Daily Overview: Today’s highlight work focuses on deepening the understanding of the electronic structure of hybrid Ruddlesden–Popper nickelates. A recent study reports the observation of non-Fermi liquid behavior in bilayer La₃Ni₂O₇ thin films: through epitaxial growth and hydrostatic pressure of only 0.53–1.41 GPa, the temperature dependence of resistivity evolves from Fermi liquid to ~T¹⁴ behavior, requiring merely 6–8% of the pressure needed in single-crystal systems, demonstrating exceptionally strong tunability in the thin-film form. Meanwhile, the suppression and emergence of spin density wave order are observed on different substrates. Combined with the multiband electronic structure revealed by Hall effect measurements, these findings provide critical experimental evidence for understanding the origin of non-Fermi liquid behavior in such materials and the thin-film route to high-pressure superconductivity. arXiv submission processing window: 2026-03-31 00:00 to 2026-03-31 00:00 UTC.

1. Non-Fermi liquid behavior in La$_3$Ni$_2$O$_7$ thin films under hydrostatic pressure

Summary: This study reports the transport properties of epitaxial bilayer La₃Ni₂O₇ thin films grown on LaAlO₃(001) and SrLaAlO₄(001) substrates, modulated by high-pressure oxygen annealing and hydrostatic pressure. Under ambient pressure, films on LaAlO₃ substrates exhibit Fermi liquid metallic behavior with a slight Kondo-like upturn at low temperatures; upon applying hydrostatic pressure from 0.53 to 1.41 GPa, the temperature dependence of resistance gradually evolves into non-Fermi liquid behavior, approaching approximately ~T¹⁴ at 1.41 GPa. Notably, this pressure is only 6–8% of that required to achieve similar effects in single crystals using diamond anvil cells, revealing unexpectedly strong tunability in the thin-film form. Additionally, signs of spin-density wave (SDW) order are observed in films on YAlO₃ substrates but suppressed on LaAlO₃ substrates. Hall effect measurements indicate a multiband electronic structure. These results demonstrate that La₃Ni₂O₇ thin films can approach a strongly fluctuating ordered state under moderate pressures, offering a new pathway for studying the origin of non-Fermi liquid behavior and high-pressure superconductivity in thin-film systems.