Abstract We studied the magnetic excitations in the quasi-one-dimensional (q-1D) ladder subsystem of Sr 14−x Ca x Cu 24 O 41 (SCCO) using Cu L 3 -edge resonant inelastic X-ray scattering (RIXS). By comparing momentum-resolved RIXS spectra with high ( x = 12.2) and without ( x = 0) Ca content, we track the evolution of the magnetic excitations from collective two-triplon (2 T) excitations ( x = 0) to weakly-dispersive gapped modes at an energy of 280 meV ( x = 12.2). Density matrix renormalization group (DMRG) calculations of the RIXS response in the doped ladders suggest that the flat magnetic dispersion and damped excitation profile observed at x = 12.2 originates from enhanced hole localization. This interpretation is supported by polarization-dependent RIXS measurements, where we disentangle the spin-conserving Δ S = 0 scattering from the predominant Δ S = 1 spin-flip signal in the RIXS spectra. The results show that the low-energy weight in the Δ S = 0 channel is depleted when Sr is replaced by Ca, consistent with a reduced carrier mobility. Our results demonstrate that off-ladder impurities can affect both the low-energy magnetic excitations and superconducting correlations in the CuO 4 plaquettes. Finally, our study characterizes the magnetic and charge fluctuations in the phase from which superconductivity emerges in SCCO at elevated pressures.
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Fingerprints of an orbital-selective Mott phase in the block magnetic state of BaFe2Se3 ladders
Resonant Inelastic X-Ray Scattering (RIXS) experiments on the iron-based ladder BaFe2Se3unveiled an unexpected two-peak structure associated with local orbital (
- NSF-PAR ID:
- 10154141
- Publisher / Repository:
- Nature Publishing Group
- Date Published:
- Journal Name:
- Communications Physics
- Volume:
- 2
- Issue:
- 1
- ISSN:
- 2399-3650
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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