKEN

  • Lingyi Xing

    • Louisiana State University, Department of Physics and Astronomy
    • Physics and Astronomy, Louisiana State University
    • Chinese Academy of Science

  • Yi Gao

    • Nanjing Normal University

  • Feng-chuan Chuang

    • Natl Sun Yat Sen Univ
    • National Sun Yat-Sen University

  • Hsin Lin

    • Institute of Physics, Academia Sinica
    • Academia Sinica
    • Institute of Physics, Academia Sinica, Taipei
    • Institute of Physics, Academia Sinica, Taiwan
    • Physics, Academia Sinica

  • Ziqiang Wang

    • Boston University
    • Physics, Boston College
    • Boston College
    • Department of Physics, Boston College

  • Changqing Jin

    • Chinese Academy of Sciences
    • Institute of Physics, Chinese Academy of Sciences
    • Chinese Academy of Science

  • Yunkyu Bang

    • Pohang University of Science and Technology

  • Zahid Hasan

    • Princeton University
    • Laboratory for Topological Quantum Matter and Spectroscopy, Department of Physics, Princeton University