Two-Dimensional Fermi Liquid Behavior of the Superconductor Sr2RuO4

We report detailed normal state measurements of the resistivity, magnetic susceptibility and specific heat of high-quality single crystals of Sr 2 RuO 4 , the only copper-free, layered perovskite superconductor ( T c ≈1 K). It is intriguing that despite its very strong anisotropy (the ratio of the interlayer to in-plane resistivity exceeds 500) arising from the essentially two-dimensional Fermi surface, the normal state properties are consistent with a universal description for a strongly correlated Fermi liquid. Therefore, Sr 2 RuO 4 serves as an ideal reference material for the investigation of the limits of applicability of Fermi liquid theory to other highly correlated layered compounds, including high- T c cuprates.