Unraveling spin and charge dynamics in two-leg spin ladders using resonant inelastic x-ray scattering

ORAL

Abstract

Resonant inelastic x-ray scattering (RIXS) has become an important tool to study the spin and charge excitations in materials. We investigate the RIXS spectra of undoped and doped antiferromagnetic spin-ladder cuprate in both the non-spin conserving (NSC) and spin-conserving (SC) channels at the Cu L3 -edge. The spectra are rich and host many exotic excitations. In the undoped NSC-channel, we identify one-triplon, triplet two-triplon excitations in the strong rung coupling limit and confined spinons in the weak rung coupling limit. In the doped NSC-channel, we identify a new dispersive quasiparticle-like spectral features composed of bound 'charge and spin-1/2' in strong rung coupling limit in addition to the excitations branches already present in the undoped case. The NSC-channel can be well described by S(q, ω). On the other hand, SC-channel is unique to RIXS and reveals new features. In the undoped SC channel, we identify singlet two-triplon for the strong rung coupling and confined spinons for the weak rung coupling. In the doped SC-channel, RIXS probes the charge excitations instead of spin-excitations, and we identify gapless and gapped charge excitations in the spectra.

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Presenters

  • Umesh Kumar

    Physics and Astronomy, University of Tennessee, Department of Physics and Astronomy, University of Tennessee, Knoxville

Authors

  • Umesh Kumar

    Physics and Astronomy, University of Tennessee, Department of Physics and Astronomy, University of Tennessee, Knoxville

  • Alberto Nocera

    University of British Columbia, Stewart Blusson Quantum Matter Institute, University of British Columbia

  • Elbio R Dagotto

    Physics, University of Tennessee-Knoxville, University of Tennessee, Department of Physics and Astronomy, University of Tennessee, Knoxville

  • Steven Johnston

    Department of Physics and Astronomy, Univ of Tennessee, Knoxville, Department of Physics and Astronomy, University of Tennesse, Physics and Astronomy, University of Tennessee, University of Tennessee, Department of Physics and Astronomy, University of Tennessee, Department of Physics and Astronomy, University of Tennessee, Knoxville