Superfluid to normal phase transition in strongly correlated bosons in two and three dimensions

TL;DR

This paper uses quantum Monte Carlo simulations to map the finite-temperature phase diagram of strongly correlated bosons in 2D and 3D, providing insights relevant for ultracold gas experiments.

Contribution

It introduces a new measurement method based on zero-momentum occupation for experimental detection of phase boundaries in inhomogeneous systems.

Findings

Finite-temperature phase diagrams for 2D and 3D bosons determined.

Finite-size scaling analysis of condensate fraction and superfluid stiffness.

A practical measurement approach for experiments with trapped ultracold gases.

Abstract

Using quantum Monte Carlo simulations, we investigate the finite-temperature phase diagram of hard-core bosons (XY model) in two- and three-dimensional lattices. To determine the phase boundaries, we perform a finite-size-scaling analysis of the condensate fraction and/or the superfluid stiffness. We then discuss how these phase diagrams can be measured in experiments with trapped ultracold gases, where the systems are inhomogeneous. For that, we introduce a method based on the measurement of the zero-momentum occupation, which is adequate for experiments dealing with both homogeneous and trapped systems, and compare it with previously proposed approaches.