Daily Overview: Today’s highlights focus on an in-depth understanding of the electronic structure of hybrid Ruddlesden-Popper nickelates. In [1], neutron scattering techniques were employed to resolve the spin ordering and dynamics of bilayer nickel oxide La₃Ni₂O₇ single crystals. Clear spin excitations were observed at reciprocal space position Q = (0, 0.5, 2.5), featuring a spin gap of approximately 5 meV and significant in-plane anisotropic dispersion. The out-of-plane modulation directly confirms antiferromagnetic interlayer coupling. Based on linear spin-wave theory, the experimental dispersion can be precisely described as a bilayer Heisenberg model incorporating competing exchange interactions, with the magnetic structure exhibiting stripe-type order. Although the spin-wave bandwidth is only 25% of that in cuprates, the normalized local dynamic magnetic susceptibility is significantly enhanced, and the total fluctuating magnetic moment is comparable to that of cuprates. This reveals that intermediate-energy spin excitations induced by strong electronic correlations are an intrinsic feature of the system, establishing a magnetic framework distinct from cuprates and providing direct evidence for understanding the superconducting pairing mechanism in this system. arXiv submission processing window: 2026-05-06 00:00 to 2026-05-06 00:00 UTC.

1. Nature of magnetism in bilayer nickelate La3Ni2O7 single crystals

  • Relevance Score: 5.8057
  • Authors: Lixing Chen, Enkang Zhang, Yiqing Hao, Yinghao Zhu, Bingkun Cui, Douglas L. Abernathy, Travis J. Williams, Yoichi Ikeda, Hao Zhang, Feiyang Liu, Wenbin Wang, Qisi Wang, Jun Zhao
  • Affiliations: Rutherford Appleton Laboratory, The Chinese University of Hong Kong, Fudan University, Tohoku University, Oak Ridge National Laboratory, Shanghai Research Center for Quantum Sciences
  • Link: https://arxiv.org/abs/2605.03448
  • Paper page: Nature of magnetism in bilayer nickelate La₃Ni₂O₇ single crystals

Summary: This study employs neutron scattering techniques to elucidate the spin order and dynamics in bilayer nickelate La₃Ni₂O₇ single crystals. In the ambient-pressure parent phase, clear spin excitations are observed at the reciprocal-space position Q = (0, 0.5, 2.5), exhibiting a spin gap of approximately 5 meV and pronounced in-plane anisotropic dispersion—band-edge softening along the transverse direction reveals competing exchange interactions. The excitations display an out-of-plane modulation with bilayer periodicity, directly confirming antiferromagnetic interlayer coupling. Based on linear spin-wave theory, the experimental dispersion can be accurately described by a bilayer Heisenberg Hamiltonian incorporating strong interlayer exchange and competing in-plane couplings, with a stripe-type magnetic order. After normalizing the spectral intensity to absolute units, it is found that although the spin-wave bandwidth is only 25% of that in cuprates, the local dynamical magnetic susceptibility is significantly enhanced at comparable energies, and the total fluctuating magnetic moment is comparable to that of cuprates. These results reveal that intermediate-energy spin excitations originating from strong electronic correlations are an intrinsic feature of this system, establishing a magnetic framework fundamentally distinct from that of cuprates and providing direct evidence for understanding the pairing mechanism of superconductivity in this system.