Daily Overview: Today’s highlighted work focuses on the theoretical study of magnetic configurations and excitation spectra in multilayer nickelates. Employing a multi-orbital itinerant electron model, one study systematically analyzes bilayer and trilayer nickelate systems, revealing the fine structure of their magnetic ground states and the characteristics of transverse-mode spin excitations. The findings show that, although the double-stripe order has a slightly lower energy in the bilayer system, the excitation spectrum of the single-stripe state qualitatively agrees with resonant inelastic X‑ray scattering and neutron scattering experiments. More importantly, the study identifies that spin-density-wave states with different interlayer mirror symmetries possess distinct interlayer optical excitation modes. This provides a clear criterion for distinguishing hidden magnetic ordered configurations in multilayer nickelates via magnetic excitation probes and supports a common itinerant origin of their magnetism. arXiv submission processing window: 2026-06-19 00:00 to 2026-06-19 00:00 UTC.

1. Magnetic configurations and excitations in high-$T_{c}$ multilayer nickelates

Summary: This study employs a multi-orbital itinerant electron framework, combined with Hartree-Fock and random phase approximation methods, to systematically analyze the magnetic ground states and transverse spin excitations of bilayer and trilayer nickelates. For the bilayer system, although the double-stripe order has slightly lower energy, the excitation spectrum of the single-stripe state exhibits anisotropic low-energy cone-shaped dispersion at the wavevector Q_BL and isotropic high-energy excitations near the Γ point, showing qualitative consistency with resonant inelastic X-ray scattering and neutron scattering experiments; it is also found that the energy of the mirror-even interlayer optical mode at Q_BL coincides with that of the mirror-odd mode at Γ. In the trilayer system, both mirror-odd and mirror-even spin-density wave orders can be stabilized, with the mirror-odd state having lower energy and hosting a near-zero-gap mode predominantly from the middle layer, whereas the mirror-even state supports only one acoustic mode and two gapped optical modes; comparison with experimental data supports the mirror-odd order picture. The results demonstrate that magnetic excitations can serve as a sensitive probe to distinguish magnetic order configurations and reinforce the conclusion that the magnetism in multilayer nickelates shares a common itinerant origin.