Anomalous high-energy dispersion in angle-resolved photoemission spectra from the insulating cuprate Ca2 CuO2 Cl2
Abstract
Angle-resolved photoelectron spectroscopic measurements have been performed on an insulating cuprate Ca2CuO2Cl2 . High-resolution data taken along the Γ to the (π,π) cut show an additional dispersive feature that merges with the known dispersion of the lowest binding energy feature, which follows the usual strongly renormalized dispersion of ≈0.35eV . This higher energy part reveals a dispersion that is very close to the unrenormalized band predicted by band theory. A transfer of spectral weight from the low energy feature to the high energy feature is observed as the Γ point is approached. By comparing with theoretical calculations the high energy feature observed here demonstrates that the incoherent portion of the spectral function has significant structure in momentum space due to the presence of various energy scales.
- Publication:
-
Physical Review B
- Pub Date:
- March 2005
- DOI:
- 10.1103/PhysRevB.71.094518
- arXiv:
- arXiv:cond-mat/0602106
- Bibcode:
- 2005PhRvB..71i4518R
- Keywords:
-
- 74.72.-h;
- 71.27.+a;
- 79.60.Bm;
- Cuprate superconductors;
- Strongly correlated electron systems;
- heavy fermions;
- Clean metal semiconductor and insulator surfaces;
- Condensed Matter - Strongly Correlated Electrons;
- Condensed Matter - Superconductivity
- E-Print:
- 5 pages, 3 figures