Angle-resolved photoemission study of Sr{sub 2}RuO{sub 4}
- Department of Physics, Tohoku University, Sendai 980-77 (Japan)
- Material Science Division, Argonne National Laboratory, 9700 South Cass Avenue, Argonne, Illinois 60439 (United States)
- Joint Research Center for Atom Technology (JRCAT), Tsukuba, Ibaraki 305 (Japan)
We present high-resolution (HR) angle-resolved photoemission spectroscopy (ARPES) measurements of the noncuprate layered perovskite superconductor Sr{sub 2}RuO{sub 4}. ARPES spectra of the whole valence-band region obtained along two high-symmetry directions in the Brillouin zone show clear dispersion, generally similar to that of a band calculation. However, HRARPES measurements taken in the vicinity of the Fermi level ({ital E}{sub {ital F}}) show narrower Ru4{ital d}{var_epsilon}({ital xy},{ital yz},{ital zx})-O2{ital p}{pi} antibonding bands than those predicted by the band calculation. More significantly, there is an extended van Hove singularity very close to {ital E}{sub {ital F}} ({ital E}{sub {ital B}}=11 meV) along the Ru-O bonding direction, which is known to exist in cuprate high-temperature superconductors. The Fermi-surface topology obtained by HRARPES (one electronlike Fermi surface sheet centered at the {Gamma} point and two holelike sheets centered at the {ital X} point) is different from the band calculation (two electronlike sheets centered at the {Gamma} point and one holelike sheet centered at the {ital X} point), although the electron count is the same in both cases. These results suggest that electron-electron correlations cause the modification of the Fermi-surface topology, and is thus necessary for understanding the electronic structure and properties of Sr{sub 2}RuO{sub 4}. {copyright} {ital 1996 The American Physical Society.}
- OSTI ID:
- 389342
- Journal Information:
- Physical Review, B: Condensed Matter, Vol. 54, Issue 18; Other Information: PBD: Nov 1996
- Country of Publication:
- United States
- Language:
- English
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