Precise magnetic structure of the low-pressure phase of La3Ni2O7

Determine the exact spin-density-wave magnetic structure of La3Ni2O7 in the low-pressure phase, including ordering wave vectors, layer stacking along the c axis, and moment orientations, and reconcile results from μSR, NMR, RIXS, neutron scattering, and transport.

Background

Multiple probes (μSR, NMR, RIXS, neutron diffraction) indicate density-wave behavior and magnetic ordering around 150 K in low-pressure La3Ni2O7, with proposals ranging from spin–charge stripe orders to double spin‑stripe configurations.

Despite this progress, the authors state that the precise magnetic structure remains under debate, likely due to sample inhomogeneity and coexistence of structural phases, underscoring the need for definitive determination on homogeneous single crystals.

References

However, the precise magnetic structure of La$_3$Ni$_2$O$_7$ remains under debate.

— Recent progress in nickelate superconductors  (2509.08386 - Wang et al., 10 Sep 2025) in Section 3.2 Density waves in 327

The dashed line marks an additional density-wave transition ($T_{\text{DW}$), whose origin remains under debate.

— Unconventional Pressure Evolution of Spin-Density-Wave State in La$_{3}$Ni$_{2}$O$_{7}$  (2608.17505 - Zhou et al., 18 Aug 2026) in Figure 1 caption, Results section

The H_{\rm int}(2){\rm M} at the O(2){\rm M} sites could not be experimentally determined, and thus here we tentatively assumed that it is similar to the value at O(3,4) sites.

— Orbital-Selective Coexistence of Interlayer Spin-Singlet Formation and SDW Order with Anomalous Spin Reconfiguration in Bilayer Nickelate La$_{3}$Ni$_{2}$O$_{7}$ Revealed by $^{17}$O-NMR  (2608.27917 - Lee et al., 28 Aug 2026) in Section III.C, subsection “Spin structure of SDW state for 115 < T < 150 K”

Although the detailed mechanism is not yet fully understood, this downward shift could be ascribed to the well-developed interlayer spin-singlet formation, which further progresses toward full development upon cooling below T_{\rm SDW}.

— Orbital-Selective Coexistence of Interlayer Spin-Singlet Formation and SDW Order with Anomalous Spin Reconfiguration in Bilayer Nickelate La$_{3}$Ni$_{2}$O$_{7}$ Revealed by $^{17}$O-NMR  (2608.27917 - Lee et al., 28 Aug 2026) in Section III.D, subsection “Anomalous interlayer spin configuration below T_A (~115 K)”

Although the charge anomaly at the ideal La(2)a site could not be explicitly observed across T{\rm A} in the previous NQR study, we cannot exclude the possible occurrence of a tiny charge anomaly below T_{\rm A}, which might be associated with the further development of spin-singlet formation upon cooling.

— Orbital-Selective Coexistence of Interlayer Spin-Singlet Formation and SDW Order with Anomalous Spin Reconfiguration in Bilayer Nickelate La$_{3}$Ni$_{2}$O$_{7}$ Revealed by $^{17}$O-NMR  (2608.27917 - Lee et al., 28 Aug 2026) in Section III.D, subsection “Anomalous interlayer spin configuration below T_A (~115 K)”

The magnetic structure and the nature of these ordered states remain unclear, as does their relationship to superconductivity.

— Selective suppression of electronic orders via interlayer coupling in superconducting bilayer nickelate thin films  (2610.01757 - Han et al., 1 Oct 2026) in Section Introduction