Ground state phase diagram of Gaussian-Core bosons in two dimensions

TL;DR

This study uses Quantum Monte Carlo simulations to map the ground state phase diagram of 2D Gaussian-Core bosons, revealing fluid, crystal, and reentrant superfluid phases without supersolidity.

Contribution

First detailed quantum Monte Carlo analysis of 2D Gaussian-Core bosons' phase diagram, showing phase transitions and absence of supersolid phases.

Findings

Fluid at weak coupling across all densities

Transition from superfluid to crystal with increasing density

Reentrant superfluid phase at high density

Abstract

The ground state of a two-dimensional (2D) system of Bose particles of spin zero, interacting via a repulsive Gaussian-Core potential, has been investigated by means of Quantum Monte Carlo simulations. The quantum phase diagram is qualitatively identical to that of 2D Yukawa bosons. While the system is a fluid at all densities for weak coupling, in the strong coupling regime it transitions upon compression from a low density superfluid to a crystal, and then into a reentrant superfluid phase. No evidence of a (supersolid) cluster crystal phase is seen.