SPECTRAL WEIGHT TRANSFER IN A DOPED STRONGLY CORRELATED INSULATOR

We study the spectral weight transfer and the chemical potential shift in strongly correlated electron systems caused by carrier doping by a pplying the dynamical mean-field theory to a two-band Hubbard model. T he parameters of the model an chosen so that the undoped system is a c harge-transfer-type insulator. We find that in the insulating phase th ere are finite intensities corresponding to local singlet states forme d by hybridized d and p electrons, and that, on doping a part of them, turn into itinerant states. The results are discussed in the light of experimental and theoretical results for high-T-c cuprates.