Locating the missing superconducting electrons in overdoped cuprates

ORAL

Abstract

Overdoped high-temperature cuprate superconductors have been widely believed to be described by the physics of d-wave BCS-like superconductivity. However, recent measurements indicate that the superconducting transition temperature (Tc) is correlated with the superfluid density rather than being independent of it as predicted by BCS theory. Here, we combine time-domain THz spectroscopy with kHz range mutual inductance measurements to determine both the superfluid and the uncondensed carrier density as a function of doping for overdoped La2-xSrxCuO4 films. A significant fraction of the carriers remain uncondensed in a Drude-like peak even as T → 0 with a conductivity and scattering rate that rules out disorder as the determining factor in suppressing the superfluid density. Analysis of the low frequency spectral weight distribution in terms of a quantum Debye Waller factor suggests the prominent role of quantum phase fluctuations as the critical doping is approached.

–

Presenters

  • Fahad Mahmood

    Department of Physics and Astronomy, The Johns Hopkins University, Johns Hopkins University, Johns Hopkins Univ

Authors

  • Fahad Mahmood

    Department of Physics and Astronomy, The Johns Hopkins University, Johns Hopkins University, Johns Hopkins Univ

  • Xi He

    Brookhaven National Laboratory, Brookhaven National Lab

  • Ivan Bozovic

    Brookhaven National Laboratory, Brookhaven National Lab

  • Peter Armitage

    Department of Physics and Astronomy, The Johns Hopkins University, Department of Physics and Astronomy, Johns Hopkins Unversity, Johns Hopkins University, Johns Hopkins Univ, Institute for Quantum Matter, Johns Hopkins University, The Johns Hopkins University