Dipolar Bose gas in a weak isotropic speckle disorder

TL;DR

This paper studies how weak isotropic speckle disorder affects the properties of a homogeneous dipolar Bose gas at finite temperature, revealing anisotropic effects on superfluidity and sound velocity.

Contribution

It introduces a beyond-mean-field Bogoliubov approach to analyze the interplay of dipole-dipole interactions and weak disorder in a 3D Bose gas.

Findings

Disorder causes anisotropy in superfluid fraction and sound velocity.

Dipolar interactions significantly influence condensate depletion.

Ground state energy and chemical potential are affected by disorder.

Abstract

We investigate the properties of a homogeneous dipolar Bose gas in a weak three-dimensional (3D) isotropic speckle disorder at finite temperature. By using the Bogoliubov theory (beyond the mean field), we calculate the condensate and the superfluid fractions as a function of density and strengths of disorder and interaction. The influence of disorder on the anomalous density, the chemical potential and the ground state energy is also analyzed. We show that the peculiar interplay of the DDI and weak disorder makes the superfluid fraction and sound velocity anisotropic.