Source capture
Authors Jiong Mei, Tianyang Xie, Kun Jiang
arXiv / Publisher http://arxiv.org/abs/2605.20148v1
PDF https://arxiv.org/pdf/2605.20148v1
Relevance score 4.998
Primary category cond-mat.str-el
Published 2026-05-19
Research paradigm Theoretical
Sample form Unknown

Summary

This paper develops a unified itinerant electron description for the nature of spin-density wave (SDW) order and magnetic excitations in Ruddlesden-Popper nickelates. The central element is the mirror symmetry of the NiO2 multilayer blocks, which organizes the low-energy electronic states into mirror-even and mirror-odd sectors. It is shown that the dominant interband nesting between mirror-opposite sectors drives a mirror-selective itinerant SDW instability, whose collective modes naturally reproduce the spin-wave-like spectra observed experimentally. In La4Ni3O10, the SDW further induces a secondary mirror-even charge density wave, giving rise to intertwined spin and charge textures. These results demonstrate that magnetism in multilayer nickelates is intrinsically itinerant rather than of local-moment origin, and establish mirror-selective interband SDW order as a unifying organizational principle for magnetic correlations in these systems.

Materials

Methods

Keywords

Highlights

  • The same itinerant SDW framework can simultaneously account for the experimentally observed ordering wave vectors, spin textures, and spin-wave-like magnetic excitation spectra.
  • The small ordered moments arise directly from Fermi-surface reconstruction within a partially metallic multiband system.
  • Establishes mirror-selective interband SDW order as a unifying organizing principle for magnetic correlations in multilayer nickelates.
  • Explains that large effective exchange couplings from spin-wave fits do not correspond to microscopic superexchange interactions.
  • Demonstrates that small ordered moments arise from Fermi surface reconstruction, not local moments.

Conclusions

  • Magnetism in multilayer nickelates is fundamentally itinerant rather than local-moment in origin.
  • Mirror-selective interband SDW order is established as a unifying organizing principle for magnetic correlations in these systems.
  • For La4Ni3O10, the SDW further induces a secondary mirror-even charge density wave, yielding intertwined spin and charge textures.
  • Dominant interband nesting between mirror-opposite bands drives a mirror-selective SDW instability.
  • The collective modes of the SDW naturally reproduce the experimentally observed spin-wave-like spectra.
  • For La4Ni3O10, the SDW induces a secondary mirror-even charge density wave, yielding intertwined spin and charge textures.

Main claims

  • The dominant magnetic instability in RP nickelates originates from mirror-odd interband scattering between nested Fermi-surface pockets.
    • Evidence: Abstract: 'dominant interband nesting between mirror-opposite bands drives a mirror-selective itinerant SDW instability'
  • Magnetism in multilayer nickelates is fundamentally itinerant, not local-moment in origin.
    • Evidence: Abstract: 'Our results demonstrate that magnetism in multilayer nickelates is fundamentally itinerant rather than local-moment in origin'
  • Magnetism in multilayer nickelates is itinerant, driven by mirror-selective interband nesting
    • Evidence: From abstract: 'dominant interband nesting between mirror-opposite bands drives a mirror-selective itinerant SDW instability',From abstract: 'magnetism in multilayer nickelates is fundamentally itinerant rather than local-moment in origin'
  • Spin-wave-like excitations naturally emerge from itinerant SDW collective modes
    • Evidence: From abstract: 'collective modes naturally reproduce the experimentally observed spin-wave-like spectra'

Workflow

  • Model construction — Mirror-selective itinerant SDW instability arises from this nesting
    • Materials: La3Ni2O7 and La4Ni3O10 crystal structures
    • Methods: Mirror-even and mirror-odd sector classification; Effective low-energy Hamiltonian
    • Observations: Dominant interband nesting between mirror-opposite bands
  • Mean-field and RPA calculation — Magnetism is itinerant rather than local-moment in origin
    • Materials: Low-energy band model with residual interactions
    • Methods: Hartree-Fock decoupling; Random phase approximation (RPA)
    • Observations: Collective modes reproduce experimental spin-wave-like spectra; Small ordered moments
  • model_construction — Low-energy states organized into mirror sectors
    • Materials: NiO2 blocks; La3Ni2O7 and La4Ni3O10
    • Methods: mirror symmetry classification; tight-binding model
    • Observations: mirror-even and mirror-odd sectors
  • self_consistent_hartree_fock_calculation — Mirror-odd interband SDW instability drives small ordered moments
    • Materials: Two-band model with interactions
    • Methods: Hartree-Fock mean-field
    • Observations: SDW order parameter; ordered moments
  • rpa_spin_response_computation — Collective modes reproduce experimentally observed spin-wave spectra
    • Materials: HF ground state
    • Methods: RPA for transverse spin response
    • Observations: collective spin excitation spectra; spin-wave-like modes