A simple model for magnetism in itinerant electron systems

TL;DR

This paper introduces a simplified lattice model for itinerant electron magnetism that preserves Hubbard model symmetries and connects to the Ising model in certain limits, providing insights into magnetic behaviors.

Contribution

It proposes a new classical lattice model for itinerant electrons that simplifies the Hubbard model while maintaining key symmetry properties.

Findings

Model reproduces magnetic behavior in 1D and mean-field cases.

In the half-filled, strongly interacting limit, it reduces to the Ising model.

Provides a framework for studying magnetism in itinerant electron systems.

Abstract

A new lattice model of interacting electrons is presented. It can be viewed as a classical Hubbard model in which the energy associated to electron itinerance is proportional to the total number of possible electron jumps. Symmetry properties of the Hubbard model are preserved. In the half-filled band with strong interaction the model becomes the Ising model. The main features of the magnetic behavior of the model in the one-dimensional and mean-field cases are studied.