Ferromagnetism in the Hubbard model with long-range and correlated hopping

TL;DR

This paper investigates how long-range and correlated hopping influence ferromagnetism in a one-dimensional Hubbard model, revealing that correlated hopping stabilizes ferromagnetic states across various interaction strengths and electron densities.

Contribution

It introduces the effect of correlated hopping on ferromagnetism in the Hubbard model and provides numerical phase diagrams for key parameter regimes.

Findings

Correlated hopping stabilizes ferromagnetism over a broad range of parameters.

Critical interaction strength $U_c$ for ferromagnetism is determined.

Ground-state phase diagrams are presented for relevant cases.

Abstract

The extrapolation of small-cluster exact-diagonalization calculations is used to examine ferromagnetism in the one-dimensional Hubbard model with long-range and correlated hopping. It is found that the correlated hopping term stabilizes the ferromagnetic state for a wide range of electron interactions $U$ and electron concentrations $n$. The critical value of the interaction strength $U_c$ above which the ferromagnetic state becomes stable is calculated numerically and the ground-state phase diagram of the model is presented for physically the most interesting cases.