Phase diagram of soft-core bosons in two dimensions

TL;DR

This paper uses numerical simulations to explore the phase diagram of 2D soft-core bosons, revealing a supersolid cluster phase that does not require long-range interactions, highlighting the minimal conditions for supersolidity.

Contribution

It demonstrates that a supersolid phase can occur in a simple soft-core boson model without long-range interactions, expanding understanding of supersolidity conditions.

Findings

A supersolid cluster phase exists in 2D soft-core bosons.

Long-range interactions are not necessary for supersolidity.

Soft-core repulsion is sufficient to produce supersolid behavior.

Abstract

The low temperature phase diagram of Bose soft disks in two dimensions is studied by numerical simulations. It is shown that a supersolid cluster phase exists, within a range of the model parameters, analogous to that recently observed for a system of aligned dipoles interacting via a softened potential at short distance. These findings indicate that a long-range tail of the interaction is unneeded to obtain such a phase, and that the soft-core repulsive interaction is the minimal model for supersolidity.