Theoretical electron-positron zone-reduced momentum density forYBa2Cu3O7: Fermi surface and wave-function effects
- 1 August 1990
- journal article
- research article
- Published by American Physical Society (APS) in Physical Review B
- Vol. 42 (4), 2696-2699
- https://doi.org/10.1103/physrevb.42.2696
Abstract
Using the linearized augmented-plane-wave (LAPW) -calculated electron and positron charge densities for , the Brillouin-zone-reduced electron-positron momentum density is computed and the zone-reduced two-dimensional angular correlation of annihilation radiation (2D ACAR) spectrum is produced. The calculations show that the relative weights of the Fermi-surface discontinuities are substantially altered due to the positron preferentially sampling the Cu-O chain region. In addition, the reduced 2D ACAR spectrum contains large k-dependent wave-function effects. The theoretical zone-reduced 2D ACAR spectrum is compared to the several existing experimental spectra. It is concluded that, at present, positron-annihilation experiments do not provide consistent and clear evidence for the existence and shapes of Fermi surfaces in .
Keywords
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