2D THz spectroscopy and anomalous non-linear response of La<sub>2−x</sub>Sr<sub>x</sub>CuO<sub>4 </sub>

ORAL

Abstract

La2−xSrxCuO4 (LSCO) is a prototypical example of hole-doped single layer cuprate superconductor. Here we investigate the low frequency broadband non-linear optical response of LSCO across a wide range of doping as a function of temperature. In addition to the large optical non-linearities that is expected in the superconducting state, we find anomalous non-linear response even in the normal state, well above the superconducting critical temperature. This is in sharp contrast to the clean BCS type superconductors where the strong non-linear response at low temperatures promptly disappear at the critical temperature. Furthermore, we perform 2D THz spectroscopy on these samples to identify the different underlying non-linear processes that give rise to the overall response. We compare our results to existing theories on the superconductivity in this class of materials.

*DARPA DRINQS project FP-017, “Long-term High Temperature Coherence in Driven Superconductors”

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Presenters

  • Dipanjan Chaudhuri

    • Johns Hopkins University

Authors

  • Dipanjan Chaudhuri

    • Johns Hopkins University

  • Fahad Mahmood

    • Department of Physics, University of Illinois Urbana-Champaign

  • David Barbalas

    • Johns Hopkins University

  • Xi He

    • Brookhaven National Laboratory

  • Ivan Bozovic

    • Brookhaven National Laboratory
    • Department of Chemistry and Energy Science Institute, Yale University; Bookhaven National Laboratory

  • Peter Armitage

    • Department of Physics and Astronomy, The Johns Hopkins University, Baltimore, MD 21218
    • Johns Hopkins University
    • Institute of Quantum Matter, Department of Physics and Astronomy, Johns Hopkins University