ARPES results onSr2RuO4: Fermi surface revisited

The electronic band structure of ${\mathrm{Sr}}_2{\mathrm{RuO}}_4$ has attracted considerable attention recently. However, it has also become a subject of an important controversy. Results of de Haas–van Alphen experiments yielded a Fermi surface consisting of two electronlike and one holelike sheets, in good agreement with the theoretical predictions. At the same time, results of angle-resolved photoemission spectroscopy (ARPES) measurements yielded one electronlike and two holelike sheets suggesting an extended van Hove singularity (evHS) similar to that found in cuprate high-temperature superconductors. In an effort to resolve this controversy we performed an extensive ARPES study using various incident photon energies. We found no conclusive evidence for an evHS.