Effect of on-site Coulomb repulsion on phase transitions in exactly solved spin-electron model

TL;DR

This paper presents an exact solution to a hybrid spin-electron model to study how on-site Coulomb repulsion influences phase transitions and critical behavior in a lattice system with localized spins and itinerant electrons.

Contribution

It introduces an exact analytical approach to analyze the effects of Coulomb repulsion on phase transitions in a hybrid lattice model with localized and itinerant electrons.

Findings

Coulomb repulsion significantly affects ground-state properties.

The model exhibits distinct phase transition behaviors depending on Coulomb interaction strength.

Exact solutions reveal critical points influenced by Coulomb repulsion.

Abstract

A hybrid lattice-statistical model on doubly decorated planar lattices, which have localized Ising spins at their nodal lattice sites and two itinerant electrons at each pair of decorating sites, is exactly solved by the use of a generalized decoration-iteration transformation. Our main attention is focused on an in uence of the on-site Coulomb repulsion on ground-state properties and critical behavior of the investigated system.