title: Evolution of the Fermi surface and quasiparticle renormalization through a van Hove singularity in Sr2-yLayRuO4.
abstract: We employ a combination of chemical substitution and angle resolved photoemission spectroscopy to prove that the Fermi level in the gamma band of Sr(2-y)La(y)RuO(4) can be made to traverse a van Hove singularity. Remarkably, the large mass renormalization has little dependence on either k or doping. By combining the results from photoemission with thermodynamic measurements on the same batches of crystals, we deduce a parametrization of the full many-body quasiparticle dispersion in Sr(2)RuO(4) which extends from the Fermi level to approximately 20 meV above it.
authors.affiliation: Department of Applied Physics and Stanford Synchrotron Radiation Laboratory, Stanford University, Stanford, California 94305, USA.
authors.forename: K M
authors.initials: KM
authors.lastname: Shen
authors.forename: N
authors.initials: N
authors.lastname: Kikugawa
authors.forename: C
authors.initials: C
authors.lastname: Bergemann
authors.forename: L
authors.initials: L
authors.lastname: Balicas
authors.forename: F
authors.initials: F
authors.lastname: Baumberger
authors.forename: W
authors.initials: W
authors.lastname: Meevasana
authors.forename: N J C
authors.initials: NJ
authors.lastname: Ingle
authors.forename: Y
authors.initials: Y
authors.lastname: Maeno
authors.forename: Z-X
authors.initials: ZX
authors.lastname: Shen
authors.forename: A P
authors.initials: AP
authors.lastname: Mackenzie