Effects of an attractive three body interaction on a spin-1 Bose Hubbard model

TL;DR

This paper investigates how an attractive three-body interaction influences the phase diagram of a spin-1 Bose-Hubbard model, revealing significant effects on Mott lobes and phase transitions using mean field theory.

Contribution

It introduces the effects of an attractive three-body interaction on a spin-1 Bose-Hubbard model, analyzing phase diagram modifications and phase transition orders.

Findings

The third Mott lobe is significantly affected and engulfs others at large interaction strength.

Formation of spin singlet and nematic Mott insulator phases is observed.

Phase diagrams show different features for antiferromagnetic and ferromagnetic interactions.

Abstract

We study the effects of an attractive three body interaction potential on a spin-1 ultracold Bose gas using mean field approach (MFA). For an antiferromagnetic (AF) interaction, the third MI lobe is predominantly affected, where it completely engulfs the second and the fourth MI lobes at large values of the interaction strength. Albeit no significant change is observed beyond the fourth MI lobe. The formation of the spin singlet (nematic) MI phase and the different order of phase transitions to the SF phase have been carefully scrutinized with the help of spin eigenvalues and spin nematic order parameter. In the ferromagnetic case, the phase diagram shows similar features as that of a scalar Bose gas. We have compared our results on the MFA phase diagrams for both types of the interaction potential via a perturbation expansion in both the cases.