Ultrafast renormalization of the onsite Coulomb repulsion in a cuprate superconductor

ORAL

Abstract

Intense ultrafast electromagnetic fields represent an increasingly important tool to stabilize and control emergent phases in quantum materials through the direct light-engineering of effective many-body interactions, such as electron hopping and electron-electron repulsion. Here, we employ time-resolved x-ray absorption spectroscopy (trXAS) to demonstrate the ultrafast renormalization of the Hubbard U parameter in the underdoped cuprate La1.905Ba0.095CuO4 (LBCO, x=9.5%). Our element-specific measurements reveal that intense femtosecond optical pulses (1.55 eV, 50 fs) induce a pronounced shift of the x-ray absorption maxima associated with transitions to the upper Hubbard bands, while the transition energy into Zhang-Rice singlet states near the Fermi level remains unaffected. Based on exact-diagonalization calculations of the time-dependent spectrum within the single- as well as the three-band Hubbard models, we assign these effects to a pump-induced suppression of the Hubbard U on the Cu sites. Our results represent a first demonstration of dynamically-renormalized Hubbard U in strongly correlated oxides and have significant implications for the on-demand engineering of their magnetic interaction spectrum.

*M. M. was supported by the William F. Milton Fund at Harvard University. D. B. acknowledges support from the Swiss National Science Foundation (P400P2_194343). B. J. K. was supported by IBS-R014-A2. H. J. acknowledges support by MSIT (Grant No. 2019R1F1A1060295). S. L., A. A. H., P. A. acknowledge support from DOE grant DE-FG02-06ER46285. P. A. acknowledges support from the Gordon and Betty Moore Foundation EPiQS Initiative (GBMF9452). Work at BNL was supported by the U.S. DOE, Office of Science, Office of Basic Energy Sciences, under Contract No. DE-SC0012704. This research used resources of the National Energy Research Scientific Computing Center (NERSC), a U.S. Department of Energy Office of Science User Facility operated under Contract No. DE-AC02-05CH11231.

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Publication: D. Baykusheva et al., Ultrafast renormalization of the onsite Coulomb repulsion in a cuprate superconductor (submitted, 2021)
https://arxiv.org/abs/2109.13229

Presenters

  • Denitsa R Baykusheva

    • Harvard University

Authors

  • Denitsa R Baykusheva

    • Harvard University

  • Hoyoung Jang

    • Pohang Accelerator Laboratory (PAL)

  • Ali A Husain

    • University of Illinois at Urbana-Champaign

  • Sangjun Lee

    • Samsung Advanced Institute of Technology
    • University of Illinois at Urbana-Champaign

  • Sophia TenHuisen

    • Harvard University

  • Preston Zhou

    • Harvard University

  • Sunwook Park

    • Department of Physics, Pohang University

  • Hoon Kim

    • Pohang Univ of Sci & Tech
    • Department of Physics, Pohang University

  • Jinkwang Kim

    • Department of Physics, Pohang University

  • Hyeong-Do Kim

    • Pohang Accelerator Laboratory
    • Pohang Accelerator Laboratory (PAL)

  • Minseok Kim

    • Pohang Accelerator Laboratory, Pohang, Gyeongbuk 37673, South Korea
    • Pohang Accelerator Laboratory (PAL)

  • Sang-Youn Park

    • Pohang Accelerator Laboratory, Pohang, Gyeongbuk 37673, South Korea
    • Pohang Accelerator Laboratory (PAL)

  • Peter Abbamonte

    • University of Illinois at Urbana-Champai
    • University of Illinois at Urbana-Champaign
    • University of Illinois

  • BJ Kim

    • Pohang Univ of Sci & Tech
    • Department of Physics, Pohang University of Science and Technology, Pohang 37673, South Korea
    • Department of Physics, Pohang University
    • Pohang Univ of Sci & Tech, Institute for Basic Science

  • Genda Gu

    • Brookhaven National Laboratory
    • Condensed Matter Physics and Materials Science Department, Brookhaven National Laboratory, Upton, NY 11973, USA

  • Yao Wang

    • Clemson University
    • clemson university
    • Department of Physics and Astronomy, Clemson University

  • Matteo Mitrano

    • Harvard University