Ferromagnetism in the Infinite-U Hubbard Model

TL;DR

This paper investigates the stability of ferromagnetism in the infinite-U Hubbard model on a square lattice, revealing it remains stable below 22% hole doping through advanced numerical methods.

Contribution

It provides new numerical evidence for the stability range of ferromagnetism in the infinite-U Hubbard model using density matrix renormalization group techniques.

Findings

Ferromagnetic state stable below 22% hole doping

Total spin decreases gradually with increased hole doping

Used approximate diagonalization on large finite lattices

Abstract

We have studied the stability of the ferromagnetic state in the infinite-U Hubbard model on a square lattice by approximate diagonalization of finite lattices using the density matrix renormalization group technique. By studying lattices with up to 5X20 sites, we have found the ferromagnetic state to be stable below the hole density of 22 percent. Beyond 22 percent of hole doping, the total spin of the ground state decreased gradually to zero with increasing hole density.