Spin and charge orderings in the atomic limit of the U-V-J model

TL;DR

This paper explores the zero-temperature phase diagram of a generalized 1D Hubbard model with additional density and spin interactions, revealing various ordered phases and their fragility.

Contribution

It extends the transfer-matrix method to analyze the zero-temperature phase diagram of the U-V-J model in the atomic limit.

Findings

Identified multiple phases with density and spin orderings.

Mapped the phase diagram for ferro and anti-ferro couplings.

Showed the fragility of spin correlations in these phases.

Abstract

In this paper we study a generalization of the 1D Hubbard model by considering density-density and Ising-type spin-spin nearest neighbor (NN) interactions, parameterized by $V$ and $J$, respectively. We present the T=0 phase diagram for both ferro ($J>0$) and anti-ferro ($J<0$) coupling obtained in the narrow-band limit by means of an extension to zero-temperature of the transfer-matrix method. Based on the values of the Hamiltonian parameters, we identify a number of phases that involve orderings of the double occupancy, NN density and spin correlations, being these latter very fragile.