Bose-Einstein Condensation Temperature of Dipolar Gas in Anisotropic Harmonic Trap

Abstract

We consider a dilute gas of dipole moments in an arbitrary harmonic trap and treat both the short-range, isotropic delta-interaction and the long-range, anisotropic dipole-dipole interaction perturbatively. With this we calculate the leading shift of the critical temperature with respect to that of an ideal gas as a function of the relative orientation of the dipole moments with respect to the harmonic trap axes. In particular, we determine those magic angles, where the dipolar shift of the Bose-Einstein condensation temperature vanishes. Furthermore, we show for the parameters of the ongoing 52Cr-experiment in Stuttgart that this dipolar shift can be enhanced by increasing the number of particles, the geometrical mean trap frequency, and the anisotropy of the trap.