Quantum phases of a spin-1 ultracold Bose gas with three body interactions

TL;DR

This paper investigates how three-body interactions influence the quantum phases of a spin-1 ultracold Bose gas, revealing asymmetries and stabilization effects in Mott lobes, with detailed analysis of spin and nematic order parameters.

Contribution

It introduces a mean field analysis of three-body interactions in spin-1 Bose gases, highlighting their effects on Mott lobes, spin nematic formation, and phase diagram features, which were not previously detailed.

Findings

Odd-even asymmetry in MI lobes with repulsive interactions

Higher order MI lobes stabilize against superfluid phase

Third MI lobe is affected by attractive three-body interactions

Abstract

We study the effects of both a repulsive and an attractive three body interaction potential on a spin-1 ultracold Bose gas using mean field approach (MFA). For an antiferromagnetic (AF) inter- action, we have found the existence of the odd-even asymmetry in the Mott insulating (MI) lobes in presence of both the repulsive two and three body interactions. In case of a purely three body repulsive interaction, the higher order MI lobes stabilize against the superfluid phase. However, the spin nematic (singlet) formation is restricted upto the first (second) MI lobes for the former one, while there is neither any asymmetry nor spin nematic (singlet) formation is observed for the later case. The results are confirmed after carefully scrutinizing the spin eigen value and spin nematic order parameter for both the cases. On the other hand, for an attractive three body 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. 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.