Terahertz Dynamics in the Stripe-ordered Cuprate La<sub>2-x</sub>Ba<sub>x</sub>CuO<sub>4</sub> (x = 0.115) Following Near-infrared Excitation

ORAL

Abstract

Numerous cuprate-based superconductors exhibit a complex interplay between spin order, charge order and superconductivity. We utilize THz time domain spectroscopy to monitor the c-axis Josephson Plasma Resonance (JPR) as a direct probe of the superconducting condensate following excitation with 1.55 eV pulses. La2-xBaxCuO4 (x=0.115) exhibits charge order below ~50K, with an onset of spin order at ~40K and a superconducting transition temperature of TC = 13K [1]. Recent work on this compound has suggested a brief enhancement of superconductivity following photoexcitation [2] which has motivated further investigation. We show that starting from the superconducting state, photoexcitation with 1.5eV near infrared pulses results in a novel electrodynamic response which persists for >300ps. In particular, c-axis polarized excitation with fluences <1mJ/cm2 induces a new plasma edge around ~0.8THz along with a commensurate increase in the spectral weight below 0.5THz. For photoexcitation at temperatures above TC, a qualitatively similar state emerges that decays on the order of several picoseconds. [1] C. C. Homes, et al, Phys. Rev. B 85, 134510 (2012) [2] D. Nicoletti, et al, Phys. Rev. B 90, 100503(R) (2014)

*Research supported by DOE-BES under DE-SC0018218

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Presenters

  • Kevin Cremin

    • Physics, University of California, San Diego

Authors

  • Kevin Cremin

    • Physics, University of California, San Diego

  • Jingdi Zhang

    • Physics, University of California, San Diego
    • Physics, Univ of California - San Diego
    • University of California San Diego
    • Department of Physics, University of California San Diego

  • Christopher Homes

    • Condensed Matter Physics and Materials Science, Brookhaven National Laboratory
    • Department of Condensed Matter Physics and Materials Science, Brookhaven National Laboratory
    • condense matter physic and material science, Brookhaven National Lab
    • CMPMS, Brookhaven Natl Lab

  • 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

  • Dimitri Basov

    • Physics, Columbia University
    • Department of Physics, Columbia University
    • Columbia Univ
    • Columbia University

  • Richard Averitt

    • Physics, University of California, San Diego
    • Physics, Univ of California - San Diego
    • Univ of California - San Diego
    • Department of Physics, University of California San Diego
    • Department of Physics, Univ of California - San Diego
    • University of California San Diego