Abstract
Polarization-dependent angle-resolved photoemission spectroscopy measurements of indicate the presence of two different Zhang-Rice singlets in the two-dimensional plane of this insulating copper oxychloride. With the aid of model calculations, we show that one singlet is moving in the antiferromagnetically ordered cupratelike subsystem and the other on the effectively paramagnetic sublattice formed by the extra atoms. The dispersion of the former is thus determined by the superexchange integral , and that of the latter by the hopping integral . Consequently, as far as the role of the magnetic background is concerned, the dispersion relation of a single hole in this system represents simultaneously both the low and very high doping limits of a cuprate plane in a single structure.
- Received 3 February 1997
DOI:https://doi.org/10.1103/PhysRevLett.78.4107
©1997 American Physical Society