WAVE-FUNCTION RENORMALIZATION OF ONE HOLE IN A STRONGLY CORRELATED SYSTEM

The wavefunction renormalization factor Z(k) of a hole injected in a h alf-filled band in a. strongly correlated system in two dimensions is evaluated analytically using the extended quasiparticle operator intro duced by Dagotto and Schrieffer. A model Hamiltonian for such an exten ded hole is proposed. We analytically calculate Z(k) for different par ameter values and observe that the Z(k) value increases as compared wi th what it would be if a bare hole operator is used. This is in confor mity with the numerical observation of Dagotto and Schrieffer.