Singular Density Fluctuations in the Strange Metal Phase of a Copper-Oxide Superconductor

ORAL

Abstract

The “strange metal” is a poorly understood phase of matter characterized by a lack of well-defined quasi-particles, violating a core tenet of Fermi Liquid theory. In ordinary metals, the interactions between quasi-particles give rise to propagating collective charge excitations; however, the analogous excitations of the strange metal are unknown. Here, we show measurements of the charge susceptibility χ(q,ω) across the phase diagram of the strange metal, Bi2.1Sr1.9CaCu2O8+x (Bi-2212) using momentum-resolved inelastic electron scattering (M-EELS). Surprisingly, we find an energy- and momentum-independent continuum of scale-invariant charge fluctuations extending to 1eV, instead of dispersing plasmons. This continuum is temperature-independent at optimal doping, but undergoes a significant redistribution of spectral weight at low temperatures away from optimal doping. Our results indicate that the strange metal phase arises from an anomalous type of charge dynamics, especially sensitive to doping, that is not described by any known theory of quantum matter.

*This work was supported by the Gordon and Betty Moore Foundation's EPiQS Initiative through Grant GBMF-4542. An early prototype of the M-EELS instrument was supported by the DOE CES under award no. DE-AC02-98CH10886.

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Presenters

  • Ali Husain

    • Univ of Illinois - Urbana
    • Physics/MRL, Univ of Illinois - Urbana
    • Department of Physics and Materials Research Laboratory, University of Illinois

Authors

  • Ali Husain

    • Univ of Illinois - Urbana
    • Physics/MRL, Univ of Illinois - Urbana
    • Department of Physics and Materials Research Laboratory, University of Illinois

  • Matteo Mitrano

    • Univ of Illinois - Urbana
    • Physics/MRL, Univ of Illinois - Urbana
    • Department of Physics and Materials Research Laboratory, University of Illinois

  • Sean Vig

    • Univ of Illinois - Urbana
    • Department of Physics and Materials Research Laboratory, University of Illinois

  • Anshul Kogar

    • Massachusetts Institute of Technology
    • Department of Physics, Massachusetts Institute of Technology

  • Melinda Rak

    • Univ of Illinois - Urbana
    • Department of Physics and Materials Research Laboratory, University of Illinois

  • Samantha Rubeck

    • Univ of Illinois - Urbana
    • Department of Physics and Materials Research Laboratory, University of Illinois

  • Jõrg Schmalian

    • Institute for Theory of Condensed Matter, Karlsruhe Inst of Tech
    • Institute for the Theory of Condensed Matter, Karlsruhe Institute of Technology

  • Bruno Uchoa

    • University of Oklahoma
    • Department of Physics and Astronomy, University of Oklahoma
    • Physics and Astronomy, Univ of Oklahoma

  • John Schneeloch

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

  • Ruidan Zhong

    • Brookhaven National Laboratory
    • Brookhaven National Labs
    • Brookhaven Natl Lab
    • Brookhaven National Lab
    • Condensed Matter Physics and Materials Science Department, Brookhaven National Laboratory

  • Genda Gu

    • Brookhaven National Laboratory
    • Brookhaven National Labs
    • Condensed Matter Physics and Materials Science Division, Brookhaven National Laboratory
    • Condensed Matter Physics and Material Science Department, Brookhaven National Laboratory
    • Condensed Matter &materials Science, Brookhaven Natl Lab
    • Brookhaven Natl Lab
    • Condensed Matter Physics and Materials Science, Brookhaven National Laboratory
    • Brookhaven Natl. Lab
    • Brookhaven National Lab
    • Condensed Matter Physics and Materials Science Department, Brookhaven National Laboratory
    • brookhaven national laboratory

  • Peter Abbamonte

    • University of Illinois
    • Univ of Illinois - Urbana
    • Physics/MRL, Univ of Illinois - Urbana
    • Department of Physics, University of Illinois
    • Department of Physics and Materials Research Laboratory, University of Illinois