We report an inelastic neutron scattering study on the Nd and Pr doped La₃Ni₂O₇ powder samples at ambient pressure^[1]. In comparison with previous report on the flat mode around 45 meV in the spin excitations of La₃Ni₂O₇^[2], we reveal that this mode splits to two modes in doped compounds at about 41 and 50 meV, along with another mode around 60 meV. While the spin excitations in La₂NdNi₂O₇ are much stronger than La₃Ni₂O₇ and La₂PrNi₂O₇. Based on a simple J₁-J₂-J_c mode on the double spin stripe antiferromagnetic order, we conclude that the interlayer coupling SJ⊥ is enhanced to about 69 meV and 73 meV for Pr and Nd doped samples, respectively. Our results highlight the crucial role of interlayer coupling in the rare-earth doped bilayer nickelates, which towards to promote high Tc via interlayer s± pairing.^[3,4].

1. H. Zhou, X. Ye, G. Wang, D. T. Adroja et al. 2601.14946.
2. T. Xie et al., Science Bulletin 69, 3221-3227 (2024).
3. C. Chen et al., Sci. China-Phys. Mech. Astron. 69, 247414 (2026).
4. Z. Qiu et al., arXiv: 2510.12359.