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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.

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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