Angle-resolved photoemission on untwinned YBa{sub 2}Cu{sub 3}O{sub 6.95}. I. Electronic structure and dispersion relations of surface and bulk bands
- Department of Applied Physics, Stanford University, Stanford, California 94305 (United States)
- Department of Applied Physics, Department of Physics, and Stanford Synchrotron Radiation Laboratory, Stanford University, Stanford, California 94305 (United States)
- Department of Applied Physics and Department of Physics, Stanford University, Stanford, California 94305 (United States)
- Department of Applied Physics and Stanford Synchrotron Radiation Laboratory, Stanford University, Stanford, California 94305 (United States)
- Department of Physics and Astronomy, University of British Columbia, Vancouver, British Columbia, V6T 1Z1 (CANADA)
Angle-resolved photoemission studies of the dispersion relations and polarization dependence of bands in the near E{sub F} region of untwinned YBa{sub 2}Cu{sub 3}O{sub 7{minus}{delta}} (Y123) single crystals reveal previously unseen details of the electronic structure and significantly expand our understanding of this system. We find that the narrow, intense feature seen along {Gamma}Y in Y123 and YBa{sub 2}Cu{sub 4}O{sub 8} (Y124) is best explained as a surface termination effect related to the quasi-one-dimensional CuO{sub 3} chains, masking underlying electronic states at the Fermi energy. Many of the previously puzzling photoemission results from these materials are readily understood within this context, including the failure to observe a superconducting gap, the weak effect of deoxygenation on the photoemission spectra for {delta}{le}0.5, the weak dependence of this feature on Pr doping, and the strong photon energy dependence of the photoemission spectra. Our data, taken in the superconducting state, reveal the bilayer splitting and c-axis dispersion of the CuO{sub 2} plane bands. We also find evidence for a one-dimensional chain Fermi surface parallel to the {Gamma}X direction, but see no indication of the BaO derived {open_quotes}stick{close_quotes} pocket centered on the S point. {copyright} {ital 1998} {ital The American Physical Society}
- OSTI ID:
- 570292
- Journal Information:
- Physical Review, B: Condensed Matter, Vol. 57, Issue 10; Other Information: PBD: Mar 1998
- Country of Publication:
- United States
- Language:
- English
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