Wavefunction renormalization of one hole in a strongly correlated system

Abstract

The wavefunction renormalization factor Z_k of a hole injected in a half-filled band in a strongly correlated system in two dimensions is evaluated analytically using the extended quasiparticle operator introduced by Dagotto and Schrieffer. A model Hamiltonian for such an extended hole is proposed. We analytically calculate Z_k for different parameter values and observe that the Z_k value increases as compared with what it would be if a bare hole operator is used. This is in conformity with the numerical observation of Dagotto and Schrieffer.