Measurement of Heavy-Fermion Cooper Pair Symmetry from Multi-Atom Quasiparticle Interference in CeCoIn<sub>5</sub>

ORAL

Abstract

In heavy fermion superconductors, the orbital symmetry of the Cooper-pair is encoded in the momentum-space symmetry of the superconductor's energy-gap function Δ(k). However, while the magnitude |Δ(k)| can be determined by a variety of techniques, the sign of Δ(k) and thus its symmetry have never been directly measured for any heavy-fermion superconductor. Recently, a new technique dubbed MAHAEM based on phase-resolved superconducting quasiparticle interference patterns at multiple impurity atoms, has proven highly effective Δ(k) determination. Here we introduce MAHAEM for heavy fermion superconductor CeCoIn5. The analysis demonstrates that the orbital symmetry of the Cooper-pair wavefunction is dx2-y2. Such capabilities to directly measure the Δ(k) of any heavy fermion superconductor presage significant advances, especially for establishing the Δ(k) of putative topological superconductors.

*P.J.H. acknowledges NSF-DMR-1849751. R.S. and J.C.S.D. acknowledge the Moore Foundation's EPiQS GBMF9457. J.C.S.D. acknowledges Science Foundation Ireland SFI 17/RP/5445. W.C, S.W., W.R. and J.C.S.D. acknowledge the European Research Council (ERC) DLV-788932.

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Presenters

  • Weijiong Chen

    • Department of Physics, University of Oxford

Authors

  • Weijiong Chen

    • Department of Physics, University of Oxford

  • Rahul Sharma

    • Department of Physics, University of Maryland

  • Shuqiu Wang

    • Department of Physics, University of Oxford

  • 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

  • Cedomir Petrovic

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

  • Tien-Ming Chuang

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

  • Milan P. Allan

    • Leiden Institute of Physics, Leiden University
    • Leiden University
    • Huygens-Kamerlingh Onnes Laboratory, Leiden University

  • Peter Hirschfeld

    • University of Florida
    • Department of Physics, University of Florida
    • Physics, University of Florida
    • univ of Florida

  • James C Davis

    • Cornell University
    • Department of Physics, University of Oxford
    • University College Cork
    • Laboratory of Atomic and Solid State Physics, Cornell University; Department of Physics, University College Cork; Max-Planck Institute for Chemical Physics of Solids; Clarend