Source capture
Authors Rustem Khasanov, Thomas J. Hicken, Igor Plokhikh, Ekaterina Pomjakushina, Hubertus Luetkens, Zurab Guguchia, Christof W. Schneider, Dariusz J. Gawryluk
arXiv / Publisher https://arxiv.org/abs/2603.20871
PDF https://arxiv.org/pdf/2603.20871
Relevance score 4.692
Primary category cond-mat.supr-con
Published 2026-03-24
Research paradigm Experimental
Sample form Unknown

Summary

This study utilized muon spin rotation spectroscopy to investigate the effect of oxygen isotope substitution (16O/18O) on the spin density wave (SDW) transition in the trilayer Ruddlesden-Popper nickelate Pr4Ni3O10. Under ambient pressure, the SDW transition temperatures for the 16O and 18O samples were 158.04 K and 159.81 K, respectively, exhibiting a finite isotope shift. Under hydrostatic pressure, the transition temperatures for both isotopes decreased linearly at nearly identical rates (approximately -4.9 K/GPa), resulting in an essentially pressure-independent isotope shift. This pressure-independent isotope effect indicates that the SDW transition primarily originates from electronic correlations rather than lattice dynamics. Combined with recent inelastic X-ray scattering results that revealed no phonon softening, this study supports a novel mechanism of intertwined charge density wave and spin density wave order stabilized by strong spin interactions in trilayer Ruddlesden-Popper nickelates. This finding contrasts with the doping-enhanced isotope effect observed in cuprates and provides critical constraints for understanding the electronic origin of density wave order and its relationship with superconductivity in nickelates.

Materials

Methods

Keywords

Highlights

  • First pressure-dependent isotope effect study in trilayer RP nickelates.
  • Provides evidence that the intertwined CDW/SDW transition is electronically driven.
  • Contrasts with cuprate isotope effect behavior.

Conclusions

  • The SDW transition shows a finite oxygen-isotope shift at ambient pressure (ΔT_SDW = 1.77 K).
  • Under hydrostatic pressure, T_SDW decreases linearly at nearly identical rates for both isotope compositions, making the isotope shift pressure-independent.
  • The absence of pressure enhancement indicates a predominantly electronic origin of the SDW transition.
  • This is consistent with recent inelastic X-ray scattering results showing no phonon softening, suggesting a new regime of intertwined order stabilized by strong spin interactions.

Main claims

  • The SDW transition shows a finite oxygen-isotope shift at ambient pressure (ΔT_SDW ≈ 1.77 K).
    • Evidence: Abstract,Full text: At ambient pressure, 16T_SDW=158.04(5) K and 18T_SDW=159.81(6) K.
  • Under pressure, T_SDW decreases linearly at nearly identical rates for both isotopes, so the isotope shift remains constant.
    • Evidence: Abstract,Full text: d16T_SDW/dp=-4.93(5) K/GPa and d18T_SDW/dp=-4.90(7) K/GPa.
  • The absence of pressure enhancement of the isotope effect points to a predominantly electronic origin of the SDW transition.
    • Evidence: Abstract,Full text: The absence of pressure enhancement… points to a predominantly electronic origin of the SDW transition.

Workflow

  • sample_preparation
    • Materials: Pr4Ni3O10; 16O/18O isotope substitution
    • Methods: oxygen-isotope exchange
    • Observations: 18O enrichment ≈70%
  • muon_SR_measurement
    • Methods: weak-transverse-field μSR; hydrostatic pressure cell
    • Observations: SDW transition temperatures for both isotopes
  • Raman_measurement
    • Methods: Raman spectroscopy
    • Observations: oxygen participation in phonon modes
  • data_analysis
    • Methods: Fermi function fit to paramagnetic fraction; linear fit of T_SDW vs pressure
    • Observations: dT_SDW/dp nearly identical for both isotopes; isotope shift constant under pressure
  • interpretation — The pressure-independent isotope effect indicates an electronic origin of the SDW transition.