Abstract
Angle-resolved photoelectron spectroscopic measurements have been performed on an insulating cuprate . High-resolution data taken along the to the 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 . 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 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.
- Received 8 November 2004
DOI:https://doi.org/10.1103/PhysRevB.71.094518
©2005 American Physical Society