Phase separation in the bosonic Hubbard model with ring exchange

TL;DR

This paper investigates how ring exchange interactions in two-dimensional soft core bosons can lead to phase separation, raising questions about the stability of Bose liquid phases under such conditions.

Contribution

It reveals that ring exchange terms induce phase separation in 2D bosonic systems, highlighting the need to reassess the stability of Bose liquids with these interactions.

Findings

Ring exchange causes phase separation in 2D bosonic systems.

Thermodynamic stability of Bose liquids with ring exchange is uncertain.

Normal Bose liquid phases may be destabilized by ring exchange effects.

Abstract

We show that soft core bosons in two dimensions with a ring exchange term exhibit a tendency for phase separation. This observation suggests that the thermodynamic stability of normal bose liquid phases driven by ring exchange should be carefully examined.