Phase transitions in dipolar spin-1 Bose gases

TL;DR

This paper investigates how long-range magnetic dipole-dipole interactions influence phase transitions in homogeneous spin-1 Bose gases, revealing stability of certain phases and instability of others depending on temperature regimes.

Contribution

It provides a detailed analysis of the effects of dipole-dipole interactions on phase stability in spin-1 Bose gases using renormalization group methods.

Findings

Dipole-dipole interactions do not affect the zero-temperature phase diagram.

Polar and ferromagnetic condensates become unstable at high temperatures due to DDI.

The spin-singlet condensate remains stable despite DDI presence.

Abstract

We study phase transitions in homogeneous spin-1 Bose gases in the presence of long-range magnetic dipole-dipole interactions (DDI). We concentrate on three-dimensional geometries and employ momentum shell renormalization group to study the possible instabilities caused by the dipole-dipole interaction. At the zero-temperature limit where quantum fluctuations prevail, we find the phase diagram to be unaffected by the dipole-dipole interaction. When the thermal fluctuations dominate, polar and ferromagnetic condensates with DDI become unstable and we discuss this crossover in detail. On the other hand, the spin-singlet condensate remains stable in the presence of dipole-dipole interactions.