Berezinskii-Kosterlitz-Thouless transition in two-dimensional dipole systems

TL;DR

This paper investigates the superfluid to normal fluid transition in two-dimensional dipolar bosons across all densities, revealing how interactions influence the Berezinskii-Kosterlitz-Thouless transition temperature and phase diagram.

Contribution

It provides a comprehensive phase diagram for 2D dipolar bosons using path integral Monte Carlo simulations, highlighting the effects of interactions at various densities.

Findings

Agreement with universal low-density results

Transition temperature affected by interactions at higher densities

Relevance to dipolar atomic, molecular systems, and excitons

Abstract

The superfluid to normal fluid transition of dipolar bosons in two dimensions is studied throughout the whole density range using path integral Monte Carlo simulations and summarized in the phase diagram. While at low densities, we find good agreement with the universal results depending only on the scattering length $a_s$, at moderate and high densities, the transition temperature is strongly affected by interactions and the elementary excitation spectrum. The results are expected to be of relevance to dipolar atomic and molecular systems and indirect excitons in quantum wells.