Renormalized Perturbation Approach for Examination of Itinerant-Localized Duality Model for Strongly Correlated Electron Systems

We present a microscopic examination for the itinerant-localized duality model which has been proposed to understand anomalous properties of strongly correlated systems like the heavy fermions by Kuramoto and Miyake, and also useful to describe the anomalous properties of the high-T_c cupurates. The action of the duality model consists of two components of dynamical degrees of freedom. One of them is coherent itinerant degree of fermion and the other is incoherent localized one describing mainly the spin which has not been explicitly considered so far. We show that the thermodynamic potential of the strongly interacting Hubbard model can be rearranged in the form of duality model on the basis of renormalized perturbation expansion of the Luttinger-Ward functional if the one-particle spectral weight exhibits triple peak structure. We also examine the incoherent degrees of freedom described as a "localized spin" and show on the basis of the pertubation expansion that there exists commensurate superexchange-type interaction among the "localized spins".