We have performed low-temperature high-resolution angle-resolved photoemission spectroscopy on a non-cuprate superconductor Sr2RuO4 (Tc ∼ 1 K) which has the same crystal structure as La2CuO4 but with RuO2 layers replacing CuO2. We found that Sr2RuO4 has an extended van-Hove singularity (VHS) close to EF(20 ± 2 meV) like high-Tc cuprates, regardless of the character of the electronic states at EF, suggesting that the extended VHS is a general feature of a two-dimensional d-electron metal. This demands re-examination of the VHS scenario for the superconducting properties of cuprates, while T-linear resistivity seems to be consistent with this result.
All Science Journal Classification (ASJC) codes
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics
- Energy Engineering and Power Technology
- Electrical and Electronic Engineering