Variational Calculations for the Effects of Magnetic Dipole-Dipole Interaction in Bose-Einstein Condensates

Employing previously developed variational calculation techniques [1, 2], we explore various possibilities for observing effects of magnetic dipole-dipole interaction (MDDI) in Bose-Einstein condensates (BECs). The effects of MDDI on both in-trap and time-of-flight expansion dynamics are investigated, as well as effects on condensate stability. The variational calculation has been verified to agree well with experimental data in Cr$^{52}$[3] and Li$^{7}$[4]. Using current knowledge of Feshbach resonances, we determine the experimental accessibility of observing MDDI effects for the bosonic alkalis and find most favorable results for Li$^{7}$, K$^{39}$, and Cs$^{133}$. We also present calculations for Dy and Er, motivated by advances in cooling such high magnetic moment species. These results would be useful to experimentalists working on dipolar quantum gases. \\[4pt] [1] S. Yi and L. You, Phys. Rev. A, \textbf{63}, 053607 (2001)\\[0pt] [2] T. Koch \emph{et al.} Nature Physcis \textbf{4}, 218-222 (2008)\\[0pt] [3] T. Lahaye \emph{et al.} Nature \textbf{448}, 672-675 (2007)\\[0pt] [4] S.E. Pollack \emph{et al.} Phys. Rev. Lett. \textbf{102}, 090402 (2009).