Daily Overview: This post sorts papers by relevance to nickelate superconductors. Summaries are AI-generated and may contain errors. arXiv submission processing window: times are unavailable (UTC).

1. Spin Fluctuations in the Rare-Earth Doped Bilayer Nickelates

Summary: The spin fluctuations in rare-earth Pr and Nd doped bilayer nickelates La₂LnNi₂O₇₋δ (Ln = La, Pr, Nd) were investigated under ambient pressure using inelastic neutron scattering. In the undoped La₃Ni₂O₇₋δ, a flat spin fluctuation mode at 45 meV was observed; upon doping, this mode splits into two modes at 43 and 48 meV, with an additional weak mode appearing at approximately 60 meV. Notably, the spin fluctuation intensity in La₂NdNi₂O₇₋δ is significantly higher than that in La₃Ni₂O₇₋δ and La₂PrNi₂O₇₋δ. These results are consistent with a description based on the stripe-type antiferromagnetic Heisenberg model, indicating that rare-earth doping enhances the interlayer magnetic coupling, with the interlayer exchange coupling SJ⊥ increasing from about 60 meV to 69–73 meV, while the intralayer coupling remains weak (≤3.5 meV). This enhancement may account for the increase in superconducting transition temperature from 80 K to near 100 K following rare-earth doping. This work reveals the regulatory role of rare-earth doping on spin dynamics and superconducting pairing in bilayer nickelates.