Critical Temperature of Weakly Interacting Dipolar Condensates

TL;DR

This paper calculates how dipolar interactions affect the Bose-Einstein condensation temperature, showing the shift depends on orientation and can be experimentally observed in chromium atom condensates.

Contribution

It provides a perturbative calculation of the dipolar shift in BEC critical temperature considering trap orientation and atomic dipole alignment.

Findings

Dipolar interactions cause a measurable shift in critical temperature.

The shift varies with the angle between trap axes and dipole moments.

Experimental conditions can enhance the observable dipolar effects.

Abstract

We calculate perturbatively the effect of a dipolar interaction upon the Bose-Einstein condensation temperature. This dipolar shift depends on the angle between the symmetry axes of the trap and the aligned atomic dipole moments, and is extremal for parallel or orthogonal orientations, respectively. The difference of both critical temperatures exhibits most clearly the dipole-dipole interaction and can be enhanced by increasing both the number of atoms and the anisotropy of the trap. Applying our results to chromium atoms, which have a large magnetic dipole moment, shows that this dipolar shift of the critical temperature could be measured in the ongoing Stuttgart experiment.