Crossover of high-energy spin fluctuations from collective triplon excitations to incoherent gapped magnetic modes in the cuprate ladders of Sr<sub>14-x</sub>Ca<sub>x</sub>Cu<sub>24</sub>O<sub>41 </sub>

ORAL

Abstract

We studied the magnetic excitations in the quasi-one-dimensional (q-1D) self-hole-doped ladder subsystem of the hybrid chain-ladder material Sr14-xCaxCu24O41 (SCCO) using Cu L3-edge resonant inelastic X-ray scattering (RIXS). We track the evolution of the spectra from collective two-triplon (2T) excitations to weakly-dispersive gapped magnetic modes as a function of Ca content. We compare the experiment to DMRG calculations of the RIXS response and find evidence of charge localization as Ca content increases. This result is supported by polarization-dependent RIXS measurements, where we disentangle the spin-conserving ΔS=0 scattering from the predominant ΔS=1 signal. We discuss the implications of the changed spin fluctuations for the interplay between Ca content and superconductivity.

*This work is supported by the Swiss National Science Foundation through project no. 200021_178867, the NCCR MARVEL and the Sinergia network Mott Physics Beyond the Heisenberg Model - MPBH (research grant CRSII2_160765/1 and CRSII2_141962), the Canada First Research Excellence Fund, and the NSF under Grant No. DMR-1842056.

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Presenters

  • Jinu Thomas

    • University of Tennessee

Authors

  • Jinu Thomas

    • University of Tennessee

  • Yi Tseng

    • Paul Scherrer Institut

  • Wenliang Zhang

    • Paul Scherrer Institut

  • Eugenio Paris

    • Paul Scherrer Institut

  • Pascal Puphal

    • Max-Planck-Institute for Solid State Research, Heisenbergstrasse 1, 70569 Stuttgart, Germany
    • Max Planck Institute for Solid State Physics
    • Paul Scherrer Institut

  • Rabindranath Bag

    • Department of Physics, Duke University
    • Physics, Indian Institute of Science education and research
    • Duke University
    • Indian Institute of Science Education and Research -Pune

  • Gouchu Deng

    • Paul Scherrer Institut

  • Teguh Citra Asmara

    • Paul Scherrer Institut

  • Vladimir N. Strocov

    • Swiss Light Source
    • Paul Scherrer Institut

  • Surjeet Singh

    • IISER Pune
    • Physics, Indian Institute of Science education and research
    • Physics, Indian institute of science education and research, Pune
    • Indian Institute of Science Education and Research -Pune

  • Ekaterina Pomjakushina

    • Laboratory for Multiscale Materials Experiments, Paul Scherrer Institute
    • Paul Scherrer Institut

  • Umesh Kumar

    • Theoretical Division, T-4, Los Alamos National Laboratory
    • University of Tennessee

  • Alberto Nocera

    • Stewart Blusson Quantum Matter Institute. University of British Columbia.
    • Physics, University of British Columbia
    • University of British Columbia

  • Henrik M Ronnow

    • Ecole Polytechnique Federale de Lausanne
    • École Polytechnique Fédérale de Lausanne (EPFL)

  • Steven S. Johnston

    • Department of Physics and Astronomy, University of Tennessee
    • Department of Physics and Astronomy and Joint Institute of Advanced Materials, The University of Tennessee, Knoxville, Tennessee 37996, USA
    • University of Tennessee
    • University of Tennessee, Knoxville

  • Thorsten Schmitt

    • Paul Scherrer Institut