Percolative Superconducting Pre-pairing in Cuprates

ORAL

Abstract

One of the important open questions in the physics of cuprate superconductors is the nature of superconducting pre-pairing above Tc. We present fundamental new insight into the pre-pairing regime, using a combination of techniques and several cuprate systems. We employ an unconventional probe – nonlinear conductivity – which is zero in the normal state, to find that the signals above Tc show an universal temperature dependence, irrespective of hole doping and cuprate family. Similar behavior is observed in nonlinear torque magnetization measurements, which unequivocally separate superconducting diamagnetism from normal-state paramagnetism, and in linear conductivity experiments. The results are incompatible with Ginzburg-Landau theory, but also rule out an extended temperature range of superconducting fluctuations. To explain our data, we employ a simple percolative model based on inhomogeneity of superconducting gaps. The calculated linear and nonlinear conductivity show excellent agreement with experiment, and the magnetization is explained qualitatively. The pre-pairing is thus controlled by intrinsic, universal nanoscale gap inhomogeneity.

*This work was funded by US DoE under DE-SC-0016371, the Croatian HRZZ under IP-11-2013-2729, FWF project P27980-N36, and ERC CG #725521.

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Presenters

  • Damjan Pelc

    • University of Minnesota

Authors

  • Damjan Pelc

    • University of Minnesota

  • Guichuan Yu

    • School of Physics and Astronomy, University of Minnesota
    • School of Physics and Astronomy, University of Minnesota Twin Cities
    • University of Minnesota

  • Marija Vuckovic

    • University of Zagreb

  • Petar Popcevic

    • Institute of Physics

  • Mihael Grbic

    • University of Zagreb

  • Kristijan Velebit

    • Technical University Vienna

  • Yuan Li

    • Peking University

  • Yang Tang

    • University of Minnesota

  • Nobu-Hisa Kaneko

    • National Institute of Advanced Industrial Science and Technology
    • NMIJ, AIST

  • Ruihua He

    • Westlake Institute for Advanced Study

  • Zachary Anderson

    • University of Minnesota

  • Xudong Zhao

    • Jilin University

  • Takao Sasagawa

    • MSL, Tokyo Inst of Tech
    • Tokyo Institute of Tech.
    • Tokyo Institute of Technology
    • Laboratory for Materials and Structures, Tokyo Inst of Tech
    • Tokyo Inst. of Tech.
    • Materials and Structures Laboratory, Tokyo institute of Technology

  • Arkady Shekhter

    • Los Alamos National Laboratory
    • National High Magnetic Field Laboratory
    • NHMFL/FSU
    • DC Facility, Nationall High Magnetic Field Laboratory

  • Miroslav Pozek

    • University of Zagreb

  • Neven Barisic

    • Technical University Vienna

  • Martin Greven

    • School of Physics and Astronomy, University of Minnesota
    • School of Physics and Astronomy, University of Minnesota Twin Cities
    • University of Minnesota